Hospital Medicine

Any time patients enter or leave the hospital, they risk being harmed by errors in their medications.¹ Adverse events from medication errors during transitions of care are common but often preventable. One key approach is to systematically review every patient’s medication list on admission and discharge and resolve any discrepancies. These transitions are also an opportunity to address other medication-related problems, such as adherence, drug interactions, and clinical appropriateness.

This article summarizes the types and prevalence of medication problems that occur during hospital-based transitions of care, and suggests strategies to decrease the risk of medication errors, focusing on medication reconciliation and related interventions that clinicians can use at the bedside to improve medication safety.

DEFINING TERMS

A medication discrepancy is any variance noted in a patient’s documented medication regimen across different medication lists or sites of care. While some differences reflect intentional and clinically appropriate changes to the regimen, others are unintentional and reflect inaccurate or incomplete information. These unintentional discrepancies are medication errors.

Depending on the clinical circumstances and medications involved, such errors may lead to an adverse drug event (ADE), defined as actual harm or injury resulting from a medication. Sometimes a medication error does not cause harm immediately but could if left uncorrected; this is called a potential ADE.

An important goal during transitions of care is to reduce unintentional medication discrepancies, thereby reducing potential and actual ADEs.

ERRORS ARISE AT DISCHARGE—AND EVEN MORE AT ADMISSION

Hospital discharge is a widely recognized transition in which patient harm occurs. As many as 70% of patients may have an unintentional medication discrepancy at hospital discharge, with many of those discrepancies having potential for harm.² Indeed, during the first few weeks after discharge, 50% of patients have a clinically important medication error,³ and 20% experience an adverse event, most commonly an ADE.⁴ ADEs are associated with excess health care utilization,^5–7 and many are preventable through strategies such as medication reconciliation.^5,8

Importantly, more errors arise at hospital admission than at other times.^9,10

Errors in medication histories are the most common source of discrepancies, affecting up to two-thirds of admitted patients.^11,12 More than one-quarter of hospital prescribing errors can be attributed to incomplete medication histories at the time of admission,¹³ and nearly three times as many clinically important medication discrepancies are related to history-taking errors on admission rather than reconciliation errors at discharge.⁹

Most discrepancies occurring at the time of admission have the potential to cause harm, particularly if the errors persist beyond discharge.¹⁴ Therefore, taking a complete and accurate medication history on hospital admission is critical to ensuring safe care transitions.

MEDICATION RECONCILIATION: BARRIERS AND FACILITATORS

Medication reconciliation is a strategy for reducing medication discrepancies in patients moving across care settings. Simply put, it is the process by which a patient’s medication list is obtained, compared, and clarified across different sites of care.¹⁵ It has consistently been shown to decrease medication errors compared with usual care,¹⁶ and it is strongly supported by national and international organizations.^17–21

In clinical practice, many physicians and institutions have found medication reconciliation difficult to implement, owing to barriers at the level of the patient, provider, and system (Table  1). In response to these challenges, two initiatives have synthesized best practices and offer toolkits that hospitals and clinicians can use: the Medications at Transitions and Clinical Handoffs (MATCH) program²² and the Multi-Center Medication Reconciliation Quality Improvement Study (MARQUIS).²³

Lack of resources is a widely acknowledged challenge. Thus, the MARQUIS investigators²³ suggested focusing on the admission history, where most errors occur, and applying the most resource-intensive interventions in patients at highest risk of ADEs, ie, those who are elderly, have multiple comorbid conditions, or take numerous medications.¹⁶

Although the risk of an ADE increases with the number of medications a patient takes,⁴ the exact number of drugs that defines high risk has not been well established. Targeting patients who take 10 or more maintenance medications is a reasonable initial approach,²⁴ but institutions should tailor risk stratification to their patient populations and available resources. Patients taking high-risk medications such as anticoagulants and insulin could also be prioritized for review, since these medications are more likely to cause serious patient harm when used without appropriate clinical oversight.⁷

Using pharmacy staff to perform medication history-taking, reconciliation, and patient counseling has been shown to produce favorable patient outcomes, particularly for higher-risk patients.^16,23

The MARQUIS investigators found they could boost the chances of success by sharing stories of patient harm to foster “buy-in” among frontline staff, providing formal training to clinicians on how to take a medication history, and obtaining the support of nursing leaders to champion improvement efforts.²³

Additionally, patients should be empowered to maintain an accurate medication list. We address strategies for improving patient engagement and adherence in a later section.

BEST PRACTICES FOR IMPROVING MEDICATION SAFETY

Medication reconciliation is one of several measures necessary to optimize medication safety during transitions of care. It typically includes the following actions:

• Interview the patient or caregiver to determine the list of medications the patient is currently taking (or supposed to be taking); consult other sources if needed.
• List medications that are being ordered during the clinical encounter.
• Compare these two lists, making note of medications that are stopped, changed, or newly prescribed.
• Resolve any discrepancies.
• Communicate the reconciled list to the patient, appropriate caregivers, and providers of follow-up care.

At a rudimentary level, medication reconciliation encompasses medication list management along the continuum of care. However, we recommend leveraging medication reconciliation as an opportunity to further enhance medication safety by reviewing the appropriateness of each medication, seizing opportunities to streamline or simplify the regimen, assessing patient and caregiver understanding of medication instructions and potential ADEs, and delivering appropriate counseling to enhance medication use. Table 2 outlines our framework for medication management during hospital-based transitions.

STEP 1: OBTAIN A COMPLETE PREADMISSION MEDICATION LIST

The “best-possible medication history” is obtained in a systematic process of interviewing the patient or caregiver plus reviewing at least one other reliable source.²³ The resulting list should include all medications the patient is taking (prescription and nonprescription), doses, directions for use, formulations if applicable, indications, start and stop dates, and medication allergies and reactions.

Review existing information. Before eliciting a history from the patient, review his or her recorded medical history and existing medication lists (eg, prior discharge summaries, records from other facilities, records from outpatient visits, pharmacy fill data). This will provide context about the regimen and help identify issues and questions that can be addressed during the history-taking.

Ask open-ended questions. Instead of just asking the patient to confirm the accuracy of the existing medication list, we recommend actively obtaining the full medication list from the patient or caregiver. The conversation should begin with an open-ended question such as, “What medications do you take at home?” This approach will also allow the clinician to gauge the patient’s level of understanding of each medication’s indication and dosing instructions. Using a series of prompts such as those recommended in Table 3 will elicit a best-possible medical history, while verifying all of the medications on the existing list.

Clarify discrepancies. Resolve differences between the existing medication lists and the patient’s or caregiver’s report during the preadmission interview. Examples include errors of omission (a medication is missing), errors of commission (an additional medication is present), and discrepancies in the strength, formulation, dosing instructions, and indications for the drugs. If necessary, other sources of information should be consulted, such as the patient’s medication bottles, pharmacy or pharmacies, primary care physician, and a family member or caregiver.

Assess adherence. The extent to which patients take their medications as directed is an important component of the history, but is often left out. Medication nonadherence rates in the United States are 40% to 70%,²⁵ contributing to poor patient outcomes and imposing extraordinary costs on the health care system.²⁶

Asking open-ended, nonjudgmental questions at the time of hospital admission will help to uncover medication-taking behaviors as well as barriers to adherence (Table 3). The patient’s responses should be taken into account when determining the treatment plan.

Document your findings. After completing the medication history and clarifying discrepancies, document the preadmission list in the medical record. All members of the health care team should have access to view and update the same list, as new information about the preadmission medications may be uncovered after the initial history.

Make clinical decisions. Complete the admission medication reconciliation by deciding whether each medication on the list should be continued, changed, held, or discontinued on the basis of the patient’s clinical condition. Well-designed information technology applications enable the provider to document each action and the rationale for it, as well as carry that information into the order-entry system. Medications marked as held or discontinued on admission should be revisited as the patient’s clinical condition changes and at discharge.

STEP 2: AVOID RECONCILIATION ERRORS

Reconciliation errors reflect discrepancies between the medication history and the medications that are ordered after admission.

Reconciliation errors are less common than medication history errors, accounting for approximately one-third of potentially harmful medication errors in hospitalized medical patients.⁹ These include errors of omission (a medication is omitted from the orders), errors of commission (a medication is prescribed with no indication for continuation), and therapeutic duplication.

Preventing errors of omission

Medications are often held at transition points for appropriate clinical reasons. Examples include holding anticoagulants and antiplatelet agents in patients who have gastrointestinal bleeding or an upcoming procedure, antihypertensives in patients with hemodynamic instability, and other chronic medications in patients with an acute illness.

Poor documentation and communication of these decisions can lead to a failure to resume the medications—an error of omission—at hospital discharge.

Hospitalized patients are at risk of unintentional discontinuation of their chronic medications, including antiplatelet drugs, anticoagulants, statins, and thyroid replacement, particularly if admitted to the intensive care unit.¹² These errors can be minimized by a standardized medication reconciliation process at each transition and clear documentation of the medication plan.

Communication among providers can be improved if the admitting clinician documents clearly whether each preadmission medication is being continued, changed, or stopped, along with the reason for doing so, and makes this information available throughout the hospital stay. Upon transfer to another unit and at discharge, the physician should review each; preadmission medication that was held and the patient’s current clinical status and, based on that information, decide whether medications that were held should be resumed. If a medication will be restarted later, specific instructions should be documented and communicated to the patient and the physicians who are taking over his or her care.

Preventing errors of commission

Failure to perform a complete reconciliation at each transition of care and match each medication with an appropriate indication can lead to errors of commission.

One study showed that 44% of patients were prescribed at least one unnecessary drug at hospital discharge, one-fourth of which were started during the hospitalization.²⁷ Commonly prescribed unnecessarily were gastrointestinal agents, central nervous system drugs, nutrients, and supplements.

It is critical to assess each medication’s ongoing need, appropriateness, and risk-benefit ratio at every transition. Medications no longer indicated should be discontinued in order to simplify the regimen, avoid unnecessary drug exposure, and prevent ADEs.

For example, proton pump inhibitors or histamine 2 receptor blockers are often started in the hospital for stress ulcer prophylaxis. One-third of patients are then discharged home on the medication, and 6 months later half of those patients are still taking the unnecessary drug.²⁸ This situation can be avoided by limiting use of these medications to appropriate circumstances, clearly marking the indication as stress ulcer prophylaxis (as opposed to an ongoing condition that will require continuing it after discharge), and discontinuing the agent when appropriate.

All drugs, even common and seemingly benign ones, carry some risk and should be discontinued when no longer needed. Thus, medications added during the hospitalization to control acute symptoms should also be reviewed at each transition to prevent inappropriate continuation when symptoms have resolved.

One study, for example, found that many patients were discharged with inappropriate prescriptions for atypical antipsychotics after receiving them in the intensive care unit, likely for delirium.²⁹ Documenting that an acute issue such as delirium has resolved should prompt the discontinuation of therapy.

Preventing therapeutic duplication

Therapeutic duplication occurs in about 8% of discharges.¹ These errors often result from formulary substitutions or altering the dosage form in the acute setting. For example, patients who receive a prescription for the substituted agent at discharge and also resume their prehospitalization medications end up with duplicate therapy.

Therapeutic substitution is common at the time of admission to the hospital as a result of formulary restrictions. Drug classes that are frequently substituted include statins, antihypertensives, urinary antispasmodics, and proton pump inhibitors. Physicians should be familiar with the preferred agents on the hospital formulary and make careful note when a substitution occurs. Furthermore, hospital systems should be developed to remind the physician to switch back to the outpatient medication at discharge.

Similar problems occur when home medications are replaced with different dosage forms with different pharmacokinetic properties. For example, a long-acting medication may be temporarily replaced with an intravenous solution or immediate-release tablet for several reasons, including nothing-by-mouth status, unstable clinical condition, need for titration, and need to crush the tablet to give the drug per tube. The differing formulations must be reconciled throughout the patient’s hospital course and at discharge to avoid therapeutic duplication and serious medication errors. Deliberate changes to the dosage form should be clearly communicated in the discharge medication list so that patients and other clinicians are aware.

Hospital systems should also have the capability to identify duplications in the medication list and to warn prescribers of these errors. The ability to group medications by drug class or sort the medication list alphabetically by generic name can help uncover duplication errors.

STEP 3: REVIEW THE LIST IN VIEW OF THE CLINICAL PICTURE

Transitions of care should prompt providers to review the medication list for possible drug-disease interactions, confirm compliance with evidence-based guidelines, and evaluate the risks and benefits of each medication in the context of the patient’s age and acute and chronic medical issues. This is also an opportunity to screen the full list for potentially inappropriate medications and high-alert drugs such as insulin or anticoagulants, which are more likely than other drugs to cause severe harm when used in error.

Acute kidney injury. New drug-disease interactions can arise during a hospitalization and can affect dosing and the choice of drug. The onset of acute kidney injury, for example, often necessitates adjusting or discontinuing nephrotoxic and renally excreted medications. ADEs or potential ADEs have been reported in 43% of hospitalized patients with acute kidney injury.³⁰

Because acute kidney injury is often transient, medications may need to be held or adjusted several times until renal function stabilizes. This can be challenging across the continuum of care and requires close monitoring of the serum creatinine level and associated drug doses and levels, if applicable. Well-designed clinical decision support tools can integrate laboratory data and alert the prescriber to a clinically important increase or decrease in serum creatinine that may warrant a change in therapy. Modifications to the regimen and a plan for timely follow-up of the serum creatinine level should be clearly documented in the discharge plan.

Liver disease. Similar attention should be given to drugs that are hepatically metabolized if a patient has acute or chronic liver impairment.

Geriatric patients, particularly those who present with altered mental status, falls, or urinary retention, should have their medication list reviewed for potentially inappropriate medications, which are drugs that pose increased risk of poor outcomes in older adults.^31,32 Patients and providers may have been willing to accept the risk of medications such as anticholinergics or sedative-hypnotics when the drugs were initiated, but circumstances can change over time, especially in this patient population. Hospitalization is a prime opportunity to screen for medications that meet the Beers criteria³¹ for agents to avoid or use with caution in older adults.

As-needed medications. Medications prescribed on an as-needed basis in the hospital should be reviewed for continuation or discontinuation at discharge. How often the medication was given can inform this decision.

For example, if as-needed opioids were used frequently, failure to develop a plan of care for pain can lead to persistent symptoms and, possibly, to readmission.^33,34 Similar scenarios occur with use of as-needed blood pressure medications, laxatives, and correction-dose insulin.

If an as-needed medication was used consistently during hospitalization, the physician should consider whether a regularly scheduled medication is needed. Conversely, if the medication was not used during the inpatient admission, it can likely be discontinued.

STEP 4: PREPARE THE PATIENT AND FOLLOW-UP PROVIDER

Once a clinician has performed medication reconciliation, including obtaining a best-possible medical history and carefully reviewing the medication list and orders for errors and clinical appropriateness, the next steps are to ensure the patient understands what he or she needs to do and to confirm that suitable follow-up plans are in place. These measures should be taken at all transitions of care but are critically important at hospital discharge.

Preparing the patient and caregiver

An accurate, reconciled medication list should be given to the patient, caregiver, or both, and should be reviewed before discharge.¹⁷

Approximately one-third of Americans have low health literacy skills, so medication lists and associated materials should be easy to understand.³⁵ Medication lists should be written in plain language and formatted for optimal readability (Table 4), clearly stating which medications to continue, change, hold temporarily, and stop.

Patients recall and comprehend about half of the information provided during a medical encounter.³⁶ Thus, medication teaching should focus on key points including changes or additions to the regimen, specific instructions for follow-up and monitoring, and how to handle common and serious side effects.

To confirm patient understanding, clinicians should use “teach-back,” ie, provide the patient with information and then ask him or her to repeat back key points.^37,38 The patient and family should also be encouraged to ask questions before discharge.

If not already addressed during the hospital stay, barriers to medication adherence and ability to obtain the medications should be attended to at this time (Table 5). Also, the plan to pick up the medications should be verified with the patient and caregiver. Verify that there is transportation to a particular pharmacy that is open at the time of discharge, and that the patient can afford the medications.

Ensuring appropriate follow-up

Studies have shown that timely in-home or telephone follow-up after discharge can decrease adverse events and postdischarge health care utilization.^39,40 Telephone follow-up that includes thorough medication reconciliation can help detect and resolve medication issues early after discharge and can close gaps related to monitoring and follow-up.

Medication reconciliation by telephone can be time-consuming. Depending on the number of medications that need to be reviewed, calls can take between 10 and 60 minutes. Postdischarge phone calls should be performed by clinical personnel who are able to identify medication-related problems. A pharmacist should be an available resource to assist with complex regimens, to help resolve medication discrepancies, and to address patient concerns. Table 6 provides tips for conducting follow-up phone calls.

Resolving discrepancies identified during follow-up calls can be difficult, as changes to the medication regimen are often not communicated effectively to other members of the care team. Physicians should document the complete medication list and plan in the discharge summary, and there should be a method for the caller to record updates to the medication list in the medical record so that they are apparent at the outpatient follow-up visit.

An additional challenge is that it is frequently unclear which physician “owns” which medications. Therefore, designating a contact person for each medication until follow-up can be very valuable. At a minimum, a “physician owner” for high-alert medications such as insulin, anticoagulants, and diuretics should be identified to provide close follow-up, titration, and monitoring.

There should also be a plan for the patient to obtain refills of essential long-term medications, such as antiplatelet agents following stent placement.

SUMMARY AND RECOMMENDATIONS

Medication-related problems during hospital admission and discharge are common and range from minor discrepancies in the medication list to errors in history-taking, prescribing, and reconciliation that can lead to potential or actual patient harm. Putting systems in place to facilitate medication reconciliation can decrease the occurrence of medication discrepancies and ADEs, thereby improving patient safety during these critical transitions between care settings and providers. Institutional medication reconciliation programs should focus resources on the admission history-taking step, target the highest-risk patients for the most intensive interventions, and involve pharmacy personnel when possible.

On an individual level, clinicians can incorporate additional interventions into their workflows to optimize medication safety for hospitalized patients. Using a structured approach to obtain a complete and accurate medication list at the time of hospital admission will help providers identify medication-related problems and prevent the propagation of errors throughout the hospital stay and at discharge. Focusing additional time and effort on a comprehensive review of the medication list for errors of omission and commission, patient-specific needs, and high-alert drugs will further decrease the risk of medication errors. Finally, providing discharge counseling targeting patient barriers to adherence and ensuring a proper handover of medication information and rationale for medication changes to outpatient providers will improve the chances of a safe transition.

Any time patients enter or leave the hospital, they risk being harmed by errors in their medications.¹ Adverse events from medication errors during transitions of care are common but often preventable. One key approach is to systematically review every patient’s medication list on admission and discharge and resolve any discrepancies. These transitions are also an opportunity to address other medication-related problems, such as adherence, drug interactions, and clinical appropriateness.

This article summarizes the types and prevalence of medication problems that occur during hospital-based transitions of care, and suggests strategies to decrease the risk of medication errors, focusing on medication reconciliation and related interventions that clinicians can use at the bedside to improve medication safety.

DEFINING TERMS

A medication discrepancy is any variance noted in a patient’s documented medication regimen across different medication lists or sites of care. While some differences reflect intentional and clinically appropriate changes to the regimen, others are unintentional and reflect inaccurate or incomplete information. These unintentional discrepancies are medication errors.

Depending on the clinical circumstances and medications involved, such errors may lead to an adverse drug event (ADE), defined as actual harm or injury resulting from a medication. Sometimes a medication error does not cause harm immediately but could if left uncorrected; this is called a potential ADE.

An important goal during transitions of care is to reduce unintentional medication discrepancies, thereby reducing potential and actual ADEs.

ERRORS ARISE AT DISCHARGE—AND EVEN MORE AT ADMISSION

Hospital discharge is a widely recognized transition in which patient harm occurs. As many as 70% of patients may have an unintentional medication discrepancy at hospital discharge, with many of those discrepancies having potential for harm.² Indeed, during the first few weeks after discharge, 50% of patients have a clinically important medication error,³ and 20% experience an adverse event, most commonly an ADE.⁴ ADEs are associated with excess health care utilization,^5–7 and many are preventable through strategies such as medication reconciliation.^5,8

Importantly, more errors arise at hospital admission than at other times.^9,10

Errors in medication histories are the most common source of discrepancies, affecting up to two-thirds of admitted patients.^11,12 More than one-quarter of hospital prescribing errors can be attributed to incomplete medication histories at the time of admission,¹³ and nearly three times as many clinically important medication discrepancies are related to history-taking errors on admission rather than reconciliation errors at discharge.⁹

Most discrepancies occurring at the time of admission have the potential to cause harm, particularly if the errors persist beyond discharge.¹⁴ Therefore, taking a complete and accurate medication history on hospital admission is critical to ensuring safe care transitions.

MEDICATION RECONCILIATION: BARRIERS AND FACILITATORS

Medication reconciliation is a strategy for reducing medication discrepancies in patients moving across care settings. Simply put, it is the process by which a patient’s medication list is obtained, compared, and clarified across different sites of care.¹⁵ It has consistently been shown to decrease medication errors compared with usual care,¹⁶ and it is strongly supported by national and international organizations.^17–21

In clinical practice, many physicians and institutions have found medication reconciliation difficult to implement, owing to barriers at the level of the patient, provider, and system (Table  1). In response to these challenges, two initiatives have synthesized best practices and offer toolkits that hospitals and clinicians can use: the Medications at Transitions and Clinical Handoffs (MATCH) program²² and the Multi-Center Medication Reconciliation Quality Improvement Study (MARQUIS).²³

Lack of resources is a widely acknowledged challenge. Thus, the MARQUIS investigators²³ suggested focusing on the admission history, where most errors occur, and applying the most resource-intensive interventions in patients at highest risk of ADEs, ie, those who are elderly, have multiple comorbid conditions, or take numerous medications.¹⁶

Although the risk of an ADE increases with the number of medications a patient takes,⁴ the exact number of drugs that defines high risk has not been well established. Targeting patients who take 10 or more maintenance medications is a reasonable initial approach,²⁴ but institutions should tailor risk stratification to their patient populations and available resources. Patients taking high-risk medications such as anticoagulants and insulin could also be prioritized for review, since these medications are more likely to cause serious patient harm when used without appropriate clinical oversight.⁷

Using pharmacy staff to perform medication history-taking, reconciliation, and patient counseling has been shown to produce favorable patient outcomes, particularly for higher-risk patients.^16,23

The MARQUIS investigators found they could boost the chances of success by sharing stories of patient harm to foster “buy-in” among frontline staff, providing formal training to clinicians on how to take a medication history, and obtaining the support of nursing leaders to champion improvement efforts.²³

Additionally, patients should be empowered to maintain an accurate medication list. We address strategies for improving patient engagement and adherence in a later section.

BEST PRACTICES FOR IMPROVING MEDICATION SAFETY

Medication reconciliation is one of several measures necessary to optimize medication safety during transitions of care. It typically includes the following actions:

• Interview the patient or caregiver to determine the list of medications the patient is currently taking (or supposed to be taking); consult other sources if needed.
• List medications that are being ordered during the clinical encounter.
• Compare these two lists, making note of medications that are stopped, changed, or newly prescribed.
• Resolve any discrepancies.
• Communicate the reconciled list to the patient, appropriate caregivers, and providers of follow-up care.

At a rudimentary level, medication reconciliation encompasses medication list management along the continuum of care. However, we recommend leveraging medication reconciliation as an opportunity to further enhance medication safety by reviewing the appropriateness of each medication, seizing opportunities to streamline or simplify the regimen, assessing patient and caregiver understanding of medication instructions and potential ADEs, and delivering appropriate counseling to enhance medication use. Table 2 outlines our framework for medication management during hospital-based transitions.

STEP 1: OBTAIN A COMPLETE PREADMISSION MEDICATION LIST

The “best-possible medication history” is obtained in a systematic process of interviewing the patient or caregiver plus reviewing at least one other reliable source.²³ The resulting list should include all medications the patient is taking (prescription and nonprescription), doses, directions for use, formulations if applicable, indications, start and stop dates, and medication allergies and reactions.

Review existing information. Before eliciting a history from the patient, review his or her recorded medical history and existing medication lists (eg, prior discharge summaries, records from other facilities, records from outpatient visits, pharmacy fill data). This will provide context about the regimen and help identify issues and questions that can be addressed during the history-taking.

Ask open-ended questions. Instead of just asking the patient to confirm the accuracy of the existing medication list, we recommend actively obtaining the full medication list from the patient or caregiver. The conversation should begin with an open-ended question such as, “What medications do you take at home?” This approach will also allow the clinician to gauge the patient’s level of understanding of each medication’s indication and dosing instructions. Using a series of prompts such as those recommended in Table 3 will elicit a best-possible medical history, while verifying all of the medications on the existing list.

Clarify discrepancies. Resolve differences between the existing medication lists and the patient’s or caregiver’s report during the preadmission interview. Examples include errors of omission (a medication is missing), errors of commission (an additional medication is present), and discrepancies in the strength, formulation, dosing instructions, and indications for the drugs. If necessary, other sources of information should be consulted, such as the patient’s medication bottles, pharmacy or pharmacies, primary care physician, and a family member or caregiver.

Assess adherence. The extent to which patients take their medications as directed is an important component of the history, but is often left out. Medication nonadherence rates in the United States are 40% to 70%,²⁵ contributing to poor patient outcomes and imposing extraordinary costs on the health care system.²⁶

Asking open-ended, nonjudgmental questions at the time of hospital admission will help to uncover medication-taking behaviors as well as barriers to adherence (Table 3). The patient’s responses should be taken into account when determining the treatment plan.

Document your findings. After completing the medication history and clarifying discrepancies, document the preadmission list in the medical record. All members of the health care team should have access to view and update the same list, as new information about the preadmission medications may be uncovered after the initial history.

Make clinical decisions. Complete the admission medication reconciliation by deciding whether each medication on the list should be continued, changed, held, or discontinued on the basis of the patient’s clinical condition. Well-designed information technology applications enable the provider to document each action and the rationale for it, as well as carry that information into the order-entry system. Medications marked as held or discontinued on admission should be revisited as the patient’s clinical condition changes and at discharge.

STEP 2: AVOID RECONCILIATION ERRORS

Reconciliation errors reflect discrepancies between the medication history and the medications that are ordered after admission.

Reconciliation errors are less common than medication history errors, accounting for approximately one-third of potentially harmful medication errors in hospitalized medical patients.⁹ These include errors of omission (a medication is omitted from the orders), errors of commission (a medication is prescribed with no indication for continuation), and therapeutic duplication.

Preventing errors of omission

Medications are often held at transition points for appropriate clinical reasons. Examples include holding anticoagulants and antiplatelet agents in patients who have gastrointestinal bleeding or an upcoming procedure, antihypertensives in patients with hemodynamic instability, and other chronic medications in patients with an acute illness.

Poor documentation and communication of these decisions can lead to a failure to resume the medications—an error of omission—at hospital discharge.

Hospitalized patients are at risk of unintentional discontinuation of their chronic medications, including antiplatelet drugs, anticoagulants, statins, and thyroid replacement, particularly if admitted to the intensive care unit.¹² These errors can be minimized by a standardized medication reconciliation process at each transition and clear documentation of the medication plan.

Communication among providers can be improved if the admitting clinician documents clearly whether each preadmission medication is being continued, changed, or stopped, along with the reason for doing so, and makes this information available throughout the hospital stay. Upon transfer to another unit and at discharge, the physician should review each; preadmission medication that was held and the patient’s current clinical status and, based on that information, decide whether medications that were held should be resumed. If a medication will be restarted later, specific instructions should be documented and communicated to the patient and the physicians who are taking over his or her care.

Preventing errors of commission

Failure to perform a complete reconciliation at each transition of care and match each medication with an appropriate indication can lead to errors of commission.

One study showed that 44% of patients were prescribed at least one unnecessary drug at hospital discharge, one-fourth of which were started during the hospitalization.²⁷ Commonly prescribed unnecessarily were gastrointestinal agents, central nervous system drugs, nutrients, and supplements.

It is critical to assess each medication’s ongoing need, appropriateness, and risk-benefit ratio at every transition. Medications no longer indicated should be discontinued in order to simplify the regimen, avoid unnecessary drug exposure, and prevent ADEs.

For example, proton pump inhibitors or histamine 2 receptor blockers are often started in the hospital for stress ulcer prophylaxis. One-third of patients are then discharged home on the medication, and 6 months later half of those patients are still taking the unnecessary drug.²⁸ This situation can be avoided by limiting use of these medications to appropriate circumstances, clearly marking the indication as stress ulcer prophylaxis (as opposed to an ongoing condition that will require continuing it after discharge), and discontinuing the agent when appropriate.

All drugs, even common and seemingly benign ones, carry some risk and should be discontinued when no longer needed. Thus, medications added during the hospitalization to control acute symptoms should also be reviewed at each transition to prevent inappropriate continuation when symptoms have resolved.

One study, for example, found that many patients were discharged with inappropriate prescriptions for atypical antipsychotics after receiving them in the intensive care unit, likely for delirium.²⁹ Documenting that an acute issue such as delirium has resolved should prompt the discontinuation of therapy.

Preventing therapeutic duplication

Therapeutic duplication occurs in about 8% of discharges.¹ These errors often result from formulary substitutions or altering the dosage form in the acute setting. For example, patients who receive a prescription for the substituted agent at discharge and also resume their prehospitalization medications end up with duplicate therapy.

Therapeutic substitution is common at the time of admission to the hospital as a result of formulary restrictions. Drug classes that are frequently substituted include statins, antihypertensives, urinary antispasmodics, and proton pump inhibitors. Physicians should be familiar with the preferred agents on the hospital formulary and make careful note when a substitution occurs. Furthermore, hospital systems should be developed to remind the physician to switch back to the outpatient medication at discharge.

Similar problems occur when home medications are replaced with different dosage forms with different pharmacokinetic properties. For example, a long-acting medication may be temporarily replaced with an intravenous solution or immediate-release tablet for several reasons, including nothing-by-mouth status, unstable clinical condition, need for titration, and need to crush the tablet to give the drug per tube. The differing formulations must be reconciled throughout the patient’s hospital course and at discharge to avoid therapeutic duplication and serious medication errors. Deliberate changes to the dosage form should be clearly communicated in the discharge medication list so that patients and other clinicians are aware.

Hospital systems should also have the capability to identify duplications in the medication list and to warn prescribers of these errors. The ability to group medications by drug class or sort the medication list alphabetically by generic name can help uncover duplication errors.

STEP 3: REVIEW THE LIST IN VIEW OF THE CLINICAL PICTURE

Transitions of care should prompt providers to review the medication list for possible drug-disease interactions, confirm compliance with evidence-based guidelines, and evaluate the risks and benefits of each medication in the context of the patient’s age and acute and chronic medical issues. This is also an opportunity to screen the full list for potentially inappropriate medications and high-alert drugs such as insulin or anticoagulants, which are more likely than other drugs to cause severe harm when used in error.

Acute kidney injury. New drug-disease interactions can arise during a hospitalization and can affect dosing and the choice of drug. The onset of acute kidney injury, for example, often necessitates adjusting or discontinuing nephrotoxic and renally excreted medications. ADEs or potential ADEs have been reported in 43% of hospitalized patients with acute kidney injury.³⁰

Because acute kidney injury is often transient, medications may need to be held or adjusted several times until renal function stabilizes. This can be challenging across the continuum of care and requires close monitoring of the serum creatinine level and associated drug doses and levels, if applicable. Well-designed clinical decision support tools can integrate laboratory data and alert the prescriber to a clinically important increase or decrease in serum creatinine that may warrant a change in therapy. Modifications to the regimen and a plan for timely follow-up of the serum creatinine level should be clearly documented in the discharge plan.

Liver disease. Similar attention should be given to drugs that are hepatically metabolized if a patient has acute or chronic liver impairment.

Geriatric patients, particularly those who present with altered mental status, falls, or urinary retention, should have their medication list reviewed for potentially inappropriate medications, which are drugs that pose increased risk of poor outcomes in older adults.^31,32 Patients and providers may have been willing to accept the risk of medications such as anticholinergics or sedative-hypnotics when the drugs were initiated, but circumstances can change over time, especially in this patient population. Hospitalization is a prime opportunity to screen for medications that meet the Beers criteria³¹ for agents to avoid or use with caution in older adults.

As-needed medications. Medications prescribed on an as-needed basis in the hospital should be reviewed for continuation or discontinuation at discharge. How often the medication was given can inform this decision.

For example, if as-needed opioids were used frequently, failure to develop a plan of care for pain can lead to persistent symptoms and, possibly, to readmission.^33,34 Similar scenarios occur with use of as-needed blood pressure medications, laxatives, and correction-dose insulin.

If an as-needed medication was used consistently during hospitalization, the physician should consider whether a regularly scheduled medication is needed. Conversely, if the medication was not used during the inpatient admission, it can likely be discontinued.

STEP 4: PREPARE THE PATIENT AND FOLLOW-UP PROVIDER

Once a clinician has performed medication reconciliation, including obtaining a best-possible medical history and carefully reviewing the medication list and orders for errors and clinical appropriateness, the next steps are to ensure the patient understands what he or she needs to do and to confirm that suitable follow-up plans are in place. These measures should be taken at all transitions of care but are critically important at hospital discharge.

Preparing the patient and caregiver

An accurate, reconciled medication list should be given to the patient, caregiver, or both, and should be reviewed before discharge.¹⁷

Approximately one-third of Americans have low health literacy skills, so medication lists and associated materials should be easy to understand.³⁵ Medication lists should be written in plain language and formatted for optimal readability (Table 4), clearly stating which medications to continue, change, hold temporarily, and stop.

Patients recall and comprehend about half of the information provided during a medical encounter.³⁶ Thus, medication teaching should focus on key points including changes or additions to the regimen, specific instructions for follow-up and monitoring, and how to handle common and serious side effects.

To confirm patient understanding, clinicians should use “teach-back,” ie, provide the patient with information and then ask him or her to repeat back key points.^37,38 The patient and family should also be encouraged to ask questions before discharge.

If not already addressed during the hospital stay, barriers to medication adherence and ability to obtain the medications should be attended to at this time (Table 5). Also, the plan to pick up the medications should be verified with the patient and caregiver. Verify that there is transportation to a particular pharmacy that is open at the time of discharge, and that the patient can afford the medications.

Ensuring appropriate follow-up

Studies have shown that timely in-home or telephone follow-up after discharge can decrease adverse events and postdischarge health care utilization.^39,40 Telephone follow-up that includes thorough medication reconciliation can help detect and resolve medication issues early after discharge and can close gaps related to monitoring and follow-up.

Medication reconciliation by telephone can be time-consuming. Depending on the number of medications that need to be reviewed, calls can take between 10 and 60 minutes. Postdischarge phone calls should be performed by clinical personnel who are able to identify medication-related problems. A pharmacist should be an available resource to assist with complex regimens, to help resolve medication discrepancies, and to address patient concerns. Table 6 provides tips for conducting follow-up phone calls.

Resolving discrepancies identified during follow-up calls can be difficult, as changes to the medication regimen are often not communicated effectively to other members of the care team. Physicians should document the complete medication list and plan in the discharge summary, and there should be a method for the caller to record updates to the medication list in the medical record so that they are apparent at the outpatient follow-up visit.

An additional challenge is that it is frequently unclear which physician “owns” which medications. Therefore, designating a contact person for each medication until follow-up can be very valuable. At a minimum, a “physician owner” for high-alert medications such as insulin, anticoagulants, and diuretics should be identified to provide close follow-up, titration, and monitoring.

There should also be a plan for the patient to obtain refills of essential long-term medications, such as antiplatelet agents following stent placement.

SUMMARY AND RECOMMENDATIONS

Medication-related problems during hospital admission and discharge are common and range from minor discrepancies in the medication list to errors in history-taking, prescribing, and reconciliation that can lead to potential or actual patient harm. Putting systems in place to facilitate medication reconciliation can decrease the occurrence of medication discrepancies and ADEs, thereby improving patient safety during these critical transitions between care settings and providers. Institutional medication reconciliation programs should focus resources on the admission history-taking step, target the highest-risk patients for the most intensive interventions, and involve pharmacy personnel when possible.

On an individual level, clinicians can incorporate additional interventions into their workflows to optimize medication safety for hospitalized patients. Using a structured approach to obtain a complete and accurate medication list at the time of hospital admission will help providers identify medication-related problems and prevent the propagation of errors throughout the hospital stay and at discharge. Focusing additional time and effort on a comprehensive review of the medication list for errors of omission and commission, patient-specific needs, and high-alert drugs will further decrease the risk of medication errors. Finally, providing discharge counseling targeting patient barriers to adherence and ensuring a proper handover of medication information and rationale for medication changes to outpatient providers will improve the chances of a safe transition.

Any time patients enter or leave the hospital, they risk being harmed by errors in their medications.¹ Adverse events from medication errors during transitions of care are common but often preventable. One key approach is to systematically review every patient’s medication list on admission and discharge and resolve any discrepancies. These transitions are also an opportunity to address other medication-related problems, such as adherence, drug interactions, and clinical appropriateness.

This article summarizes the types and prevalence of medication problems that occur during hospital-based transitions of care, and suggests strategies to decrease the risk of medication errors, focusing on medication reconciliation and related interventions that clinicians can use at the bedside to improve medication safety.

DEFINING TERMS

A medication discrepancy is any variance noted in a patient’s documented medication regimen across different medication lists or sites of care. While some differences reflect intentional and clinically appropriate changes to the regimen, others are unintentional and reflect inaccurate or incomplete information. These unintentional discrepancies are medication errors.

Depending on the clinical circumstances and medications involved, such errors may lead to an adverse drug event (ADE), defined as actual harm or injury resulting from a medication. Sometimes a medication error does not cause harm immediately but could if left uncorrected; this is called a potential ADE.

An important goal during transitions of care is to reduce unintentional medication discrepancies, thereby reducing potential and actual ADEs.

ERRORS ARISE AT DISCHARGE—AND EVEN MORE AT ADMISSION

Hospital discharge is a widely recognized transition in which patient harm occurs. As many as 70% of patients may have an unintentional medication discrepancy at hospital discharge, with many of those discrepancies having potential for harm.² Indeed, during the first few weeks after discharge, 50% of patients have a clinically important medication error,³ and 20% experience an adverse event, most commonly an ADE.⁴ ADEs are associated with excess health care utilization,^5–7 and many are preventable through strategies such as medication reconciliation.^5,8

Importantly, more errors arise at hospital admission than at other times.^9,10

Errors in medication histories are the most common source of discrepancies, affecting up to two-thirds of admitted patients.^11,12 More than one-quarter of hospital prescribing errors can be attributed to incomplete medication histories at the time of admission,¹³ and nearly three times as many clinically important medication discrepancies are related to history-taking errors on admission rather than reconciliation errors at discharge.⁹

Most discrepancies occurring at the time of admission have the potential to cause harm, particularly if the errors persist beyond discharge.¹⁴ Therefore, taking a complete and accurate medication history on hospital admission is critical to ensuring safe care transitions.

MEDICATION RECONCILIATION: BARRIERS AND FACILITATORS

Medication reconciliation is a strategy for reducing medication discrepancies in patients moving across care settings. Simply put, it is the process by which a patient’s medication list is obtained, compared, and clarified across different sites of care.¹⁵ It has consistently been shown to decrease medication errors compared with usual care,¹⁶ and it is strongly supported by national and international organizations.^17–21

In clinical practice, many physicians and institutions have found medication reconciliation difficult to implement, owing to barriers at the level of the patient, provider, and system (Table  1). In response to these challenges, two initiatives have synthesized best practices and offer toolkits that hospitals and clinicians can use: the Medications at Transitions and Clinical Handoffs (MATCH) program²² and the Multi-Center Medication Reconciliation Quality Improvement Study (MARQUIS).²³

Lack of resources is a widely acknowledged challenge. Thus, the MARQUIS investigators²³ suggested focusing on the admission history, where most errors occur, and applying the most resource-intensive interventions in patients at highest risk of ADEs, ie, those who are elderly, have multiple comorbid conditions, or take numerous medications.¹⁶

Although the risk of an ADE increases with the number of medications a patient takes,⁴ the exact number of drugs that defines high risk has not been well established. Targeting patients who take 10 or more maintenance medications is a reasonable initial approach,²⁴ but institutions should tailor risk stratification to their patient populations and available resources. Patients taking high-risk medications such as anticoagulants and insulin could also be prioritized for review, since these medications are more likely to cause serious patient harm when used without appropriate clinical oversight.⁷

Using pharmacy staff to perform medication history-taking, reconciliation, and patient counseling has been shown to produce favorable patient outcomes, particularly for higher-risk patients.^16,23

The MARQUIS investigators found they could boost the chances of success by sharing stories of patient harm to foster “buy-in” among frontline staff, providing formal training to clinicians on how to take a medication history, and obtaining the support of nursing leaders to champion improvement efforts.²³

Additionally, patients should be empowered to maintain an accurate medication list. We address strategies for improving patient engagement and adherence in a later section.

BEST PRACTICES FOR IMPROVING MEDICATION SAFETY

Medication reconciliation is one of several measures necessary to optimize medication safety during transitions of care. It typically includes the following actions:

• Interview the patient or caregiver to determine the list of medications the patient is currently taking (or supposed to be taking); consult other sources if needed.
• List medications that are being ordered during the clinical encounter.
• Compare these two lists, making note of medications that are stopped, changed, or newly prescribed.
• Resolve any discrepancies.
• Communicate the reconciled list to the patient, appropriate caregivers, and providers of follow-up care.

At a rudimentary level, medication reconciliation encompasses medication list management along the continuum of care. However, we recommend leveraging medication reconciliation as an opportunity to further enhance medication safety by reviewing the appropriateness of each medication, seizing opportunities to streamline or simplify the regimen, assessing patient and caregiver understanding of medication instructions and potential ADEs, and delivering appropriate counseling to enhance medication use. Table 2 outlines our framework for medication management during hospital-based transitions.

STEP 1: OBTAIN A COMPLETE PREADMISSION MEDICATION LIST

The “best-possible medication history” is obtained in a systematic process of interviewing the patient or caregiver plus reviewing at least one other reliable source.²³ The resulting list should include all medications the patient is taking (prescription and nonprescription), doses, directions for use, formulations if applicable, indications, start and stop dates, and medication allergies and reactions.

Review existing information. Before eliciting a history from the patient, review his or her recorded medical history and existing medication lists (eg, prior discharge summaries, records from other facilities, records from outpatient visits, pharmacy fill data). This will provide context about the regimen and help identify issues and questions that can be addressed during the history-taking.

Ask open-ended questions. Instead of just asking the patient to confirm the accuracy of the existing medication list, we recommend actively obtaining the full medication list from the patient or caregiver. The conversation should begin with an open-ended question such as, “What medications do you take at home?” This approach will also allow the clinician to gauge the patient’s level of understanding of each medication’s indication and dosing instructions. Using a series of prompts such as those recommended in Table 3 will elicit a best-possible medical history, while verifying all of the medications on the existing list.

Clarify discrepancies. Resolve differences between the existing medication lists and the patient’s or caregiver’s report during the preadmission interview. Examples include errors of omission (a medication is missing), errors of commission (an additional medication is present), and discrepancies in the strength, formulation, dosing instructions, and indications for the drugs. If necessary, other sources of information should be consulted, such as the patient’s medication bottles, pharmacy or pharmacies, primary care physician, and a family member or caregiver.

Assess adherence. The extent to which patients take their medications as directed is an important component of the history, but is often left out. Medication nonadherence rates in the United States are 40% to 70%,²⁵ contributing to poor patient outcomes and imposing extraordinary costs on the health care system.²⁶

Asking open-ended, nonjudgmental questions at the time of hospital admission will help to uncover medication-taking behaviors as well as barriers to adherence (Table 3). The patient’s responses should be taken into account when determining the treatment plan.

Document your findings. After completing the medication history and clarifying discrepancies, document the preadmission list in the medical record. All members of the health care team should have access to view and update the same list, as new information about the preadmission medications may be uncovered after the initial history.

Make clinical decisions. Complete the admission medication reconciliation by deciding whether each medication on the list should be continued, changed, held, or discontinued on the basis of the patient’s clinical condition. Well-designed information technology applications enable the provider to document each action and the rationale for it, as well as carry that information into the order-entry system. Medications marked as held or discontinued on admission should be revisited as the patient’s clinical condition changes and at discharge.

STEP 2: AVOID RECONCILIATION ERRORS

Reconciliation errors reflect discrepancies between the medication history and the medications that are ordered after admission.

Reconciliation errors are less common than medication history errors, accounting for approximately one-third of potentially harmful medication errors in hospitalized medical patients.⁹ These include errors of omission (a medication is omitted from the orders), errors of commission (a medication is prescribed with no indication for continuation), and therapeutic duplication.

Preventing errors of omission

Medications are often held at transition points for appropriate clinical reasons. Examples include holding anticoagulants and antiplatelet agents in patients who have gastrointestinal bleeding or an upcoming procedure, antihypertensives in patients with hemodynamic instability, and other chronic medications in patients with an acute illness.

Poor documentation and communication of these decisions can lead to a failure to resume the medications—an error of omission—at hospital discharge.

Hospitalized patients are at risk of unintentional discontinuation of their chronic medications, including antiplatelet drugs, anticoagulants, statins, and thyroid replacement, particularly if admitted to the intensive care unit.¹² These errors can be minimized by a standardized medication reconciliation process at each transition and clear documentation of the medication plan.

Communication among providers can be improved if the admitting clinician documents clearly whether each preadmission medication is being continued, changed, or stopped, along with the reason for doing so, and makes this information available throughout the hospital stay. Upon transfer to another unit and at discharge, the physician should review each; preadmission medication that was held and the patient’s current clinical status and, based on that information, decide whether medications that were held should be resumed. If a medication will be restarted later, specific instructions should be documented and communicated to the patient and the physicians who are taking over his or her care.

Preventing errors of commission

Failure to perform a complete reconciliation at each transition of care and match each medication with an appropriate indication can lead to errors of commission.

One study showed that 44% of patients were prescribed at least one unnecessary drug at hospital discharge, one-fourth of which were started during the hospitalization.²⁷ Commonly prescribed unnecessarily were gastrointestinal agents, central nervous system drugs, nutrients, and supplements.

It is critical to assess each medication’s ongoing need, appropriateness, and risk-benefit ratio at every transition. Medications no longer indicated should be discontinued in order to simplify the regimen, avoid unnecessary drug exposure, and prevent ADEs.

For example, proton pump inhibitors or histamine 2 receptor blockers are often started in the hospital for stress ulcer prophylaxis. One-third of patients are then discharged home on the medication, and 6 months later half of those patients are still taking the unnecessary drug.²⁸ This situation can be avoided by limiting use of these medications to appropriate circumstances, clearly marking the indication as stress ulcer prophylaxis (as opposed to an ongoing condition that will require continuing it after discharge), and discontinuing the agent when appropriate.

All drugs, even common and seemingly benign ones, carry some risk and should be discontinued when no longer needed. Thus, medications added during the hospitalization to control acute symptoms should also be reviewed at each transition to prevent inappropriate continuation when symptoms have resolved.

One study, for example, found that many patients were discharged with inappropriate prescriptions for atypical antipsychotics after receiving them in the intensive care unit, likely for delirium.²⁹ Documenting that an acute issue such as delirium has resolved should prompt the discontinuation of therapy.

Preventing therapeutic duplication

Therapeutic duplication occurs in about 8% of discharges.¹ These errors often result from formulary substitutions or altering the dosage form in the acute setting. For example, patients who receive a prescription for the substituted agent at discharge and also resume their prehospitalization medications end up with duplicate therapy.

Therapeutic substitution is common at the time of admission to the hospital as a result of formulary restrictions. Drug classes that are frequently substituted include statins, antihypertensives, urinary antispasmodics, and proton pump inhibitors. Physicians should be familiar with the preferred agents on the hospital formulary and make careful note when a substitution occurs. Furthermore, hospital systems should be developed to remind the physician to switch back to the outpatient medication at discharge.

Similar problems occur when home medications are replaced with different dosage forms with different pharmacokinetic properties. For example, a long-acting medication may be temporarily replaced with an intravenous solution or immediate-release tablet for several reasons, including nothing-by-mouth status, unstable clinical condition, need for titration, and need to crush the tablet to give the drug per tube. The differing formulations must be reconciled throughout the patient’s hospital course and at discharge to avoid therapeutic duplication and serious medication errors. Deliberate changes to the dosage form should be clearly communicated in the discharge medication list so that patients and other clinicians are aware.

Hospital systems should also have the capability to identify duplications in the medication list and to warn prescribers of these errors. The ability to group medications by drug class or sort the medication list alphabetically by generic name can help uncover duplication errors.

STEP 3: REVIEW THE LIST IN VIEW OF THE CLINICAL PICTURE

Transitions of care should prompt providers to review the medication list for possible drug-disease interactions, confirm compliance with evidence-based guidelines, and evaluate the risks and benefits of each medication in the context of the patient’s age and acute and chronic medical issues. This is also an opportunity to screen the full list for potentially inappropriate medications and high-alert drugs such as insulin or anticoagulants, which are more likely than other drugs to cause severe harm when used in error.

Acute kidney injury. New drug-disease interactions can arise during a hospitalization and can affect dosing and the choice of drug. The onset of acute kidney injury, for example, often necessitates adjusting or discontinuing nephrotoxic and renally excreted medications. ADEs or potential ADEs have been reported in 43% of hospitalized patients with acute kidney injury.³⁰

Because acute kidney injury is often transient, medications may need to be held or adjusted several times until renal function stabilizes. This can be challenging across the continuum of care and requires close monitoring of the serum creatinine level and associated drug doses and levels, if applicable. Well-designed clinical decision support tools can integrate laboratory data and alert the prescriber to a clinically important increase or decrease in serum creatinine that may warrant a change in therapy. Modifications to the regimen and a plan for timely follow-up of the serum creatinine level should be clearly documented in the discharge plan.

Liver disease. Similar attention should be given to drugs that are hepatically metabolized if a patient has acute or chronic liver impairment.

Geriatric patients, particularly those who present with altered mental status, falls, or urinary retention, should have their medication list reviewed for potentially inappropriate medications, which are drugs that pose increased risk of poor outcomes in older adults.^31,32 Patients and providers may have been willing to accept the risk of medications such as anticholinergics or sedative-hypnotics when the drugs were initiated, but circumstances can change over time, especially in this patient population. Hospitalization is a prime opportunity to screen for medications that meet the Beers criteria³¹ for agents to avoid or use with caution in older adults.

As-needed medications. Medications prescribed on an as-needed basis in the hospital should be reviewed for continuation or discontinuation at discharge. How often the medication was given can inform this decision.

For example, if as-needed opioids were used frequently, failure to develop a plan of care for pain can lead to persistent symptoms and, possibly, to readmission.^33,34 Similar scenarios occur with use of as-needed blood pressure medications, laxatives, and correction-dose insulin.

If an as-needed medication was used consistently during hospitalization, the physician should consider whether a regularly scheduled medication is needed. Conversely, if the medication was not used during the inpatient admission, it can likely be discontinued.

STEP 4: PREPARE THE PATIENT AND FOLLOW-UP PROVIDER

Once a clinician has performed medication reconciliation, including obtaining a best-possible medical history and carefully reviewing the medication list and orders for errors and clinical appropriateness, the next steps are to ensure the patient understands what he or she needs to do and to confirm that suitable follow-up plans are in place. These measures should be taken at all transitions of care but are critically important at hospital discharge.

Preparing the patient and caregiver

An accurate, reconciled medication list should be given to the patient, caregiver, or both, and should be reviewed before discharge.¹⁷

Approximately one-third of Americans have low health literacy skills, so medication lists and associated materials should be easy to understand.³⁵ Medication lists should be written in plain language and formatted for optimal readability (Table 4), clearly stating which medications to continue, change, hold temporarily, and stop.

Patients recall and comprehend about half of the information provided during a medical encounter.³⁶ Thus, medication teaching should focus on key points including changes or additions to the regimen, specific instructions for follow-up and monitoring, and how to handle common and serious side effects.

To confirm patient understanding, clinicians should use “teach-back,” ie, provide the patient with information and then ask him or her to repeat back key points.^37,38 The patient and family should also be encouraged to ask questions before discharge.

If not already addressed during the hospital stay, barriers to medication adherence and ability to obtain the medications should be attended to at this time (Table 5). Also, the plan to pick up the medications should be verified with the patient and caregiver. Verify that there is transportation to a particular pharmacy that is open at the time of discharge, and that the patient can afford the medications.

Ensuring appropriate follow-up

Studies have shown that timely in-home or telephone follow-up after discharge can decrease adverse events and postdischarge health care utilization.^39,40 Telephone follow-up that includes thorough medication reconciliation can help detect and resolve medication issues early after discharge and can close gaps related to monitoring and follow-up.

Medication reconciliation by telephone can be time-consuming. Depending on the number of medications that need to be reviewed, calls can take between 10 and 60 minutes. Postdischarge phone calls should be performed by clinical personnel who are able to identify medication-related problems. A pharmacist should be an available resource to assist with complex regimens, to help resolve medication discrepancies, and to address patient concerns. Table 6 provides tips for conducting follow-up phone calls.

Resolving discrepancies identified during follow-up calls can be difficult, as changes to the medication regimen are often not communicated effectively to other members of the care team. Physicians should document the complete medication list and plan in the discharge summary, and there should be a method for the caller to record updates to the medication list in the medical record so that they are apparent at the outpatient follow-up visit.

An additional challenge is that it is frequently unclear which physician “owns” which medications. Therefore, designating a contact person for each medication until follow-up can be very valuable. At a minimum, a “physician owner” for high-alert medications such as insulin, anticoagulants, and diuretics should be identified to provide close follow-up, titration, and monitoring.

There should also be a plan for the patient to obtain refills of essential long-term medications, such as antiplatelet agents following stent placement.

SUMMARY AND RECOMMENDATIONS

Medication-related problems during hospital admission and discharge are common and range from minor discrepancies in the medication list to errors in history-taking, prescribing, and reconciliation that can lead to potential or actual patient harm. Putting systems in place to facilitate medication reconciliation can decrease the occurrence of medication discrepancies and ADEs, thereby improving patient safety during these critical transitions between care settings and providers. Institutional medication reconciliation programs should focus resources on the admission history-taking step, target the highest-risk patients for the most intensive interventions, and involve pharmacy personnel when possible.

On an individual level, clinicians can incorporate additional interventions into their workflows to optimize medication safety for hospitalized patients. Using a structured approach to obtain a complete and accurate medication list at the time of hospital admission will help providers identify medication-related problems and prevent the propagation of errors throughout the hospital stay and at discharge. Focusing additional time and effort on a comprehensive review of the medication list for errors of omission and commission, patient-specific needs, and high-alert drugs will further decrease the risk of medication errors. Finally, providing discharge counseling targeting patient barriers to adherence and ensuring a proper handover of medication information and rationale for medication changes to outpatient providers will improve the chances of a safe transition.

Sepsis is familiar to most physicians in clinical practice, but guidance from the medical literature on how best to manage it has traditionally been confusing.

Starting in 2002, the Surviving Sepsis Campaign has worked to reduce worldwide mortality from severe sepsis and septic shock by developing and publicizing guidelines of best practices based on evidence from the literature. The campaign published its first management guidelines in 2004.

In this article, I review the most recent guidelines^1,2 (published in 2013) and discuss the campaign’s ongoing performance-improvement program.

DEFINING SEPSIS

Sepsis is a known or suspected infection plus systemic manifestations of infection. This includes the sepsis inflammatory response syndrome. Criteria include:

• Tachycardia (heart rate > 90 beats per minute)
• Tachypnea (> 20 breaths/minute or Paco₂ < 32 mm Hg)
• Fever (temperature > 38.3°C [100.9°F]) or hypothermia (core temperature < 36°C [96.8°F])
• High or low white blood cell count (> 12.0 × 10⁹/L or < 4.0 × 10⁹/L), or a normal count with more than 10% immature cells.

The definition of sepsis was broadened in 2002 to include other systemic manifestations of infection, such as changes in blood glucose level and organ dysfunction.

Severe sepsis is defined as sepsis plus either acute organ dysfunction or tissue hypoperfusion due to infection, with tissue hypoperfusion defined as:

• Hypotension (systolic blood pressure < 90 mm Hg, or a drop in systolic blood pressure of > 40 mm Hg)
• Elevated lactate
• Low urine output
• Altered mental status.

In severe sepsis, organ dysfunction is caused by blood-borne toxins and involves acute lung and kidney injury, coagulopathy (thrombocytopenia and increased international normalized ratio), and liver dysfunction.

Septic shock is present when a patient requires vasopressors after adequate intravascular volume repletion.

SEPSIS IS DEADLY AND COSTLY

Severe sepsis is the leading cause of hospital death. Patients admitted with severe sepsis are eight times more likely to die than those admitted with other conditions.³ The economic burden is enormous: it is the most expensive condition treated in US hospitals, costing an estimated $20.3 billion in 2011, of which $12.7 billion came from Medicare.

THE SURVIVING SEPSIS CAMPAIGN

The Surviving Sepsis Campaign is a global effort to reduce the rate of death from severe sepsis. The campaign’s methods include:

Patients with severe sepsis are eight times more likely to die than those with other conditions

• Educating physicians, the public, the media, and government about the high rates of morbidity and death in severe sepsis
• Creating evidence-based guidelines for managing sepsis and establishing global best-practice standards
• Facilitating the transfer of knowledge by developing performance-improvement programs to change bedside practice.

The campaign is funded with a grant from the Gordon and Betty Moore Foundation. The campaign’s guidelines are not associated with any direct or indirect industry support. The 2013 guidelines were backed by 30 international organizations.^1,2

All recommendations are ranked with numerical and letter scores, according to the GRADE system: 1 indicates a strong recommendation and 2 a weak one. The letters A through D reflect the quality of evidence, ranging from high (A) to very low (D).

GIVING ANTIBIOTICS EARLY IMPROVES OUTCOMES

A number of studies have suggested that starting appropriate antibiotics early improves outcomes in severe sepsis and septic shock. The death rate increases with each hour of delay.⁴

Recommendation. Intravenous antibiotic therapy should be started as soon as possible, and within the first hour after recognition of septic shock (grade 1B) and severe sepsis without septic shock (grade 1C).

The feasibility of achieving this goal has not been scientifically validated, and the recommendation should not be misinterpreted as the current standard of care. Even hospitals that participate in performance-improvement programs often struggle to start antibiotics, even within 6 hours of recognition. Nevertheless, the goal is a good one.

Some have questioned the early antibiotic recommendation because of concerns about antibiotic overuse and resistance. For a patient with some manifestation of systemic inflammation, such as organ dysfunction or hypotension with no clear cause, the campaign’s position is to provide empiric antibiotics early and then, if a noninfectious cause is found, to stop the antibiotics. Moreover, as soon as a causative pathogen has been identified, the regimen should be switched to the most appropriate antimicrobial that covers the pathogen and is safe and cost-effective. Collaboration with an antimicrobial stewardship program, if available, is encouraged.

FIND THE INFECTION SOURCE PROMPTLY: SOURCE CONTROL MAY BE REQUIRED

Recommendation. A specific anatomic diagnosis of infection (eg, necrotizing soft-tissue infection, peritonitis complicated by intra-abdominal infection, cholangitis, intestinal infarction) requiring consideration of emergency source control should be confirmed or excluded as soon as possible. If needed, surgical drainage should be undertaken for source control within the first 12 hours after a diagnosis is made (grade 1C).

FLUID THERAPY: CRYSTALLOIDS FIRST

Recommendation. In fluid resuscitation of severe sepsis, use crystalloids first (grade 1B).

Mortality risk increases with each hour of delay in starting antibiotics

No head-to-head trial has shown albumin to be superior to crystalloids, and crystalloids are less expensive. However, normal saline has a higher chloride content than plasma, which leads to non-anion-gap metabolic acidosis. It is called an unbalanced crystalloid, having a high chloride content and no buffer. There is concern that this reduces renal blood flow and the glomerular filtration rate, creating the potential for acute kidney injury. Although no high-level evidence supports this concern, some animal studies and historical control studies suggest that a balanced crystalloid such as Ringer’s lactate, Ringer’s acetate, or PlasmaLyte (having a chloride content close to that of plasma and the buffers acetate or lactate) may be associated with better outcome in resuscitation of severe sepsis.

Use albumin solution if necessary

Recommendation. Albumin should be used in the fluid resuscitation of severe sepsis and septic shock for patients who require substantial amounts of crystalloids (grade 2C).

Finfer et al⁵ compared the effect of fluid resuscitation with either an albumin or saline solution in nearly 7,000 patients in intensive care and found that death rates over 28 days were nearly identical between the two groups. Although this study was not designed to measure an effect in subsets of patients, the subgroup with severe sepsis had a lower mortality rate with albumin (relative risk 0.87, 95% confidence interval 0.74–1.02). In a meta-analysis of 17 studies of albumin vs crystalloids or albumin vs saline, Delaney et al⁶ found a significant survival advantage with an albumin solution in patients with sepsis and severe septic shock.

Sometimes, in patients admitted to intensive care with septic shock and receiving two or three vasopressors and large amounts of a crystalloid solution, vasopressors can be reduced when fluid is being given, but as soon as the fluid infusion rate is decreased, the need for increasing vasopressors returns. This scenario is an indication for changing to an albumin solution.

Recommendation. Initial fluid challenge in sepsis-induced tissue hypoperfusion (as evidenced by hypotension or elevated lactate) with suspicion of hypovolemia should be a minimum of 30 mL/kg of crystalloids, a portion of which can be an albumin equivalent. Some patients require more rapid administration and greater amounts of fluid (grade 1B).

Other fluid resuscitation considerations

Recommendation. Hydroxyethyl starch (hetastarch) should not be used for fluid resuscitation of severe sepsis and septic shock (grade 1B).

Five large clinical trials^7–11 compared hetastarch with crystalloids in the resuscitation of severe sepsis or septic shock. None found an advantage to using hetastarch, and three found it to be associated with higher rates of acute kidney injury and renal-replacement therapy.

Blood is not considered a resuscitation fluid.

Full fluid replacement is still needed in heart or kidney disease

Often, doctors hesitate to administer full fluid resuscitation to patients with septic shock or sepsis-induced hypotension who have baseline cardiomyopathy with a low ejection fraction or who have end-stage renal disease and are anuric. However, these patients’ baseline intravascular volume status has changed because of venodilation and capillary leak leading to reduced blood return to the heart. They require the same amount of fluids as other patients to return to their baseline state.

To avoid fluid overload in these patients, however, we recommend providing fluid in smaller boluses. For a young, previously healthy patient, 2 L of crystalloid should be provided as quickly as possible. Patients with heart or kidney disease should receive smaller (250- or 500-mL) boluses, with oxygen saturation checked after each dose, as hypoxemia is one of only two potential downsides of aggressive fluid resuscitation (the other being the further raising of intra-abdominal pressure in the intra-abdominal compartment syndrome).

WHAT DRIVES HYPOTENSION IN SEPTIC SHOCK?

In septic shock, mechanisms that can lower the blood pressure include capillary leakage (loss of intravascular volume), decreased arteriolar resistance, decreased cardiac contractility, increased ventricular compliance, and increased venous capacitance (loss of intra-arterial volume).

Capillary leakage ranges from moderate to severe, and it is difficult to know the severity early on during resuscitation. The extent of capillary leakage is often apparent only after 24 hours of fluid resuscitation, when the large amount of fluid needed to maintain intravascular volume produces significant tissue edema. Within the first 24 hours of resuscitation of a patient with septic shock or in the presence of ongoing inflammation, one cannot use intake and output to judge the adequacy of fluid resuscitation.

Reduced arteriolar resistance may be an advantage in the nonhypotensive severely septic patient, compensating for the decreased ejection fraction, but it becomes problematic in the presence of hypotension. In addition, venodilation increases venous capacitance, producing a “sink” for blood and inadequate return of blood volume to the heart.

Decreased contractility of the left and right ventricles leads to compensatory sinus tachycardia.¹² Reduced heart contractility can be seen by radionuclide angiography: little difference in chamber size is apparent in systole (immediately before contraction) vs diastole (immediately after contraction) (Figure 1).

Images courtesy of Joseph E. Parrillo, MD.

NOREPINEPHRINE IS THE FIRST-CHOICE VASOPRESSOR

If a patient remains hypotensive after replacement of intravascular volume, the hypotension is due to a combination of vasodilation and reduced contractility, and a combined inotrope-vasopressor is an appropriate drug to raise blood pressure. Therefore, the drug of first choice for raising blood pressure should be a combined inotrope-vasopressor.

There are three combined inotrope-vasopressors: dopamine, norepinephrine, and epinephrine. Head-to-head comparisons of norepinephrine and dopamine have supported a survival advantage with norepinephrine in patients with shock, including septic shock.¹³ A meta-analysis of six randomized trials totaling 2,768 patients also supports norepinephrine over dopamine in septic shock. Dopamine has been associated with a higher incidence of tachyarrhythmic events.¹⁴

Recommendations. Norepinephrine is the first choice for vasopressor therapy (grade 1B). If an additional agent is needed to maintain blood pressure, epinephrine should be added to norepinephrine (grade 2B). Alternatively, vasopressin (0.03 U/minute) can be added to norepinephrine to raise mean arterial pressure to target or to decrease the norepinephrine dose (ungraded recommendation).

Dopamine is not recommended as empiric or additive therapy for septic shock. It may be considered, however, in the presence of septic shock with sinus bradycardia.

Phenylephrine for special cases

Phenylephrine is a pure vasopressor: it decreases stroke volume and is particularly disadvantageous in patients with low cardiac output.

Recommendation. Phenylephrine is not recommended as empiric or additive therapy in the treatment of septic shock, with these exceptions (grade 1C):

• In unusual cases in which norepinephrine is associated with serious tachyarrhythmia, phenylephrine would be the least likely vasopressor to exacerbate arrhythmia
• If cardiac output is known to be high and blood pressure is persistently low
• If it is used as salvage therapy when combined inotrope-vasopressor drugs and low-dose vasopressin have failed to achieve the mean arterial pressure target.

RESUSCITATION OF SEPSIS-INDUCED TISSUE HYPOPERFUSION

A more severe form of sepsis-induced tissue hypoperfusion occurs in patients with severe sepsis, who require vasopressors after fluid challenge or have a lactate level of at least 4 mmol/L (36 mg/dL). Initial resuscitation is of utmost importance in these patients and often is done in the emergency department or regular hospital unit. These patients are targeted for “quantitative resuscitation,” ie, a protocol of fluid therapy and vasoactive agent support to achieve predefined end points.

Rivers et al¹⁵ published a landmark study of “early goal-directed therapy” targeting the early management of sepsis-induced tissue hypoperfusion (vasopressor requirement after fluid resuscitation or lactate > 4 mmol/L) and reported significant improvement in the survival rate when resuscitation was targeted to a superior vena cava oxygen saturation of 70%. Both control-group and active-treatment-group patients had central venous pressure targets of 8 mm Hg or greater. The Surviving Sepsis Campaign adopted these targets as recommendations in the original 2004 guidelines and continued through the 2013 guidelines, although the campaign’s sepsis management “bundles” that had originally included specific targets for central venous pressure and central venous oxygen saturation as above were changed in the 2013 guidelines to only measuring these variables (see discussion below).

Jones et al¹⁶ analyzed studies that involved early (within 24 hours of presentation) vs late (after 24 hours or unknown) quantitative resuscitation for sepsis-induced tissue hypoperfusion and found a significant reduction in the rate of death with early resuscitation but no difference with late resuscitation compared with standard therapy.

ALTERNATIVES TO MEASURING PRESSURE TO PREDICT RESPONSE TO FLUID

The campaign recognizes the limitation of pressure measurements to predict the response to fluid resuscitation. Some clinicians have objected to the guidelines, arguing that new bedside technology provides better information than central venous pressure or superior vena cava oxygen saturation.

It is useful to recall the Starling principle, which is based on the behavior of isolated myocardial fibrils that are put under the strain of graduated weights and then are stimulated to contract, modeling the contractility of the heart. The more the fibril is stretched, the more intense the contraction. Increased contractility explains why fluid resuscitation increases cardiac output; it is not simply a matter of increasing fluid volume in the veins. Increased volume in the left ventricle increases stretch, causing more intense contractility and higher stroke-volume cardiac output.

Crystalloids should be used for initial fluid resuscitation

The guidelines are based on pressure measurements, but volume is the important measure that drives contractility. For this reason, the 2013 guidelines encourage the use of alternative measures if a hospital has the capability to assess and use them. These alternative measures include changes in pulse pressure, systolic pressure, and stroke volume during the respiratory cycle or with fluid bolus. The greater the variation in these measures, the more likely the patient will respond to additional fluid therapy.¹⁷ Normal values:

• Pulse pressure variation: < 13%
• Systolic pressure variation: < 10 mm Hg
• Stroke volume variation: < 10%.

The problem with the more sophisticated technologies is that they tend to be available only in academic centers and not at hospitals doing the critical early resuscitation of septic shock.

The serum lactate level

Measuring serum lactate levels is an alternative method for monitoring resuscitation of early septic shock. This method is widely available even with point-of-care testing. If the lactate level is elevated, quantitative resuscitation, fluids, inotropes, and oxygen delivery can be targeted to lactate clearance.

Recommendation. In patients in whom elevated lactate levels are used as a marker of tissue hypoperfusion, resuscitation should be targeted to normalize lactate as rapidly as possible (grade 2C).

STEROID THERAPY IS CONTROVERSIAL

Corticosteroid therapy for septic shock remains controversial. Although it has been deemphasized, it likely has a role in select patients.

Recommendation. Intravenous corticosteroids should not be used in adults with septic shock if adequate fluid resuscitation and vasopressor therapy restore hemodynamic stability (grade 2C). However, a patient on high doses of multiple vasopressors after adequate fluid resuscitation would likely benefit.

Recommendation. If corticosteroid therapy is used, hydrocortisone 200 mg should be given over 24 hours, preferentially by continuous intravenous infusion but alternatively 50 mg every 6 hours (grade 2D). This regimen can be continued for up to 7 days or tapered when shock resolves.

SURVIVING SEPSIS CAMPAIGN PERFORMANCE-IMPROVEMENT PROGRAM

By themselves, guidelines change bedside care very slowly. To effect change, protocols must be put in place and quality indicators must be measured. Beginning in 2005, the Surviving Sepsis Campaign converted its guidelines to selected sets of quality indicators, ie, severe sepsis bundles. The campaign published tools that hospitals could use to initiate performance improvement programs for diagnosis and management of severe sepsis and septic shock. The information was disseminated worldwide with a free software program. The program allowed data collection at the bedside to record performance with quality indicators.

In addition, the campaign requested user data so that performance could be tracked over time. In 2010, data on more than 10,000 patients in participating hospitals showed improved ability to achieve quality indicators. The longer a hospital continued the program, the better its compliance with management bundles; in addition, there was a concomitant reduction in hospital mortality rates.¹⁸

Among participants, mortality rates decreased from 37% in the first quarter to 26% in the 16th

At this time, the database holds records for more than 30,000 patients. Mortality rates among campaign participants decreased from 37% in the first quarter to 26% in the 16th quarter worldwide, with a reduced relative risk of mortality of 28%.¹⁹ To assess whether background factors unrelated to campaign participation were contributing to the reduced rates, mortality rates of long-term participants were compared with those of new program participants; the finding supported the association with program participation.

Bundles revised

The campaign published updated performance bundles in the 2013 guidelines.

The 3-hour bundle remains the same. Within the first 3 hours of presentation with sepsis:

• Measure the serum lactate level.
• Obtain blood cultures before starting antibiotics.
• Start broad-spectrum antibiotics.
• Give a crystalloid (30 mL/kg) for hypotension or for lactate ≥ 4 mmol/L.

The 6-hour bundle has changed somewhat. Within 6 hours of presentation:

• If hypotension does not respond to initial fluid resuscitation, apply vasopressors to maintain mean arterial pressure ≥ 65 mm Hg.
• In the event of persistent arterial hypotension despite volume resuscitation (septic shock) or initial lactate ≥ 4 mmol/L, measure central venous pressure and central venous oxygen saturation.
• Remeasure lactate if the initial lactate level was elevated.

In light of the campaign’s recognition of alternatives to central venous pressure and central venous oxygen saturation for quantitative resuscitation targets, specific targets for these measures were not defined, allowing institutions the flexibility to base decisions on other technologies, such as inferior vena cava ultrasonography, systolic pressure variation, and changes in flow measures or estimates with fluid boluses if they have the capability.

Moreover, the second point in the 6-hour bundle is being further revised. The Protocolized Care for Early Septic Shock (ProCESS) trial²⁰ and the Australasian Resuscitation in Sepsis Evaluation (ARISE) trial,²¹ both published in 2013, demonstrated that measuring central venous pressure and central venous oxygen saturation, although safe, is not necessary for successful resuscitation of patients with septic shock. Therefore, newer versions of the 6-hour bundle propose that physicians reassess intravascular volume status and tissue perfusion, after initial 30 mL/kg crystalloid administration, in the event of persistent hypotension (mean arterial pressure < 65 mm Hg, ie, vasopressor requirement) or an initial lactate level of 4 mmol/L or higher, and then document the findings. To meet the requirements, one must document either a repeat focused examination by a licensed independent practitioner (to include vital signs, cardiopulmonary, capillary refill, pulse, and skin findings) or two alternative items from the following options: central venous pressure, central venous oxygen saturation, bedside cardiovascular ultrasonography,  and dynamic assessment of fluid responsiveness with passive leg-raising or fluid challenge.

Of interest, the ProCESS²⁰ and ARISE²¹ trials supported early identification of septic shock, early use of antibiotics, and early aggressive fluid resuscitation as the likely reasons for the reduced mortality rates across all treatment groups in these studies.

REDUCING HOSPITAL MORTALITY RATES

Phase 3 of the campaign involves data from 30,000 patients with severe sepsis or septic shock in emergency departments (52%), medical and surgical units (35%), and critical care units (13%).

Hospital mortality rates were 28% for those who presented to the emergency department with sepsis vs 47% for those who developed it in the hospital.²² The reason for the substantial difference is unclear; possibly, diagnosis takes longer in medical and surgical units because of a lower nurse-to-patient ratio, leading to delay in diagnosis and treatment.

Phase 4 of the campaign: Improve recognition of sepsis in the hospital

The finding of the greater risk of dying from sepsis in those who develop severe sepsis on medical and surgical floors has led to initiation of phase 4 of the campaign, conducted in four US-based collaborative groups in California, Illinois, New Jersey, and Florida, with 12 to 20 sites per collaborative. The collaborative is funded by the Moore Foundation and sponsored by the Society of Critical Care Medicine and the Society of Hospital Medicine. The purpose is to improve early recognition of severe sepsis through nurse screening of every patient during every shift of every day of hospitalization. The program empowers nurses to recognize and report sepsis, severe sepsis, and septic shock. The response differs depending on the hospital: some employ a rapid response or “sepsis alert,” others have a designated hospitalist on each shift who is informed, and hospitals that use private doctors may have a call-in system.

MUCH REMAINS TO BE DONE

The Surviving Sepsis Campaign has come far since the initial guidelines published in 2004. Thirty international organizations now sponsor and support the evidence-based guidelines. The sepsis performance improvement program deployed internationally has been associated with significant improvement in outcome in patients with severe sepsis.

How much of this is related to the campaign as opposed to other changes in health care cannot be clearly ascertained. In addition, how much of the Surviving Sepsis Campaign’s performance-improvement program effect is from attention to this patient group or from precise indicators is difficult to deduce. However, most experts in the field believe the Surviving Sepsis Campaign has significantly improved outcomes since its inception in 2002. Much still needs to be done as new evidence evolves.

Sepsis is familiar to most physicians in clinical practice, but guidance from the medical literature on how best to manage it has traditionally been confusing.

Starting in 2002, the Surviving Sepsis Campaign has worked to reduce worldwide mortality from severe sepsis and septic shock by developing and publicizing guidelines of best practices based on evidence from the literature. The campaign published its first management guidelines in 2004.

In this article, I review the most recent guidelines^1,2 (published in 2013) and discuss the campaign’s ongoing performance-improvement program.

DEFINING SEPSIS

Sepsis is a known or suspected infection plus systemic manifestations of infection. This includes the sepsis inflammatory response syndrome. Criteria include:

• Tachycardia (heart rate > 90 beats per minute)
• Tachypnea (> 20 breaths/minute or Paco₂ < 32 mm Hg)
• Fever (temperature > 38.3°C [100.9°F]) or hypothermia (core temperature < 36°C [96.8°F])
• High or low white blood cell count (> 12.0 × 10⁹/L or < 4.0 × 10⁹/L), or a normal count with more than 10% immature cells.

The definition of sepsis was broadened in 2002 to include other systemic manifestations of infection, such as changes in blood glucose level and organ dysfunction.

Severe sepsis is defined as sepsis plus either acute organ dysfunction or tissue hypoperfusion due to infection, with tissue hypoperfusion defined as:

• Hypotension (systolic blood pressure < 90 mm Hg, or a drop in systolic blood pressure of > 40 mm Hg)
• Elevated lactate
• Low urine output
• Altered mental status.

In severe sepsis, organ dysfunction is caused by blood-borne toxins and involves acute lung and kidney injury, coagulopathy (thrombocytopenia and increased international normalized ratio), and liver dysfunction.

Septic shock is present when a patient requires vasopressors after adequate intravascular volume repletion.

SEPSIS IS DEADLY AND COSTLY

Severe sepsis is the leading cause of hospital death. Patients admitted with severe sepsis are eight times more likely to die than those admitted with other conditions.³ The economic burden is enormous: it is the most expensive condition treated in US hospitals, costing an estimated $20.3 billion in 2011, of which $12.7 billion came from Medicare.

THE SURVIVING SEPSIS CAMPAIGN

The Surviving Sepsis Campaign is a global effort to reduce the rate of death from severe sepsis. The campaign’s methods include:

Patients with severe sepsis are eight times more likely to die than those with other conditions

• Educating physicians, the public, the media, and government about the high rates of morbidity and death in severe sepsis
• Creating evidence-based guidelines for managing sepsis and establishing global best-practice standards
• Facilitating the transfer of knowledge by developing performance-improvement programs to change bedside practice.

The campaign is funded with a grant from the Gordon and Betty Moore Foundation. The campaign’s guidelines are not associated with any direct or indirect industry support. The 2013 guidelines were backed by 30 international organizations.^1,2

All recommendations are ranked with numerical and letter scores, according to the GRADE system: 1 indicates a strong recommendation and 2 a weak one. The letters A through D reflect the quality of evidence, ranging from high (A) to very low (D).

GIVING ANTIBIOTICS EARLY IMPROVES OUTCOMES

A number of studies have suggested that starting appropriate antibiotics early improves outcomes in severe sepsis and septic shock. The death rate increases with each hour of delay.⁴

Recommendation. Intravenous antibiotic therapy should be started as soon as possible, and within the first hour after recognition of septic shock (grade 1B) and severe sepsis without septic shock (grade 1C).

The feasibility of achieving this goal has not been scientifically validated, and the recommendation should not be misinterpreted as the current standard of care. Even hospitals that participate in performance-improvement programs often struggle to start antibiotics, even within 6 hours of recognition. Nevertheless, the goal is a good one.

Some have questioned the early antibiotic recommendation because of concerns about antibiotic overuse and resistance. For a patient with some manifestation of systemic inflammation, such as organ dysfunction or hypotension with no clear cause, the campaign’s position is to provide empiric antibiotics early and then, if a noninfectious cause is found, to stop the antibiotics. Moreover, as soon as a causative pathogen has been identified, the regimen should be switched to the most appropriate antimicrobial that covers the pathogen and is safe and cost-effective. Collaboration with an antimicrobial stewardship program, if available, is encouraged.

FIND THE INFECTION SOURCE PROMPTLY: SOURCE CONTROL MAY BE REQUIRED

Recommendation. A specific anatomic diagnosis of infection (eg, necrotizing soft-tissue infection, peritonitis complicated by intra-abdominal infection, cholangitis, intestinal infarction) requiring consideration of emergency source control should be confirmed or excluded as soon as possible. If needed, surgical drainage should be undertaken for source control within the first 12 hours after a diagnosis is made (grade 1C).

FLUID THERAPY: CRYSTALLOIDS FIRST

Recommendation. In fluid resuscitation of severe sepsis, use crystalloids first (grade 1B).

Mortality risk increases with each hour of delay in starting antibiotics

No head-to-head trial has shown albumin to be superior to crystalloids, and crystalloids are less expensive. However, normal saline has a higher chloride content than plasma, which leads to non-anion-gap metabolic acidosis. It is called an unbalanced crystalloid, having a high chloride content and no buffer. There is concern that this reduces renal blood flow and the glomerular filtration rate, creating the potential for acute kidney injury. Although no high-level evidence supports this concern, some animal studies and historical control studies suggest that a balanced crystalloid such as Ringer’s lactate, Ringer’s acetate, or PlasmaLyte (having a chloride content close to that of plasma and the buffers acetate or lactate) may be associated with better outcome in resuscitation of severe sepsis.

Use albumin solution if necessary

Recommendation. Albumin should be used in the fluid resuscitation of severe sepsis and septic shock for patients who require substantial amounts of crystalloids (grade 2C).

Finfer et al⁵ compared the effect of fluid resuscitation with either an albumin or saline solution in nearly 7,000 patients in intensive care and found that death rates over 28 days were nearly identical between the two groups. Although this study was not designed to measure an effect in subsets of patients, the subgroup with severe sepsis had a lower mortality rate with albumin (relative risk 0.87, 95% confidence interval 0.74–1.02). In a meta-analysis of 17 studies of albumin vs crystalloids or albumin vs saline, Delaney et al⁶ found a significant survival advantage with an albumin solution in patients with sepsis and severe septic shock.

Sometimes, in patients admitted to intensive care with septic shock and receiving two or three vasopressors and large amounts of a crystalloid solution, vasopressors can be reduced when fluid is being given, but as soon as the fluid infusion rate is decreased, the need for increasing vasopressors returns. This scenario is an indication for changing to an albumin solution.

Recommendation. Initial fluid challenge in sepsis-induced tissue hypoperfusion (as evidenced by hypotension or elevated lactate) with suspicion of hypovolemia should be a minimum of 30 mL/kg of crystalloids, a portion of which can be an albumin equivalent. Some patients require more rapid administration and greater amounts of fluid (grade 1B).

Other fluid resuscitation considerations

Recommendation. Hydroxyethyl starch (hetastarch) should not be used for fluid resuscitation of severe sepsis and septic shock (grade 1B).

Five large clinical trials^7–11 compared hetastarch with crystalloids in the resuscitation of severe sepsis or septic shock. None found an advantage to using hetastarch, and three found it to be associated with higher rates of acute kidney injury and renal-replacement therapy.

Blood is not considered a resuscitation fluid.

Full fluid replacement is still needed in heart or kidney disease

Often, doctors hesitate to administer full fluid resuscitation to patients with septic shock or sepsis-induced hypotension who have baseline cardiomyopathy with a low ejection fraction or who have end-stage renal disease and are anuric. However, these patients’ baseline intravascular volume status has changed because of venodilation and capillary leak leading to reduced blood return to the heart. They require the same amount of fluids as other patients to return to their baseline state.

To avoid fluid overload in these patients, however, we recommend providing fluid in smaller boluses. For a young, previously healthy patient, 2 L of crystalloid should be provided as quickly as possible. Patients with heart or kidney disease should receive smaller (250- or 500-mL) boluses, with oxygen saturation checked after each dose, as hypoxemia is one of only two potential downsides of aggressive fluid resuscitation (the other being the further raising of intra-abdominal pressure in the intra-abdominal compartment syndrome).

WHAT DRIVES HYPOTENSION IN SEPTIC SHOCK?

In septic shock, mechanisms that can lower the blood pressure include capillary leakage (loss of intravascular volume), decreased arteriolar resistance, decreased cardiac contractility, increased ventricular compliance, and increased venous capacitance (loss of intra-arterial volume).

Capillary leakage ranges from moderate to severe, and it is difficult to know the severity early on during resuscitation. The extent of capillary leakage is often apparent only after 24 hours of fluid resuscitation, when the large amount of fluid needed to maintain intravascular volume produces significant tissue edema. Within the first 24 hours of resuscitation of a patient with septic shock or in the presence of ongoing inflammation, one cannot use intake and output to judge the adequacy of fluid resuscitation.

Reduced arteriolar resistance may be an advantage in the nonhypotensive severely septic patient, compensating for the decreased ejection fraction, but it becomes problematic in the presence of hypotension. In addition, venodilation increases venous capacitance, producing a “sink” for blood and inadequate return of blood volume to the heart.

Decreased contractility of the left and right ventricles leads to compensatory sinus tachycardia.¹² Reduced heart contractility can be seen by radionuclide angiography: little difference in chamber size is apparent in systole (immediately before contraction) vs diastole (immediately after contraction) (Figure 1).

Images courtesy of Joseph E. Parrillo, MD.

NOREPINEPHRINE IS THE FIRST-CHOICE VASOPRESSOR

If a patient remains hypotensive after replacement of intravascular volume, the hypotension is due to a combination of vasodilation and reduced contractility, and a combined inotrope-vasopressor is an appropriate drug to raise blood pressure. Therefore, the drug of first choice for raising blood pressure should be a combined inotrope-vasopressor.

There are three combined inotrope-vasopressors: dopamine, norepinephrine, and epinephrine. Head-to-head comparisons of norepinephrine and dopamine have supported a survival advantage with norepinephrine in patients with shock, including septic shock.¹³ A meta-analysis of six randomized trials totaling 2,768 patients also supports norepinephrine over dopamine in septic shock. Dopamine has been associated with a higher incidence of tachyarrhythmic events.¹⁴

Recommendations. Norepinephrine is the first choice for vasopressor therapy (grade 1B). If an additional agent is needed to maintain blood pressure, epinephrine should be added to norepinephrine (grade 2B). Alternatively, vasopressin (0.03 U/minute) can be added to norepinephrine to raise mean arterial pressure to target or to decrease the norepinephrine dose (ungraded recommendation).

Dopamine is not recommended as empiric or additive therapy for septic shock. It may be considered, however, in the presence of septic shock with sinus bradycardia.

Phenylephrine for special cases

Phenylephrine is a pure vasopressor: it decreases stroke volume and is particularly disadvantageous in patients with low cardiac output.

Recommendation. Phenylephrine is not recommended as empiric or additive therapy in the treatment of septic shock, with these exceptions (grade 1C):

• In unusual cases in which norepinephrine is associated with serious tachyarrhythmia, phenylephrine would be the least likely vasopressor to exacerbate arrhythmia
• If cardiac output is known to be high and blood pressure is persistently low
• If it is used as salvage therapy when combined inotrope-vasopressor drugs and low-dose vasopressin have failed to achieve the mean arterial pressure target.

RESUSCITATION OF SEPSIS-INDUCED TISSUE HYPOPERFUSION

A more severe form of sepsis-induced tissue hypoperfusion occurs in patients with severe sepsis, who require vasopressors after fluid challenge or have a lactate level of at least 4 mmol/L (36 mg/dL). Initial resuscitation is of utmost importance in these patients and often is done in the emergency department or regular hospital unit. These patients are targeted for “quantitative resuscitation,” ie, a protocol of fluid therapy and vasoactive agent support to achieve predefined end points.

Rivers et al¹⁵ published a landmark study of “early goal-directed therapy” targeting the early management of sepsis-induced tissue hypoperfusion (vasopressor requirement after fluid resuscitation or lactate > 4 mmol/L) and reported significant improvement in the survival rate when resuscitation was targeted to a superior vena cava oxygen saturation of 70%. Both control-group and active-treatment-group patients had central venous pressure targets of 8 mm Hg or greater. The Surviving Sepsis Campaign adopted these targets as recommendations in the original 2004 guidelines and continued through the 2013 guidelines, although the campaign’s sepsis management “bundles” that had originally included specific targets for central venous pressure and central venous oxygen saturation as above were changed in the 2013 guidelines to only measuring these variables (see discussion below).

Jones et al¹⁶ analyzed studies that involved early (within 24 hours of presentation) vs late (after 24 hours or unknown) quantitative resuscitation for sepsis-induced tissue hypoperfusion and found a significant reduction in the rate of death with early resuscitation but no difference with late resuscitation compared with standard therapy.

ALTERNATIVES TO MEASURING PRESSURE TO PREDICT RESPONSE TO FLUID

The campaign recognizes the limitation of pressure measurements to predict the response to fluid resuscitation. Some clinicians have objected to the guidelines, arguing that new bedside technology provides better information than central venous pressure or superior vena cava oxygen saturation.

It is useful to recall the Starling principle, which is based on the behavior of isolated myocardial fibrils that are put under the strain of graduated weights and then are stimulated to contract, modeling the contractility of the heart. The more the fibril is stretched, the more intense the contraction. Increased contractility explains why fluid resuscitation increases cardiac output; it is not simply a matter of increasing fluid volume in the veins. Increased volume in the left ventricle increases stretch, causing more intense contractility and higher stroke-volume cardiac output.

Crystalloids should be used for initial fluid resuscitation

The guidelines are based on pressure measurements, but volume is the important measure that drives contractility. For this reason, the 2013 guidelines encourage the use of alternative measures if a hospital has the capability to assess and use them. These alternative measures include changes in pulse pressure, systolic pressure, and stroke volume during the respiratory cycle or with fluid bolus. The greater the variation in these measures, the more likely the patient will respond to additional fluid therapy.¹⁷ Normal values:

• Pulse pressure variation: < 13%
• Systolic pressure variation: < 10 mm Hg
• Stroke volume variation: < 10%.

The problem with the more sophisticated technologies is that they tend to be available only in academic centers and not at hospitals doing the critical early resuscitation of septic shock.

The serum lactate level

Measuring serum lactate levels is an alternative method for monitoring resuscitation of early septic shock. This method is widely available even with point-of-care testing. If the lactate level is elevated, quantitative resuscitation, fluids, inotropes, and oxygen delivery can be targeted to lactate clearance.

Recommendation. In patients in whom elevated lactate levels are used as a marker of tissue hypoperfusion, resuscitation should be targeted to normalize lactate as rapidly as possible (grade 2C).

STEROID THERAPY IS CONTROVERSIAL

Corticosteroid therapy for septic shock remains controversial. Although it has been deemphasized, it likely has a role in select patients.

Recommendation. Intravenous corticosteroids should not be used in adults with septic shock if adequate fluid resuscitation and vasopressor therapy restore hemodynamic stability (grade 2C). However, a patient on high doses of multiple vasopressors after adequate fluid resuscitation would likely benefit.

Recommendation. If corticosteroid therapy is used, hydrocortisone 200 mg should be given over 24 hours, preferentially by continuous intravenous infusion but alternatively 50 mg every 6 hours (grade 2D). This regimen can be continued for up to 7 days or tapered when shock resolves.

SURVIVING SEPSIS CAMPAIGN PERFORMANCE-IMPROVEMENT PROGRAM

By themselves, guidelines change bedside care very slowly. To effect change, protocols must be put in place and quality indicators must be measured. Beginning in 2005, the Surviving Sepsis Campaign converted its guidelines to selected sets of quality indicators, ie, severe sepsis bundles. The campaign published tools that hospitals could use to initiate performance improvement programs for diagnosis and management of severe sepsis and septic shock. The information was disseminated worldwide with a free software program. The program allowed data collection at the bedside to record performance with quality indicators.

In addition, the campaign requested user data so that performance could be tracked over time. In 2010, data on more than 10,000 patients in participating hospitals showed improved ability to achieve quality indicators. The longer a hospital continued the program, the better its compliance with management bundles; in addition, there was a concomitant reduction in hospital mortality rates.¹⁸

Among participants, mortality rates decreased from 37% in the first quarter to 26% in the 16th

At this time, the database holds records for more than 30,000 patients. Mortality rates among campaign participants decreased from 37% in the first quarter to 26% in the 16th quarter worldwide, with a reduced relative risk of mortality of 28%.¹⁹ To assess whether background factors unrelated to campaign participation were contributing to the reduced rates, mortality rates of long-term participants were compared with those of new program participants; the finding supported the association with program participation.

Bundles revised

The campaign published updated performance bundles in the 2013 guidelines.

The 3-hour bundle remains the same. Within the first 3 hours of presentation with sepsis:

• Measure the serum lactate level.
• Obtain blood cultures before starting antibiotics.
• Start broad-spectrum antibiotics.
• Give a crystalloid (30 mL/kg) for hypotension or for lactate ≥ 4 mmol/L.

The 6-hour bundle has changed somewhat. Within 6 hours of presentation:

• If hypotension does not respond to initial fluid resuscitation, apply vasopressors to maintain mean arterial pressure ≥ 65 mm Hg.
• In the event of persistent arterial hypotension despite volume resuscitation (septic shock) or initial lactate ≥ 4 mmol/L, measure central venous pressure and central venous oxygen saturation.
• Remeasure lactate if the initial lactate level was elevated.

In light of the campaign’s recognition of alternatives to central venous pressure and central venous oxygen saturation for quantitative resuscitation targets, specific targets for these measures were not defined, allowing institutions the flexibility to base decisions on other technologies, such as inferior vena cava ultrasonography, systolic pressure variation, and changes in flow measures or estimates with fluid boluses if they have the capability.

Moreover, the second point in the 6-hour bundle is being further revised. The Protocolized Care for Early Septic Shock (ProCESS) trial²⁰ and the Australasian Resuscitation in Sepsis Evaluation (ARISE) trial,²¹ both published in 2013, demonstrated that measuring central venous pressure and central venous oxygen saturation, although safe, is not necessary for successful resuscitation of patients with septic shock. Therefore, newer versions of the 6-hour bundle propose that physicians reassess intravascular volume status and tissue perfusion, after initial 30 mL/kg crystalloid administration, in the event of persistent hypotension (mean arterial pressure < 65 mm Hg, ie, vasopressor requirement) or an initial lactate level of 4 mmol/L or higher, and then document the findings. To meet the requirements, one must document either a repeat focused examination by a licensed independent practitioner (to include vital signs, cardiopulmonary, capillary refill, pulse, and skin findings) or two alternative items from the following options: central venous pressure, central venous oxygen saturation, bedside cardiovascular ultrasonography,  and dynamic assessment of fluid responsiveness with passive leg-raising or fluid challenge.

Of interest, the ProCESS²⁰ and ARISE²¹ trials supported early identification of septic shock, early use of antibiotics, and early aggressive fluid resuscitation as the likely reasons for the reduced mortality rates across all treatment groups in these studies.

REDUCING HOSPITAL MORTALITY RATES

Phase 3 of the campaign involves data from 30,000 patients with severe sepsis or septic shock in emergency departments (52%), medical and surgical units (35%), and critical care units (13%).

Hospital mortality rates were 28% for those who presented to the emergency department with sepsis vs 47% for those who developed it in the hospital.²² The reason for the substantial difference is unclear; possibly, diagnosis takes longer in medical and surgical units because of a lower nurse-to-patient ratio, leading to delay in diagnosis and treatment.

Phase 4 of the campaign: Improve recognition of sepsis in the hospital

The finding of the greater risk of dying from sepsis in those who develop severe sepsis on medical and surgical floors has led to initiation of phase 4 of the campaign, conducted in four US-based collaborative groups in California, Illinois, New Jersey, and Florida, with 12 to 20 sites per collaborative. The collaborative is funded by the Moore Foundation and sponsored by the Society of Critical Care Medicine and the Society of Hospital Medicine. The purpose is to improve early recognition of severe sepsis through nurse screening of every patient during every shift of every day of hospitalization. The program empowers nurses to recognize and report sepsis, severe sepsis, and septic shock. The response differs depending on the hospital: some employ a rapid response or “sepsis alert,” others have a designated hospitalist on each shift who is informed, and hospitals that use private doctors may have a call-in system.

MUCH REMAINS TO BE DONE

The Surviving Sepsis Campaign has come far since the initial guidelines published in 2004. Thirty international organizations now sponsor and support the evidence-based guidelines. The sepsis performance improvement program deployed internationally has been associated with significant improvement in outcome in patients with severe sepsis.

How much of this is related to the campaign as opposed to other changes in health care cannot be clearly ascertained. In addition, how much of the Surviving Sepsis Campaign’s performance-improvement program effect is from attention to this patient group or from precise indicators is difficult to deduce. However, most experts in the field believe the Surviving Sepsis Campaign has significantly improved outcomes since its inception in 2002. Much still needs to be done as new evidence evolves.

Sepsis is familiar to most physicians in clinical practice, but guidance from the medical literature on how best to manage it has traditionally been confusing.

Starting in 2002, the Surviving Sepsis Campaign has worked to reduce worldwide mortality from severe sepsis and septic shock by developing and publicizing guidelines of best practices based on evidence from the literature. The campaign published its first management guidelines in 2004.

In this article, I review the most recent guidelines^1,2 (published in 2013) and discuss the campaign’s ongoing performance-improvement program.

DEFINING SEPSIS

Sepsis is a known or suspected infection plus systemic manifestations of infection. This includes the sepsis inflammatory response syndrome. Criteria include:

• Tachycardia (heart rate > 90 beats per minute)
• Tachypnea (> 20 breaths/minute or Paco₂ < 32 mm Hg)
• Fever (temperature > 38.3°C [100.9°F]) or hypothermia (core temperature < 36°C [96.8°F])
• High or low white blood cell count (> 12.0 × 10⁹/L or < 4.0 × 10⁹/L), or a normal count with more than 10% immature cells.

The definition of sepsis was broadened in 2002 to include other systemic manifestations of infection, such as changes in blood glucose level and organ dysfunction.

Severe sepsis is defined as sepsis plus either acute organ dysfunction or tissue hypoperfusion due to infection, with tissue hypoperfusion defined as:

• Hypotension (systolic blood pressure < 90 mm Hg, or a drop in systolic blood pressure of > 40 mm Hg)
• Elevated lactate
• Low urine output
• Altered mental status.

In severe sepsis, organ dysfunction is caused by blood-borne toxins and involves acute lung and kidney injury, coagulopathy (thrombocytopenia and increased international normalized ratio), and liver dysfunction.

Septic shock is present when a patient requires vasopressors after adequate intravascular volume repletion.

SEPSIS IS DEADLY AND COSTLY

Severe sepsis is the leading cause of hospital death. Patients admitted with severe sepsis are eight times more likely to die than those admitted with other conditions.³ The economic burden is enormous: it is the most expensive condition treated in US hospitals, costing an estimated $20.3 billion in 2011, of which $12.7 billion came from Medicare.

THE SURVIVING SEPSIS CAMPAIGN

The Surviving Sepsis Campaign is a global effort to reduce the rate of death from severe sepsis. The campaign’s methods include:

Patients with severe sepsis are eight times more likely to die than those with other conditions

• Educating physicians, the public, the media, and government about the high rates of morbidity and death in severe sepsis
• Creating evidence-based guidelines for managing sepsis and establishing global best-practice standards
• Facilitating the transfer of knowledge by developing performance-improvement programs to change bedside practice.

The campaign is funded with a grant from the Gordon and Betty Moore Foundation. The campaign’s guidelines are not associated with any direct or indirect industry support. The 2013 guidelines were backed by 30 international organizations.^1,2

All recommendations are ranked with numerical and letter scores, according to the GRADE system: 1 indicates a strong recommendation and 2 a weak one. The letters A through D reflect the quality of evidence, ranging from high (A) to very low (D).

GIVING ANTIBIOTICS EARLY IMPROVES OUTCOMES

A number of studies have suggested that starting appropriate antibiotics early improves outcomes in severe sepsis and septic shock. The death rate increases with each hour of delay.⁴

Recommendation. Intravenous antibiotic therapy should be started as soon as possible, and within the first hour after recognition of septic shock (grade 1B) and severe sepsis without septic shock (grade 1C).

The feasibility of achieving this goal has not been scientifically validated, and the recommendation should not be misinterpreted as the current standard of care. Even hospitals that participate in performance-improvement programs often struggle to start antibiotics, even within 6 hours of recognition. Nevertheless, the goal is a good one.

Some have questioned the early antibiotic recommendation because of concerns about antibiotic overuse and resistance. For a patient with some manifestation of systemic inflammation, such as organ dysfunction or hypotension with no clear cause, the campaign’s position is to provide empiric antibiotics early and then, if a noninfectious cause is found, to stop the antibiotics. Moreover, as soon as a causative pathogen has been identified, the regimen should be switched to the most appropriate antimicrobial that covers the pathogen and is safe and cost-effective. Collaboration with an antimicrobial stewardship program, if available, is encouraged.

FIND THE INFECTION SOURCE PROMPTLY: SOURCE CONTROL MAY BE REQUIRED

Recommendation. A specific anatomic diagnosis of infection (eg, necrotizing soft-tissue infection, peritonitis complicated by intra-abdominal infection, cholangitis, intestinal infarction) requiring consideration of emergency source control should be confirmed or excluded as soon as possible. If needed, surgical drainage should be undertaken for source control within the first 12 hours after a diagnosis is made (grade 1C).

FLUID THERAPY: CRYSTALLOIDS FIRST

Recommendation. In fluid resuscitation of severe sepsis, use crystalloids first (grade 1B).

Mortality risk increases with each hour of delay in starting antibiotics

No head-to-head trial has shown albumin to be superior to crystalloids, and crystalloids are less expensive. However, normal saline has a higher chloride content than plasma, which leads to non-anion-gap metabolic acidosis. It is called an unbalanced crystalloid, having a high chloride content and no buffer. There is concern that this reduces renal blood flow and the glomerular filtration rate, creating the potential for acute kidney injury. Although no high-level evidence supports this concern, some animal studies and historical control studies suggest that a balanced crystalloid such as Ringer’s lactate, Ringer’s acetate, or PlasmaLyte (having a chloride content close to that of plasma and the buffers acetate or lactate) may be associated with better outcome in resuscitation of severe sepsis.

Use albumin solution if necessary

Recommendation. Albumin should be used in the fluid resuscitation of severe sepsis and septic shock for patients who require substantial amounts of crystalloids (grade 2C).

Finfer et al⁵ compared the effect of fluid resuscitation with either an albumin or saline solution in nearly 7,000 patients in intensive care and found that death rates over 28 days were nearly identical between the two groups. Although this study was not designed to measure an effect in subsets of patients, the subgroup with severe sepsis had a lower mortality rate with albumin (relative risk 0.87, 95% confidence interval 0.74–1.02). In a meta-analysis of 17 studies of albumin vs crystalloids or albumin vs saline, Delaney et al⁶ found a significant survival advantage with an albumin solution in patients with sepsis and severe septic shock.

Sometimes, in patients admitted to intensive care with septic shock and receiving two or three vasopressors and large amounts of a crystalloid solution, vasopressors can be reduced when fluid is being given, but as soon as the fluid infusion rate is decreased, the need for increasing vasopressors returns. This scenario is an indication for changing to an albumin solution.

Recommendation. Initial fluid challenge in sepsis-induced tissue hypoperfusion (as evidenced by hypotension or elevated lactate) with suspicion of hypovolemia should be a minimum of 30 mL/kg of crystalloids, a portion of which can be an albumin equivalent. Some patients require more rapid administration and greater amounts of fluid (grade 1B).

Other fluid resuscitation considerations

Recommendation. Hydroxyethyl starch (hetastarch) should not be used for fluid resuscitation of severe sepsis and septic shock (grade 1B).

Five large clinical trials^7–11 compared hetastarch with crystalloids in the resuscitation of severe sepsis or septic shock. None found an advantage to using hetastarch, and three found it to be associated with higher rates of acute kidney injury and renal-replacement therapy.

Blood is not considered a resuscitation fluid.

Full fluid replacement is still needed in heart or kidney disease

Often, doctors hesitate to administer full fluid resuscitation to patients with septic shock or sepsis-induced hypotension who have baseline cardiomyopathy with a low ejection fraction or who have end-stage renal disease and are anuric. However, these patients’ baseline intravascular volume status has changed because of venodilation and capillary leak leading to reduced blood return to the heart. They require the same amount of fluids as other patients to return to their baseline state.

To avoid fluid overload in these patients, however, we recommend providing fluid in smaller boluses. For a young, previously healthy patient, 2 L of crystalloid should be provided as quickly as possible. Patients with heart or kidney disease should receive smaller (250- or 500-mL) boluses, with oxygen saturation checked after each dose, as hypoxemia is one of only two potential downsides of aggressive fluid resuscitation (the other being the further raising of intra-abdominal pressure in the intra-abdominal compartment syndrome).

WHAT DRIVES HYPOTENSION IN SEPTIC SHOCK?

In septic shock, mechanisms that can lower the blood pressure include capillary leakage (loss of intravascular volume), decreased arteriolar resistance, decreased cardiac contractility, increased ventricular compliance, and increased venous capacitance (loss of intra-arterial volume).

Capillary leakage ranges from moderate to severe, and it is difficult to know the severity early on during resuscitation. The extent of capillary leakage is often apparent only after 24 hours of fluid resuscitation, when the large amount of fluid needed to maintain intravascular volume produces significant tissue edema. Within the first 24 hours of resuscitation of a patient with septic shock or in the presence of ongoing inflammation, one cannot use intake and output to judge the adequacy of fluid resuscitation.

Reduced arteriolar resistance may be an advantage in the nonhypotensive severely septic patient, compensating for the decreased ejection fraction, but it becomes problematic in the presence of hypotension. In addition, venodilation increases venous capacitance, producing a “sink” for blood and inadequate return of blood volume to the heart.

Decreased contractility of the left and right ventricles leads to compensatory sinus tachycardia.¹² Reduced heart contractility can be seen by radionuclide angiography: little difference in chamber size is apparent in systole (immediately before contraction) vs diastole (immediately after contraction) (Figure 1).

Images courtesy of Joseph E. Parrillo, MD.

NOREPINEPHRINE IS THE FIRST-CHOICE VASOPRESSOR

If a patient remains hypotensive after replacement of intravascular volume, the hypotension is due to a combination of vasodilation and reduced contractility, and a combined inotrope-vasopressor is an appropriate drug to raise blood pressure. Therefore, the drug of first choice for raising blood pressure should be a combined inotrope-vasopressor.

There are three combined inotrope-vasopressors: dopamine, norepinephrine, and epinephrine. Head-to-head comparisons of norepinephrine and dopamine have supported a survival advantage with norepinephrine in patients with shock, including septic shock.¹³ A meta-analysis of six randomized trials totaling 2,768 patients also supports norepinephrine over dopamine in septic shock. Dopamine has been associated with a higher incidence of tachyarrhythmic events.¹⁴

Recommendations. Norepinephrine is the first choice for vasopressor therapy (grade 1B). If an additional agent is needed to maintain blood pressure, epinephrine should be added to norepinephrine (grade 2B). Alternatively, vasopressin (0.03 U/minute) can be added to norepinephrine to raise mean arterial pressure to target or to decrease the norepinephrine dose (ungraded recommendation).

Dopamine is not recommended as empiric or additive therapy for septic shock. It may be considered, however, in the presence of septic shock with sinus bradycardia.

Phenylephrine for special cases

Phenylephrine is a pure vasopressor: it decreases stroke volume and is particularly disadvantageous in patients with low cardiac output.

Recommendation. Phenylephrine is not recommended as empiric or additive therapy in the treatment of septic shock, with these exceptions (grade 1C):

• In unusual cases in which norepinephrine is associated with serious tachyarrhythmia, phenylephrine would be the least likely vasopressor to exacerbate arrhythmia
• If cardiac output is known to be high and blood pressure is persistently low
• If it is used as salvage therapy when combined inotrope-vasopressor drugs and low-dose vasopressin have failed to achieve the mean arterial pressure target.

RESUSCITATION OF SEPSIS-INDUCED TISSUE HYPOPERFUSION

A more severe form of sepsis-induced tissue hypoperfusion occurs in patients with severe sepsis, who require vasopressors after fluid challenge or have a lactate level of at least 4 mmol/L (36 mg/dL). Initial resuscitation is of utmost importance in these patients and often is done in the emergency department or regular hospital unit. These patients are targeted for “quantitative resuscitation,” ie, a protocol of fluid therapy and vasoactive agent support to achieve predefined end points.

Rivers et al¹⁵ published a landmark study of “early goal-directed therapy” targeting the early management of sepsis-induced tissue hypoperfusion (vasopressor requirement after fluid resuscitation or lactate > 4 mmol/L) and reported significant improvement in the survival rate when resuscitation was targeted to a superior vena cava oxygen saturation of 70%. Both control-group and active-treatment-group patients had central venous pressure targets of 8 mm Hg or greater. The Surviving Sepsis Campaign adopted these targets as recommendations in the original 2004 guidelines and continued through the 2013 guidelines, although the campaign’s sepsis management “bundles” that had originally included specific targets for central venous pressure and central venous oxygen saturation as above were changed in the 2013 guidelines to only measuring these variables (see discussion below).

Jones et al¹⁶ analyzed studies that involved early (within 24 hours of presentation) vs late (after 24 hours or unknown) quantitative resuscitation for sepsis-induced tissue hypoperfusion and found a significant reduction in the rate of death with early resuscitation but no difference with late resuscitation compared with standard therapy.

ALTERNATIVES TO MEASURING PRESSURE TO PREDICT RESPONSE TO FLUID

The campaign recognizes the limitation of pressure measurements to predict the response to fluid resuscitation. Some clinicians have objected to the guidelines, arguing that new bedside technology provides better information than central venous pressure or superior vena cava oxygen saturation.

It is useful to recall the Starling principle, which is based on the behavior of isolated myocardial fibrils that are put under the strain of graduated weights and then are stimulated to contract, modeling the contractility of the heart. The more the fibril is stretched, the more intense the contraction. Increased contractility explains why fluid resuscitation increases cardiac output; it is not simply a matter of increasing fluid volume in the veins. Increased volume in the left ventricle increases stretch, causing more intense contractility and higher stroke-volume cardiac output.

Crystalloids should be used for initial fluid resuscitation

The guidelines are based on pressure measurements, but volume is the important measure that drives contractility. For this reason, the 2013 guidelines encourage the use of alternative measures if a hospital has the capability to assess and use them. These alternative measures include changes in pulse pressure, systolic pressure, and stroke volume during the respiratory cycle or with fluid bolus. The greater the variation in these measures, the more likely the patient will respond to additional fluid therapy.¹⁷ Normal values:

• Pulse pressure variation: < 13%
• Systolic pressure variation: < 10 mm Hg
• Stroke volume variation: < 10%.

The problem with the more sophisticated technologies is that they tend to be available only in academic centers and not at hospitals doing the critical early resuscitation of septic shock.

The serum lactate level

Measuring serum lactate levels is an alternative method for monitoring resuscitation of early septic shock. This method is widely available even with point-of-care testing. If the lactate level is elevated, quantitative resuscitation, fluids, inotropes, and oxygen delivery can be targeted to lactate clearance.

Recommendation. In patients in whom elevated lactate levels are used as a marker of tissue hypoperfusion, resuscitation should be targeted to normalize lactate as rapidly as possible (grade 2C).

STEROID THERAPY IS CONTROVERSIAL

Corticosteroid therapy for septic shock remains controversial. Although it has been deemphasized, it likely has a role in select patients.

Recommendation. Intravenous corticosteroids should not be used in adults with septic shock if adequate fluid resuscitation and vasopressor therapy restore hemodynamic stability (grade 2C). However, a patient on high doses of multiple vasopressors after adequate fluid resuscitation would likely benefit.

Recommendation. If corticosteroid therapy is used, hydrocortisone 200 mg should be given over 24 hours, preferentially by continuous intravenous infusion but alternatively 50 mg every 6 hours (grade 2D). This regimen can be continued for up to 7 days or tapered when shock resolves.

SURVIVING SEPSIS CAMPAIGN PERFORMANCE-IMPROVEMENT PROGRAM

By themselves, guidelines change bedside care very slowly. To effect change, protocols must be put in place and quality indicators must be measured. Beginning in 2005, the Surviving Sepsis Campaign converted its guidelines to selected sets of quality indicators, ie, severe sepsis bundles. The campaign published tools that hospitals could use to initiate performance improvement programs for diagnosis and management of severe sepsis and septic shock. The information was disseminated worldwide with a free software program. The program allowed data collection at the bedside to record performance with quality indicators.

In addition, the campaign requested user data so that performance could be tracked over time. In 2010, data on more than 10,000 patients in participating hospitals showed improved ability to achieve quality indicators. The longer a hospital continued the program, the better its compliance with management bundles; in addition, there was a concomitant reduction in hospital mortality rates.¹⁸

Among participants, mortality rates decreased from 37% in the first quarter to 26% in the 16th

At this time, the database holds records for more than 30,000 patients. Mortality rates among campaign participants decreased from 37% in the first quarter to 26% in the 16th quarter worldwide, with a reduced relative risk of mortality of 28%.¹⁹ To assess whether background factors unrelated to campaign participation were contributing to the reduced rates, mortality rates of long-term participants were compared with those of new program participants; the finding supported the association with program participation.

Bundles revised

The campaign published updated performance bundles in the 2013 guidelines.

The 3-hour bundle remains the same. Within the first 3 hours of presentation with sepsis:

• Measure the serum lactate level.
• Obtain blood cultures before starting antibiotics.
• Start broad-spectrum antibiotics.
• Give a crystalloid (30 mL/kg) for hypotension or for lactate ≥ 4 mmol/L.

The 6-hour bundle has changed somewhat. Within 6 hours of presentation:

• If hypotension does not respond to initial fluid resuscitation, apply vasopressors to maintain mean arterial pressure ≥ 65 mm Hg.
• In the event of persistent arterial hypotension despite volume resuscitation (septic shock) or initial lactate ≥ 4 mmol/L, measure central venous pressure and central venous oxygen saturation.
• Remeasure lactate if the initial lactate level was elevated.

In light of the campaign’s recognition of alternatives to central venous pressure and central venous oxygen saturation for quantitative resuscitation targets, specific targets for these measures were not defined, allowing institutions the flexibility to base decisions on other technologies, such as inferior vena cava ultrasonography, systolic pressure variation, and changes in flow measures or estimates with fluid boluses if they have the capability.

Moreover, the second point in the 6-hour bundle is being further revised. The Protocolized Care for Early Septic Shock (ProCESS) trial²⁰ and the Australasian Resuscitation in Sepsis Evaluation (ARISE) trial,²¹ both published in 2013, demonstrated that measuring central venous pressure and central venous oxygen saturation, although safe, is not necessary for successful resuscitation of patients with septic shock. Therefore, newer versions of the 6-hour bundle propose that physicians reassess intravascular volume status and tissue perfusion, after initial 30 mL/kg crystalloid administration, in the event of persistent hypotension (mean arterial pressure < 65 mm Hg, ie, vasopressor requirement) or an initial lactate level of 4 mmol/L or higher, and then document the findings. To meet the requirements, one must document either a repeat focused examination by a licensed independent practitioner (to include vital signs, cardiopulmonary, capillary refill, pulse, and skin findings) or two alternative items from the following options: central venous pressure, central venous oxygen saturation, bedside cardiovascular ultrasonography,  and dynamic assessment of fluid responsiveness with passive leg-raising or fluid challenge.

Of interest, the ProCESS²⁰ and ARISE²¹ trials supported early identification of septic shock, early use of antibiotics, and early aggressive fluid resuscitation as the likely reasons for the reduced mortality rates across all treatment groups in these studies.

REDUCING HOSPITAL MORTALITY RATES

Phase 3 of the campaign involves data from 30,000 patients with severe sepsis or septic shock in emergency departments (52%), medical and surgical units (35%), and critical care units (13%).

Hospital mortality rates were 28% for those who presented to the emergency department with sepsis vs 47% for those who developed it in the hospital.²² The reason for the substantial difference is unclear; possibly, diagnosis takes longer in medical and surgical units because of a lower nurse-to-patient ratio, leading to delay in diagnosis and treatment.

Phase 4 of the campaign: Improve recognition of sepsis in the hospital

The finding of the greater risk of dying from sepsis in those who develop severe sepsis on medical and surgical floors has led to initiation of phase 4 of the campaign, conducted in four US-based collaborative groups in California, Illinois, New Jersey, and Florida, with 12 to 20 sites per collaborative. The collaborative is funded by the Moore Foundation and sponsored by the Society of Critical Care Medicine and the Society of Hospital Medicine. The purpose is to improve early recognition of severe sepsis through nurse screening of every patient during every shift of every day of hospitalization. The program empowers nurses to recognize and report sepsis, severe sepsis, and septic shock. The response differs depending on the hospital: some employ a rapid response or “sepsis alert,” others have a designated hospitalist on each shift who is informed, and hospitals that use private doctors may have a call-in system.

MUCH REMAINS TO BE DONE

The Surviving Sepsis Campaign has come far since the initial guidelines published in 2004. Thirty international organizations now sponsor and support the evidence-based guidelines. The sepsis performance improvement program deployed internationally has been associated with significant improvement in outcome in patients with severe sepsis.

How much of this is related to the campaign as opposed to other changes in health care cannot be clearly ascertained. In addition, how much of the Surviving Sepsis Campaign’s performance-improvement program effect is from attention to this patient group or from precise indicators is difficult to deduce. However, most experts in the field believe the Surviving Sepsis Campaign has significantly improved outcomes since its inception in 2002. Much still needs to be done as new evidence evolves.

A 57-year-old woman presented to the emergency department with left lower quadrant pain, which had started 1 week earlier and was constant, dull, aching, and nonradiating. There were no aggravating or alleviating factors. The pain was associated with low-grade fever and nausea. She reported no vomiting, no change in bowel habits, and no hematemesis, hematochezia, or melena. She did not have urinary urgency, frequency, or dysuria. She had no cardiac, respiratory, or neurologic symptoms.

Her medical history included hypothyroidism, type 2 diabetes mellitus, diverticulosis, and chronic obstructive pulmonary disease. Her medications included metformin, insulin, levothyroxine, and inhaled tiotropium. She had no allergies. She had never undergone surgery, including cesarean delivery. She was postmenopausal. She had two children, both of whom had been born vaginally at full term. She denied using alcohol, tobacco, and illicit drugs. Her family history was noncontributory.

On examination, she was not in acute distress. Her temperature was 36.7°C (98.1°F), blood pressure 130/90 mm Hg, heart rate 86 beats per minute and regular, respiratory rate 16 breaths per minute, and oxygen saturation 98% on ambient air. Examination of her head and neck was unremarkable. Cardiopulmonary examination was normal. Abdominal examination revealed normal bowel sounds, mild tenderness in the left lower quadrant with localized guarding, and rebound tenderness. Neurologic examination was unremarkable.

Initial laboratory data showed mild leukocytosis. Computed tomography with contrast of the abdomen and pelvis suggested acute diverticulitis.

ATRIAL FIBRILLATION, AND THEN A TURN FOR THE WORSE

The patient was admitted with an initial diagnosis of acute diverticulitis. She was started on antibiotics, hydration, and pain medications, and her abdominal pain gradually improved.

On the third hospital day, she suddenly experienced shortness of breath and palpitations. At the time of admission her electrocardiogram had been normal, but it now showed atrial fibrillation with a rapid ventricular response. She also developed elevated troponin levels, which were thought to represent type 2 non-ST-elevation myocardial infarction.

She was started on aspirin, clopidogrel, and anticoagulation with heparin bridged with warfarin for the new-onset atrial fibrillation. Her heart rate was controlled with metoprolol, and her shortness of breath improved. An echocardiogram was normal.

On the seventh hospital day, she developed severe right-sided lower abdominal pain and bruising. Her blood pressure was 90/60 mm Hg, heart rate 110 beats per minute and irregularly irregular, respiratory rate 22 breaths per minute, and oxygen saturation 97% on room air. Her abdomen was diffusely tender with a palpable mass in the right lower quadrant and hypoactive bowel sounds. Ecchymosis was noted (Figure 1).

DIFFERENTIAL DIAGNOSIS

1. What is the likely cause of her decompensation?

• Acute mesenteric ischemia
• Perforation of the gastrointestinal tract
• Rectus sheath hematoma
• Abdominal compartment syndrome due to acute pancreatitis

Acute mesenteric ischemia

Signs and symptoms of acute mesenteric ischemia can be vague. Moreover, when it leads to bowel necrosis the mortality rate is high, ranging from 30% to 65%.¹ Hence, one should suspect it and try to diagnose it early.

Most patients with this condition have comorbidities; risk factors include atherosclerotic disease, cardiac conditions (congestive heart failure, recent myocardial infarction, and atrial fibrillation), systemic illness, and inherited or acquired hypercoagulable states.²

The four major causes are:

• Acute thromboembolic occlusion of the superior mesenteric artery (the most common site of occlusion because of the acute angle of origin from the aorta)
• Acute thrombosis of the mesenteric vein
• Acute thrombosis of the mesenteric artery
• Nonocclusive disease affecting the mesenteric vessels²

Nonocclusive disease is seen in conditions in which the mesenteric vessels are already compromised due to background stenosis owing to atherosclerosis. Also, conditions such as septic and cardiogenic shock can compromise these arteries, leading to ischemia, which, if it persists, can lead to bowel infarction. Ischemic colitis falls under this category. It commonly involves the descending and sigmoid colon.³

The initial symptom of ischemia may be abdominal pain that is brought on by eating large meals (“postprandial intestinal angina.”² When the ischemia worsens to infarction, patients may have a diffusely tender abdomen and constant pain that does not vary with palpation. Surprisingly, patients do not exhibit peritoneal signs early on. This gives rise to the description of “pain out of proportion to the physical findings” traditionally associated with acute mesenteric ischemia.²

Diagnosis. Supportive laboratory data include marked leukocytosis, elevated hematocrit due to hemoconcentration, metabolic acidosis, and elevated lactate.⁴ Newer markers such as serum alpha-glutathione S-transferase (alpha-GST) and intestinal fatty acid-binding protein (I-FABP) may be used to support the diagnosis.

Elevated alpha-GST has 72% sensitivity and 77% specificity in the diagnosis of acute mesenteric ischemia.⁵ The caveat is that it cannot reliably differentiate ischemia from infarction. Its sensitivity can be improved to 97% to 100% by using the white blood cell count and lactate levels in combination.⁵

An I-FABP level higher than 100 ng/mL has 100% sensitivity for diagnosing mesenteric infarction but only 25% sensitivity for bowel strangulation.⁶

Early use of abdominal computed tomography with contrast can aid in recognizing this diagnosis.⁷ Thus, it should be ordered in suspected cases, even in patients who have elevated creatinine levels (which would normally preclude the use of contrast), since early diagnosis followed by endovascular therapy is associated with survival benefit, and the risk of contrast-induced nephropathy appears to be small.⁸ Computed tomography helps to determine the state of mesenteric vessels and bowel perfusion before ischemia progresses to infarction. It also helps to rule out other common diagnoses. Findings that suggest acute mesenteric ischemia include segmental bowel wall thickening, intestinal pneumatosis with gas in the portal vein, bowel dilation, mesenteric stranding, portomesenteric thrombosis, and solid-organ infarction.⁹

Treatment. If superior mesenteric artery occlusion is diagnosed on computed tomography, the next step is to determine if there is peritonitis.¹⁰ In patients who have evidence of peritonitis, exploratory laparotomy is performed. For emboli in such patients, open embolectomy followed by on-table angiography is carried out in combination with damage-control surgery. For patients with peritonitis and acute thrombosis, stenting along with damage-control surgery is preferred.¹⁰

On the other hand, if there is no peritonitis, the thrombosis may be amenable to endovascular intervention. For patients with acute embolic occlusion with no contraindications to thrombolysis, aspiration embolectomy in combination with local catheter-directed thrombolysis with recombinant tissue plasminogen activator can be performed. This can be combined with endovascular mechanical embolectomy for more complete management.¹⁰ Patients with contraindications to thrombolysis can be treated either with aspiration and mechanical embolectomy or with open embolectomy with angiography.¹⁰

During laparotomy, the surgeon carefully inspects the bowel for signs of necrosis. Signs that bowel is still viable include pink color, bleeding from cut surfaces, good peristalsis, and visible pulsations in the arterial arcade of the mesentery.

On day 7 she developed acute decompensation—what was the cause?

Acute mesenteric artery thrombosis arising from chronic atherosclerotic disease can be treated with stenting of the stenotic lesion.¹⁰ Patients with this condition would also benefit from aggressive management of atherosclerotic disease with statins along with antiplatelet agents.¹⁰

Mesenteric vein thrombosis requires prompt institution of anticoagulation. However, in advanced cases leading to bowel infarction, exploratory laparotomy with resection of the necrotic bowel may be required. Anticoagulation should be continued for at least 6 months, and further therapy should be determined by the underlying precipitating condition.¹⁰

Critically ill patients who develop mesenteric ischemia secondary to persistent hypotension usually respond to adequate volume resuscitation, cessation of vasopressors, and overall improvement in their hemodynamic status. These patients must be closely monitored for development of gangrene of the bowel because they may be intubated and not able to complain. Any sudden deterioration in their condition should prompt physicians to consider bowel necrosis developing in these patients. Elevation of lactate levels out of proportion to the degree of hypotension may be corroborative evidence.⁴

Our patient had risk factors for acute mesenteric ischemia that included atrial fibrillation and recent non-ST-elevation myocardial infarction. She could have had arterial emboli due to atrial fibrillation, in situ superior mesenteric arterial thrombosis, or splanchnic arterial vasoconstriction due to the myocardial infarction associated with transient hypotension.

Arguing against this diagnosis, although she had a grossly distended abdomen, abdominal bruising usually is not seen. Also, a palpable mass in the right lower quadrant is uncommon except when acute mesenteric ischemia occurs due to segmental intestinal strangulation, as with strangulated hernia or volvulus. She also had therapeutic international normalized ratio (INR) levels constantly while on anticoagulation. Nevertheless, acute mesenteric ischemia should be strongly considered in the initial differential diagnosis of this patient’s acute decompensation.

Perforation of the gastrointestinal tract

Diverticulitis is the acute inflammation of one or more diverticula, which are small pouches created by herniation of the mucosa into the wall of the colon. The condition is caused by microscopic or macroscopic perforation of the diverticula. Microscopic perforation is usually self-limited (uncomplicated diverticulitis) and responds to conservative treatment, whereas macroscopic perforation can be associated with fecal or purulent peritonitis, abscess, enteric fistula, bowel obstruction, and stricture (complicated diverticulitis), in which case surgery may be necessary.

Signs and symptoms of acute mesenteric ischemia can be vague

Patients with peritonitis due to free perforation present with generalized tenderness with rebound tenderness and guarding on abdominal examination. The abdomen may be distended and tympanic to percussion, with diminished or absent bowel sounds. Patients may have hemodynamic compromise.

Plain upright abdominal radiographs may show free air under the diaphragm. Computed tomography may show oral contrast outside the lumen and detect even small amounts of free intraperitoneal air (more clearly seen on a lung window setting).

Our patient initially presented with acute diverticulitis. She later developed diffuse abdominal tenderness with hypoactive bowel sounds. Bowel perforation is certainly a possibility at this stage, though it is usually not associated with abdominal bruising. She would need additional imaging to rule out this complication.

Other differential diagnoses to be considered in this patient with right lower-quadrant pain include acute appendicitis, incarcerated inguinal hernia, volvulus (particularly cecal volvulus), small-bowel obstruction, pyelonephritis, and gynecologic causes such as adnexal torsion, ruptured ovarian cyst, and tubo-ovarian abscess. Computed tomography helps to differentiate most of these causes.

Rectus sheath hematoma

Rectus sheath hematoma is relatively uncommon and often not considered in the initial differential diagnosis of an acute abdomen. This gives it the rightful term “a great masquerader.” It usually results from bleeding into the rectus sheath from damage to the superior (more common) or inferior epigastric arteries and occasionally from a direct tear of the rectus abdominis muscle. Predisposing factors include anticoagulant therapy (most common), advanced age, hypertension, previous abdominal surgery, trauma, paroxysmal coughing, medication injections, pregnancy, blood dyscrasias, severe vomiting, violent physical activity, and leukemia.¹¹

Clinical manifestations include acute abdominal pain, often associated with fever, nausea, and vomiting. Physical examination may reveal signs of hypovolemic shock, a palpable nonpulsatile abdominal mass, and signs of local peritoneal irritation. The Carnett sign¹¹ (tenderness within the abdominal wall that persists and does not improve with raising the head) and the Fothergill sign¹¹ (a tender abdominal mass that does not cross the midline and remains palpable with tensing of the rectus sheath) may be elicited.

Computed tomography is more sensitive than abdominal ultrasonography in differentiating rectus sheath hematoma from an intra-abdominal pathology.¹¹ In addition, computed tomography also helps to determine if the bleeding is active or not, which has therapeutic implications.

In our patient, rectus sheath hematoma is a possibility because of her ongoing anticoagulation, findings of localized abdominal bruising, and palpable right lower-quadrant mass, and it is high on the list of differential diagnoses. Rectus sheath hematoma should be considered in the differential diagnosis of lower abdominal pain particularly in elderly women who are on anticoagulation and in whom the onset of pain coincides with a paroxysm of cough.¹² Women are twice as likely as men to develop rectus sheath hematoma, owing to their different muscle mass.¹³ In addition, anterior abdominal wall muscles are stretched during pregnancy.¹³

Abdominal compartment syndrome

Abdominal compartment syndrome has been classically associated with surgical patients. However, it is being increasingly recognized in critically ill medical patients, in whom detecting and treating it early may result in significant reduction in rates of morbidity and death.¹⁴

Abdominal compartment syndrome is of three types: primary, secondary, and recurrent. Primary abdominal compartment syndrome refers to the classic surgical patients with evidence of direct injury to the abdominal or pelvic organs through major trauma or extensive abdominal surgeries. Secondary abdominal compartment syndrome refers to its development in critically ill intensive care patients in whom the pathology does not directly involve the abdominal or pelvic organs.

Various medical conditions can culminate in abdominal compartment syndrome and result in multiorgan failure. Recurrent abdominal compartment syndrome refers to its development after management of either primary or secondary intra-abdominal hypertension or abdominal compartment syndrome.¹⁵ Clinicians thus must be aware of secondary and recurrent abdominal compartment syndrome occurring in critically ill patients.

The normal intra-abdominal pressure is around 5 to 7 mm Hg, even in most critically ill patients. Persistent elevation, ie, higher than 12 mm Hg, is referred to as intra-abdominal hypertension.^16–18 Intra-abdominal hypertension is subdivided into four grades:

• Grade I: 12–15 mm Hg
• Grade II: 16–20 mm Hg
• Grade III: 21–25 mm Hg
• Grade IV: > 25 mm Hg.

The World Society of the Abdominal Compartment Syndrome (WSACS) defines abdominal compartment syndrome as pressure higher than 20 mm Hg along with organ damage.¹⁸ It may or may not be associated with an abdominal perfusion pressure less than 60 mm Hg.¹⁸

Risk factors associated with abdominal compartment syndrome include conditions causing decreased gut motility (gastroparesis, ileus, and colonic pseudo-obstruction), intra-abdominal or retroperitoneal masses or abscesses, ascites, hemoperitoneum, acute pancreatitis, third-spacing due to massive fluid resuscitation with transfusions, peritoneal dialysis, and shock.^18,19

Microscopic perforation is usually self-limited, whereas macroscopic perforation may need surgery

Physical examination has a sensitivity of only 40% to 60% in detecting intra-abdominal hypertension.²⁰ The gold-standard method of measuring the intra-abdominal pressure is the modified Kron technique,¹⁸ using a Foley catheter in the bladder connected to a pressure transducer. With the patient in the supine position, the transducer is zeroed at the mid-axillary line at the level of the iliac crest, and 25 mL of normal saline is instilled into the bladder and maintained for 30 to 60 seconds to let the detrusor muscle relax.¹⁵ Pressure tracings are then recorded at the end of expiration. Factors that are known to affect the transbladder pressure include patient position, respiratory movement, and body mass index, and should be taken into account when reading the pressure recordings.^15,21 Other techniques that can be used include intragastric, intra-inferior vena cava, and intrarectal approaches.¹⁵

The WSACS recommends that any patient admitted to a critical care unit or in whom new organ failure develops should be screened for risk factors for intra-abdominal hypertension and abdominal compartment syndrome. If a patient has at least two of the risk factors suggested by WSACS, a baseline intra-abdominal pressure measurement should be obtained. Patients at risk for intra-abdominal hypertension should have the intra-abdominal pressure measured every 4 to 6 hours. However, in the face of hemodynamic instability and worsening multiorgan failure, the pressure may need to be measured hourly.¹⁸

Clinicians managing patients in the intensive care unit should think of intra-abdominal pressure alongside blood pressure, urine output, and mental status when evaluating hemodynamic status. Clinical manifestations of abdominal compartment syndrome reflect the underlying organ dysfunction and include hypotension, refractory shock, decreased urine output, intracranial hypertension, progressive hypoxemia and hypercarbia, elevated pulmonary peak pressures, and worsening of metabolic acidosis.²²

Treatment. The standard treatment for primary abdominal compartment syndrome is surgical decompression. According to WSACS guidelines, insertion of a percutaneous drainage catheter should be advocated in patients with gross ascites and in whom decompressive surgery is not feasible. A damage-control resuscitation strategy used for patients undergoing damage-control laparotomy has been found to increase the 30-day survival rate.²³ A damage-control resuscitation strategy consists of increasing the use of plasma and platelet transfusions over packed red cell transfusions, limiting the use of crystalloid solutions in early fluid resuscitation, and allowing for permissive hypotension.

Rectus sheath hematoma is relatively uncommon and is not often considered in the initial differential diagnosis of an acute abdomen

Secondary abdominal compartment syndrome is treated conservatively in most cases, since patients with this condition are very poor surgical candidates owing to their comorbidities.¹⁸ However, in patients with progressive organ dysfunction in whom medical management has failed, surgical decompression should be considered.¹⁸ Medical management of secondary abdominal compartment syndrome depends on the underlying etiology. Strategies include nasogastric or colonic decompression, use of prokinetic agents, paracentesis in cases with gross ascites, and maintaining a cumulative negative fluid balance. The WSACS does not recommend routine use of diuretics, albumin infusion, or renal replacement strategies. Pain should be adequately controlled to improve abdominal wall compliance.^18,24 Neuromuscular blockade agents may be used to aid this process. Neostigmine may be used to treat colonic pseudo-obstruction when other conservative methods fail. Use of enteral nutrition should be minimized.¹⁸

Our patient might have abdominal compartment syndrome, but a definitive diagnosis cannot be made at this point without measuring the intra-abdominal pressure.

WHICH IMAGING TEST WOULD BE BEST?

2. Which imaging test would be best for establishing the diagnosis in this patient?

• Plain abdominal radiography
• Abdominal ultrasonography
• Computed tomography of the abdomen and pelvis with contrast
• Magnetic resonance imaging of the abdomen and pelvis

Plain abdominal radiography

Plain abdominal radiography can help to determine if there is free gas under the diaphragm (due to bowel perforation), obstructed bowel, sentinel loop, volvulus, or fecoliths causing the abdominal pain. It cannot diagnose rectus sheath hematoma or acute mesenteric ischemia.

Abdominal ultrasonography

Abdominal ultrasonography can be used as the first diagnostic test, as it is widely available, safe, effective, and tolerable. It does not expose the patient to radiation or intravenous contrast agents. It helps to diagnose rectus sheath hematoma and helps to follow its maturation and resolution once a diagnosis is made. It can provide a rapid assessment of the size, location, extent, and physical characteristics of the mass.

Ultrasonography is widely available, safe, effective, and tolerable

Rectus sheath hematoma appears spindle-shaped on sagittal sections and ovoid on coronal sections. It often appears sonolucent in the early stages and sonodense in the late stage, but the appearance may be heterogeneous depending on the combined presence of clot and fresh blood. These findings are sufficient to make the diagnosis.

Abdominal ultrasonography has 85% to 96% sensitivity in diagnosing rectus sheath hematoma.²⁵ It can help diagnose other causes of the abdominal pain, such as renal stones and cholecystitis. It is the preferred imaging test in pediatric patients, pregnant patients, and those with renal insufficiency.

Abdominal computed tomography

Abdominal computed tomography has a sensitivity and specificity of 100% for diagnosing acute rectus sheath hematoma with a duration of less than 5 days.²⁵ It not only helps to determine the precise location and extent, but also helps to determine if there is active extravasation. Even in patients with renal insufficiency, noncontrast computed tomography will help to confirm the diagnosis, although it may not show extravasation or it may miss certain abdominal pathologies because of the lack of contrast.

Acute rectus sheath hematoma appears as a hyperdense mass posterior to the rectus abdominis muscle with ipsilateral anterolateral muscular enlargement. Chronic rectus sheath hematoma appears isodense or hypodense relative to the surrounding muscle. Above the arcuate line, rectus sheath hematoma has a spindle shape; below the arcuate line, it is typically spherical.

In 1996, Berná et al²⁶ classified rectus sheath hematoma into three grades based on findings of computed tomography:

• Grade I is intramuscular and unilateral
• Grade II may involve bilateral rectus muscles without extension into the prevesicular space
• Grade III extends into the peritoneum and prevesicular space

Magnetic resonance imaging

Magnetic resonance imaging is useful to differentiate chronic rectus sheath hematoma (greater than 5-day duration) from an anterior abdominal wall mass. Chronic rectus sheath hematoma will have high signal intensity on both T1- and T2-weighted images up to 10 months after the onset of the hematoma.²⁷

Back to our patient

Since our patient’s symptoms are acute and of less than 5 days’ duration, computed tomography of the abdomen and pelvis would be the best diagnostic test, with therapeutic implications if there is ongoing extravasation.

Computed tomography of the abdomen with contrast showed a new hematoma, measuring 25 by 14 by 13.5 cm, in the right rectus sheath (Figure 2), with no other findings. The hematoma was grade I, since it was intramuscular and unilateral without extension elsewhere.

Laboratory workup showed that the patient’s hematocrit was falling, from 34% to 24%, and her INR was elevated at 2.5. She was resuscitated with fluids, blood transfusion, and fresh-frozen plasma. Anticoagulation was withheld. In spite of resuscitation, her hematocrit kept falling, though she remained hemodynamically stable.

THE WAY FORWARD

3. At this point, what would be the best approach to management in this patient?

• Serial clinical examinations and frequent monitoring of the complete blood cell count
• Urgent surgical consult for exploratory laparotomy with evaluation of the hematoma and ligation of the bleeding vessel
• Repeat computed tomographic angiography to identify a possible bleeding vessel; consideration of radiographically guided arterial embolization
• Measuring the intra-abdominal pressure using the intrabladder pressure for abdominal compartment syndrome and consideration of surgical drainage

The key clinical concern in a patient with a rectus sheath hematoma who is hemodynamically stable is whether the hematoma is expanding. This patient responded to initial resuscitation, but her falling hematocrit was evidence of ongoing bleeding leading to an expanding rectus sheath hematoma. Thus, serial clinical examinations and frequent monitoring of the complete blood cell count would not be enough, as it could miss fatal ongoing bleeding.

Radiographically guided embolization with Gelfoam, thrombin, or coils should be attempted first, as this is less invasive than exploratory laparotomy.²⁸ It can achieve hemostasis, decrease the size of the hematoma, limit the need for blood products, and prevent rupture into the abdomen. If this is unsuccessful, the next step is ligation of the bleeding vessel.²⁹

Surgical treatment includes evacuation of the hematoma, repair of the rectus sheath, ligation of bleeding vessels, and abdominal wall closure. Surgical evacuation or guided drainage of a rectus sheath hematoma on its own is not normally indicated and may indeed cause persistent bleeding by diminishing a potential tamponade effect. However, it may become necessary if the hematoma is very large or infected, if it causes marked respiratory impairment, or if abdominal compartment syndrome is suspected.

Abdominal compartment syndrome is very rare but is associated with a 50% mortality rate.³⁰ It should be suspected in patients with oliguria, low cardiac output, changes in minute ventilation, and altered splanchnic blood flow. The diagnosis is confirmed with indwelling catheter manometry of the bladder to measure intra-abdominal pressure. Intra-abominal pressure above 25 mm Hg should be treated with decompressive laparotomy.³⁰ However, the clinical suspicion of abdominal compartment syndrome was low in this patient.

The best choice at this point would be urgent computed tomographic angiography to identify a bleeding vessel, along with consideration of radiographically guided arterial embolization.

TREATMENT IS USUALLY CONSERVATIVE

Treatment of rectus sheath hematoma is conservative in most hemodynamically stable patients, with embolization or surgical intervention reserved for unstable patients or those in whom the hematoma is expanding.

Knowledge of the grading system of Berná et al²⁶ helps to assess the patient’s risk and to anticipate potential complications. Grade I hematomas are mild and do not necessitate admission. Patients with grade II hematoma can be admitted to the floor for 24 to 48 hours for observation. Grade III usually occurs in patients receiving anticoagulant therapy and frequently requires blood products. These patients have a prolonged hospital stay and more complications, including hypovolemic shock, myonecrosis, acute coronary syndrome, arrhythmias, acute renal failure, small-bowel infarction, and abdominal compartment syndrome—all of which increases the risk of morbidity and death. Thus, patients who are on anticoagulation who develop grade III rectus sheath hematoma should be admitted to the hospital, preferably to the intensive care unit, to ensure that the hematoma is not expanding and to plan reinstitution of anticoagulation as appropriate.

In most cases, rectus sheath hematomas resolve within 1 to 3 months. Resolution of large hematomas may be hastened with the use of pulsed ultrasound.³¹ However, this treatment should be used only after the acute phase is over, when there is evidence of an organized thrombus and coagulation measures have returned to the target range. This helps to reduce the risk of bleeding and to prevent symptoms from worsening.³¹

OUR PATIENT’S COURSE

Our patient underwent urgent computed tomographic angiography, which showed a modest increase in the size of the rectus sheath hematoma. However, no definitive blush of contrast was seen to suggest active arterial bleeding. Her hematocrit stabilized, and she remained hemodynamically stable without requiring additional intervention. Most likely her bleeding was self-contained. She had normal intra-abdominal pressure on serial monitoring. She was later transferred to acute inpatient rehabilitation in view of deconditioning and is currently doing well. The hematoma persisted, decreasing only slightly in size over the next 3 weeks.

A 57-year-old woman presented to the emergency department with left lower quadrant pain, which had started 1 week earlier and was constant, dull, aching, and nonradiating. There were no aggravating or alleviating factors. The pain was associated with low-grade fever and nausea. She reported no vomiting, no change in bowel habits, and no hematemesis, hematochezia, or melena. She did not have urinary urgency, frequency, or dysuria. She had no cardiac, respiratory, or neurologic symptoms.

Her medical history included hypothyroidism, type 2 diabetes mellitus, diverticulosis, and chronic obstructive pulmonary disease. Her medications included metformin, insulin, levothyroxine, and inhaled tiotropium. She had no allergies. She had never undergone surgery, including cesarean delivery. She was postmenopausal. She had two children, both of whom had been born vaginally at full term. She denied using alcohol, tobacco, and illicit drugs. Her family history was noncontributory.

On examination, she was not in acute distress. Her temperature was 36.7°C (98.1°F), blood pressure 130/90 mm Hg, heart rate 86 beats per minute and regular, respiratory rate 16 breaths per minute, and oxygen saturation 98% on ambient air. Examination of her head and neck was unremarkable. Cardiopulmonary examination was normal. Abdominal examination revealed normal bowel sounds, mild tenderness in the left lower quadrant with localized guarding, and rebound tenderness. Neurologic examination was unremarkable.

Initial laboratory data showed mild leukocytosis. Computed tomography with contrast of the abdomen and pelvis suggested acute diverticulitis.

ATRIAL FIBRILLATION, AND THEN A TURN FOR THE WORSE

The patient was admitted with an initial diagnosis of acute diverticulitis. She was started on antibiotics, hydration, and pain medications, and her abdominal pain gradually improved.

On the third hospital day, she suddenly experienced shortness of breath and palpitations. At the time of admission her electrocardiogram had been normal, but it now showed atrial fibrillation with a rapid ventricular response. She also developed elevated troponin levels, which were thought to represent type 2 non-ST-elevation myocardial infarction.

She was started on aspirin, clopidogrel, and anticoagulation with heparin bridged with warfarin for the new-onset atrial fibrillation. Her heart rate was controlled with metoprolol, and her shortness of breath improved. An echocardiogram was normal.

On the seventh hospital day, she developed severe right-sided lower abdominal pain and bruising. Her blood pressure was 90/60 mm Hg, heart rate 110 beats per minute and irregularly irregular, respiratory rate 22 breaths per minute, and oxygen saturation 97% on room air. Her abdomen was diffusely tender with a palpable mass in the right lower quadrant and hypoactive bowel sounds. Ecchymosis was noted (Figure 1).

DIFFERENTIAL DIAGNOSIS

1. What is the likely cause of her decompensation?

• Acute mesenteric ischemia
• Perforation of the gastrointestinal tract
• Rectus sheath hematoma
• Abdominal compartment syndrome due to acute pancreatitis

Acute mesenteric ischemia

Signs and symptoms of acute mesenteric ischemia can be vague. Moreover, when it leads to bowel necrosis the mortality rate is high, ranging from 30% to 65%.¹ Hence, one should suspect it and try to diagnose it early.

Most patients with this condition have comorbidities; risk factors include atherosclerotic disease, cardiac conditions (congestive heart failure, recent myocardial infarction, and atrial fibrillation), systemic illness, and inherited or acquired hypercoagulable states.²

The four major causes are:

• Acute thromboembolic occlusion of the superior mesenteric artery (the most common site of occlusion because of the acute angle of origin from the aorta)
• Acute thrombosis of the mesenteric vein
• Acute thrombosis of the mesenteric artery
• Nonocclusive disease affecting the mesenteric vessels²

Nonocclusive disease is seen in conditions in which the mesenteric vessels are already compromised due to background stenosis owing to atherosclerosis. Also, conditions such as septic and cardiogenic shock can compromise these arteries, leading to ischemia, which, if it persists, can lead to bowel infarction. Ischemic colitis falls under this category. It commonly involves the descending and sigmoid colon.³

The initial symptom of ischemia may be abdominal pain that is brought on by eating large meals (“postprandial intestinal angina.”² When the ischemia worsens to infarction, patients may have a diffusely tender abdomen and constant pain that does not vary with palpation. Surprisingly, patients do not exhibit peritoneal signs early on. This gives rise to the description of “pain out of proportion to the physical findings” traditionally associated with acute mesenteric ischemia.²

Diagnosis. Supportive laboratory data include marked leukocytosis, elevated hematocrit due to hemoconcentration, metabolic acidosis, and elevated lactate.⁴ Newer markers such as serum alpha-glutathione S-transferase (alpha-GST) and intestinal fatty acid-binding protein (I-FABP) may be used to support the diagnosis.

Elevated alpha-GST has 72% sensitivity and 77% specificity in the diagnosis of acute mesenteric ischemia.⁵ The caveat is that it cannot reliably differentiate ischemia from infarction. Its sensitivity can be improved to 97% to 100% by using the white blood cell count and lactate levels in combination.⁵

An I-FABP level higher than 100 ng/mL has 100% sensitivity for diagnosing mesenteric infarction but only 25% sensitivity for bowel strangulation.⁶

Early use of abdominal computed tomography with contrast can aid in recognizing this diagnosis.⁷ Thus, it should be ordered in suspected cases, even in patients who have elevated creatinine levels (which would normally preclude the use of contrast), since early diagnosis followed by endovascular therapy is associated with survival benefit, and the risk of contrast-induced nephropathy appears to be small.⁸ Computed tomography helps to determine the state of mesenteric vessels and bowel perfusion before ischemia progresses to infarction. It also helps to rule out other common diagnoses. Findings that suggest acute mesenteric ischemia include segmental bowel wall thickening, intestinal pneumatosis with gas in the portal vein, bowel dilation, mesenteric stranding, portomesenteric thrombosis, and solid-organ infarction.⁹

Treatment. If superior mesenteric artery occlusion is diagnosed on computed tomography, the next step is to determine if there is peritonitis.¹⁰ In patients who have evidence of peritonitis, exploratory laparotomy is performed. For emboli in such patients, open embolectomy followed by on-table angiography is carried out in combination with damage-control surgery. For patients with peritonitis and acute thrombosis, stenting along with damage-control surgery is preferred.¹⁰

On the other hand, if there is no peritonitis, the thrombosis may be amenable to endovascular intervention. For patients with acute embolic occlusion with no contraindications to thrombolysis, aspiration embolectomy in combination with local catheter-directed thrombolysis with recombinant tissue plasminogen activator can be performed. This can be combined with endovascular mechanical embolectomy for more complete management.¹⁰ Patients with contraindications to thrombolysis can be treated either with aspiration and mechanical embolectomy or with open embolectomy with angiography.¹⁰

During laparotomy, the surgeon carefully inspects the bowel for signs of necrosis. Signs that bowel is still viable include pink color, bleeding from cut surfaces, good peristalsis, and visible pulsations in the arterial arcade of the mesentery.

On day 7 she developed acute decompensation—what was the cause?

Acute mesenteric artery thrombosis arising from chronic atherosclerotic disease can be treated with stenting of the stenotic lesion.¹⁰ Patients with this condition would also benefit from aggressive management of atherosclerotic disease with statins along with antiplatelet agents.¹⁰

Mesenteric vein thrombosis requires prompt institution of anticoagulation. However, in advanced cases leading to bowel infarction, exploratory laparotomy with resection of the necrotic bowel may be required. Anticoagulation should be continued for at least 6 months, and further therapy should be determined by the underlying precipitating condition.¹⁰

Critically ill patients who develop mesenteric ischemia secondary to persistent hypotension usually respond to adequate volume resuscitation, cessation of vasopressors, and overall improvement in their hemodynamic status. These patients must be closely monitored for development of gangrene of the bowel because they may be intubated and not able to complain. Any sudden deterioration in their condition should prompt physicians to consider bowel necrosis developing in these patients. Elevation of lactate levels out of proportion to the degree of hypotension may be corroborative evidence.⁴

Our patient had risk factors for acute mesenteric ischemia that included atrial fibrillation and recent non-ST-elevation myocardial infarction. She could have had arterial emboli due to atrial fibrillation, in situ superior mesenteric arterial thrombosis, or splanchnic arterial vasoconstriction due to the myocardial infarction associated with transient hypotension.

Arguing against this diagnosis, although she had a grossly distended abdomen, abdominal bruising usually is not seen. Also, a palpable mass in the right lower quadrant is uncommon except when acute mesenteric ischemia occurs due to segmental intestinal strangulation, as with strangulated hernia or volvulus. She also had therapeutic international normalized ratio (INR) levels constantly while on anticoagulation. Nevertheless, acute mesenteric ischemia should be strongly considered in the initial differential diagnosis of this patient’s acute decompensation.

Perforation of the gastrointestinal tract

Diverticulitis is the acute inflammation of one or more diverticula, which are small pouches created by herniation of the mucosa into the wall of the colon. The condition is caused by microscopic or macroscopic perforation of the diverticula. Microscopic perforation is usually self-limited (uncomplicated diverticulitis) and responds to conservative treatment, whereas macroscopic perforation can be associated with fecal or purulent peritonitis, abscess, enteric fistula, bowel obstruction, and stricture (complicated diverticulitis), in which case surgery may be necessary.

Signs and symptoms of acute mesenteric ischemia can be vague

Patients with peritonitis due to free perforation present with generalized tenderness with rebound tenderness and guarding on abdominal examination. The abdomen may be distended and tympanic to percussion, with diminished or absent bowel sounds. Patients may have hemodynamic compromise.

Plain upright abdominal radiographs may show free air under the diaphragm. Computed tomography may show oral contrast outside the lumen and detect even small amounts of free intraperitoneal air (more clearly seen on a lung window setting).

Our patient initially presented with acute diverticulitis. She later developed diffuse abdominal tenderness with hypoactive bowel sounds. Bowel perforation is certainly a possibility at this stage, though it is usually not associated with abdominal bruising. She would need additional imaging to rule out this complication.

Other differential diagnoses to be considered in this patient with right lower-quadrant pain include acute appendicitis, incarcerated inguinal hernia, volvulus (particularly cecal volvulus), small-bowel obstruction, pyelonephritis, and gynecologic causes such as adnexal torsion, ruptured ovarian cyst, and tubo-ovarian abscess. Computed tomography helps to differentiate most of these causes.

Rectus sheath hematoma

Rectus sheath hematoma is relatively uncommon and often not considered in the initial differential diagnosis of an acute abdomen. This gives it the rightful term “a great masquerader.” It usually results from bleeding into the rectus sheath from damage to the superior (more common) or inferior epigastric arteries and occasionally from a direct tear of the rectus abdominis muscle. Predisposing factors include anticoagulant therapy (most common), advanced age, hypertension, previous abdominal surgery, trauma, paroxysmal coughing, medication injections, pregnancy, blood dyscrasias, severe vomiting, violent physical activity, and leukemia.¹¹

Clinical manifestations include acute abdominal pain, often associated with fever, nausea, and vomiting. Physical examination may reveal signs of hypovolemic shock, a palpable nonpulsatile abdominal mass, and signs of local peritoneal irritation. The Carnett sign¹¹ (tenderness within the abdominal wall that persists and does not improve with raising the head) and the Fothergill sign¹¹ (a tender abdominal mass that does not cross the midline and remains palpable with tensing of the rectus sheath) may be elicited.

Computed tomography is more sensitive than abdominal ultrasonography in differentiating rectus sheath hematoma from an intra-abdominal pathology.¹¹ In addition, computed tomography also helps to determine if the bleeding is active or not, which has therapeutic implications.

In our patient, rectus sheath hematoma is a possibility because of her ongoing anticoagulation, findings of localized abdominal bruising, and palpable right lower-quadrant mass, and it is high on the list of differential diagnoses. Rectus sheath hematoma should be considered in the differential diagnosis of lower abdominal pain particularly in elderly women who are on anticoagulation and in whom the onset of pain coincides with a paroxysm of cough.¹² Women are twice as likely as men to develop rectus sheath hematoma, owing to their different muscle mass.¹³ In addition, anterior abdominal wall muscles are stretched during pregnancy.¹³

Abdominal compartment syndrome

Abdominal compartment syndrome has been classically associated with surgical patients. However, it is being increasingly recognized in critically ill medical patients, in whom detecting and treating it early may result in significant reduction in rates of morbidity and death.¹⁴

Abdominal compartment syndrome is of three types: primary, secondary, and recurrent. Primary abdominal compartment syndrome refers to the classic surgical patients with evidence of direct injury to the abdominal or pelvic organs through major trauma or extensive abdominal surgeries. Secondary abdominal compartment syndrome refers to its development in critically ill intensive care patients in whom the pathology does not directly involve the abdominal or pelvic organs.

Various medical conditions can culminate in abdominal compartment syndrome and result in multiorgan failure. Recurrent abdominal compartment syndrome refers to its development after management of either primary or secondary intra-abdominal hypertension or abdominal compartment syndrome.¹⁵ Clinicians thus must be aware of secondary and recurrent abdominal compartment syndrome occurring in critically ill patients.

The normal intra-abdominal pressure is around 5 to 7 mm Hg, even in most critically ill patients. Persistent elevation, ie, higher than 12 mm Hg, is referred to as intra-abdominal hypertension.^16–18 Intra-abdominal hypertension is subdivided into four grades:

• Grade I: 12–15 mm Hg
• Grade II: 16–20 mm Hg
• Grade III: 21–25 mm Hg
• Grade IV: > 25 mm Hg.

The World Society of the Abdominal Compartment Syndrome (WSACS) defines abdominal compartment syndrome as pressure higher than 20 mm Hg along with organ damage.¹⁸ It may or may not be associated with an abdominal perfusion pressure less than 60 mm Hg.¹⁸

Risk factors associated with abdominal compartment syndrome include conditions causing decreased gut motility (gastroparesis, ileus, and colonic pseudo-obstruction), intra-abdominal or retroperitoneal masses or abscesses, ascites, hemoperitoneum, acute pancreatitis, third-spacing due to massive fluid resuscitation with transfusions, peritoneal dialysis, and shock.^18,19

Microscopic perforation is usually self-limited, whereas macroscopic perforation may need surgery

Physical examination has a sensitivity of only 40% to 60% in detecting intra-abdominal hypertension.²⁰ The gold-standard method of measuring the intra-abdominal pressure is the modified Kron technique,¹⁸ using a Foley catheter in the bladder connected to a pressure transducer. With the patient in the supine position, the transducer is zeroed at the mid-axillary line at the level of the iliac crest, and 25 mL of normal saline is instilled into the bladder and maintained for 30 to 60 seconds to let the detrusor muscle relax.¹⁵ Pressure tracings are then recorded at the end of expiration. Factors that are known to affect the transbladder pressure include patient position, respiratory movement, and body mass index, and should be taken into account when reading the pressure recordings.^15,21 Other techniques that can be used include intragastric, intra-inferior vena cava, and intrarectal approaches.¹⁵

The WSACS recommends that any patient admitted to a critical care unit or in whom new organ failure develops should be screened for risk factors for intra-abdominal hypertension and abdominal compartment syndrome. If a patient has at least two of the risk factors suggested by WSACS, a baseline intra-abdominal pressure measurement should be obtained. Patients at risk for intra-abdominal hypertension should have the intra-abdominal pressure measured every 4 to 6 hours. However, in the face of hemodynamic instability and worsening multiorgan failure, the pressure may need to be measured hourly.¹⁸

Clinicians managing patients in the intensive care unit should think of intra-abdominal pressure alongside blood pressure, urine output, and mental status when evaluating hemodynamic status. Clinical manifestations of abdominal compartment syndrome reflect the underlying organ dysfunction and include hypotension, refractory shock, decreased urine output, intracranial hypertension, progressive hypoxemia and hypercarbia, elevated pulmonary peak pressures, and worsening of metabolic acidosis.²²

Treatment. The standard treatment for primary abdominal compartment syndrome is surgical decompression. According to WSACS guidelines, insertion of a percutaneous drainage catheter should be advocated in patients with gross ascites and in whom decompressive surgery is not feasible. A damage-control resuscitation strategy used for patients undergoing damage-control laparotomy has been found to increase the 30-day survival rate.²³ A damage-control resuscitation strategy consists of increasing the use of plasma and platelet transfusions over packed red cell transfusions, limiting the use of crystalloid solutions in early fluid resuscitation, and allowing for permissive hypotension.

Rectus sheath hematoma is relatively uncommon and is not often considered in the initial differential diagnosis of an acute abdomen

Secondary abdominal compartment syndrome is treated conservatively in most cases, since patients with this condition are very poor surgical candidates owing to their comorbidities.¹⁸ However, in patients with progressive organ dysfunction in whom medical management has failed, surgical decompression should be considered.¹⁸ Medical management of secondary abdominal compartment syndrome depends on the underlying etiology. Strategies include nasogastric or colonic decompression, use of prokinetic agents, paracentesis in cases with gross ascites, and maintaining a cumulative negative fluid balance. The WSACS does not recommend routine use of diuretics, albumin infusion, or renal replacement strategies. Pain should be adequately controlled to improve abdominal wall compliance.^18,24 Neuromuscular blockade agents may be used to aid this process. Neostigmine may be used to treat colonic pseudo-obstruction when other conservative methods fail. Use of enteral nutrition should be minimized.¹⁸

Our patient might have abdominal compartment syndrome, but a definitive diagnosis cannot be made at this point without measuring the intra-abdominal pressure.

WHICH IMAGING TEST WOULD BE BEST?

2. Which imaging test would be best for establishing the diagnosis in this patient?

• Plain abdominal radiography
• Abdominal ultrasonography
• Computed tomography of the abdomen and pelvis with contrast
• Magnetic resonance imaging of the abdomen and pelvis

Plain abdominal radiography

Plain abdominal radiography can help to determine if there is free gas under the diaphragm (due to bowel perforation), obstructed bowel, sentinel loop, volvulus, or fecoliths causing the abdominal pain. It cannot diagnose rectus sheath hematoma or acute mesenteric ischemia.

Abdominal ultrasonography

Abdominal ultrasonography can be used as the first diagnostic test, as it is widely available, safe, effective, and tolerable. It does not expose the patient to radiation or intravenous contrast agents. It helps to diagnose rectus sheath hematoma and helps to follow its maturation and resolution once a diagnosis is made. It can provide a rapid assessment of the size, location, extent, and physical characteristics of the mass.

Ultrasonography is widely available, safe, effective, and tolerable

Rectus sheath hematoma appears spindle-shaped on sagittal sections and ovoid on coronal sections. It often appears sonolucent in the early stages and sonodense in the late stage, but the appearance may be heterogeneous depending on the combined presence of clot and fresh blood. These findings are sufficient to make the diagnosis.

Abdominal ultrasonography has 85% to 96% sensitivity in diagnosing rectus sheath hematoma.²⁵ It can help diagnose other causes of the abdominal pain, such as renal stones and cholecystitis. It is the preferred imaging test in pediatric patients, pregnant patients, and those with renal insufficiency.

Abdominal computed tomography

Abdominal computed tomography has a sensitivity and specificity of 100% for diagnosing acute rectus sheath hematoma with a duration of less than 5 days.²⁵ It not only helps to determine the precise location and extent, but also helps to determine if there is active extravasation. Even in patients with renal insufficiency, noncontrast computed tomography will help to confirm the diagnosis, although it may not show extravasation or it may miss certain abdominal pathologies because of the lack of contrast.

Acute rectus sheath hematoma appears as a hyperdense mass posterior to the rectus abdominis muscle with ipsilateral anterolateral muscular enlargement. Chronic rectus sheath hematoma appears isodense or hypodense relative to the surrounding muscle. Above the arcuate line, rectus sheath hematoma has a spindle shape; below the arcuate line, it is typically spherical.

In 1996, Berná et al²⁶ classified rectus sheath hematoma into three grades based on findings of computed tomography:

• Grade I is intramuscular and unilateral
• Grade II may involve bilateral rectus muscles without extension into the prevesicular space
• Grade III extends into the peritoneum and prevesicular space

Magnetic resonance imaging

Magnetic resonance imaging is useful to differentiate chronic rectus sheath hematoma (greater than 5-day duration) from an anterior abdominal wall mass. Chronic rectus sheath hematoma will have high signal intensity on both T1- and T2-weighted images up to 10 months after the onset of the hematoma.²⁷

Back to our patient

Since our patient’s symptoms are acute and of less than 5 days’ duration, computed tomography of the abdomen and pelvis would be the best diagnostic test, with therapeutic implications if there is ongoing extravasation.

Computed tomography of the abdomen with contrast showed a new hematoma, measuring 25 by 14 by 13.5 cm, in the right rectus sheath (Figure 2), with no other findings. The hematoma was grade I, since it was intramuscular and unilateral without extension elsewhere.

Laboratory workup showed that the patient’s hematocrit was falling, from 34% to 24%, and her INR was elevated at 2.5. She was resuscitated with fluids, blood transfusion, and fresh-frozen plasma. Anticoagulation was withheld. In spite of resuscitation, her hematocrit kept falling, though she remained hemodynamically stable.

THE WAY FORWARD

3. At this point, what would be the best approach to management in this patient?

• Serial clinical examinations and frequent monitoring of the complete blood cell count
• Urgent surgical consult for exploratory laparotomy with evaluation of the hematoma and ligation of the bleeding vessel
• Repeat computed tomographic angiography to identify a possible bleeding vessel; consideration of radiographically guided arterial embolization
• Measuring the intra-abdominal pressure using the intrabladder pressure for abdominal compartment syndrome and consideration of surgical drainage

The key clinical concern in a patient with a rectus sheath hematoma who is hemodynamically stable is whether the hematoma is expanding. This patient responded to initial resuscitation, but her falling hematocrit was evidence of ongoing bleeding leading to an expanding rectus sheath hematoma. Thus, serial clinical examinations and frequent monitoring of the complete blood cell count would not be enough, as it could miss fatal ongoing bleeding.

Radiographically guided embolization with Gelfoam, thrombin, or coils should be attempted first, as this is less invasive than exploratory laparotomy.²⁸ It can achieve hemostasis, decrease the size of the hematoma, limit the need for blood products, and prevent rupture into the abdomen. If this is unsuccessful, the next step is ligation of the bleeding vessel.²⁹

Surgical treatment includes evacuation of the hematoma, repair of the rectus sheath, ligation of bleeding vessels, and abdominal wall closure. Surgical evacuation or guided drainage of a rectus sheath hematoma on its own is not normally indicated and may indeed cause persistent bleeding by diminishing a potential tamponade effect. However, it may become necessary if the hematoma is very large or infected, if it causes marked respiratory impairment, or if abdominal compartment syndrome is suspected.

Abdominal compartment syndrome is very rare but is associated with a 50% mortality rate.³⁰ It should be suspected in patients with oliguria, low cardiac output, changes in minute ventilation, and altered splanchnic blood flow. The diagnosis is confirmed with indwelling catheter manometry of the bladder to measure intra-abdominal pressure. Intra-abominal pressure above 25 mm Hg should be treated with decompressive laparotomy.³⁰ However, the clinical suspicion of abdominal compartment syndrome was low in this patient.

The best choice at this point would be urgent computed tomographic angiography to identify a bleeding vessel, along with consideration of radiographically guided arterial embolization.

TREATMENT IS USUALLY CONSERVATIVE

Treatment of rectus sheath hematoma is conservative in most hemodynamically stable patients, with embolization or surgical intervention reserved for unstable patients or those in whom the hematoma is expanding.

Knowledge of the grading system of Berná et al²⁶ helps to assess the patient’s risk and to anticipate potential complications. Grade I hematomas are mild and do not necessitate admission. Patients with grade II hematoma can be admitted to the floor for 24 to 48 hours for observation. Grade III usually occurs in patients receiving anticoagulant therapy and frequently requires blood products. These patients have a prolonged hospital stay and more complications, including hypovolemic shock, myonecrosis, acute coronary syndrome, arrhythmias, acute renal failure, small-bowel infarction, and abdominal compartment syndrome—all of which increases the risk of morbidity and death. Thus, patients who are on anticoagulation who develop grade III rectus sheath hematoma should be admitted to the hospital, preferably to the intensive care unit, to ensure that the hematoma is not expanding and to plan reinstitution of anticoagulation as appropriate.

In most cases, rectus sheath hematomas resolve within 1 to 3 months. Resolution of large hematomas may be hastened with the use of pulsed ultrasound.³¹ However, this treatment should be used only after the acute phase is over, when there is evidence of an organized thrombus and coagulation measures have returned to the target range. This helps to reduce the risk of bleeding and to prevent symptoms from worsening.³¹

OUR PATIENT’S COURSE

Our patient underwent urgent computed tomographic angiography, which showed a modest increase in the size of the rectus sheath hematoma. However, no definitive blush of contrast was seen to suggest active arterial bleeding. Her hematocrit stabilized, and she remained hemodynamically stable without requiring additional intervention. Most likely her bleeding was self-contained. She had normal intra-abdominal pressure on serial monitoring. She was later transferred to acute inpatient rehabilitation in view of deconditioning and is currently doing well. The hematoma persisted, decreasing only slightly in size over the next 3 weeks.

A 57-year-old woman presented to the emergency department with left lower quadrant pain, which had started 1 week earlier and was constant, dull, aching, and nonradiating. There were no aggravating or alleviating factors. The pain was associated with low-grade fever and nausea. She reported no vomiting, no change in bowel habits, and no hematemesis, hematochezia, or melena. She did not have urinary urgency, frequency, or dysuria. She had no cardiac, respiratory, or neurologic symptoms.

Her medical history included hypothyroidism, type 2 diabetes mellitus, diverticulosis, and chronic obstructive pulmonary disease. Her medications included metformin, insulin, levothyroxine, and inhaled tiotropium. She had no allergies. She had never undergone surgery, including cesarean delivery. She was postmenopausal. She had two children, both of whom had been born vaginally at full term. She denied using alcohol, tobacco, and illicit drugs. Her family history was noncontributory.

On examination, she was not in acute distress. Her temperature was 36.7°C (98.1°F), blood pressure 130/90 mm Hg, heart rate 86 beats per minute and regular, respiratory rate 16 breaths per minute, and oxygen saturation 98% on ambient air. Examination of her head and neck was unremarkable. Cardiopulmonary examination was normal. Abdominal examination revealed normal bowel sounds, mild tenderness in the left lower quadrant with localized guarding, and rebound tenderness. Neurologic examination was unremarkable.

Initial laboratory data showed mild leukocytosis. Computed tomography with contrast of the abdomen and pelvis suggested acute diverticulitis.

ATRIAL FIBRILLATION, AND THEN A TURN FOR THE WORSE

The patient was admitted with an initial diagnosis of acute diverticulitis. She was started on antibiotics, hydration, and pain medications, and her abdominal pain gradually improved.

On the third hospital day, she suddenly experienced shortness of breath and palpitations. At the time of admission her electrocardiogram had been normal, but it now showed atrial fibrillation with a rapid ventricular response. She also developed elevated troponin levels, which were thought to represent type 2 non-ST-elevation myocardial infarction.

She was started on aspirin, clopidogrel, and anticoagulation with heparin bridged with warfarin for the new-onset atrial fibrillation. Her heart rate was controlled with metoprolol, and her shortness of breath improved. An echocardiogram was normal.

On the seventh hospital day, she developed severe right-sided lower abdominal pain and bruising. Her blood pressure was 90/60 mm Hg, heart rate 110 beats per minute and irregularly irregular, respiratory rate 22 breaths per minute, and oxygen saturation 97% on room air. Her abdomen was diffusely tender with a palpable mass in the right lower quadrant and hypoactive bowel sounds. Ecchymosis was noted (Figure 1).

DIFFERENTIAL DIAGNOSIS

1. What is the likely cause of her decompensation?

• Acute mesenteric ischemia
• Perforation of the gastrointestinal tract
• Rectus sheath hematoma
• Abdominal compartment syndrome due to acute pancreatitis

Acute mesenteric ischemia

Signs and symptoms of acute mesenteric ischemia can be vague. Moreover, when it leads to bowel necrosis the mortality rate is high, ranging from 30% to 65%.¹ Hence, one should suspect it and try to diagnose it early.

Most patients with this condition have comorbidities; risk factors include atherosclerotic disease, cardiac conditions (congestive heart failure, recent myocardial infarction, and atrial fibrillation), systemic illness, and inherited or acquired hypercoagulable states.²

The four major causes are:

• Acute thromboembolic occlusion of the superior mesenteric artery (the most common site of occlusion because of the acute angle of origin from the aorta)
• Acute thrombosis of the mesenteric vein
• Acute thrombosis of the mesenteric artery
• Nonocclusive disease affecting the mesenteric vessels²

Nonocclusive disease is seen in conditions in which the mesenteric vessels are already compromised due to background stenosis owing to atherosclerosis. Also, conditions such as septic and cardiogenic shock can compromise these arteries, leading to ischemia, which, if it persists, can lead to bowel infarction. Ischemic colitis falls under this category. It commonly involves the descending and sigmoid colon.³

The initial symptom of ischemia may be abdominal pain that is brought on by eating large meals (“postprandial intestinal angina.”² When the ischemia worsens to infarction, patients may have a diffusely tender abdomen and constant pain that does not vary with palpation. Surprisingly, patients do not exhibit peritoneal signs early on. This gives rise to the description of “pain out of proportion to the physical findings” traditionally associated with acute mesenteric ischemia.²

Diagnosis. Supportive laboratory data include marked leukocytosis, elevated hematocrit due to hemoconcentration, metabolic acidosis, and elevated lactate.⁴ Newer markers such as serum alpha-glutathione S-transferase (alpha-GST) and intestinal fatty acid-binding protein (I-FABP) may be used to support the diagnosis.

Elevated alpha-GST has 72% sensitivity and 77% specificity in the diagnosis of acute mesenteric ischemia.⁵ The caveat is that it cannot reliably differentiate ischemia from infarction. Its sensitivity can be improved to 97% to 100% by using the white blood cell count and lactate levels in combination.⁵

An I-FABP level higher than 100 ng/mL has 100% sensitivity for diagnosing mesenteric infarction but only 25% sensitivity for bowel strangulation.⁶

Early use of abdominal computed tomography with contrast can aid in recognizing this diagnosis.⁷ Thus, it should be ordered in suspected cases, even in patients who have elevated creatinine levels (which would normally preclude the use of contrast), since early diagnosis followed by endovascular therapy is associated with survival benefit, and the risk of contrast-induced nephropathy appears to be small.⁸ Computed tomography helps to determine the state of mesenteric vessels and bowel perfusion before ischemia progresses to infarction. It also helps to rule out other common diagnoses. Findings that suggest acute mesenteric ischemia include segmental bowel wall thickening, intestinal pneumatosis with gas in the portal vein, bowel dilation, mesenteric stranding, portomesenteric thrombosis, and solid-organ infarction.⁹

Treatment. If superior mesenteric artery occlusion is diagnosed on computed tomography, the next step is to determine if there is peritonitis.¹⁰ In patients who have evidence of peritonitis, exploratory laparotomy is performed. For emboli in such patients, open embolectomy followed by on-table angiography is carried out in combination with damage-control surgery. For patients with peritonitis and acute thrombosis, stenting along with damage-control surgery is preferred.¹⁰

On the other hand, if there is no peritonitis, the thrombosis may be amenable to endovascular intervention. For patients with acute embolic occlusion with no contraindications to thrombolysis, aspiration embolectomy in combination with local catheter-directed thrombolysis with recombinant tissue plasminogen activator can be performed. This can be combined with endovascular mechanical embolectomy for more complete management.¹⁰ Patients with contraindications to thrombolysis can be treated either with aspiration and mechanical embolectomy or with open embolectomy with angiography.¹⁰

During laparotomy, the surgeon carefully inspects the bowel for signs of necrosis. Signs that bowel is still viable include pink color, bleeding from cut surfaces, good peristalsis, and visible pulsations in the arterial arcade of the mesentery.

On day 7 she developed acute decompensation—what was the cause?

Acute mesenteric artery thrombosis arising from chronic atherosclerotic disease can be treated with stenting of the stenotic lesion.¹⁰ Patients with this condition would also benefit from aggressive management of atherosclerotic disease with statins along with antiplatelet agents.¹⁰

Mesenteric vein thrombosis requires prompt institution of anticoagulation. However, in advanced cases leading to bowel infarction, exploratory laparotomy with resection of the necrotic bowel may be required. Anticoagulation should be continued for at least 6 months, and further therapy should be determined by the underlying precipitating condition.¹⁰

Critically ill patients who develop mesenteric ischemia secondary to persistent hypotension usually respond to adequate volume resuscitation, cessation of vasopressors, and overall improvement in their hemodynamic status. These patients must be closely monitored for development of gangrene of the bowel because they may be intubated and not able to complain. Any sudden deterioration in their condition should prompt physicians to consider bowel necrosis developing in these patients. Elevation of lactate levels out of proportion to the degree of hypotension may be corroborative evidence.⁴

Our patient had risk factors for acute mesenteric ischemia that included atrial fibrillation and recent non-ST-elevation myocardial infarction. She could have had arterial emboli due to atrial fibrillation, in situ superior mesenteric arterial thrombosis, or splanchnic arterial vasoconstriction due to the myocardial infarction associated with transient hypotension.

Arguing against this diagnosis, although she had a grossly distended abdomen, abdominal bruising usually is not seen. Also, a palpable mass in the right lower quadrant is uncommon except when acute mesenteric ischemia occurs due to segmental intestinal strangulation, as with strangulated hernia or volvulus. She also had therapeutic international normalized ratio (INR) levels constantly while on anticoagulation. Nevertheless, acute mesenteric ischemia should be strongly considered in the initial differential diagnosis of this patient’s acute decompensation.

Perforation of the gastrointestinal tract

Diverticulitis is the acute inflammation of one or more diverticula, which are small pouches created by herniation of the mucosa into the wall of the colon. The condition is caused by microscopic or macroscopic perforation of the diverticula. Microscopic perforation is usually self-limited (uncomplicated diverticulitis) and responds to conservative treatment, whereas macroscopic perforation can be associated with fecal or purulent peritonitis, abscess, enteric fistula, bowel obstruction, and stricture (complicated diverticulitis), in which case surgery may be necessary.

Signs and symptoms of acute mesenteric ischemia can be vague

Patients with peritonitis due to free perforation present with generalized tenderness with rebound tenderness and guarding on abdominal examination. The abdomen may be distended and tympanic to percussion, with diminished or absent bowel sounds. Patients may have hemodynamic compromise.

Plain upright abdominal radiographs may show free air under the diaphragm. Computed tomography may show oral contrast outside the lumen and detect even small amounts of free intraperitoneal air (more clearly seen on a lung window setting).

Our patient initially presented with acute diverticulitis. She later developed diffuse abdominal tenderness with hypoactive bowel sounds. Bowel perforation is certainly a possibility at this stage, though it is usually not associated with abdominal bruising. She would need additional imaging to rule out this complication.

Other differential diagnoses to be considered in this patient with right lower-quadrant pain include acute appendicitis, incarcerated inguinal hernia, volvulus (particularly cecal volvulus), small-bowel obstruction, pyelonephritis, and gynecologic causes such as adnexal torsion, ruptured ovarian cyst, and tubo-ovarian abscess. Computed tomography helps to differentiate most of these causes.

Rectus sheath hematoma

Rectus sheath hematoma is relatively uncommon and often not considered in the initial differential diagnosis of an acute abdomen. This gives it the rightful term “a great masquerader.” It usually results from bleeding into the rectus sheath from damage to the superior (more common) or inferior epigastric arteries and occasionally from a direct tear of the rectus abdominis muscle. Predisposing factors include anticoagulant therapy (most common), advanced age, hypertension, previous abdominal surgery, trauma, paroxysmal coughing, medication injections, pregnancy, blood dyscrasias, severe vomiting, violent physical activity, and leukemia.¹¹

Clinical manifestations include acute abdominal pain, often associated with fever, nausea, and vomiting. Physical examination may reveal signs of hypovolemic shock, a palpable nonpulsatile abdominal mass, and signs of local peritoneal irritation. The Carnett sign¹¹ (tenderness within the abdominal wall that persists and does not improve with raising the head) and the Fothergill sign¹¹ (a tender abdominal mass that does not cross the midline and remains palpable with tensing of the rectus sheath) may be elicited.

Computed tomography is more sensitive than abdominal ultrasonography in differentiating rectus sheath hematoma from an intra-abdominal pathology.¹¹ In addition, computed tomography also helps to determine if the bleeding is active or not, which has therapeutic implications.

In our patient, rectus sheath hematoma is a possibility because of her ongoing anticoagulation, findings of localized abdominal bruising, and palpable right lower-quadrant mass, and it is high on the list of differential diagnoses. Rectus sheath hematoma should be considered in the differential diagnosis of lower abdominal pain particularly in elderly women who are on anticoagulation and in whom the onset of pain coincides with a paroxysm of cough.¹² Women are twice as likely as men to develop rectus sheath hematoma, owing to their different muscle mass.¹³ In addition, anterior abdominal wall muscles are stretched during pregnancy.¹³

Abdominal compartment syndrome

Abdominal compartment syndrome has been classically associated with surgical patients. However, it is being increasingly recognized in critically ill medical patients, in whom detecting and treating it early may result in significant reduction in rates of morbidity and death.¹⁴

Abdominal compartment syndrome is of three types: primary, secondary, and recurrent. Primary abdominal compartment syndrome refers to the classic surgical patients with evidence of direct injury to the abdominal or pelvic organs through major trauma or extensive abdominal surgeries. Secondary abdominal compartment syndrome refers to its development in critically ill intensive care patients in whom the pathology does not directly involve the abdominal or pelvic organs.

Various medical conditions can culminate in abdominal compartment syndrome and result in multiorgan failure. Recurrent abdominal compartment syndrome refers to its development after management of either primary or secondary intra-abdominal hypertension or abdominal compartment syndrome.¹⁵ Clinicians thus must be aware of secondary and recurrent abdominal compartment syndrome occurring in critically ill patients.

The normal intra-abdominal pressure is around 5 to 7 mm Hg, even in most critically ill patients. Persistent elevation, ie, higher than 12 mm Hg, is referred to as intra-abdominal hypertension.^16–18 Intra-abdominal hypertension is subdivided into four grades:

• Grade I: 12–15 mm Hg
• Grade II: 16–20 mm Hg
• Grade III: 21–25 mm Hg
• Grade IV: > 25 mm Hg.

The World Society of the Abdominal Compartment Syndrome (WSACS) defines abdominal compartment syndrome as pressure higher than 20 mm Hg along with organ damage.¹⁸ It may or may not be associated with an abdominal perfusion pressure less than 60 mm Hg.¹⁸

Risk factors associated with abdominal compartment syndrome include conditions causing decreased gut motility (gastroparesis, ileus, and colonic pseudo-obstruction), intra-abdominal or retroperitoneal masses or abscesses, ascites, hemoperitoneum, acute pancreatitis, third-spacing due to massive fluid resuscitation with transfusions, peritoneal dialysis, and shock.^18,19

Microscopic perforation is usually self-limited, whereas macroscopic perforation may need surgery

Physical examination has a sensitivity of only 40% to 60% in detecting intra-abdominal hypertension.²⁰ The gold-standard method of measuring the intra-abdominal pressure is the modified Kron technique,¹⁸ using a Foley catheter in the bladder connected to a pressure transducer. With the patient in the supine position, the transducer is zeroed at the mid-axillary line at the level of the iliac crest, and 25 mL of normal saline is instilled into the bladder and maintained for 30 to 60 seconds to let the detrusor muscle relax.¹⁵ Pressure tracings are then recorded at the end of expiration. Factors that are known to affect the transbladder pressure include patient position, respiratory movement, and body mass index, and should be taken into account when reading the pressure recordings.^15,21 Other techniques that can be used include intragastric, intra-inferior vena cava, and intrarectal approaches.¹⁵

The WSACS recommends that any patient admitted to a critical care unit or in whom new organ failure develops should be screened for risk factors for intra-abdominal hypertension and abdominal compartment syndrome. If a patient has at least two of the risk factors suggested by WSACS, a baseline intra-abdominal pressure measurement should be obtained. Patients at risk for intra-abdominal hypertension should have the intra-abdominal pressure measured every 4 to 6 hours. However, in the face of hemodynamic instability and worsening multiorgan failure, the pressure may need to be measured hourly.¹⁸

Clinicians managing patients in the intensive care unit should think of intra-abdominal pressure alongside blood pressure, urine output, and mental status when evaluating hemodynamic status. Clinical manifestations of abdominal compartment syndrome reflect the underlying organ dysfunction and include hypotension, refractory shock, decreased urine output, intracranial hypertension, progressive hypoxemia and hypercarbia, elevated pulmonary peak pressures, and worsening of metabolic acidosis.²²

Treatment. The standard treatment for primary abdominal compartment syndrome is surgical decompression. According to WSACS guidelines, insertion of a percutaneous drainage catheter should be advocated in patients with gross ascites and in whom decompressive surgery is not feasible. A damage-control resuscitation strategy used for patients undergoing damage-control laparotomy has been found to increase the 30-day survival rate.²³ A damage-control resuscitation strategy consists of increasing the use of plasma and platelet transfusions over packed red cell transfusions, limiting the use of crystalloid solutions in early fluid resuscitation, and allowing for permissive hypotension.

Rectus sheath hematoma is relatively uncommon and is not often considered in the initial differential diagnosis of an acute abdomen

Secondary abdominal compartment syndrome is treated conservatively in most cases, since patients with this condition are very poor surgical candidates owing to their comorbidities.¹⁸ However, in patients with progressive organ dysfunction in whom medical management has failed, surgical decompression should be considered.¹⁸ Medical management of secondary abdominal compartment syndrome depends on the underlying etiology. Strategies include nasogastric or colonic decompression, use of prokinetic agents, paracentesis in cases with gross ascites, and maintaining a cumulative negative fluid balance. The WSACS does not recommend routine use of diuretics, albumin infusion, or renal replacement strategies. Pain should be adequately controlled to improve abdominal wall compliance.^18,24 Neuromuscular blockade agents may be used to aid this process. Neostigmine may be used to treat colonic pseudo-obstruction when other conservative methods fail. Use of enteral nutrition should be minimized.¹⁸

Our patient might have abdominal compartment syndrome, but a definitive diagnosis cannot be made at this point without measuring the intra-abdominal pressure.

WHICH IMAGING TEST WOULD BE BEST?

2. Which imaging test would be best for establishing the diagnosis in this patient?

• Plain abdominal radiography
• Abdominal ultrasonography
• Computed tomography of the abdomen and pelvis with contrast
• Magnetic resonance imaging of the abdomen and pelvis

Plain abdominal radiography

Plain abdominal radiography can help to determine if there is free gas under the diaphragm (due to bowel perforation), obstructed bowel, sentinel loop, volvulus, or fecoliths causing the abdominal pain. It cannot diagnose rectus sheath hematoma or acute mesenteric ischemia.

Abdominal ultrasonography

Abdominal ultrasonography can be used as the first diagnostic test, as it is widely available, safe, effective, and tolerable. It does not expose the patient to radiation or intravenous contrast agents. It helps to diagnose rectus sheath hematoma and helps to follow its maturation and resolution once a diagnosis is made. It can provide a rapid assessment of the size, location, extent, and physical characteristics of the mass.

Ultrasonography is widely available, safe, effective, and tolerable

Rectus sheath hematoma appears spindle-shaped on sagittal sections and ovoid on coronal sections. It often appears sonolucent in the early stages and sonodense in the late stage, but the appearance may be heterogeneous depending on the combined presence of clot and fresh blood. These findings are sufficient to make the diagnosis.

Abdominal ultrasonography has 85% to 96% sensitivity in diagnosing rectus sheath hematoma.²⁵ It can help diagnose other causes of the abdominal pain, such as renal stones and cholecystitis. It is the preferred imaging test in pediatric patients, pregnant patients, and those with renal insufficiency.

Abdominal computed tomography

Abdominal computed tomography has a sensitivity and specificity of 100% for diagnosing acute rectus sheath hematoma with a duration of less than 5 days.²⁵ It not only helps to determine the precise location and extent, but also helps to determine if there is active extravasation. Even in patients with renal insufficiency, noncontrast computed tomography will help to confirm the diagnosis, although it may not show extravasation or it may miss certain abdominal pathologies because of the lack of contrast.

Acute rectus sheath hematoma appears as a hyperdense mass posterior to the rectus abdominis muscle with ipsilateral anterolateral muscular enlargement. Chronic rectus sheath hematoma appears isodense or hypodense relative to the surrounding muscle. Above the arcuate line, rectus sheath hematoma has a spindle shape; below the arcuate line, it is typically spherical.

In 1996, Berná et al²⁶ classified rectus sheath hematoma into three grades based on findings of computed tomography:

• Grade I is intramuscular and unilateral
• Grade II may involve bilateral rectus muscles without extension into the prevesicular space
• Grade III extends into the peritoneum and prevesicular space

Magnetic resonance imaging

Magnetic resonance imaging is useful to differentiate chronic rectus sheath hematoma (greater than 5-day duration) from an anterior abdominal wall mass. Chronic rectus sheath hematoma will have high signal intensity on both T1- and T2-weighted images up to 10 months after the onset of the hematoma.²⁷

Back to our patient

Since our patient’s symptoms are acute and of less than 5 days’ duration, computed tomography of the abdomen and pelvis would be the best diagnostic test, with therapeutic implications if there is ongoing extravasation.

Computed tomography of the abdomen with contrast showed a new hematoma, measuring 25 by 14 by 13.5 cm, in the right rectus sheath (Figure 2), with no other findings. The hematoma was grade I, since it was intramuscular and unilateral without extension elsewhere.

Laboratory workup showed that the patient’s hematocrit was falling, from 34% to 24%, and her INR was elevated at 2.5. She was resuscitated with fluids, blood transfusion, and fresh-frozen plasma. Anticoagulation was withheld. In spite of resuscitation, her hematocrit kept falling, though she remained hemodynamically stable.

THE WAY FORWARD

3. At this point, what would be the best approach to management in this patient?

• Serial clinical examinations and frequent monitoring of the complete blood cell count
• Urgent surgical consult for exploratory laparotomy with evaluation of the hematoma and ligation of the bleeding vessel
• Repeat computed tomographic angiography to identify a possible bleeding vessel; consideration of radiographically guided arterial embolization
• Measuring the intra-abdominal pressure using the intrabladder pressure for abdominal compartment syndrome and consideration of surgical drainage

The key clinical concern in a patient with a rectus sheath hematoma who is hemodynamically stable is whether the hematoma is expanding. This patient responded to initial resuscitation, but her falling hematocrit was evidence of ongoing bleeding leading to an expanding rectus sheath hematoma. Thus, serial clinical examinations and frequent monitoring of the complete blood cell count would not be enough, as it could miss fatal ongoing bleeding.

Radiographically guided embolization with Gelfoam, thrombin, or coils should be attempted first, as this is less invasive than exploratory laparotomy.²⁸ It can achieve hemostasis, decrease the size of the hematoma, limit the need for blood products, and prevent rupture into the abdomen. If this is unsuccessful, the next step is ligation of the bleeding vessel.²⁹

Surgical treatment includes evacuation of the hematoma, repair of the rectus sheath, ligation of bleeding vessels, and abdominal wall closure. Surgical evacuation or guided drainage of a rectus sheath hematoma on its own is not normally indicated and may indeed cause persistent bleeding by diminishing a potential tamponade effect. However, it may become necessary if the hematoma is very large or infected, if it causes marked respiratory impairment, or if abdominal compartment syndrome is suspected.

Abdominal compartment syndrome is very rare but is associated with a 50% mortality rate.³⁰ It should be suspected in patients with oliguria, low cardiac output, changes in minute ventilation, and altered splanchnic blood flow. The diagnosis is confirmed with indwelling catheter manometry of the bladder to measure intra-abdominal pressure. Intra-abominal pressure above 25 mm Hg should be treated with decompressive laparotomy.³⁰ However, the clinical suspicion of abdominal compartment syndrome was low in this patient.

The best choice at this point would be urgent computed tomographic angiography to identify a bleeding vessel, along with consideration of radiographically guided arterial embolization.

TREATMENT IS USUALLY CONSERVATIVE

Treatment of rectus sheath hematoma is conservative in most hemodynamically stable patients, with embolization or surgical intervention reserved for unstable patients or those in whom the hematoma is expanding.

Knowledge of the grading system of Berná et al²⁶ helps to assess the patient’s risk and to anticipate potential complications. Grade I hematomas are mild and do not necessitate admission. Patients with grade II hematoma can be admitted to the floor for 24 to 48 hours for observation. Grade III usually occurs in patients receiving anticoagulant therapy and frequently requires blood products. These patients have a prolonged hospital stay and more complications, including hypovolemic shock, myonecrosis, acute coronary syndrome, arrhythmias, acute renal failure, small-bowel infarction, and abdominal compartment syndrome—all of which increases the risk of morbidity and death. Thus, patients who are on anticoagulation who develop grade III rectus sheath hematoma should be admitted to the hospital, preferably to the intensive care unit, to ensure that the hematoma is not expanding and to plan reinstitution of anticoagulation as appropriate.

In most cases, rectus sheath hematomas resolve within 1 to 3 months. Resolution of large hematomas may be hastened with the use of pulsed ultrasound.³¹ However, this treatment should be used only after the acute phase is over, when there is evidence of an organized thrombus and coagulation measures have returned to the target range. This helps to reduce the risk of bleeding and to prevent symptoms from worsening.³¹

OUR PATIENT’S COURSE

Our patient underwent urgent computed tomographic angiography, which showed a modest increase in the size of the rectus sheath hematoma. However, no definitive blush of contrast was seen to suggest active arterial bleeding. Her hematocrit stabilized, and she remained hemodynamically stable without requiring additional intervention. Most likely her bleeding was self-contained. She had normal intra-abdominal pressure on serial monitoring. She was later transferred to acute inpatient rehabilitation in view of deconditioning and is currently doing well. The hematoma persisted, decreasing only slightly in size over the next 3 weeks.

Alcoholic hepatitis, a severe manifestation of alcoholic liver disease, is rising in incidence. Complete abstinence from alcohol remains the cornerstone of treatment, while other specific interventions aim to decrease short-term mortality rates.

Despite current treatments, about 25% of patients with severe alcoholic hepatitis eventually die of it. For those who survive hospitalization, measures need to be taken to prevent recidivism. Although liver transplantation seems to hold promise, early transplantation is still largely experimental in alcoholic hepatitis and will likely be available to only a small subset of patients, especially in view of ethical issues and the possible wider implications for transplant centers.

New treatments will largely depend on a better understanding of the disease’s pathophysiology, and future clinical trials should evaluate therapies that improve short-term as well as long-term outcomes.

ACUTE HEPATIC DECOMPENSATION IN A HEAVY DRINKER

Excessive alcohol consumption is very common worldwide, is a major risk factor for liver disease, and is a leading cause of preventable death. Alcoholic cirrhosis is the eighth most common cause of death in the United States and in 2010 was responsible for nearly half of cirrhosis-related deaths worldwide.¹

Alcoholic liver disease is a spectrum. Nearly all heavy drinkers (ie, those consuming 40 g or more of alcohol per day, Table 1) have fatty liver changes, 20% to 40% develop fibrosis, 10% to 20% progress to cirrhosis, and of those with cirrhosis, 1% to 2% are diagnosed with hepatocellular carcinoma every year.²

Within this spectrum, alcoholic hepatitis is a well-defined clinical syndrome characterized by acute hepatic decompensation that typically results from long-standing alcohol abuse. Binge drinkers may also be at risk for alcoholic hepatitis, but good data on the association between drinking patterns and the risk of alcoholic hepatitis are limited.

Alcoholic hepatitis varies in severity from mild to life-threatening.³ Although its exact incidence is unknown, its prevalence in alcoholics has been estimated at 20%.⁴ Nearly half of patients with alcoholic hepatitis have cirrhosis at the time of their acute presentation, and these patients generally have a poor prognosis, with a 28-day death rate as high as 50% in severe cases.^5,6 Moreover, although alcoholic hepatitis develops in only a subset of patients with alcoholic liver disease, hospitalizations for it are increasing in the United States.⁷

Women are at higher risk of developing alcoholic hepatitis, an observation attributed to the effect of estrogens on oxidative stress and inflammation, lower gastric alcohol dehydrogenase levels resulting in slower first-pass metabolism of alcohol, and higher body fat content causing a lower volume of distribution for alcohol than in men.⁸ The incidence of alcoholic hepatitis is also influenced by a number of demographic and genetic factors as well as nutritional status and coexistence of other liver diseases.⁹ Most patients diagnosed with alcoholic hepatitis are active drinkers, but it can develop even after significantly reducing or stopping alcohol consumption.

FATTY ACIDS, ENZYMES, CYTOKINES, INFLAMMATION

Alcohol consumption induces fatty acid synthesis and inhibits fatty acid oxidation, thereby promoting fat deposition in the liver.

The major enzymes involved in alcohol metabolism are cytochrome P450 2E1 (CYP2E1) and alcohol dehydrogenase. CYP2E1 is inducible and is up-regulated when excess alcohol is ingested, while alcohol dehydrogen-
ase function is relatively stable. Oxidative degradation of alcohol by these enzymes generates reactive oxygen species and acetaldehyde, inducing liver injury.¹⁰ Interestingly, it has been proposed that variations in the genes for these enzymes influence alcohol consumption and dependency as well as alcohol-driven tissue damage.

In addition, alcohol disrupts the intestinal mucosal barrier, allowing lipopolysaccharides from gram-negative bacteria to travel to the liver via the portal vein. These lipopolysaccharides then bind to and activate sinusoidal Kupffer cells, leading to production of several cytokines such as tumor necrosis factor alpha, interleukin 1, and transforming growth factor beta. These cytokines promote hepatocyte inflammation, apoptosis, and necrosis (Figure 1).¹¹

Besides activating the innate immune system, the reactive oxygen species resulting from alcohol metabolism interact with cellular components, leading to production of protein adducts. These act as antigens that activate the adaptive immune response, followed by B- and T-lymphocyte infiltration, which in turn contribute to liver injury and inflammation.¹²

THE DIAGNOSIS IS MAINLY CLINICAL

The diagnosis of alcoholic hepatitis is mainly clinical. In its usual presentation, jaundice develops rapidly in a person with a known history of heavy alcohol use. Other symptoms and signs may include ascites, encephalopathy, and fever. On examination, the liver may be enlarged and tender, and a hepatic bruit has been reported.¹³

Other classic signs of liver disease such as parotid enlargement, Dupuytren contracture, dilated abdominal wall veins, and spider nevi can be present, but none is highly specific or sensitive for alcoholic hepatitis.

Elevated liver enzymes and other clues

Laboratory tests are important in evaluating potential alcoholic hepatitis, although no single laboratory marker can definitively establish alcohol as the cause of liver disease. To detect alcohol consumption, biochemical markers such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), mean corpuscular volume, carbohydrate-deficient transferrin, and, more commonly, gamma-glutamyl transpeptidase are used.

In the acute setting, typical biochemical derangements in alcoholic hepatitis include elevated AST (up to 2 to 6 times the upper limit of normal; usually less than 300 IU/L) and elevated ALT to a lesser extent,¹⁴ with an AST-to-ALT ratio greater than 2. Neutrophilia, anemia, hyperbilirubinemia, and coagulopathy with an elevated international normalized ratio are common.

Patients with alcoholic hepatitis are also prone to develop bacterial infections, and about 7% develop hepatorenal syndrome, itself an ominous sign.¹⁵

Imaging studies are valuable in excluding other causes of abnormal liver test results in patients who abuse alcohol, such as biliary obstruction, infiltrative liver diseases, and hepatocellular carcinoma.

Screen for alcohol intake

During the initial evaluation of suspected alcoholic hepatitis, one should screen for excessive drinking. In a US Centers for Disease Control and Prevention study, only one of six US adults, including binge drinkers, said they had ever discussed alcohol consumption with a health professional.¹⁶ Many patients with alcoholic liver disease in general and alcoholic hepatitis in particular deny alcohol abuse or underreport their intake.¹⁷

Screening tests such as the CAGE questionnaire and the Alcohol Use Disorders Identification Test can be used to assess alcohol dependence or abuse.^18,19 The CAGE questionnaire consists of four questions:

• Have you ever felt you should cut down on your drinking?
• Have people annoyed you by criticizing your drinking?
• Have you ever felt guilty about your drinking?
• Have you ever had a drink first thing in the morning (an eye-opener) to steady your nerves or to get rid of a hangover?

A yes answer to two or more questions is considered clinically significant.

Is liver biopsy always needed?

Although alcoholic hepatitis can be suspected on the basis of clinical and biochemical clues, liver biopsy remains the gold standard diagnostic tool. It confirms the clinical diagnosis of alcoholic hepatitis in about 85% of all patients and in up to 95% when significant hyperbilirubinemia is present.²⁰

However, whether a particular patient needs a biopsy is not always clear. The American Association for the Study of Liver Diseases (AASLD) recommends biopsy in patients who have a clinical diagnosis of severe alcoholic hepatitis for whom medical treatment is being considered and in those with an uncertain underlying diagnosis.

Findings on liver biopsy in alcoholic hepatitis include steatosis, hepatocyte ballooning, neutrophilic infiltration, Mallory bodies (which represent aggregated cytokeratin intermediate filaments and other proteins), and scarring with a typical perivenular distribution as opposed to the periportal fibrosis seen in chronic viral hepatitis. Some histologic findings, such as centrilobular necrosis, may overlap alcoholic hepatitis and nonalcoholic steatohepatitis.

In addition to confirming the diagnosis and staging the disease, liver biopsy has prognostic value. The severity of inflammation and cholestatic changes correlates with poor prognosis and may also predict response to corticosteroid treatment in severe cases of alcoholic hepatitis.²¹

However, the utility of liver biopsy in confirming the diagnosis and assessing the prognosis of alcoholic hepatitis is controversial for several reasons. Coagulopathy, thrombocytopenia, and ascites are all common in patients with alcoholic hepatitis, often making percutaneous liver biopsy contraindicated. Trans-
jugular liver biopsy is not universally available outside tertiary care centers.

The major enzymes involved in alcohol metabolism are CYP2E1 and ADH

Needed is a minimally invasive test for assessing this disease. Breath analysis might be such a test, offering a noninvasive means to study the composition of volatile organic compounds and elemental gases and an attractive method to evaluate health and disease in a patient-friendly manner. Our group devised a model based on breath levels of trimethylamine and pentane. When we tested it, we found that it distinguishes patients with alcoholic hepatitis from those with acute liver decompensation from causes other than alcohol and controls without liver disease with up to 90% sensitivity and 80% specificity.²²

ASSESSING THE SEVERITY OF ALCOHOLIC HEPATITIS

Several models have been developed to assess the severity of alcoholic hepatitis and guide treatment decisions (Table 2). 

The MDF (Maddrey Discriminant Function)⁶ system was the first scoring system developed and is still the most widely used. A score of 32 or higher indicates severe alcoholic hepatitis and has been used as the threshold for starting treatment with corticosteroids.⁶

The MDF has limitations. Patients with a score lower than 32 are considered not to have severe alcoholic hepatitis, but up to 17% of them still die. Also, since it uses the prothrombin time, its results can vary considerably among laboratories, depending on the sensitivity of the thromboplastin reagent used.

The MELD (Model for End-stage Liver Disease) score. Sheth et al²³ compared the MELD and the MDF scores in assessing the severity of alcoholic hepatitis. They found that the MELD performed as well as the MDF in predicting 30-day mortality. A MELD score of greater than 11 had a sensitivity in predicting 30-day mortality of 86% and a specificity of 81%, compared with 86% and 48%, respectively, for MDF scores greater than 32.

Another study found a MELD score of 21 to have the highest sensitivity and specificity in predicting mortality (an estimated 90-day death rate of 20%). Thus, a MELD score of 21 is an appropriate threshold for prompt consideration of specific therapies such as corticosteroids.²⁴

The MELD score has become increasingly important in patients with alcoholic hepatitis, as some of them may become candidates for liver transplantation (see below). Also, serial MELD scores in hospitalized patients have prognostic implications, since an increase of 2 or more points in the first week has been shown to predict in-hospital mortality.²⁵

The GAHS (Glasgow Alcoholic Hepatitis Score)²⁶ was shown to identify patients with alcoholic hepatitis who have an especially poor prognosis and need corticosteroid therapy. In those with a GAHS of 9 or higher, the 28-day survival rate was 78% with corticosteroid treatment and 52% without corticosteroid treatment; survival rates at 84 days were 59% and 38%, respectively.²⁶

The ABIC scoring system (Age, Serum Bilirubin, INR, and Serum Creatinine) stratifies patients by risk of death at 90 days²⁷:

• Score less than 6.71: low risk (100% survival)
• A score 6.71–8.99: intermediate risk (70% survival)
• A score 9.0 or higher: high risk (25% survival). 

Both the GAHS and ABIC score are limited by lack of external validation.

The Lille score.²⁸ While the above scores are used to identify patients at risk of death from alcoholic hepatitis and to decide on starting corticosteroids, the Lille score is designed to assess response to corticosteroids after 1 week of treatment. It is calculated based on five pretreatment variables and the change in serum bilirubin level at day 7 of corticosteroid therapy. Lille scores range from 0 to 1; a score higher than 0.45 is associated with a 75% mortality rate at 6 months and indicates a lack of response to corticosteroids and that these drugs should be discontinued.²⁸

MANAGEMENT

Supportive treatment

Abstinence from alcohol is the cornerstone of treatment of alcoholic hepatitis. Early management of alcohol abuse or dependence is, therefore, warranted in all patients with alcoholic hepatitis. Referral to addiction specialists, motivational therapies, and anticraving drugs such as baclofen can be utilized.

Treat alcohol withdrawal. Alcoholics who suddenly decrease or discontinue their alcohol use are at high risk of alcohol withdrawal syndrome. Within 24 hours after the last drink, patients can experience increases in their heart rate and blood pressure, along with irritability and hyperreflexia. Within the next few days, more dangerous complications including seizures and delirium tremens can arise.

Alcohol withdrawal symptoms should be treated with short-acting benzodiazepines or clomethiazole, keeping the risk of worsening encephalopathy in mind.²⁹ If present, complications of cirrhosis such as encephalopathy, ascites, and variceal bleeding should be managed.

Usual presentation: Rapid onset of jaundice in a person with a history of heavy alcohol use

Nutritional support is important. Protein-calorie malnutrition is common in alcoholics, as are deficiencies of vitamin A, vitamin D, thiamine, folate, pyridoxine, and zinc.³⁰ Although a randomized controlled trial comparing enteral nutrition (2,000 kcal/day) vs corticosteroids (prednisolone 40 mg/day) in patients with alcoholic hepatitis did not show any difference in the 28-day mortality rate, those who received nutritional support and survived the first month had a lower mortality rate than those treated with corticosteroids (8% vs 37%).³¹ A daily protein intake of 1.5 g per kilogram of body weight is therefore recommended, even in patients with hepatic encephalopathy.¹⁵

Combining enteral nutrition and corticosteroid treatment may have a synergistic effect but is yet to be investigated.

Screen for infection. Patients with alcoholic hepatitis should be screened for infection, as about 25% of those with severe alcoholic hepatitis have an infection at admission.³² Since many of these patients meet the criteria for systemic inflammatory response syndrome, infections can be particularly difficult to diagnose. Patients require close clinical monitoring as well as regular pancultures for early detection. Antibiotics are frequently started empirically even though we lack specific evidence-based guidelines on this practice.³³

Corticosteroids

Various studies have evaluated the role of corticosteroids in treating alcoholic hepatitis, differing considerably in sample populations, methods, and end points. Although the results of individual trials differ, meta-analyses indicate that corticosteroids have a moderate beneficial effect in patients with severe alcoholic hepatitis.

For example, Rambaldi et al³⁴ performed a meta-analysis that concluded the mortality rate was lower in alcoholic hepatitis patients with MDF scores of at least 32 or hepatic encephalopathy who were treated with corticosteroids than in controls (relative risk 0.37, 95% confidence interval 0.16–0.86).

Therefore, in the absence of contraindications, the AASLD recommends starting corticosteroids in patients with severe alcoholic hepatitis, defined as an MDF score of 32 or higher.²¹ The preferred agent is oral prednisolone 40 mg daily or parenteral methylprednisolone 32 mg daily for 4 weeks and then tapered over the next 2 to 4 weeks or abruptly discontinued. Because activation of prednisone is decreased in patients with liver disease, prednisolone (the active form) is preferred over prednisone (the inactive precursor).³⁵ In alcoholic hepatitis, the number needed to treat with corticosteroids to prevent one death has been calculated³⁶ at 5.

As mentioned, response to corticosteroids is commonly assessed at 1 week of treatment using the Lille score. A score higher than 0.45 predicts a poor response and should trigger discontinuation of corticosteroids, particularly in those classified as null responders (Lille score > 0.56).

Typical biochemical derangements include elevated AST and, to a lesser extent, ALT

Adverse effects of steroids include sepsis, gastrointestinal bleeding, and steroid psychosis. Of note, patients who have evidence of hepatorenal syndrome or gastrointestinal bleeding tend to have a less favorable response to corticosteroids. Also, while infections were once considered a contraindication to steroid therapy, recent evidence suggests that steroid use might not be precluded in infected patients after appropriate antibiotic therapy. Infections occur in about a quarter of all alcoholic hepatitis patients treated with steroids, more frequently in null responders (42.5%) than in responders (11.1%), which supports corticosteroid discontinuance at 1 week in null responders.³²

Pentoxifylline

An oral phosphodiesterase inhibitor, pentoxifylline, also inhibits production of several cytokines, including tumor necrosis factor alpha. At a dose of 400 mg orally three times daily for 4 weeks, pentoxifylline has been used in treating severe alcoholic hepatitis (MDF score ≥ 32) and is recommended especially if corticosteroids are contraindicated, as with sepsis.²¹

An early double-blind clinical trial randomized patients with severe alcoholic hepatitis to receive either pentoxifylline 400 mg orally three times daily or placebo. Of the patients who received pentoxifylline, 24.5% died during the index hospitalization, compared with 46.1% of patients who received placebo. This survival benefit was mainly related to a markedly lower incidence of hepatorenal syndrome as the cause of death in the pentoxifylline group than in the placebo group (50% vs 91.7% of deaths).³⁷

In a small clinical trial in patients with severe alcoholic hepatitis, pentoxifylline recipients had a higher 3-month survival rate than prednisolone recipients (35.29% vs 14.71%, P = .04).³⁸ However, a larger trial showed no improvement in 6-month survival with the combination of prednisolone and pentoxifylline compared with prednisolone alone (69.9% vs 69.2%, P = .91).³⁹ Also, a meta-analysis of five randomized clinical trials found no survival benefit with pentoxifylline therapy.⁴⁰

Of note, in the unfortunate subgroup of patients who have a poor response to corticosteroids, no alternative treatment, including pentoxifylline, has been shown to be effective.⁴¹

Prednisone or pentoxifylline? Very recently, results of the Steroids or Pentoxifylline for Alcoholic Hepatitis (STOPAH) trial have been released.⁴² This is a large, multicenter, double-blinded clinical trial that aimed to provide a definitive answer to whether corticosteroids or pentoxifylline (or both) are beneficial in patients with alcoholic hepatitis. The study included 1,103 adult patients with severe alcoholic hepatitis (MDF score ≥ 32) who were randomized to monotherapy with prednisolone or pentoxifylline, combination therapy, or placebo. The primary end point was mortality at 28 days, and secondary end points included mortality at 90 days and at 1 year. Prednisolone reduced 28-day mortality by about 39%. In contrast, the 28-day mortality rate was similar in patients who received pentoxifylline and those who did not. Also, neither drug was significantly associated with a survival benefit beyond 28 days. The investigators concluded that pentoxifylline has no impact on disease progression and should not be used for the treatment of severe alcoholic hepatitis.⁴²

Other tumor necrosis factor alpha inhibitors not recommended

Two other tumor necrosis factor alpha inhibitors, infliximab and etanercept, have been tested in clinical trials in alcoholic hepatitis. Unfortunately, the results were not encouraging, with no major reduction in mortality.^43–45 In fact, these trials demonstrated a significantly increased risk of infections in the treatment groups. Therefore, these drugs are not recommended for treating alcoholic hepatitis.

A possible explanation is that tumor necrosis factor alpha plays an important role in liver regeneration, aiding in recovery from alcohol-induced liver injury, and inhibiting it can have deleterious consequences.

Other agents

A number of other agents have undergone clinical trials in alcoholic hepatitis.

N-acetylcysteine, an antioxidant that replenishes glutathione stores in hepatocytes, was evaluated in a randomized clinical trial in combination with prednisolone.⁴⁶ Although the 1-month mortality rate was significantly lower in the combination group than in the prednisolone-only group (8% vs 24%, P = .006), 3-month and 6-month mortality rates were not. Nonetheless, the rates of infection and hepatorenal syndrome were lower in the combination group. Therefore, corticosteroids and N-acetylcysteine may have synergistic effects, but the optimum duration of N-acetylcysteine therapy needs to be determined in further studies.

Vitamin E, silymarin, propylthiouracil, colchicine, and oxandrolone (an anabolic steroid) have also been studied, but with no convincing benefit.²¹

Role of liver transplantation

Liver transplantation for alcoholic liver disease has been a topic of great medical and social controversy. The view that alcoholic patients are responsible for their own illness led to caution when contemplating liver transplantation. Many countries require 6 months of abstinence from alcohol before placing a patient on the liver transplant list, posing a major obstacle to patients with alcoholic hepatitis, as almost all are active drinkers at the time of presentation and many will die within 6 months. Reasons for this 6-month rule include donor shortage and risk of recidivism.⁴⁷

Abstinence from alcohol is the cornerstone of treatment of alcoholic hepatitis

With regard to survival following alcoholic hepatitis, a study utilizing the United Network for Organ Sharing database matched patients with alcoholic hepatitis and alcoholic cirrhosis who underwent liver transplantation. Rates of 5-year graft survival were 75% in those with alcoholic hepatitis and 73% in those with alcoholic cirrhosis (P = .97), and rates of patient survival were 80% and 78% (P = .90), respectively. Proportional regression analysis adjusting for other variables showed no impact of the etiology of liver disease on graft or patient survival. The investigators concluded that liver transplantation could be considered in a select group of patients with alcoholic hepatitis who do not improve with medical therapy.⁴⁸

In a pivotal case-control prospective study,⁴⁹ 26 patients with Lille scores greater than 0.45 were listed for liver transplantation within a median of 13 days after nonresponse to medical therapy. The cumulative 6-month survival rate was higher in patients who received a liver transplant early than in those who did not (77% vs 23%, P < .001). This benefit was maintained through 2 years of follow-up (hazard ratio 6.08, P = .004). Of note, all these patients had supportive family members, no severe coexisting conditions, and a commitment to alcohol abstinence (although 3 patients resumed drinking after liver transplantation).⁴⁹

Although these studies support early liver transplantation in carefully selected patients with severe alcoholic hepatitis, the criteria for transplantation in this group need to be refined. Views on alcoholism also need to be reconciled, as strong evidence is emerging that implicates genetic and environmental influences on alcohol dependence.

Management algorithm

Adapted from the guidelines of the AASLD and European Association for the Study of the Liver.

Figure 2 shows a suggested management algorithm for alcoholic hepatitis, adapted from the guidelines of the AASLD and European Association for the Study of the Liver.

NEW THERAPIES NEEDED

Novel therapies for severe alcoholic hepatitis are urgently needed to help combat this devastating condition. Advances in understanding its pathophysiology have uncovered several new therapeutic targets, and new agents are already being evaluated in clinical trials.

IMM 124-E, a hyperimmune bovine colostrum enriched with immunoglobulin G anti-lipopolysaccharide, is going to be evaluated in combination with prednisolone in patients with severe alcoholic hepatitis.

Anakinra, an interleukin 1 receptor antagonist, has significant anti-inflammatory activity and is used to treat rheumatoid arthritis. A clinical trial to evaluate its role in alcoholic hepatitis has been designed in which patients with severe alcoholic hepatitis (defined as a MELD score ≥ 21) will be randomized to receive either methylprednisolone or a combination of anakinra, pentoxifylline, and zinc (a mineral that improves gut integrity).

Emricasan, an orally active caspase protease inhibitor, is another agent currently being tested in a phase 2 clinical trial in patients with severe alcoholic hepatitis. Since caspases induce apoptosis, inhibiting them should theoretically dampen alcohol-induced hepatocyte injury.

Interleukin 22, a hepatoprotective cytokine, shows promise as a treatment and will soon be evaluated in alcoholic hepatitis.

Alcoholic hepatitis, a severe manifestation of alcoholic liver disease, is rising in incidence. Complete abstinence from alcohol remains the cornerstone of treatment, while other specific interventions aim to decrease short-term mortality rates.

Despite current treatments, about 25% of patients with severe alcoholic hepatitis eventually die of it. For those who survive hospitalization, measures need to be taken to prevent recidivism. Although liver transplantation seems to hold promise, early transplantation is still largely experimental in alcoholic hepatitis and will likely be available to only a small subset of patients, especially in view of ethical issues and the possible wider implications for transplant centers.

New treatments will largely depend on a better understanding of the disease’s pathophysiology, and future clinical trials should evaluate therapies that improve short-term as well as long-term outcomes.

ACUTE HEPATIC DECOMPENSATION IN A HEAVY DRINKER

Excessive alcohol consumption is very common worldwide, is a major risk factor for liver disease, and is a leading cause of preventable death. Alcoholic cirrhosis is the eighth most common cause of death in the United States and in 2010 was responsible for nearly half of cirrhosis-related deaths worldwide.¹

Alcoholic liver disease is a spectrum. Nearly all heavy drinkers (ie, those consuming 40 g or more of alcohol per day, Table 1) have fatty liver changes, 20% to 40% develop fibrosis, 10% to 20% progress to cirrhosis, and of those with cirrhosis, 1% to 2% are diagnosed with hepatocellular carcinoma every year.²

Within this spectrum, alcoholic hepatitis is a well-defined clinical syndrome characterized by acute hepatic decompensation that typically results from long-standing alcohol abuse. Binge drinkers may also be at risk for alcoholic hepatitis, but good data on the association between drinking patterns and the risk of alcoholic hepatitis are limited.

Alcoholic hepatitis varies in severity from mild to life-threatening.³ Although its exact incidence is unknown, its prevalence in alcoholics has been estimated at 20%.⁴ Nearly half of patients with alcoholic hepatitis have cirrhosis at the time of their acute presentation, and these patients generally have a poor prognosis, with a 28-day death rate as high as 50% in severe cases.^5,6 Moreover, although alcoholic hepatitis develops in only a subset of patients with alcoholic liver disease, hospitalizations for it are increasing in the United States.⁷

Women are at higher risk of developing alcoholic hepatitis, an observation attributed to the effect of estrogens on oxidative stress and inflammation, lower gastric alcohol dehydrogenase levels resulting in slower first-pass metabolism of alcohol, and higher body fat content causing a lower volume of distribution for alcohol than in men.⁸ The incidence of alcoholic hepatitis is also influenced by a number of demographic and genetic factors as well as nutritional status and coexistence of other liver diseases.⁹ Most patients diagnosed with alcoholic hepatitis are active drinkers, but it can develop even after significantly reducing or stopping alcohol consumption.

FATTY ACIDS, ENZYMES, CYTOKINES, INFLAMMATION

Alcohol consumption induces fatty acid synthesis and inhibits fatty acid oxidation, thereby promoting fat deposition in the liver.

The major enzymes involved in alcohol metabolism are cytochrome P450 2E1 (CYP2E1) and alcohol dehydrogenase. CYP2E1 is inducible and is up-regulated when excess alcohol is ingested, while alcohol dehydrogen-
ase function is relatively stable. Oxidative degradation of alcohol by these enzymes generates reactive oxygen species and acetaldehyde, inducing liver injury.¹⁰ Interestingly, it has been proposed that variations in the genes for these enzymes influence alcohol consumption and dependency as well as alcohol-driven tissue damage.

In addition, alcohol disrupts the intestinal mucosal barrier, allowing lipopolysaccharides from gram-negative bacteria to travel to the liver via the portal vein. These lipopolysaccharides then bind to and activate sinusoidal Kupffer cells, leading to production of several cytokines such as tumor necrosis factor alpha, interleukin 1, and transforming growth factor beta. These cytokines promote hepatocyte inflammation, apoptosis, and necrosis (Figure 1).¹¹

Besides activating the innate immune system, the reactive oxygen species resulting from alcohol metabolism interact with cellular components, leading to production of protein adducts. These act as antigens that activate the adaptive immune response, followed by B- and T-lymphocyte infiltration, which in turn contribute to liver injury and inflammation.¹²

THE DIAGNOSIS IS MAINLY CLINICAL

The diagnosis of alcoholic hepatitis is mainly clinical. In its usual presentation, jaundice develops rapidly in a person with a known history of heavy alcohol use. Other symptoms and signs may include ascites, encephalopathy, and fever. On examination, the liver may be enlarged and tender, and a hepatic bruit has been reported.¹³

Other classic signs of liver disease such as parotid enlargement, Dupuytren contracture, dilated abdominal wall veins, and spider nevi can be present, but none is highly specific or sensitive for alcoholic hepatitis.

Elevated liver enzymes and other clues

Laboratory tests are important in evaluating potential alcoholic hepatitis, although no single laboratory marker can definitively establish alcohol as the cause of liver disease. To detect alcohol consumption, biochemical markers such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), mean corpuscular volume, carbohydrate-deficient transferrin, and, more commonly, gamma-glutamyl transpeptidase are used.

In the acute setting, typical biochemical derangements in alcoholic hepatitis include elevated AST (up to 2 to 6 times the upper limit of normal; usually less than 300 IU/L) and elevated ALT to a lesser extent,¹⁴ with an AST-to-ALT ratio greater than 2. Neutrophilia, anemia, hyperbilirubinemia, and coagulopathy with an elevated international normalized ratio are common.

Patients with alcoholic hepatitis are also prone to develop bacterial infections, and about 7% develop hepatorenal syndrome, itself an ominous sign.¹⁵

Imaging studies are valuable in excluding other causes of abnormal liver test results in patients who abuse alcohol, such as biliary obstruction, infiltrative liver diseases, and hepatocellular carcinoma.

Screen for alcohol intake

During the initial evaluation of suspected alcoholic hepatitis, one should screen for excessive drinking. In a US Centers for Disease Control and Prevention study, only one of six US adults, including binge drinkers, said they had ever discussed alcohol consumption with a health professional.¹⁶ Many patients with alcoholic liver disease in general and alcoholic hepatitis in particular deny alcohol abuse or underreport their intake.¹⁷

Screening tests such as the CAGE questionnaire and the Alcohol Use Disorders Identification Test can be used to assess alcohol dependence or abuse.^18,19 The CAGE questionnaire consists of four questions:

• Have you ever felt you should cut down on your drinking?
• Have people annoyed you by criticizing your drinking?
• Have you ever felt guilty about your drinking?
• Have you ever had a drink first thing in the morning (an eye-opener) to steady your nerves or to get rid of a hangover?

A yes answer to two or more questions is considered clinically significant.

Is liver biopsy always needed?

Although alcoholic hepatitis can be suspected on the basis of clinical and biochemical clues, liver biopsy remains the gold standard diagnostic tool. It confirms the clinical diagnosis of alcoholic hepatitis in about 85% of all patients and in up to 95% when significant hyperbilirubinemia is present.²⁰

However, whether a particular patient needs a biopsy is not always clear. The American Association for the Study of Liver Diseases (AASLD) recommends biopsy in patients who have a clinical diagnosis of severe alcoholic hepatitis for whom medical treatment is being considered and in those with an uncertain underlying diagnosis.

Findings on liver biopsy in alcoholic hepatitis include steatosis, hepatocyte ballooning, neutrophilic infiltration, Mallory bodies (which represent aggregated cytokeratin intermediate filaments and other proteins), and scarring with a typical perivenular distribution as opposed to the periportal fibrosis seen in chronic viral hepatitis. Some histologic findings, such as centrilobular necrosis, may overlap alcoholic hepatitis and nonalcoholic steatohepatitis.

In addition to confirming the diagnosis and staging the disease, liver biopsy has prognostic value. The severity of inflammation and cholestatic changes correlates with poor prognosis and may also predict response to corticosteroid treatment in severe cases of alcoholic hepatitis.²¹

However, the utility of liver biopsy in confirming the diagnosis and assessing the prognosis of alcoholic hepatitis is controversial for several reasons. Coagulopathy, thrombocytopenia, and ascites are all common in patients with alcoholic hepatitis, often making percutaneous liver biopsy contraindicated. Trans-
jugular liver biopsy is not universally available outside tertiary care centers.

The major enzymes involved in alcohol metabolism are CYP2E1 and ADH

Needed is a minimally invasive test for assessing this disease. Breath analysis might be such a test, offering a noninvasive means to study the composition of volatile organic compounds and elemental gases and an attractive method to evaluate health and disease in a patient-friendly manner. Our group devised a model based on breath levels of trimethylamine and pentane. When we tested it, we found that it distinguishes patients with alcoholic hepatitis from those with acute liver decompensation from causes other than alcohol and controls without liver disease with up to 90% sensitivity and 80% specificity.²²

ASSESSING THE SEVERITY OF ALCOHOLIC HEPATITIS

Several models have been developed to assess the severity of alcoholic hepatitis and guide treatment decisions (Table 2). 

The MDF (Maddrey Discriminant Function)⁶ system was the first scoring system developed and is still the most widely used. A score of 32 or higher indicates severe alcoholic hepatitis and has been used as the threshold for starting treatment with corticosteroids.⁶

The MDF has limitations. Patients with a score lower than 32 are considered not to have severe alcoholic hepatitis, but up to 17% of them still die. Also, since it uses the prothrombin time, its results can vary considerably among laboratories, depending on the sensitivity of the thromboplastin reagent used.

The MELD (Model for End-stage Liver Disease) score. Sheth et al²³ compared the MELD and the MDF scores in assessing the severity of alcoholic hepatitis. They found that the MELD performed as well as the MDF in predicting 30-day mortality. A MELD score of greater than 11 had a sensitivity in predicting 30-day mortality of 86% and a specificity of 81%, compared with 86% and 48%, respectively, for MDF scores greater than 32.

Another study found a MELD score of 21 to have the highest sensitivity and specificity in predicting mortality (an estimated 90-day death rate of 20%). Thus, a MELD score of 21 is an appropriate threshold for prompt consideration of specific therapies such as corticosteroids.²⁴

The MELD score has become increasingly important in patients with alcoholic hepatitis, as some of them may become candidates for liver transplantation (see below). Also, serial MELD scores in hospitalized patients have prognostic implications, since an increase of 2 or more points in the first week has been shown to predict in-hospital mortality.²⁵

The GAHS (Glasgow Alcoholic Hepatitis Score)²⁶ was shown to identify patients with alcoholic hepatitis who have an especially poor prognosis and need corticosteroid therapy. In those with a GAHS of 9 or higher, the 28-day survival rate was 78% with corticosteroid treatment and 52% without corticosteroid treatment; survival rates at 84 days were 59% and 38%, respectively.²⁶

The ABIC scoring system (Age, Serum Bilirubin, INR, and Serum Creatinine) stratifies patients by risk of death at 90 days²⁷:

• Score less than 6.71: low risk (100% survival)
• A score 6.71–8.99: intermediate risk (70% survival)
• A score 9.0 or higher: high risk (25% survival). 

Both the GAHS and ABIC score are limited by lack of external validation.

The Lille score.²⁸ While the above scores are used to identify patients at risk of death from alcoholic hepatitis and to decide on starting corticosteroids, the Lille score is designed to assess response to corticosteroids after 1 week of treatment. It is calculated based on five pretreatment variables and the change in serum bilirubin level at day 7 of corticosteroid therapy. Lille scores range from 0 to 1; a score higher than 0.45 is associated with a 75% mortality rate at 6 months and indicates a lack of response to corticosteroids and that these drugs should be discontinued.²⁸

MANAGEMENT

Supportive treatment

Abstinence from alcohol is the cornerstone of treatment of alcoholic hepatitis. Early management of alcohol abuse or dependence is, therefore, warranted in all patients with alcoholic hepatitis. Referral to addiction specialists, motivational therapies, and anticraving drugs such as baclofen can be utilized.

Treat alcohol withdrawal. Alcoholics who suddenly decrease or discontinue their alcohol use are at high risk of alcohol withdrawal syndrome. Within 24 hours after the last drink, patients can experience increases in their heart rate and blood pressure, along with irritability and hyperreflexia. Within the next few days, more dangerous complications including seizures and delirium tremens can arise.

Alcohol withdrawal symptoms should be treated with short-acting benzodiazepines or clomethiazole, keeping the risk of worsening encephalopathy in mind.²⁹ If present, complications of cirrhosis such as encephalopathy, ascites, and variceal bleeding should be managed.

Usual presentation: Rapid onset of jaundice in a person with a history of heavy alcohol use

Nutritional support is important. Protein-calorie malnutrition is common in alcoholics, as are deficiencies of vitamin A, vitamin D, thiamine, folate, pyridoxine, and zinc.³⁰ Although a randomized controlled trial comparing enteral nutrition (2,000 kcal/day) vs corticosteroids (prednisolone 40 mg/day) in patients with alcoholic hepatitis did not show any difference in the 28-day mortality rate, those who received nutritional support and survived the first month had a lower mortality rate than those treated with corticosteroids (8% vs 37%).³¹ A daily protein intake of 1.5 g per kilogram of body weight is therefore recommended, even in patients with hepatic encephalopathy.¹⁵

Combining enteral nutrition and corticosteroid treatment may have a synergistic effect but is yet to be investigated.

Screen for infection. Patients with alcoholic hepatitis should be screened for infection, as about 25% of those with severe alcoholic hepatitis have an infection at admission.³² Since many of these patients meet the criteria for systemic inflammatory response syndrome, infections can be particularly difficult to diagnose. Patients require close clinical monitoring as well as regular pancultures for early detection. Antibiotics are frequently started empirically even though we lack specific evidence-based guidelines on this practice.³³

Corticosteroids

Various studies have evaluated the role of corticosteroids in treating alcoholic hepatitis, differing considerably in sample populations, methods, and end points. Although the results of individual trials differ, meta-analyses indicate that corticosteroids have a moderate beneficial effect in patients with severe alcoholic hepatitis.

For example, Rambaldi et al³⁴ performed a meta-analysis that concluded the mortality rate was lower in alcoholic hepatitis patients with MDF scores of at least 32 or hepatic encephalopathy who were treated with corticosteroids than in controls (relative risk 0.37, 95% confidence interval 0.16–0.86).

Therefore, in the absence of contraindications, the AASLD recommends starting corticosteroids in patients with severe alcoholic hepatitis, defined as an MDF score of 32 or higher.²¹ The preferred agent is oral prednisolone 40 mg daily or parenteral methylprednisolone 32 mg daily for 4 weeks and then tapered over the next 2 to 4 weeks or abruptly discontinued. Because activation of prednisone is decreased in patients with liver disease, prednisolone (the active form) is preferred over prednisone (the inactive precursor).³⁵ In alcoholic hepatitis, the number needed to treat with corticosteroids to prevent one death has been calculated³⁶ at 5.

As mentioned, response to corticosteroids is commonly assessed at 1 week of treatment using the Lille score. A score higher than 0.45 predicts a poor response and should trigger discontinuation of corticosteroids, particularly in those classified as null responders (Lille score > 0.56).

Typical biochemical derangements include elevated AST and, to a lesser extent, ALT

Adverse effects of steroids include sepsis, gastrointestinal bleeding, and steroid psychosis. Of note, patients who have evidence of hepatorenal syndrome or gastrointestinal bleeding tend to have a less favorable response to corticosteroids. Also, while infections were once considered a contraindication to steroid therapy, recent evidence suggests that steroid use might not be precluded in infected patients after appropriate antibiotic therapy. Infections occur in about a quarter of all alcoholic hepatitis patients treated with steroids, more frequently in null responders (42.5%) than in responders (11.1%), which supports corticosteroid discontinuance at 1 week in null responders.³²

Pentoxifylline

An oral phosphodiesterase inhibitor, pentoxifylline, also inhibits production of several cytokines, including tumor necrosis factor alpha. At a dose of 400 mg orally three times daily for 4 weeks, pentoxifylline has been used in treating severe alcoholic hepatitis (MDF score ≥ 32) and is recommended especially if corticosteroids are contraindicated, as with sepsis.²¹

An early double-blind clinical trial randomized patients with severe alcoholic hepatitis to receive either pentoxifylline 400 mg orally three times daily or placebo. Of the patients who received pentoxifylline, 24.5% died during the index hospitalization, compared with 46.1% of patients who received placebo. This survival benefit was mainly related to a markedly lower incidence of hepatorenal syndrome as the cause of death in the pentoxifylline group than in the placebo group (50% vs 91.7% of deaths).³⁷

In a small clinical trial in patients with severe alcoholic hepatitis, pentoxifylline recipients had a higher 3-month survival rate than prednisolone recipients (35.29% vs 14.71%, P = .04).³⁸ However, a larger trial showed no improvement in 6-month survival with the combination of prednisolone and pentoxifylline compared with prednisolone alone (69.9% vs 69.2%, P = .91).³⁹ Also, a meta-analysis of five randomized clinical trials found no survival benefit with pentoxifylline therapy.⁴⁰

Of note, in the unfortunate subgroup of patients who have a poor response to corticosteroids, no alternative treatment, including pentoxifylline, has been shown to be effective.⁴¹

Prednisone or pentoxifylline? Very recently, results of the Steroids or Pentoxifylline for Alcoholic Hepatitis (STOPAH) trial have been released.⁴² This is a large, multicenter, double-blinded clinical trial that aimed to provide a definitive answer to whether corticosteroids or pentoxifylline (or both) are beneficial in patients with alcoholic hepatitis. The study included 1,103 adult patients with severe alcoholic hepatitis (MDF score ≥ 32) who were randomized to monotherapy with prednisolone or pentoxifylline, combination therapy, or placebo. The primary end point was mortality at 28 days, and secondary end points included mortality at 90 days and at 1 year. Prednisolone reduced 28-day mortality by about 39%. In contrast, the 28-day mortality rate was similar in patients who received pentoxifylline and those who did not. Also, neither drug was significantly associated with a survival benefit beyond 28 days. The investigators concluded that pentoxifylline has no impact on disease progression and should not be used for the treatment of severe alcoholic hepatitis.⁴²

Other tumor necrosis factor alpha inhibitors not recommended

Two other tumor necrosis factor alpha inhibitors, infliximab and etanercept, have been tested in clinical trials in alcoholic hepatitis. Unfortunately, the results were not encouraging, with no major reduction in mortality.^43–45 In fact, these trials demonstrated a significantly increased risk of infections in the treatment groups. Therefore, these drugs are not recommended for treating alcoholic hepatitis.

A possible explanation is that tumor necrosis factor alpha plays an important role in liver regeneration, aiding in recovery from alcohol-induced liver injury, and inhibiting it can have deleterious consequences.

Other agents

A number of other agents have undergone clinical trials in alcoholic hepatitis.

N-acetylcysteine, an antioxidant that replenishes glutathione stores in hepatocytes, was evaluated in a randomized clinical trial in combination with prednisolone.⁴⁶ Although the 1-month mortality rate was significantly lower in the combination group than in the prednisolone-only group (8% vs 24%, P = .006), 3-month and 6-month mortality rates were not. Nonetheless, the rates of infection and hepatorenal syndrome were lower in the combination group. Therefore, corticosteroids and N-acetylcysteine may have synergistic effects, but the optimum duration of N-acetylcysteine therapy needs to be determined in further studies.

Vitamin E, silymarin, propylthiouracil, colchicine, and oxandrolone (an anabolic steroid) have also been studied, but with no convincing benefit.²¹

Role of liver transplantation

Liver transplantation for alcoholic liver disease has been a topic of great medical and social controversy. The view that alcoholic patients are responsible for their own illness led to caution when contemplating liver transplantation. Many countries require 6 months of abstinence from alcohol before placing a patient on the liver transplant list, posing a major obstacle to patients with alcoholic hepatitis, as almost all are active drinkers at the time of presentation and many will die within 6 months. Reasons for this 6-month rule include donor shortage and risk of recidivism.⁴⁷

Abstinence from alcohol is the cornerstone of treatment of alcoholic hepatitis

With regard to survival following alcoholic hepatitis, a study utilizing the United Network for Organ Sharing database matched patients with alcoholic hepatitis and alcoholic cirrhosis who underwent liver transplantation. Rates of 5-year graft survival were 75% in those with alcoholic hepatitis and 73% in those with alcoholic cirrhosis (P = .97), and rates of patient survival were 80% and 78% (P = .90), respectively. Proportional regression analysis adjusting for other variables showed no impact of the etiology of liver disease on graft or patient survival. The investigators concluded that liver transplantation could be considered in a select group of patients with alcoholic hepatitis who do not improve with medical therapy.⁴⁸

In a pivotal case-control prospective study,⁴⁹ 26 patients with Lille scores greater than 0.45 were listed for liver transplantation within a median of 13 days after nonresponse to medical therapy. The cumulative 6-month survival rate was higher in patients who received a liver transplant early than in those who did not (77% vs 23%, P < .001). This benefit was maintained through 2 years of follow-up (hazard ratio 6.08, P = .004). Of note, all these patients had supportive family members, no severe coexisting conditions, and a commitment to alcohol abstinence (although 3 patients resumed drinking after liver transplantation).⁴⁹

Although these studies support early liver transplantation in carefully selected patients with severe alcoholic hepatitis, the criteria for transplantation in this group need to be refined. Views on alcoholism also need to be reconciled, as strong evidence is emerging that implicates genetic and environmental influences on alcohol dependence.

Management algorithm

Adapted from the guidelines of the AASLD and European Association for the Study of the Liver.

Figure 2 shows a suggested management algorithm for alcoholic hepatitis, adapted from the guidelines of the AASLD and European Association for the Study of the Liver.

NEW THERAPIES NEEDED

Novel therapies for severe alcoholic hepatitis are urgently needed to help combat this devastating condition. Advances in understanding its pathophysiology have uncovered several new therapeutic targets, and new agents are already being evaluated in clinical trials.

IMM 124-E, a hyperimmune bovine colostrum enriched with immunoglobulin G anti-lipopolysaccharide, is going to be evaluated in combination with prednisolone in patients with severe alcoholic hepatitis.

Anakinra, an interleukin 1 receptor antagonist, has significant anti-inflammatory activity and is used to treat rheumatoid arthritis. A clinical trial to evaluate its role in alcoholic hepatitis has been designed in which patients with severe alcoholic hepatitis (defined as a MELD score ≥ 21) will be randomized to receive either methylprednisolone or a combination of anakinra, pentoxifylline, and zinc (a mineral that improves gut integrity).

Emricasan, an orally active caspase protease inhibitor, is another agent currently being tested in a phase 2 clinical trial in patients with severe alcoholic hepatitis. Since caspases induce apoptosis, inhibiting them should theoretically dampen alcohol-induced hepatocyte injury.

Interleukin 22, a hepatoprotective cytokine, shows promise as a treatment and will soon be evaluated in alcoholic hepatitis.

Alcoholic hepatitis, a severe manifestation of alcoholic liver disease, is rising in incidence. Complete abstinence from alcohol remains the cornerstone of treatment, while other specific interventions aim to decrease short-term mortality rates.

Despite current treatments, about 25% of patients with severe alcoholic hepatitis eventually die of it. For those who survive hospitalization, measures need to be taken to prevent recidivism. Although liver transplantation seems to hold promise, early transplantation is still largely experimental in alcoholic hepatitis and will likely be available to only a small subset of patients, especially in view of ethical issues and the possible wider implications for transplant centers.

New treatments will largely depend on a better understanding of the disease’s pathophysiology, and future clinical trials should evaluate therapies that improve short-term as well as long-term outcomes.

ACUTE HEPATIC DECOMPENSATION IN A HEAVY DRINKER

Excessive alcohol consumption is very common worldwide, is a major risk factor for liver disease, and is a leading cause of preventable death. Alcoholic cirrhosis is the eighth most common cause of death in the United States and in 2010 was responsible for nearly half of cirrhosis-related deaths worldwide.¹

Alcoholic liver disease is a spectrum. Nearly all heavy drinkers (ie, those consuming 40 g or more of alcohol per day, Table 1) have fatty liver changes, 20% to 40% develop fibrosis, 10% to 20% progress to cirrhosis, and of those with cirrhosis, 1% to 2% are diagnosed with hepatocellular carcinoma every year.²

Within this spectrum, alcoholic hepatitis is a well-defined clinical syndrome characterized by acute hepatic decompensation that typically results from long-standing alcohol abuse. Binge drinkers may also be at risk for alcoholic hepatitis, but good data on the association between drinking patterns and the risk of alcoholic hepatitis are limited.

Alcoholic hepatitis varies in severity from mild to life-threatening.³ Although its exact incidence is unknown, its prevalence in alcoholics has been estimated at 20%.⁴ Nearly half of patients with alcoholic hepatitis have cirrhosis at the time of their acute presentation, and these patients generally have a poor prognosis, with a 28-day death rate as high as 50% in severe cases.^5,6 Moreover, although alcoholic hepatitis develops in only a subset of patients with alcoholic liver disease, hospitalizations for it are increasing in the United States.⁷

Women are at higher risk of developing alcoholic hepatitis, an observation attributed to the effect of estrogens on oxidative stress and inflammation, lower gastric alcohol dehydrogenase levels resulting in slower first-pass metabolism of alcohol, and higher body fat content causing a lower volume of distribution for alcohol than in men.⁸ The incidence of alcoholic hepatitis is also influenced by a number of demographic and genetic factors as well as nutritional status and coexistence of other liver diseases.⁹ Most patients diagnosed with alcoholic hepatitis are active drinkers, but it can develop even after significantly reducing or stopping alcohol consumption.

FATTY ACIDS, ENZYMES, CYTOKINES, INFLAMMATION

Alcohol consumption induces fatty acid synthesis and inhibits fatty acid oxidation, thereby promoting fat deposition in the liver.

The major enzymes involved in alcohol metabolism are cytochrome P450 2E1 (CYP2E1) and alcohol dehydrogenase. CYP2E1 is inducible and is up-regulated when excess alcohol is ingested, while alcohol dehydrogen-
ase function is relatively stable. Oxidative degradation of alcohol by these enzymes generates reactive oxygen species and acetaldehyde, inducing liver injury.¹⁰ Interestingly, it has been proposed that variations in the genes for these enzymes influence alcohol consumption and dependency as well as alcohol-driven tissue damage.

In addition, alcohol disrupts the intestinal mucosal barrier, allowing lipopolysaccharides from gram-negative bacteria to travel to the liver via the portal vein. These lipopolysaccharides then bind to and activate sinusoidal Kupffer cells, leading to production of several cytokines such as tumor necrosis factor alpha, interleukin 1, and transforming growth factor beta. These cytokines promote hepatocyte inflammation, apoptosis, and necrosis (Figure 1).¹¹

Besides activating the innate immune system, the reactive oxygen species resulting from alcohol metabolism interact with cellular components, leading to production of protein adducts. These act as antigens that activate the adaptive immune response, followed by B- and T-lymphocyte infiltration, which in turn contribute to liver injury and inflammation.¹²

THE DIAGNOSIS IS MAINLY CLINICAL

The diagnosis of alcoholic hepatitis is mainly clinical. In its usual presentation, jaundice develops rapidly in a person with a known history of heavy alcohol use. Other symptoms and signs may include ascites, encephalopathy, and fever. On examination, the liver may be enlarged and tender, and a hepatic bruit has been reported.¹³

Other classic signs of liver disease such as parotid enlargement, Dupuytren contracture, dilated abdominal wall veins, and spider nevi can be present, but none is highly specific or sensitive for alcoholic hepatitis.

Elevated liver enzymes and other clues

Laboratory tests are important in evaluating potential alcoholic hepatitis, although no single laboratory marker can definitively establish alcohol as the cause of liver disease. To detect alcohol consumption, biochemical markers such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), mean corpuscular volume, carbohydrate-deficient transferrin, and, more commonly, gamma-glutamyl transpeptidase are used.

In the acute setting, typical biochemical derangements in alcoholic hepatitis include elevated AST (up to 2 to 6 times the upper limit of normal; usually less than 300 IU/L) and elevated ALT to a lesser extent,¹⁴ with an AST-to-ALT ratio greater than 2. Neutrophilia, anemia, hyperbilirubinemia, and coagulopathy with an elevated international normalized ratio are common.

Patients with alcoholic hepatitis are also prone to develop bacterial infections, and about 7% develop hepatorenal syndrome, itself an ominous sign.¹⁵

Imaging studies are valuable in excluding other causes of abnormal liver test results in patients who abuse alcohol, such as biliary obstruction, infiltrative liver diseases, and hepatocellular carcinoma.

Screen for alcohol intake

During the initial evaluation of suspected alcoholic hepatitis, one should screen for excessive drinking. In a US Centers for Disease Control and Prevention study, only one of six US adults, including binge drinkers, said they had ever discussed alcohol consumption with a health professional.¹⁶ Many patients with alcoholic liver disease in general and alcoholic hepatitis in particular deny alcohol abuse or underreport their intake.¹⁷

Screening tests such as the CAGE questionnaire and the Alcohol Use Disorders Identification Test can be used to assess alcohol dependence or abuse.^18,19 The CAGE questionnaire consists of four questions:

• Have you ever felt you should cut down on your drinking?
• Have people annoyed you by criticizing your drinking?
• Have you ever felt guilty about your drinking?
• Have you ever had a drink first thing in the morning (an eye-opener) to steady your nerves or to get rid of a hangover?

A yes answer to two or more questions is considered clinically significant.

Is liver biopsy always needed?

Although alcoholic hepatitis can be suspected on the basis of clinical and biochemical clues, liver biopsy remains the gold standard diagnostic tool. It confirms the clinical diagnosis of alcoholic hepatitis in about 85% of all patients and in up to 95% when significant hyperbilirubinemia is present.²⁰

However, whether a particular patient needs a biopsy is not always clear. The American Association for the Study of Liver Diseases (AASLD) recommends biopsy in patients who have a clinical diagnosis of severe alcoholic hepatitis for whom medical treatment is being considered and in those with an uncertain underlying diagnosis.

Findings on liver biopsy in alcoholic hepatitis include steatosis, hepatocyte ballooning, neutrophilic infiltration, Mallory bodies (which represent aggregated cytokeratin intermediate filaments and other proteins), and scarring with a typical perivenular distribution as opposed to the periportal fibrosis seen in chronic viral hepatitis. Some histologic findings, such as centrilobular necrosis, may overlap alcoholic hepatitis and nonalcoholic steatohepatitis.

In addition to confirming the diagnosis and staging the disease, liver biopsy has prognostic value. The severity of inflammation and cholestatic changes correlates with poor prognosis and may also predict response to corticosteroid treatment in severe cases of alcoholic hepatitis.²¹

However, the utility of liver biopsy in confirming the diagnosis and assessing the prognosis of alcoholic hepatitis is controversial for several reasons. Coagulopathy, thrombocytopenia, and ascites are all common in patients with alcoholic hepatitis, often making percutaneous liver biopsy contraindicated. Trans-
jugular liver biopsy is not universally available outside tertiary care centers.

The major enzymes involved in alcohol metabolism are CYP2E1 and ADH

Needed is a minimally invasive test for assessing this disease. Breath analysis might be such a test, offering a noninvasive means to study the composition of volatile organic compounds and elemental gases and an attractive method to evaluate health and disease in a patient-friendly manner. Our group devised a model based on breath levels of trimethylamine and pentane. When we tested it, we found that it distinguishes patients with alcoholic hepatitis from those with acute liver decompensation from causes other than alcohol and controls without liver disease with up to 90% sensitivity and 80% specificity.²²

ASSESSING THE SEVERITY OF ALCOHOLIC HEPATITIS

Several models have been developed to assess the severity of alcoholic hepatitis and guide treatment decisions (Table 2). 

The MDF (Maddrey Discriminant Function)⁶ system was the first scoring system developed and is still the most widely used. A score of 32 or higher indicates severe alcoholic hepatitis and has been used as the threshold for starting treatment with corticosteroids.⁶

The MDF has limitations. Patients with a score lower than 32 are considered not to have severe alcoholic hepatitis, but up to 17% of them still die. Also, since it uses the prothrombin time, its results can vary considerably among laboratories, depending on the sensitivity of the thromboplastin reagent used.

The MELD (Model for End-stage Liver Disease) score. Sheth et al²³ compared the MELD and the MDF scores in assessing the severity of alcoholic hepatitis. They found that the MELD performed as well as the MDF in predicting 30-day mortality. A MELD score of greater than 11 had a sensitivity in predicting 30-day mortality of 86% and a specificity of 81%, compared with 86% and 48%, respectively, for MDF scores greater than 32.

Another study found a MELD score of 21 to have the highest sensitivity and specificity in predicting mortality (an estimated 90-day death rate of 20%). Thus, a MELD score of 21 is an appropriate threshold for prompt consideration of specific therapies such as corticosteroids.²⁴

The MELD score has become increasingly important in patients with alcoholic hepatitis, as some of them may become candidates for liver transplantation (see below). Also, serial MELD scores in hospitalized patients have prognostic implications, since an increase of 2 or more points in the first week has been shown to predict in-hospital mortality.²⁵

The GAHS (Glasgow Alcoholic Hepatitis Score)²⁶ was shown to identify patients with alcoholic hepatitis who have an especially poor prognosis and need corticosteroid therapy. In those with a GAHS of 9 or higher, the 28-day survival rate was 78% with corticosteroid treatment and 52% without corticosteroid treatment; survival rates at 84 days were 59% and 38%, respectively.²⁶

The ABIC scoring system (Age, Serum Bilirubin, INR, and Serum Creatinine) stratifies patients by risk of death at 90 days²⁷:

• Score less than 6.71: low risk (100% survival)
• A score 6.71–8.99: intermediate risk (70% survival)
• A score 9.0 or higher: high risk (25% survival). 

Both the GAHS and ABIC score are limited by lack of external validation.

The Lille score.²⁸ While the above scores are used to identify patients at risk of death from alcoholic hepatitis and to decide on starting corticosteroids, the Lille score is designed to assess response to corticosteroids after 1 week of treatment. It is calculated based on five pretreatment variables and the change in serum bilirubin level at day 7 of corticosteroid therapy. Lille scores range from 0 to 1; a score higher than 0.45 is associated with a 75% mortality rate at 6 months and indicates a lack of response to corticosteroids and that these drugs should be discontinued.²⁸

MANAGEMENT

Supportive treatment

Abstinence from alcohol is the cornerstone of treatment of alcoholic hepatitis. Early management of alcohol abuse or dependence is, therefore, warranted in all patients with alcoholic hepatitis. Referral to addiction specialists, motivational therapies, and anticraving drugs such as baclofen can be utilized.

Treat alcohol withdrawal. Alcoholics who suddenly decrease or discontinue their alcohol use are at high risk of alcohol withdrawal syndrome. Within 24 hours after the last drink, patients can experience increases in their heart rate and blood pressure, along with irritability and hyperreflexia. Within the next few days, more dangerous complications including seizures and delirium tremens can arise.

Alcohol withdrawal symptoms should be treated with short-acting benzodiazepines or clomethiazole, keeping the risk of worsening encephalopathy in mind.²⁹ If present, complications of cirrhosis such as encephalopathy, ascites, and variceal bleeding should be managed.

Usual presentation: Rapid onset of jaundice in a person with a history of heavy alcohol use

Nutritional support is important. Protein-calorie malnutrition is common in alcoholics, as are deficiencies of vitamin A, vitamin D, thiamine, folate, pyridoxine, and zinc.³⁰ Although a randomized controlled trial comparing enteral nutrition (2,000 kcal/day) vs corticosteroids (prednisolone 40 mg/day) in patients with alcoholic hepatitis did not show any difference in the 28-day mortality rate, those who received nutritional support and survived the first month had a lower mortality rate than those treated with corticosteroids (8% vs 37%).³¹ A daily protein intake of 1.5 g per kilogram of body weight is therefore recommended, even in patients with hepatic encephalopathy.¹⁵

Combining enteral nutrition and corticosteroid treatment may have a synergistic effect but is yet to be investigated.

Screen for infection. Patients with alcoholic hepatitis should be screened for infection, as about 25% of those with severe alcoholic hepatitis have an infection at admission.³² Since many of these patients meet the criteria for systemic inflammatory response syndrome, infections can be particularly difficult to diagnose. Patients require close clinical monitoring as well as regular pancultures for early detection. Antibiotics are frequently started empirically even though we lack specific evidence-based guidelines on this practice.³³

Corticosteroids

Various studies have evaluated the role of corticosteroids in treating alcoholic hepatitis, differing considerably in sample populations, methods, and end points. Although the results of individual trials differ, meta-analyses indicate that corticosteroids have a moderate beneficial effect in patients with severe alcoholic hepatitis.

For example, Rambaldi et al³⁴ performed a meta-analysis that concluded the mortality rate was lower in alcoholic hepatitis patients with MDF scores of at least 32 or hepatic encephalopathy who were treated with corticosteroids than in controls (relative risk 0.37, 95% confidence interval 0.16–0.86).

Therefore, in the absence of contraindications, the AASLD recommends starting corticosteroids in patients with severe alcoholic hepatitis, defined as an MDF score of 32 or higher.²¹ The preferred agent is oral prednisolone 40 mg daily or parenteral methylprednisolone 32 mg daily for 4 weeks and then tapered over the next 2 to 4 weeks or abruptly discontinued. Because activation of prednisone is decreased in patients with liver disease, prednisolone (the active form) is preferred over prednisone (the inactive precursor).³⁵ In alcoholic hepatitis, the number needed to treat with corticosteroids to prevent one death has been calculated³⁶ at 5.

As mentioned, response to corticosteroids is commonly assessed at 1 week of treatment using the Lille score. A score higher than 0.45 predicts a poor response and should trigger discontinuation of corticosteroids, particularly in those classified as null responders (Lille score > 0.56).

Typical biochemical derangements include elevated AST and, to a lesser extent, ALT

Adverse effects of steroids include sepsis, gastrointestinal bleeding, and steroid psychosis. Of note, patients who have evidence of hepatorenal syndrome or gastrointestinal bleeding tend to have a less favorable response to corticosteroids. Also, while infections were once considered a contraindication to steroid therapy, recent evidence suggests that steroid use might not be precluded in infected patients after appropriate antibiotic therapy. Infections occur in about a quarter of all alcoholic hepatitis patients treated with steroids, more frequently in null responders (42.5%) than in responders (11.1%), which supports corticosteroid discontinuance at 1 week in null responders.³²

Pentoxifylline

An oral phosphodiesterase inhibitor, pentoxifylline, also inhibits production of several cytokines, including tumor necrosis factor alpha. At a dose of 400 mg orally three times daily for 4 weeks, pentoxifylline has been used in treating severe alcoholic hepatitis (MDF score ≥ 32) and is recommended especially if corticosteroids are contraindicated, as with sepsis.²¹

An early double-blind clinical trial randomized patients with severe alcoholic hepatitis to receive either pentoxifylline 400 mg orally three times daily or placebo. Of the patients who received pentoxifylline, 24.5% died during the index hospitalization, compared with 46.1% of patients who received placebo. This survival benefit was mainly related to a markedly lower incidence of hepatorenal syndrome as the cause of death in the pentoxifylline group than in the placebo group (50% vs 91.7% of deaths).³⁷

In a small clinical trial in patients with severe alcoholic hepatitis, pentoxifylline recipients had a higher 3-month survival rate than prednisolone recipients (35.29% vs 14.71%, P = .04).³⁸ However, a larger trial showed no improvement in 6-month survival with the combination of prednisolone and pentoxifylline compared with prednisolone alone (69.9% vs 69.2%, P = .91).³⁹ Also, a meta-analysis of five randomized clinical trials found no survival benefit with pentoxifylline therapy.⁴⁰

Of note, in the unfortunate subgroup of patients who have a poor response to corticosteroids, no alternative treatment, including pentoxifylline, has been shown to be effective.⁴¹

Prednisone or pentoxifylline? Very recently, results of the Steroids or Pentoxifylline for Alcoholic Hepatitis (STOPAH) trial have been released.⁴² This is a large, multicenter, double-blinded clinical trial that aimed to provide a definitive answer to whether corticosteroids or pentoxifylline (or both) are beneficial in patients with alcoholic hepatitis. The study included 1,103 adult patients with severe alcoholic hepatitis (MDF score ≥ 32) who were randomized to monotherapy with prednisolone or pentoxifylline, combination therapy, or placebo. The primary end point was mortality at 28 days, and secondary end points included mortality at 90 days and at 1 year. Prednisolone reduced 28-day mortality by about 39%. In contrast, the 28-day mortality rate was similar in patients who received pentoxifylline and those who did not. Also, neither drug was significantly associated with a survival benefit beyond 28 days. The investigators concluded that pentoxifylline has no impact on disease progression and should not be used for the treatment of severe alcoholic hepatitis.⁴²

Other tumor necrosis factor alpha inhibitors not recommended

Two other tumor necrosis factor alpha inhibitors, infliximab and etanercept, have been tested in clinical trials in alcoholic hepatitis. Unfortunately, the results were not encouraging, with no major reduction in mortality.^43–45 In fact, these trials demonstrated a significantly increased risk of infections in the treatment groups. Therefore, these drugs are not recommended for treating alcoholic hepatitis.

A possible explanation is that tumor necrosis factor alpha plays an important role in liver regeneration, aiding in recovery from alcohol-induced liver injury, and inhibiting it can have deleterious consequences.

Other agents

A number of other agents have undergone clinical trials in alcoholic hepatitis.

N-acetylcysteine, an antioxidant that replenishes glutathione stores in hepatocytes, was evaluated in a randomized clinical trial in combination with prednisolone.⁴⁶ Although the 1-month mortality rate was significantly lower in the combination group than in the prednisolone-only group (8% vs 24%, P = .006), 3-month and 6-month mortality rates were not. Nonetheless, the rates of infection and hepatorenal syndrome were lower in the combination group. Therefore, corticosteroids and N-acetylcysteine may have synergistic effects, but the optimum duration of N-acetylcysteine therapy needs to be determined in further studies.

Vitamin E, silymarin, propylthiouracil, colchicine, and oxandrolone (an anabolic steroid) have also been studied, but with no convincing benefit.²¹

Role of liver transplantation

Liver transplantation for alcoholic liver disease has been a topic of great medical and social controversy. The view that alcoholic patients are responsible for their own illness led to caution when contemplating liver transplantation. Many countries require 6 months of abstinence from alcohol before placing a patient on the liver transplant list, posing a major obstacle to patients with alcoholic hepatitis, as almost all are active drinkers at the time of presentation and many will die within 6 months. Reasons for this 6-month rule include donor shortage and risk of recidivism.⁴⁷

Abstinence from alcohol is the cornerstone of treatment of alcoholic hepatitis

With regard to survival following alcoholic hepatitis, a study utilizing the United Network for Organ Sharing database matched patients with alcoholic hepatitis and alcoholic cirrhosis who underwent liver transplantation. Rates of 5-year graft survival were 75% in those with alcoholic hepatitis and 73% in those with alcoholic cirrhosis (P = .97), and rates of patient survival were 80% and 78% (P = .90), respectively. Proportional regression analysis adjusting for other variables showed no impact of the etiology of liver disease on graft or patient survival. The investigators concluded that liver transplantation could be considered in a select group of patients with alcoholic hepatitis who do not improve with medical therapy.⁴⁸

In a pivotal case-control prospective study,⁴⁹ 26 patients with Lille scores greater than 0.45 were listed for liver transplantation within a median of 13 days after nonresponse to medical therapy. The cumulative 6-month survival rate was higher in patients who received a liver transplant early than in those who did not (77% vs 23%, P < .001). This benefit was maintained through 2 years of follow-up (hazard ratio 6.08, P = .004). Of note, all these patients had supportive family members, no severe coexisting conditions, and a commitment to alcohol abstinence (although 3 patients resumed drinking after liver transplantation).⁴⁹

Although these studies support early liver transplantation in carefully selected patients with severe alcoholic hepatitis, the criteria for transplantation in this group need to be refined. Views on alcoholism also need to be reconciled, as strong evidence is emerging that implicates genetic and environmental influences on alcohol dependence.

Management algorithm

Adapted from the guidelines of the AASLD and European Association for the Study of the Liver.

Figure 2 shows a suggested management algorithm for alcoholic hepatitis, adapted from the guidelines of the AASLD and European Association for the Study of the Liver.

NEW THERAPIES NEEDED

Novel therapies for severe alcoholic hepatitis are urgently needed to help combat this devastating condition. Advances in understanding its pathophysiology have uncovered several new therapeutic targets, and new agents are already being evaluated in clinical trials.

IMM 124-E, a hyperimmune bovine colostrum enriched with immunoglobulin G anti-lipopolysaccharide, is going to be evaluated in combination with prednisolone in patients with severe alcoholic hepatitis.

Anakinra, an interleukin 1 receptor antagonist, has significant anti-inflammatory activity and is used to treat rheumatoid arthritis. A clinical trial to evaluate its role in alcoholic hepatitis has been designed in which patients with severe alcoholic hepatitis (defined as a MELD score ≥ 21) will be randomized to receive either methylprednisolone or a combination of anakinra, pentoxifylline, and zinc (a mineral that improves gut integrity).

Emricasan, an orally active caspase protease inhibitor, is another agent currently being tested in a phase 2 clinical trial in patients with severe alcoholic hepatitis. Since caspases induce apoptosis, inhibiting them should theoretically dampen alcohol-induced hepatocyte injury.

Interleukin 22, a hepatoprotective cytokine, shows promise as a treatment and will soon be evaluated in alcoholic hepatitis.

Aneurysmal subarachnoid hemorrhage is a devastating condition, with an estimated death rate of 30% during the initial episode.^1,2 Approximately the same number of patients survive but leave the hospital with disabling neurologic deficits.³

However, better outcomes can be achieved by systems that are able to work as a team on the collective goal of quick intervention to secure the ruptured aneurysm, followed by the implementation of measures to minimize secondary brain injury. Although the search for new diagnostic, prognostic, and therapeutic modalities continues, it is clear that there exists no “silver bullet” that will help all patients. Instead, it is the systematic integration and application of small advances that will ultimately maximize the patient’s chances of survival and neurologic recovery.

This review focuses on the management of aneurysmal subarachnoid hemorrhage and its systemic and neurologic complications.

ANEURYSM IS THE MOST COMMON CAUSE OF SUBARACHNOID BLEEDING

Aneurysmal subarachnoid hemorrhage, ie, rupture of an intracranial aneurysm, flooding  the subarachnoid space with blood, affects about 24,000 Americans each year.^1,2 A ruptured aneurysm is the most common cause of subarachnoid hemorrhage, accounting for about 85% of cases. Less common causes include idiopathic benign perimesencephalic hemorrhage, arteriovenous malformation, dural arteriovenous fistula, and hemorrhagic mycotic aneurysm. These have their own natural history, pathophysiology, and specific treatment, and will not be addressed in this article.

Risk factors for aneurysmal subarachnoid hemorrhage include having a first-degree relative who had the disease, hypertension, smoking, and consuming more than 150 g of alcohol per week.⁴

CLINICAL PRESENTATION AND DIAGNOSIS

The key symptom of aneurysmal subarachnoid hemorrhage is the abrupt onset of severe headache that peaks in intensity over 1 hour,⁵ often described as “the worst headache of my life.” Headache is accompanied by brief loss of consciousness in 53% of cases (conversely, nearly half of patients maintain normal mental status), by nausea or vomiting in 77%, and by meningismus (neck pain or stiffness) in 35%.⁶

These clinical manifestations and risk factors have been incorporated into a decision rule:

Obtain brain imaging if the patient has acute headache reaching maximal intensity within 1 hour, associated with any of the following factors:

• Age 40 or older

• Neck pain or stiffness

• Witnessed loss of consciousness

• Onset during exertion

• “Thunderclap” headache (ie, instantly peaking pain)

• Limited neck flexion on examination.⁵

This decision rule has nearly 100% sensitivity for aneurysmal subarachnoid hemorrhage in clinical practice.⁵ All patients require brain imaging if they have a severe headache plus either abnormal neurologic findings (eg, a focal neurologic deficit) or a history of cerebral aneurysm.

Emergency physicians should have a low threshold for ordering noncontrast computed tomography (CT) of the head in patients with even mild symptoms suggesting aneurysmal subarachnoid hemorrhage. Failure to order CT is the most common diagnostic error in this situation.⁶ CT performed within 6 hours of headache onset is nearly 100% sensitive for this condition,⁷ but the sensitivity falls to 93% after the first 24 hours and to less than 60% after 5 days.⁸ In patients who have symptoms highly suggestive of aneurysmal subarachnoid hemorrhage but a normal CT, lumbar puncture is the next diagnostic step.

There are two alternatives to CT followed by lumbar puncture: ie, noncontrast CT followed by CT angiography,^9,10 and magnetic resonance imaging followed by magnetic resonance angiography. In patients with suspicious clinical symptoms but negative CT results, CT followed by CT angiography can rule out aneurysmal subarachnoid hemorrhage with a 99% probability.^9,10 However, CT followed by lumbar puncture remains the standard of care and carries a class I recommendation in the American Heart Association guidelines for ruling out subarachnoid hemorrhage.⁵

GRADING THE SEVERITY OF SUBARACHNOID HEMORRHAGE

Age, the thickness of the blood layer in the subarachnoid space, intraventricular hemorrhage and the findings of the neurologic examination at presentation are predictors of long-term outcomes in aneurysmal subarachnoid hemorrhage (Figure 1).

Different grading systems used in clinical practice are based on the findings on the initial neurologic examination and on the initial noncontrast CT (ie, the thickness of the blood, and whether intraventricular hemorrhage is present). Among the most widely used are those developed by Hunt and Hess¹² and by the World Federation of Neurological Surgeons¹¹ (WFNS), and the CT grading scales (Fisher¹³ or its modified version¹⁴)  (Tables 1 and 2). With either the Hunt and Hess scale or the WFNS scale, the higher the score, the worse the patient’s probable outcome. Scores on both Fisher scales correlate with the risk of angiographic vasospasm. The higher the grade, the higher the risk of angiographic vasospasm.

The VASOGRADE score—a combination of the WFNS score and the modified Fisher scale—stratifies patients at risk of delayed cerebral ischemia, allowing for a tailored monitoring strategy.¹⁵ There are three variations:

• VASOGRADE green—Modified Fisher 1 or 2 and WFNS 1 or 2

• VASOGRADE yellow—Modified Fisher 3 or 4 and WFNS 1, 2, or 3

• VASOGRADE red—WFNS 4 or 5. 

After the initial bleeding event, patients with aneurysmal subarachnoid hemorrhage are at high risk of delayed systemic and neurologic complications, with poor functional outcomes. Delayed cerebral ischemia holds the greatest risk of an unfavorable outcome and ultimately can lead to cerebral infarction, disability, and death.^6,7

INITIAL MANAGEMENT

After aneurysmal subarachnoid hemorrhage is diagnosed, the initial management (Figure 2) includes appropriate medical prevention of rebleeding (which includes supportive care, blood pressure management, and, perhaps, the early use of a short course of an antifibrinolytic drug) and early transfer to a high-volume center for securing the aneurysm. The reported incidence of rebleeding varies from 5% to 22% in the first 72 hours. “Ultra-early” rebleeding (within 24 hours of hemorrhage) has been reported, with an incidence as high as 15% and a fatality rate around 70%. Patients with poor-grade aneurysmal subarachnoid hemorrhage, larger aneurysms, and “sentinel bleeds” are at higher risk of rebleeding.16

Outcomes are much better when patients are managed in a high-volume center, with a specialized neurointensive care unit¹⁷ and access to an interdisciplinary team.¹⁸ Regardless of the initial grade, patients with aneurysmal subarachnoid hemorrhage should be quickly transferred to a high-volume center, defined as one treating at least 35 cases per year, and the benefit is greater in centers treating more than 60 cases per year.¹⁹ The higher the caseload in any given hospital, the better the clinical outcomes in this population.²⁰

Treating cerebral aneurysm: Clipping or coiling

Early aneurysm repair is generally considered the standard of care and the best strategy to reduce the risk of rebleeding. Further, early treatment may be associated with a lower risk of delayed cerebral ischemia²¹ and better outcomes.²²

Three randomized clinical trials have compared surgical clipping and endovascular repair (placement of small metal coils within the aneurysm to promote clotting).

The International Subarachnoid Aneurysm Trial²³ showed a reduction of 23% in relative risk and of 7% in absolute risk in patients who underwent endovascular treatment compared with surgery. The survival benefit persisted at a mean of 9 years (range 6–14 years), but with a higher annual rate of aneurysm recurrence in the coiling group (2.9% vs 0.9%).²⁴ Of note, this trial included only patients with aneurysms deemed suitable for both coiling and clipping, so that the exclusion rate was high. Most of the patients presented with good-grade (WFNS score 1–3), small aneurysms (< 5 mm) in the anterior circulation.

A single-center Finnish study²⁵ found no differences in rates of recovery, disability, and  death at 1 year, comparing surgery and endovascular treatment. Additionally, survival rates at a mean follow-up of 39 months were similar, with no late recurrences or aneurysmal bleeding.

Lastly, the Barrow Ruptured Aneurysm Trial26,27 found that patients assigned to endovascular treatment had better 1-year neurologic outcomes, defined as a modified Rankin score of 2 or less. Importantly, 37.7% of patients originally assigned to endovascular treatment crossed over to surgical treatment. The authors then performed intention-to-treat and as-treated analyses. Either way, patients treated by endovascular means had better neurologic outcomes at 1 year. However, no difference in the relative risk reduction in worse outcome was found on 3-year follow-up, and patients treated surgically had higher rates of aneurysm obliteration and required less aneurysm retreatment, both of which were statistically significant.

The question that remains is not whether to clip or whether to coil, but whom to clip and whom to coil.²⁸ That question must be answered on a patient-to-patient basis and requires the expertise of an interventional neuroradiologist and a vascular neurosurgeon—one of the reasons these patients are best cared for in high-volume centers providing such expertise.

MEDICAL PREVENTION OF REBLEEDING

Blood pressure management

There are no systematic data on the optimal blood pressure before securing an aneurysm. Early studies of hemodynamic augmentation in cases of ruptured untreated aneurysm reported rebleeding when the systolic blood pressure was allowed to rise above 160 mm Hg.^29,30 A recent study evaluating hypertensive intracerebral hemorrhage revealed better functional outcomes with intensive lowering of blood pressure (defined as systolic blood pressure < 140 mm Hg) but no significant reduction in the combined rate of death or severe disability.³¹ It is difficult to know if these results can be extrapolated to patients with aneurysmal subarachnoid hemorrhage. Current guidelines^3,32 say that before the aneurysm is treated, the systolic pressure should be lower than 160 mm Hg.

There is no specific drug of choice, but a short-acting, titratable medication is preferable. Nicardipine is a very good option, and labetalol might be an appropriate alternative.³³ Once the aneurysm is secured, all antihypertensive drugs should be held. Hypertension should not be treated unless the patient has clinical signs of a hypertensive crisis, such as flash pulmonary edema, myocardial infarction, or hypertensive encephalopathy.

Antifibrinolytic therapy

Risk factors: Family history, hypertension, smoking, heavy drinking

The role of antifibrinolytic therapy in aneurysmal subarachnoid hemorrhage is controversial and has been studied in 10 clinical trials. In a Swedish study,³⁴ early use of tranexamic acid (1 g intravenously over 10 minutes followed by 1 g every 6 hours for a maximum of 24 hours) reduced the rebleeding rate substantially, from 10.8% to 2.4%, with an 80% reduction in the mortality rate from ultra-early rebleeding. However, a recent Cochrane review that included this study found no overall benefit.³⁵

An ongoing multicenter randomized trial in the Netherlands will, we hope, answer this question in the near future.³⁶ At present, some centers would consider a short course of tranexamic acid before aneurysm treatment.

DIAGNOSIS AND TREATMENT OF COMPLICATIONS

Medical complications are extremely common after aneurysmal subarachnoid hemorrhage. Between 75% and 100% of patients develop some type of systemic or further neurologic derangement, which in turn has a negative impact on the long-term outcome.^37,38 In the first 72 hours, rebleeding is the most feared complication, and as mentioned previously, appropriate blood pressure management and early securing of the aneurysm minimize its risk.

NEUROLOGIC COMPLICATIONS

Hydrocephalus

Hydrocephalus is the most common early neurologic complication after aneurysmal subarachnoid hemorrhage, with an overall incidence of 50%.³⁹ Many patients with poor-grade aneurysmal subarachnoid hemorrhage and patients whose condition deteriorates due to worsening of hydrocephalus require the insertion of an external ventricular drain (Figure 1).

Up to 30% of patients who have a poor-grade aneurysmal subarachnoid hemorrhage improve neurologically with cerebrospinal fluid drainage.⁴⁰ An external ventricular drain can be safely placed, even before aneurysm treatment, and placement does not appear to increase the risk of rebleeding.^39,41 After placement, rapid weaning from the drain (clamping within 24 hours of insertion) is safe, decreases length of stay in the intensive care unit and hospital, and may be more cost-effective than gradual weaning over 96 hours.⁴²

Increased intracranial pressure

Intracranial hypertension is another potential early complication, and is frequently due to the development of hydrocephalus, cerebral edema, or rebleeding. The treatment of increased intracranial pressure does not differ from the approach used in managing severe traumatic brain injury, which includes elevating the head of the bed, sedation, analgesia, normoventilation, and cerebrospinal fluid drainage.

Hypertonic saline has been tested in several studies that were very small but nevertheless consistently showed control of intracranial pressure levels and improvement in cerebral blood flow measured by xenon CT.^43–47 Two of these studies even showed better outcomes at discharge.^43,44 However, the small number of patients prevents any meaningful conclusion regarding the use of hypertonic saline and functional outcomes.

Outcomes are much better when patients are managed in a high-volume center

Barbiturates, hypothermia, and decompressive craniectomy could be tried in refractory cases.⁴⁸ Seule et al⁴⁹ evaluated the role of therapeutic hypothermia with or without barbiturate coma in 100 patients with refractory intracranial hypertension. Only 13 patients received hypothermia by itself. At 1 year, 32 patients had achieved a good functional outcome (Glasgow Outcome Scale score 4 or 5). The remaining patients were severely disabled or had died. Of interest, the median duration of hypothermia was 7 days, and 93% of patients developed some medical complication such as electrolyte disorders (77%), pneumonia (52%), thrombocytopenia (47%), or septic shock syndrome (40%). Six patients died as a consequence of one of these complications.

Decompressive craniectomy can be life-saving in patients with refractory intracranial hypertension. However, most of these patients will die or remain severely disabled or comatose.⁵⁰

Seizure prophylaxis is controversial

Seizures can occur at the onset of intracranial hemorrhage, perioperatively, or later (ie, after the first week). The incidence varied considerably in different reports, ranging from 4% to 26%.⁵¹ Seizures occurring perioperatively, ie, after hospital admission, are less frequent and are usually the manifestation of aneurysm rebleeding.²⁴

The question is not whether to clip or coil, but whom to clip and whom to coil

Seizure prophylaxis remains controversial, especially because the use of phenytoin is associated with increased incidence of cerebral vasospasm, infarction, and worse cognitive outcomes after aneurysmal subarachnoid hemorrhage.^52,53 Therefore, routine prophylactic use of phenytoin is not recommended in these patients,³ although the effect of other antiepileptic drugs is less studied and less clear. Patients may be considered for this therapy if they have multiple risk factors for seizures, such as intraparenchymal hematoma, advanced age (> 65), middle cerebral artery aneurysm, craniotomy for aneurysm clipping, and a short course (≤ 72 hours) of an antiepileptic drug other than phenytoin, especially while the aneurysm is unsecured.³

Levetiracetam may be an alternative to phenytoin, having better pharmacodynamic and kinetic profiles, minimal protein binding, and absence of hepatic metabolism, resulting in a very low risk of drug interaction and better tolerability.^54,55 Because of these advantages, levetiracetam has become the drug of choice in several centers treating aneurysmal subarachnoid hemorrhage in the United States.

Addressing this question, a survey was sent to 25 high-volume aneurysmal subarachnoid hemorrhage academic centers in the United States. All 25 institutions answered the survey, and interestingly, levetiracetam was the first-line agent for 16 (94%) of the 17 responders that used prophylaxis, while only 1 used phenytoin as the agent of choice.⁵⁶

A retrospective cohort study by Murphy-Human et al⁵⁷ showed that a short course of levetiracetam (≤ 72 hours) was associated with higher rates of in-hospital seizures compared with an extended course of phenytoin (eg, entire hospital stay). However, the study did not address functional outcomes.⁵⁷

Continuous electroencephalographic monitoring may be considered in comatose patients, in patients requiring controlled ventilation and sedation, or in patients with unexplained alteration in consciousness. In one series of patients with aneurysmal subarachnoid hemorrhage who received continuous monitoring, the incidence of nonconvulsive status epilepticus was 19%, with an associated mortality rate of 100%.⁵⁸

Continuous quantitative electroencephalography is useful to monitor and to detect angiographic vasospasm and delayed cerebral ischemia. Relative alpha variability and the alpha-delta ratio decrease with ischemia, and this effect can precede angiographic vasospasm by 3 days.^59,60

Delayed cerebral ischemia

Delayed cerebral ischemia is defined as the occurrence of focal neurologic impairment, or a decrease of at least 2 points on the Glasgow Coma Scale that lasts for at least 1 hour, is not apparent immediately after aneurysm occlusion, and not attributable to other causes (eg, hyponatremia, fever).⁶¹

Classically, neurologic deficits that occurred within 2 weeks of aneurysm rupture were ascribed to reduced cerebral blood flow caused by delayed large-vessel vasospasm causing cerebral ischemia.⁶² However, perfusion abnormalities have also been observed with either mild or no demonstrable vasospasm.⁶³ Almost 70% of patients who survive the initial hemorrhage develop some degree of angiographic vasospasm. However, only 30% of those patients will experience symptoms.

In addition to vasospasm of large cerebral arteries, impaired autoregulation and early brain injury within the first 72 hours following subarachnoid hemorrhage may play important roles in the development of delayed cerebral ischemia.⁶⁴ Therefore, the modern concept of delayed cerebral ischemia monitoring should focus on cerebral perfusion rather than vessel diameter measurements. This underscores the importance of comprehensive, standardized monitoring techniques that provide information not only on microvasculature, but also at the level of the microcirculation, with information on perfusion, oxygen utilization and extraction, and autoregulation.

Although transcranial Doppler has been the most commonly applied tool to monitor for angiographic vasospasm, it has a low sensitivity and negative predictive value.³⁷ It is nevertheless a useful technique to monitor good-grade aneurysmal subarachnoid hemorrhage patients (WFNS score 1–3) combined with frequent neurologic examinations (Figure 3).

CT angiography is a good noninvasive alternative to digital subtraction angiography. However, it tends to overestimate the degree of vasoconstriction and does not provide information about perfusion and autoregulation.⁶⁵ Nevertheless, CT angiography combined with a CT perfusion scan can add information about autoregulation and cerebral perfusion and has been shown to be more sensitive for the diagnosis of angiographic vasospasm than transcranial Doppler and digital subtraction angiography (Figure 4).

Patients with a poor clinical condition (WFNS score 4 or 5) or receiving continuous sedation constitute a challenge in monitoring for delayed neurologic deterioration. Neurologic examination is not sensitive enough in this setting to detect subtle changes. In these specific and challenging circumstances, multimodality neuromonitoring may be useful in the early detection of delayed cerebral ischemia and may help guide therapy.⁶⁷

Several noninvasive and invasive techniques have been studied to monitor patients at risk of delayed cerebral ischemia after subarachnoid hemorrhage.⁶⁶ These include continuous electroencephalography, brain tissue oxygenation monitoring (Ptio₂), cerebral microdialysis, thermal diffusion flowmetry, and near-infrared spectroscopy. Of these techniques, Ptio₂, cerebral microdialysis, and continuous electroencephalography (see discussion of seizure prophylaxis above) have been more extensively studied. However, most of the studies were observational and very small, limiting any recommendations for using these techniques in routine clinical practice.⁶⁸

Ptio₂ is measured by inserting an intraparenchymal oxygen-sensitive microelectrode, and microdialysis requires a microcatheter with a semipermeable membrane that allows small soluble substances to cross it into the dialysate. These substances, which include markers of ischemia (ie, glucose, lactate, and pyruvate), excitotoxins (ie, glutamate and aspartate), and membrane cell damage products (ie, glycerol), can be measured. Low Ptio₂ values (< 15 mm Hg) and abnormal mycrodialysate findings (eg, glucose < 0.8 mmol/L, lactate-to-pyruvate ratio > 40) have both been associated with cerebral ischemic events and poor outcome.⁶⁸

Preventing delayed cerebral ischemia

Oral nimodipine 60 mg every 4 hours for 21 days, started on admission, carries a class I, level of evidence A recommendation in the management of aneurysmal subarachnoid hemorrhage.^3,32,69 It improves clinical outcome despite having no effect on the risk of angiographic vasospasm. The mechanism of improved outcome is unclear, but the effect may be a neuroprotective phenomenon limiting the extension of delayed cerebral ischemia.⁷⁰

If hypotension occurs, the dose can be lowered to 30 mg every 2 hours. Whether to discontinue nimodipine in this situation is controversial. Of note, the clinical benefits of nimodipine have not been replicated with other calcium channel blockers (eg, nicardipine).⁷¹

Prophylactic hyperdynamic fluid therapy, known as “triple-H” (hypervolemia, hemodilution, and hypertension) was for years the mainstay of treatment in preventing delayed cerebral ischemia due to vasospasm. However, the clinical data supporting this intervention have been called into question, as analysis of two trials found that hypervolemia did not improve outcomes or reduce the incidence of delayed cerebral ischemia, and in fact increased the rate of complications.^72,73 Based on these findings, current guidelines recommend maintaining euvolemia rather than prophylactic hypervolemia in patients with aneurysmal subarachnoid hemorrhage.^3,32,69

TREATING DELAYED CEREBRAL ISCHEMIA

Hemodynamic augmentation

In patients with neurologic deterioration due to delayed cerebral ischemia, hemodynamic augmentation is the cornerstone of treatment. This is done according to a protocol, started early, involving specific physiologic goals, clinical improvement, and escalation to invasive therapies in a timely fashion in patients at high risk of further neurologic insult (Figure 5).

The physiologic goal is to increase the delivery of oxygen and glucose to the ischemic brain. Hypertension seems to be the most effective component of hemodynamic augmentation regardless of volume status, increasing cerebral blood flow and brain tissue oxygenation, with reversal of delayed cerebral ischemic symptoms in up to two-thirds of treated patients.^74,75 However, this information comes from very small studies, with no randomized trials of induced hypertension available.

The effect of a normal saline fluid bolus in patients suspected of having delayed cerebral ischemia has been shown to increase cerebral blood flow in areas of cerebral ischemia.⁷⁴ If volume augmentation fails to improve the neurologic status, the next step is to artificially induce hypertension using vasopressors. The blood pressure target should be based on clinical improvement. A stepwise approach is reasonable in this situation, and the lowest level of blood pressure at which there is a complete reversal of the new focal neurologic deficit should be maintained.^3,29

Inotropic agents such as dobutamine or milrinone can be considered as alternatives in patients who have new neurologic deficits that are refractory to fluid boluses and vasopressors, or in a setting of subarachnoid hemorrhage-induced cardiomyopathy.^76,77

Once the neurologic deficit is reversed by hemodynamic augmentation, the blood pressure should be maintained for 48 to 72 hours at the level that reversed the deficit completely, carefully reassessed thereafter, and the patient weaned slowly. Unruptured unsecured aneurysms should not prevent blood pressure augmentation in a setting of delayed cerebral ischemia if the culprit aneurysm is treated.^3,32 If the ruptured aneurysm has not been secured, careful blood pressure augmentation can be attempted, keeping in mind that hypertension (> 160/95 mm Hg) is a risk factor for fatal aneurysm rupture.

Endovascular management of delayed cerebral ischemia

When medical augmentation fails to completely reverse the neurologic deficits, endovascular treatment can be considered. Although patients treated early in the course of delayed cerebral ischemia have better neurologic recovery, prophylactic endovascular treatment in asymptomatic patients, even if angiographic signs of spasm are present, does not improve clinical outcomes and carries the risk of fatal arterial rupture.⁷⁸

SYSTEMIC COMPLICATIONS

Hyponatremia and hypovolemia

Aneurysmal subarachnoid hemorrhage is commonly associated with abnormalities of fluid balance and electrolyte derangements. Hyponatremia (serum sodium < 135 mmol/L) occurs in 30% to 50% of patients, while the rate of hypovolemia (decreased circulating blood volume) ranges from 17% to 30%.⁷⁹ Both can negatively affect long-term outcomes.^80,81

Decreased circulating blood volume is a well-described contributor to delayed cerebral ischemia and cerebral infarction after aneurysmal subarachnoid hemorrhage.^80–82 Clinical variables such as heart rate, blood pressure, fluid balance, and serum sodium concentration are usually the cornerstones of intravascular volume status assessment. However, these variables correlate poorly with measured circulating blood volumes in those with aneurysmal subarachnoid hemorrhage.^83,84

The mechanisms responsible for the development of hyponatremia and hypovolemia after aneurysmal subarachnoid hemorrhage are not completely understood. Several factors have been described and may contribute to the increased natriuresis and, hence, to a reduction in circulating blood volume: increased circulating natriuretic peptide concentrations,^85–87 sympathetic nervous system hyperactivation,⁸⁸ and hyperreninemic hypo-
aldosteronism syndrome.^89,90

Guidelines: Before treating the aneurysm, the systolic pressure should be < 160 mm Hg

Lastly, the cerebral salt wasting syndrome, described in the 1950s,⁹¹ was thought to be a key mechanism in the development of hyponatremia and hypovolemia after aneurysmal subarachnoid hemorrhage. In contrast to the syndrome of inappropriate antidiuretic hormone, which is characterized by hyponatremia with a normal or slightly elevated intravascular volume, the characteristic feature of cerebral salt wasting syndrome is the development of hyponatremia in a setting of intravascular volume depletion.⁹² In critically ill neurologic and neurosurgical patients, this differential diagnosis is very difficult, especially in those with aneurysmal subarachnoid hemorrhage in whom the clinical assessment of fluid status is not reliable. These two syndromes might coexist and contribute to the development of hyponatremia after aneurysmal subarachnoid hemorrhage.^92,93

Hoff et al^83,84 prospectively compared the clinical assessment of fluid status by critical and intermediate care nurses and direct measurements of blood volume using pulse dye densitometry. The clinical assessment failed to accurately assess patients’ volume status. Using the same technique to measure circulating blood volume, this group showed that calculation of fluid balance does not provide adequate assessment of fluid status.^83,84

Hemodynamic monitoring tools can help guide fluid replacement in this population. Mutoh et al⁹⁴ randomized 160 patients within 24 hours of hemorrhage to receive early goal-directed fluid therapy (ie, preload volume and cardiac output monitored by transpulmonary thermodilution) vs standard therapy (ie, fluid balance or central venous pressure). Overall, no difference was found in the rates of delayed cerebral ischemia (33% vs 42%; P = .33) or favorable outcome (67% vs 57%; P = .22). However, in the subgroup of poor-grade patients (WFNS score 4 or 5), early goal-directed therapy was associated with a lower rate of delayed cerebral ischemia (5% vs 14%; P = .036) and with better functional outcomes at 3 months (52% vs 36%; P = .026).

Fluid restriction to treat hyponatremia in aneurysmal subarachnoid hemorrhage is no longer recommended because of the increased risk of cerebral infarction due to hypovolemic hypoperfusion.⁸²

Prophylactic use of mineralocorticoids (eg, fludrocortisone, hydrocortisone) has been shown to limit natriuresis, hyponatremia, and the amount of fluid required to maintain euvolemia.^95,96 Higher rates of hypokalemia and hyperglycemia, which can be easily treated, are the most common complications associated with this approach. Additionally, hypertonic saline (eg, 3% saline) can be used to correct hyponatremia in a setting of aneurysmal subarachnoid hemorrhage.⁷⁹

Cardiac complications

Cardiac complications after subarachnoid hemorrhage are most likely related to sympathetic hyperactivity and catecholamine-induced myocyte dysfunction. The pathophysiology is complex, but cardiac complications have a significant negative impact on long-term outcome in these patients.⁹⁷

Electrocardiographic changes and positive cardiac enzymes associated with aneurysmal subarachnoid hemorrhage have been extensively reported. More recently, data from studies of two-dimensional echocardiography have shown that subarachnoid hemorrhage can also be associated with significant wall-motion abnormalities and even overt cardiogenic shock.^98–100

There is no specific curative therapy; the treatment is mainly supportive. Vasopressors and inotropes may be used for hemodynamic augmentation.

Pulmonary complications

Pulmonary complications occur in 20% to 30% of all aneurysmal subarachnoid hemorrhage patients and are associated with a higher risk of delayed cerebral ischemia and death. Common pulmonary complications in this population are mild acute respiratory distress syndrome (27%), hospital-acquired pneumonia (9%), cardiogenic pulmonary edema (8%), aspiration pneumonia (6%), neurogenic pulmonary edema (2%), and pulmonary embolism (1%).^101–103

SUPPORTIVE CARE

Hyperthermia, hyperglycemia, and liberal use of transfusions have all been associated with longer stays in the intensive care unit and hospital, poorer neurologic outcomes, and higher mortality rates in patients with acute brain injury.¹⁰⁴ Noninfectious fever is the most common systemic complication after subarachnoid hemorrhage.

Antipyretic drugs such as acetaminophen and ibuprofen are not very effective in reducing fever in the subarachnoid hemorrhage population, but should still be used as first-line therapy. The use of surface and intravascular devices can be considered when fevers do not respond to nonsteroidal anti-inflammatory drugs.

Fluid restriction to treat hyponatremia in aneurysmal subarachnoid hemorrhage is no longer recommended

Although no prospective randomized trial has addressed the impact of induced normothermia on long-term outcome and mortality in aneurysmal subarachnoid hemorrhage patients, fever control has been shown to reduce cerebral metabolic distress, irrespective of intracranial pressure.¹⁰⁵ Maintenance of normothermia (< 37.5°C) seems reasonable, especially in aneurysmal subarachnoid hemorrhage patients at risk of or with active delayed cerebral ischemia.¹⁰⁶

Current guidelines^3,32,69 strongly recommend avoiding hypoglycemia, defined as a serum glucose level less than 80 mg/dL, but suggest keeping the blood sugar level below 180 or 200 mg/dL.

At the moment, there is no clear threshold for transfusion in patients with aneurysmal subarachnoid hemorrhage. Current guidelines suggest keeping hemoglobin levels between 8 and 10 g/dL.³

Preventing venous thromboembolism

The incidence of venous thromboembolism after aneurysmal subarachnoid hemorrhage varies widely, from 1.5% to 18%.¹⁰⁷ Active surveillance with venous Doppler ultrasonography has found asymptomatic deep vein thrombosis in up to 3.4% of poor-grade aneurysmal subarachnoid hemorrhage patients receiving pharmacologic thromboprophylaxis.¹⁰⁸

In a retrospective study of 170 patients, our group showed that giving drugs to prevent venous thromboembolism (unfractionated heparin 5,000 IU subcutaneously every 12 hours or dalteparin 5,000 IU subcutaneously daily), starting within 24 hours of aneurysm treatment, could be safe.¹⁰⁹ Fifty-eight percent of these patients had an external ventricular drain in place. One patient developed a major cerebral hemorrhagic complication and died while on unfractionated heparin; however, the patient was also on dual antiplatelet therapy with aspirin and clopidogrel.¹⁰⁹

Current guidelines suggest that intermittent compression devices be applied in all patients before aneurysm treatment. Pharmacologic thromboprophylaxis with a heparinoid can be started 12 to 24 hours after aneurysm treatment.^3,109

A TEAM APPROACH

Patients with subarachnoid hemorrhage need integrated care from different medical and nursing specialties. The best outcomes are achieved by systems that can focus as a team on the collective goal of quick intervention to secure the aneurysm, followed by measures to minimize secondary brain injury.

The modern concept of cerebral monitoring in a setting of subarachnoid hemorrhage should focus on brain perfusion rather than vascular diameter. Although the search continues for new diagnostic, prognostic, and therapeutic tools, there is no “silver bullet” that will help all patients. Instead, it is the systematic integration and application of many small advances that will ultimately lead to better outcomes.

ACKNOWLEDGMENT

This work was supported by research funding provided by the Bitove Foundation, which has been supportive of our clinical and research work for several years.

Aneurysmal subarachnoid hemorrhage is a devastating condition, with an estimated death rate of 30% during the initial episode.^1,2 Approximately the same number of patients survive but leave the hospital with disabling neurologic deficits.³

However, better outcomes can be achieved by systems that are able to work as a team on the collective goal of quick intervention to secure the ruptured aneurysm, followed by the implementation of measures to minimize secondary brain injury. Although the search for new diagnostic, prognostic, and therapeutic modalities continues, it is clear that there exists no “silver bullet” that will help all patients. Instead, it is the systematic integration and application of small advances that will ultimately maximize the patient’s chances of survival and neurologic recovery.

This review focuses on the management of aneurysmal subarachnoid hemorrhage and its systemic and neurologic complications.

ANEURYSM IS THE MOST COMMON CAUSE OF SUBARACHNOID BLEEDING

Aneurysmal subarachnoid hemorrhage, ie, rupture of an intracranial aneurysm, flooding  the subarachnoid space with blood, affects about 24,000 Americans each year.^1,2 A ruptured aneurysm is the most common cause of subarachnoid hemorrhage, accounting for about 85% of cases. Less common causes include idiopathic benign perimesencephalic hemorrhage, arteriovenous malformation, dural arteriovenous fistula, and hemorrhagic mycotic aneurysm. These have their own natural history, pathophysiology, and specific treatment, and will not be addressed in this article.

Risk factors for aneurysmal subarachnoid hemorrhage include having a first-degree relative who had the disease, hypertension, smoking, and consuming more than 150 g of alcohol per week.⁴

CLINICAL PRESENTATION AND DIAGNOSIS

The key symptom of aneurysmal subarachnoid hemorrhage is the abrupt onset of severe headache that peaks in intensity over 1 hour,⁵ often described as “the worst headache of my life.” Headache is accompanied by brief loss of consciousness in 53% of cases (conversely, nearly half of patients maintain normal mental status), by nausea or vomiting in 77%, and by meningismus (neck pain or stiffness) in 35%.⁶

These clinical manifestations and risk factors have been incorporated into a decision rule:

Obtain brain imaging if the patient has acute headache reaching maximal intensity within 1 hour, associated with any of the following factors:

• Age 40 or older

• Neck pain or stiffness

• Witnessed loss of consciousness

• Onset during exertion

• “Thunderclap” headache (ie, instantly peaking pain)

• Limited neck flexion on examination.⁵

This decision rule has nearly 100% sensitivity for aneurysmal subarachnoid hemorrhage in clinical practice.⁵ All patients require brain imaging if they have a severe headache plus either abnormal neurologic findings (eg, a focal neurologic deficit) or a history of cerebral aneurysm.

Emergency physicians should have a low threshold for ordering noncontrast computed tomography (CT) of the head in patients with even mild symptoms suggesting aneurysmal subarachnoid hemorrhage. Failure to order CT is the most common diagnostic error in this situation.⁶ CT performed within 6 hours of headache onset is nearly 100% sensitive for this condition,⁷ but the sensitivity falls to 93% after the first 24 hours and to less than 60% after 5 days.⁸ In patients who have symptoms highly suggestive of aneurysmal subarachnoid hemorrhage but a normal CT, lumbar puncture is the next diagnostic step.

There are two alternatives to CT followed by lumbar puncture: ie, noncontrast CT followed by CT angiography,^9,10 and magnetic resonance imaging followed by magnetic resonance angiography. In patients with suspicious clinical symptoms but negative CT results, CT followed by CT angiography can rule out aneurysmal subarachnoid hemorrhage with a 99% probability.^9,10 However, CT followed by lumbar puncture remains the standard of care and carries a class I recommendation in the American Heart Association guidelines for ruling out subarachnoid hemorrhage.⁵

GRADING THE SEVERITY OF SUBARACHNOID HEMORRHAGE

Age, the thickness of the blood layer in the subarachnoid space, intraventricular hemorrhage and the findings of the neurologic examination at presentation are predictors of long-term outcomes in aneurysmal subarachnoid hemorrhage (Figure 1).

Different grading systems used in clinical practice are based on the findings on the initial neurologic examination and on the initial noncontrast CT (ie, the thickness of the blood, and whether intraventricular hemorrhage is present). Among the most widely used are those developed by Hunt and Hess¹² and by the World Federation of Neurological Surgeons¹¹ (WFNS), and the CT grading scales (Fisher¹³ or its modified version¹⁴)  (Tables 1 and 2). With either the Hunt and Hess scale or the WFNS scale, the higher the score, the worse the patient’s probable outcome. Scores on both Fisher scales correlate with the risk of angiographic vasospasm. The higher the grade, the higher the risk of angiographic vasospasm.

The VASOGRADE score—a combination of the WFNS score and the modified Fisher scale—stratifies patients at risk of delayed cerebral ischemia, allowing for a tailored monitoring strategy.¹⁵ There are three variations:

• VASOGRADE green—Modified Fisher 1 or 2 and WFNS 1 or 2

• VASOGRADE yellow—Modified Fisher 3 or 4 and WFNS 1, 2, or 3

• VASOGRADE red—WFNS 4 or 5. 

After the initial bleeding event, patients with aneurysmal subarachnoid hemorrhage are at high risk of delayed systemic and neurologic complications, with poor functional outcomes. Delayed cerebral ischemia holds the greatest risk of an unfavorable outcome and ultimately can lead to cerebral infarction, disability, and death.^6,7

INITIAL MANAGEMENT

After aneurysmal subarachnoid hemorrhage is diagnosed, the initial management (Figure 2) includes appropriate medical prevention of rebleeding (which includes supportive care, blood pressure management, and, perhaps, the early use of a short course of an antifibrinolytic drug) and early transfer to a high-volume center for securing the aneurysm. The reported incidence of rebleeding varies from 5% to 22% in the first 72 hours. “Ultra-early” rebleeding (within 24 hours of hemorrhage) has been reported, with an incidence as high as 15% and a fatality rate around 70%. Patients with poor-grade aneurysmal subarachnoid hemorrhage, larger aneurysms, and “sentinel bleeds” are at higher risk of rebleeding.16

Outcomes are much better when patients are managed in a high-volume center, with a specialized neurointensive care unit¹⁷ and access to an interdisciplinary team.¹⁸ Regardless of the initial grade, patients with aneurysmal subarachnoid hemorrhage should be quickly transferred to a high-volume center, defined as one treating at least 35 cases per year, and the benefit is greater in centers treating more than 60 cases per year.¹⁹ The higher the caseload in any given hospital, the better the clinical outcomes in this population.²⁰

Treating cerebral aneurysm: Clipping or coiling

Early aneurysm repair is generally considered the standard of care and the best strategy to reduce the risk of rebleeding. Further, early treatment may be associated with a lower risk of delayed cerebral ischemia²¹ and better outcomes.²²

Three randomized clinical trials have compared surgical clipping and endovascular repair (placement of small metal coils within the aneurysm to promote clotting).

The International Subarachnoid Aneurysm Trial²³ showed a reduction of 23% in relative risk and of 7% in absolute risk in patients who underwent endovascular treatment compared with surgery. The survival benefit persisted at a mean of 9 years (range 6–14 years), but with a higher annual rate of aneurysm recurrence in the coiling group (2.9% vs 0.9%).²⁴ Of note, this trial included only patients with aneurysms deemed suitable for both coiling and clipping, so that the exclusion rate was high. Most of the patients presented with good-grade (WFNS score 1–3), small aneurysms (< 5 mm) in the anterior circulation.

A single-center Finnish study²⁵ found no differences in rates of recovery, disability, and  death at 1 year, comparing surgery and endovascular treatment. Additionally, survival rates at a mean follow-up of 39 months were similar, with no late recurrences or aneurysmal bleeding.

Lastly, the Barrow Ruptured Aneurysm Trial26,27 found that patients assigned to endovascular treatment had better 1-year neurologic outcomes, defined as a modified Rankin score of 2 or less. Importantly, 37.7% of patients originally assigned to endovascular treatment crossed over to surgical treatment. The authors then performed intention-to-treat and as-treated analyses. Either way, patients treated by endovascular means had better neurologic outcomes at 1 year. However, no difference in the relative risk reduction in worse outcome was found on 3-year follow-up, and patients treated surgically had higher rates of aneurysm obliteration and required less aneurysm retreatment, both of which were statistically significant.

The question that remains is not whether to clip or whether to coil, but whom to clip and whom to coil.²⁸ That question must be answered on a patient-to-patient basis and requires the expertise of an interventional neuroradiologist and a vascular neurosurgeon—one of the reasons these patients are best cared for in high-volume centers providing such expertise.

MEDICAL PREVENTION OF REBLEEDING

Blood pressure management

There are no systematic data on the optimal blood pressure before securing an aneurysm. Early studies of hemodynamic augmentation in cases of ruptured untreated aneurysm reported rebleeding when the systolic blood pressure was allowed to rise above 160 mm Hg.^29,30 A recent study evaluating hypertensive intracerebral hemorrhage revealed better functional outcomes with intensive lowering of blood pressure (defined as systolic blood pressure < 140 mm Hg) but no significant reduction in the combined rate of death or severe disability.³¹ It is difficult to know if these results can be extrapolated to patients with aneurysmal subarachnoid hemorrhage. Current guidelines^3,32 say that before the aneurysm is treated, the systolic pressure should be lower than 160 mm Hg.

There is no specific drug of choice, but a short-acting, titratable medication is preferable. Nicardipine is a very good option, and labetalol might be an appropriate alternative.³³ Once the aneurysm is secured, all antihypertensive drugs should be held. Hypertension should not be treated unless the patient has clinical signs of a hypertensive crisis, such as flash pulmonary edema, myocardial infarction, or hypertensive encephalopathy.

Antifibrinolytic therapy

Risk factors: Family history, hypertension, smoking, heavy drinking

The role of antifibrinolytic therapy in aneurysmal subarachnoid hemorrhage is controversial and has been studied in 10 clinical trials. In a Swedish study,³⁴ early use of tranexamic acid (1 g intravenously over 10 minutes followed by 1 g every 6 hours for a maximum of 24 hours) reduced the rebleeding rate substantially, from 10.8% to 2.4%, with an 80% reduction in the mortality rate from ultra-early rebleeding. However, a recent Cochrane review that included this study found no overall benefit.³⁵

An ongoing multicenter randomized trial in the Netherlands will, we hope, answer this question in the near future.³⁶ At present, some centers would consider a short course of tranexamic acid before aneurysm treatment.

DIAGNOSIS AND TREATMENT OF COMPLICATIONS

Medical complications are extremely common after aneurysmal subarachnoid hemorrhage. Between 75% and 100% of patients develop some type of systemic or further neurologic derangement, which in turn has a negative impact on the long-term outcome.^37,38 In the first 72 hours, rebleeding is the most feared complication, and as mentioned previously, appropriate blood pressure management and early securing of the aneurysm minimize its risk.

NEUROLOGIC COMPLICATIONS

Hydrocephalus

Hydrocephalus is the most common early neurologic complication after aneurysmal subarachnoid hemorrhage, with an overall incidence of 50%.³⁹ Many patients with poor-grade aneurysmal subarachnoid hemorrhage and patients whose condition deteriorates due to worsening of hydrocephalus require the insertion of an external ventricular drain (Figure 1).

Up to 30% of patients who have a poor-grade aneurysmal subarachnoid hemorrhage improve neurologically with cerebrospinal fluid drainage.⁴⁰ An external ventricular drain can be safely placed, even before aneurysm treatment, and placement does not appear to increase the risk of rebleeding.^39,41 After placement, rapid weaning from the drain (clamping within 24 hours of insertion) is safe, decreases length of stay in the intensive care unit and hospital, and may be more cost-effective than gradual weaning over 96 hours.⁴²

Increased intracranial pressure

Intracranial hypertension is another potential early complication, and is frequently due to the development of hydrocephalus, cerebral edema, or rebleeding. The treatment of increased intracranial pressure does not differ from the approach used in managing severe traumatic brain injury, which includes elevating the head of the bed, sedation, analgesia, normoventilation, and cerebrospinal fluid drainage.

Hypertonic saline has been tested in several studies that were very small but nevertheless consistently showed control of intracranial pressure levels and improvement in cerebral blood flow measured by xenon CT.^43–47 Two of these studies even showed better outcomes at discharge.^43,44 However, the small number of patients prevents any meaningful conclusion regarding the use of hypertonic saline and functional outcomes.

Outcomes are much better when patients are managed in a high-volume center

Barbiturates, hypothermia, and decompressive craniectomy could be tried in refractory cases.⁴⁸ Seule et al⁴⁹ evaluated the role of therapeutic hypothermia with or without barbiturate coma in 100 patients with refractory intracranial hypertension. Only 13 patients received hypothermia by itself. At 1 year, 32 patients had achieved a good functional outcome (Glasgow Outcome Scale score 4 or 5). The remaining patients were severely disabled or had died. Of interest, the median duration of hypothermia was 7 days, and 93% of patients developed some medical complication such as electrolyte disorders (77%), pneumonia (52%), thrombocytopenia (47%), or septic shock syndrome (40%). Six patients died as a consequence of one of these complications.

Decompressive craniectomy can be life-saving in patients with refractory intracranial hypertension. However, most of these patients will die or remain severely disabled or comatose.⁵⁰

Seizure prophylaxis is controversial

Seizures can occur at the onset of intracranial hemorrhage, perioperatively, or later (ie, after the first week). The incidence varied considerably in different reports, ranging from 4% to 26%.⁵¹ Seizures occurring perioperatively, ie, after hospital admission, are less frequent and are usually the manifestation of aneurysm rebleeding.²⁴

The question is not whether to clip or coil, but whom to clip and whom to coil

Seizure prophylaxis remains controversial, especially because the use of phenytoin is associated with increased incidence of cerebral vasospasm, infarction, and worse cognitive outcomes after aneurysmal subarachnoid hemorrhage.^52,53 Therefore, routine prophylactic use of phenytoin is not recommended in these patients,³ although the effect of other antiepileptic drugs is less studied and less clear. Patients may be considered for this therapy if they have multiple risk factors for seizures, such as intraparenchymal hematoma, advanced age (> 65), middle cerebral artery aneurysm, craniotomy for aneurysm clipping, and a short course (≤ 72 hours) of an antiepileptic drug other than phenytoin, especially while the aneurysm is unsecured.³

Levetiracetam may be an alternative to phenytoin, having better pharmacodynamic and kinetic profiles, minimal protein binding, and absence of hepatic metabolism, resulting in a very low risk of drug interaction and better tolerability.^54,55 Because of these advantages, levetiracetam has become the drug of choice in several centers treating aneurysmal subarachnoid hemorrhage in the United States.

Addressing this question, a survey was sent to 25 high-volume aneurysmal subarachnoid hemorrhage academic centers in the United States. All 25 institutions answered the survey, and interestingly, levetiracetam was the first-line agent for 16 (94%) of the 17 responders that used prophylaxis, while only 1 used phenytoin as the agent of choice.⁵⁶

A retrospective cohort study by Murphy-Human et al⁵⁷ showed that a short course of levetiracetam (≤ 72 hours) was associated with higher rates of in-hospital seizures compared with an extended course of phenytoin (eg, entire hospital stay). However, the study did not address functional outcomes.⁵⁷

Continuous electroencephalographic monitoring may be considered in comatose patients, in patients requiring controlled ventilation and sedation, or in patients with unexplained alteration in consciousness. In one series of patients with aneurysmal subarachnoid hemorrhage who received continuous monitoring, the incidence of nonconvulsive status epilepticus was 19%, with an associated mortality rate of 100%.⁵⁸

Continuous quantitative electroencephalography is useful to monitor and to detect angiographic vasospasm and delayed cerebral ischemia. Relative alpha variability and the alpha-delta ratio decrease with ischemia, and this effect can precede angiographic vasospasm by 3 days.^59,60

Delayed cerebral ischemia

Delayed cerebral ischemia is defined as the occurrence of focal neurologic impairment, or a decrease of at least 2 points on the Glasgow Coma Scale that lasts for at least 1 hour, is not apparent immediately after aneurysm occlusion, and not attributable to other causes (eg, hyponatremia, fever).⁶¹

Classically, neurologic deficits that occurred within 2 weeks of aneurysm rupture were ascribed to reduced cerebral blood flow caused by delayed large-vessel vasospasm causing cerebral ischemia.⁶² However, perfusion abnormalities have also been observed with either mild or no demonstrable vasospasm.⁶³ Almost 70% of patients who survive the initial hemorrhage develop some degree of angiographic vasospasm. However, only 30% of those patients will experience symptoms.

In addition to vasospasm of large cerebral arteries, impaired autoregulation and early brain injury within the first 72 hours following subarachnoid hemorrhage may play important roles in the development of delayed cerebral ischemia.⁶⁴ Therefore, the modern concept of delayed cerebral ischemia monitoring should focus on cerebral perfusion rather than vessel diameter measurements. This underscores the importance of comprehensive, standardized monitoring techniques that provide information not only on microvasculature, but also at the level of the microcirculation, with information on perfusion, oxygen utilization and extraction, and autoregulation.

Although transcranial Doppler has been the most commonly applied tool to monitor for angiographic vasospasm, it has a low sensitivity and negative predictive value.³⁷ It is nevertheless a useful technique to monitor good-grade aneurysmal subarachnoid hemorrhage patients (WFNS score 1–3) combined with frequent neurologic examinations (Figure 3).

CT angiography is a good noninvasive alternative to digital subtraction angiography. However, it tends to overestimate the degree of vasoconstriction and does not provide information about perfusion and autoregulation.⁶⁵ Nevertheless, CT angiography combined with a CT perfusion scan can add information about autoregulation and cerebral perfusion and has been shown to be more sensitive for the diagnosis of angiographic vasospasm than transcranial Doppler and digital subtraction angiography (Figure 4).

Patients with a poor clinical condition (WFNS score 4 or 5) or receiving continuous sedation constitute a challenge in monitoring for delayed neurologic deterioration. Neurologic examination is not sensitive enough in this setting to detect subtle changes. In these specific and challenging circumstances, multimodality neuromonitoring may be useful in the early detection of delayed cerebral ischemia and may help guide therapy.⁶⁷

Several noninvasive and invasive techniques have been studied to monitor patients at risk of delayed cerebral ischemia after subarachnoid hemorrhage.⁶⁶ These include continuous electroencephalography, brain tissue oxygenation monitoring (Ptio₂), cerebral microdialysis, thermal diffusion flowmetry, and near-infrared spectroscopy. Of these techniques, Ptio₂, cerebral microdialysis, and continuous electroencephalography (see discussion of seizure prophylaxis above) have been more extensively studied. However, most of the studies were observational and very small, limiting any recommendations for using these techniques in routine clinical practice.⁶⁸

Ptio₂ is measured by inserting an intraparenchymal oxygen-sensitive microelectrode, and microdialysis requires a microcatheter with a semipermeable membrane that allows small soluble substances to cross it into the dialysate. These substances, which include markers of ischemia (ie, glucose, lactate, and pyruvate), excitotoxins (ie, glutamate and aspartate), and membrane cell damage products (ie, glycerol), can be measured. Low Ptio₂ values (< 15 mm Hg) and abnormal mycrodialysate findings (eg, glucose < 0.8 mmol/L, lactate-to-pyruvate ratio > 40) have both been associated with cerebral ischemic events and poor outcome.⁶⁸

Preventing delayed cerebral ischemia

Oral nimodipine 60 mg every 4 hours for 21 days, started on admission, carries a class I, level of evidence A recommendation in the management of aneurysmal subarachnoid hemorrhage.^3,32,69 It improves clinical outcome despite having no effect on the risk of angiographic vasospasm. The mechanism of improved outcome is unclear, but the effect may be a neuroprotective phenomenon limiting the extension of delayed cerebral ischemia.⁷⁰

If hypotension occurs, the dose can be lowered to 30 mg every 2 hours. Whether to discontinue nimodipine in this situation is controversial. Of note, the clinical benefits of nimodipine have not been replicated with other calcium channel blockers (eg, nicardipine).⁷¹

Prophylactic hyperdynamic fluid therapy, known as “triple-H” (hypervolemia, hemodilution, and hypertension) was for years the mainstay of treatment in preventing delayed cerebral ischemia due to vasospasm. However, the clinical data supporting this intervention have been called into question, as analysis of two trials found that hypervolemia did not improve outcomes or reduce the incidence of delayed cerebral ischemia, and in fact increased the rate of complications.^72,73 Based on these findings, current guidelines recommend maintaining euvolemia rather than prophylactic hypervolemia in patients with aneurysmal subarachnoid hemorrhage.^3,32,69

TREATING DELAYED CEREBRAL ISCHEMIA

Hemodynamic augmentation

In patients with neurologic deterioration due to delayed cerebral ischemia, hemodynamic augmentation is the cornerstone of treatment. This is done according to a protocol, started early, involving specific physiologic goals, clinical improvement, and escalation to invasive therapies in a timely fashion in patients at high risk of further neurologic insult (Figure 5).

The physiologic goal is to increase the delivery of oxygen and glucose to the ischemic brain. Hypertension seems to be the most effective component of hemodynamic augmentation regardless of volume status, increasing cerebral blood flow and brain tissue oxygenation, with reversal of delayed cerebral ischemic symptoms in up to two-thirds of treated patients.^74,75 However, this information comes from very small studies, with no randomized trials of induced hypertension available.

The effect of a normal saline fluid bolus in patients suspected of having delayed cerebral ischemia has been shown to increase cerebral blood flow in areas of cerebral ischemia.⁷⁴ If volume augmentation fails to improve the neurologic status, the next step is to artificially induce hypertension using vasopressors. The blood pressure target should be based on clinical improvement. A stepwise approach is reasonable in this situation, and the lowest level of blood pressure at which there is a complete reversal of the new focal neurologic deficit should be maintained.^3,29

Inotropic agents such as dobutamine or milrinone can be considered as alternatives in patients who have new neurologic deficits that are refractory to fluid boluses and vasopressors, or in a setting of subarachnoid hemorrhage-induced cardiomyopathy.^76,77

Once the neurologic deficit is reversed by hemodynamic augmentation, the blood pressure should be maintained for 48 to 72 hours at the level that reversed the deficit completely, carefully reassessed thereafter, and the patient weaned slowly. Unruptured unsecured aneurysms should not prevent blood pressure augmentation in a setting of delayed cerebral ischemia if the culprit aneurysm is treated.^3,32 If the ruptured aneurysm has not been secured, careful blood pressure augmentation can be attempted, keeping in mind that hypertension (> 160/95 mm Hg) is a risk factor for fatal aneurysm rupture.

Endovascular management of delayed cerebral ischemia

When medical augmentation fails to completely reverse the neurologic deficits, endovascular treatment can be considered. Although patients treated early in the course of delayed cerebral ischemia have better neurologic recovery, prophylactic endovascular treatment in asymptomatic patients, even if angiographic signs of spasm are present, does not improve clinical outcomes and carries the risk of fatal arterial rupture.⁷⁸

SYSTEMIC COMPLICATIONS

Hyponatremia and hypovolemia

Aneurysmal subarachnoid hemorrhage is commonly associated with abnormalities of fluid balance and electrolyte derangements. Hyponatremia (serum sodium < 135 mmol/L) occurs in 30% to 50% of patients, while the rate of hypovolemia (decreased circulating blood volume) ranges from 17% to 30%.⁷⁹ Both can negatively affect long-term outcomes.^80,81

Decreased circulating blood volume is a well-described contributor to delayed cerebral ischemia and cerebral infarction after aneurysmal subarachnoid hemorrhage.^80–82 Clinical variables such as heart rate, blood pressure, fluid balance, and serum sodium concentration are usually the cornerstones of intravascular volume status assessment. However, these variables correlate poorly with measured circulating blood volumes in those with aneurysmal subarachnoid hemorrhage.^83,84

The mechanisms responsible for the development of hyponatremia and hypovolemia after aneurysmal subarachnoid hemorrhage are not completely understood. Several factors have been described and may contribute to the increased natriuresis and, hence, to a reduction in circulating blood volume: increased circulating natriuretic peptide concentrations,^85–87 sympathetic nervous system hyperactivation,⁸⁸ and hyperreninemic hypo-
aldosteronism syndrome.^89,90

Guidelines: Before treating the aneurysm, the systolic pressure should be < 160 mm Hg

Lastly, the cerebral salt wasting syndrome, described in the 1950s,⁹¹ was thought to be a key mechanism in the development of hyponatremia and hypovolemia after aneurysmal subarachnoid hemorrhage. In contrast to the syndrome of inappropriate antidiuretic hormone, which is characterized by hyponatremia with a normal or slightly elevated intravascular volume, the characteristic feature of cerebral salt wasting syndrome is the development of hyponatremia in a setting of intravascular volume depletion.⁹² In critically ill neurologic and neurosurgical patients, this differential diagnosis is very difficult, especially in those with aneurysmal subarachnoid hemorrhage in whom the clinical assessment of fluid status is not reliable. These two syndromes might coexist and contribute to the development of hyponatremia after aneurysmal subarachnoid hemorrhage.^92,93

Hoff et al^83,84 prospectively compared the clinical assessment of fluid status by critical and intermediate care nurses and direct measurements of blood volume using pulse dye densitometry. The clinical assessment failed to accurately assess patients’ volume status. Using the same technique to measure circulating blood volume, this group showed that calculation of fluid balance does not provide adequate assessment of fluid status.^83,84

Hemodynamic monitoring tools can help guide fluid replacement in this population. Mutoh et al⁹⁴ randomized 160 patients within 24 hours of hemorrhage to receive early goal-directed fluid therapy (ie, preload volume and cardiac output monitored by transpulmonary thermodilution) vs standard therapy (ie, fluid balance or central venous pressure). Overall, no difference was found in the rates of delayed cerebral ischemia (33% vs 42%; P = .33) or favorable outcome (67% vs 57%; P = .22). However, in the subgroup of poor-grade patients (WFNS score 4 or 5), early goal-directed therapy was associated with a lower rate of delayed cerebral ischemia (5% vs 14%; P = .036) and with better functional outcomes at 3 months (52% vs 36%; P = .026).

Fluid restriction to treat hyponatremia in aneurysmal subarachnoid hemorrhage is no longer recommended because of the increased risk of cerebral infarction due to hypovolemic hypoperfusion.⁸²

Prophylactic use of mineralocorticoids (eg, fludrocortisone, hydrocortisone) has been shown to limit natriuresis, hyponatremia, and the amount of fluid required to maintain euvolemia.^95,96 Higher rates of hypokalemia and hyperglycemia, which can be easily treated, are the most common complications associated with this approach. Additionally, hypertonic saline (eg, 3% saline) can be used to correct hyponatremia in a setting of aneurysmal subarachnoid hemorrhage.⁷⁹

Cardiac complications

Cardiac complications after subarachnoid hemorrhage are most likely related to sympathetic hyperactivity and catecholamine-induced myocyte dysfunction. The pathophysiology is complex, but cardiac complications have a significant negative impact on long-term outcome in these patients.⁹⁷

Electrocardiographic changes and positive cardiac enzymes associated with aneurysmal subarachnoid hemorrhage have been extensively reported. More recently, data from studies of two-dimensional echocardiography have shown that subarachnoid hemorrhage can also be associated with significant wall-motion abnormalities and even overt cardiogenic shock.^98–100

There is no specific curative therapy; the treatment is mainly supportive. Vasopressors and inotropes may be used for hemodynamic augmentation.

Pulmonary complications

Pulmonary complications occur in 20% to 30% of all aneurysmal subarachnoid hemorrhage patients and are associated with a higher risk of delayed cerebral ischemia and death. Common pulmonary complications in this population are mild acute respiratory distress syndrome (27%), hospital-acquired pneumonia (9%), cardiogenic pulmonary edema (8%), aspiration pneumonia (6%), neurogenic pulmonary edema (2%), and pulmonary embolism (1%).^101–103

SUPPORTIVE CARE

Hyperthermia, hyperglycemia, and liberal use of transfusions have all been associated with longer stays in the intensive care unit and hospital, poorer neurologic outcomes, and higher mortality rates in patients with acute brain injury.¹⁰⁴ Noninfectious fever is the most common systemic complication after subarachnoid hemorrhage.

Antipyretic drugs such as acetaminophen and ibuprofen are not very effective in reducing fever in the subarachnoid hemorrhage population, but should still be used as first-line therapy. The use of surface and intravascular devices can be considered when fevers do not respond to nonsteroidal anti-inflammatory drugs.

Fluid restriction to treat hyponatremia in aneurysmal subarachnoid hemorrhage is no longer recommended

Although no prospective randomized trial has addressed the impact of induced normothermia on long-term outcome and mortality in aneurysmal subarachnoid hemorrhage patients, fever control has been shown to reduce cerebral metabolic distress, irrespective of intracranial pressure.¹⁰⁵ Maintenance of normothermia (< 37.5°C) seems reasonable, especially in aneurysmal subarachnoid hemorrhage patients at risk of or with active delayed cerebral ischemia.¹⁰⁶

Current guidelines^3,32,69 strongly recommend avoiding hypoglycemia, defined as a serum glucose level less than 80 mg/dL, but suggest keeping the blood sugar level below 180 or 200 mg/dL.

At the moment, there is no clear threshold for transfusion in patients with aneurysmal subarachnoid hemorrhage. Current guidelines suggest keeping hemoglobin levels between 8 and 10 g/dL.³

Preventing venous thromboembolism

The incidence of venous thromboembolism after aneurysmal subarachnoid hemorrhage varies widely, from 1.5% to 18%.¹⁰⁷ Active surveillance with venous Doppler ultrasonography has found asymptomatic deep vein thrombosis in up to 3.4% of poor-grade aneurysmal subarachnoid hemorrhage patients receiving pharmacologic thromboprophylaxis.¹⁰⁸

In a retrospective study of 170 patients, our group showed that giving drugs to prevent venous thromboembolism (unfractionated heparin 5,000 IU subcutaneously every 12 hours or dalteparin 5,000 IU subcutaneously daily), starting within 24 hours of aneurysm treatment, could be safe.¹⁰⁹ Fifty-eight percent of these patients had an external ventricular drain in place. One patient developed a major cerebral hemorrhagic complication and died while on unfractionated heparin; however, the patient was also on dual antiplatelet therapy with aspirin and clopidogrel.¹⁰⁹

Current guidelines suggest that intermittent compression devices be applied in all patients before aneurysm treatment. Pharmacologic thromboprophylaxis with a heparinoid can be started 12 to 24 hours after aneurysm treatment.^3,109

A TEAM APPROACH

Patients with subarachnoid hemorrhage need integrated care from different medical and nursing specialties. The best outcomes are achieved by systems that can focus as a team on the collective goal of quick intervention to secure the aneurysm, followed by measures to minimize secondary brain injury.

The modern concept of cerebral monitoring in a setting of subarachnoid hemorrhage should focus on brain perfusion rather than vascular diameter. Although the search continues for new diagnostic, prognostic, and therapeutic tools, there is no “silver bullet” that will help all patients. Instead, it is the systematic integration and application of many small advances that will ultimately lead to better outcomes.

ACKNOWLEDGMENT

This work was supported by research funding provided by the Bitove Foundation, which has been supportive of our clinical and research work for several years.

Aneurysmal subarachnoid hemorrhage is a devastating condition, with an estimated death rate of 30% during the initial episode.^1,2 Approximately the same number of patients survive but leave the hospital with disabling neurologic deficits.³

However, better outcomes can be achieved by systems that are able to work as a team on the collective goal of quick intervention to secure the ruptured aneurysm, followed by the implementation of measures to minimize secondary brain injury. Although the search for new diagnostic, prognostic, and therapeutic modalities continues, it is clear that there exists no “silver bullet” that will help all patients. Instead, it is the systematic integration and application of small advances that will ultimately maximize the patient’s chances of survival and neurologic recovery.

This review focuses on the management of aneurysmal subarachnoid hemorrhage and its systemic and neurologic complications.

ANEURYSM IS THE MOST COMMON CAUSE OF SUBARACHNOID BLEEDING

Aneurysmal subarachnoid hemorrhage, ie, rupture of an intracranial aneurysm, flooding  the subarachnoid space with blood, affects about 24,000 Americans each year.^1,2 A ruptured aneurysm is the most common cause of subarachnoid hemorrhage, accounting for about 85% of cases. Less common causes include idiopathic benign perimesencephalic hemorrhage, arteriovenous malformation, dural arteriovenous fistula, and hemorrhagic mycotic aneurysm. These have their own natural history, pathophysiology, and specific treatment, and will not be addressed in this article.

Risk factors for aneurysmal subarachnoid hemorrhage include having a first-degree relative who had the disease, hypertension, smoking, and consuming more than 150 g of alcohol per week.⁴

CLINICAL PRESENTATION AND DIAGNOSIS

The key symptom of aneurysmal subarachnoid hemorrhage is the abrupt onset of severe headache that peaks in intensity over 1 hour,⁵ often described as “the worst headache of my life.” Headache is accompanied by brief loss of consciousness in 53% of cases (conversely, nearly half of patients maintain normal mental status), by nausea or vomiting in 77%, and by meningismus (neck pain or stiffness) in 35%.⁶

These clinical manifestations and risk factors have been incorporated into a decision rule:

Obtain brain imaging if the patient has acute headache reaching maximal intensity within 1 hour, associated with any of the following factors:

• Age 40 or older

• Neck pain or stiffness

• Witnessed loss of consciousness

• Onset during exertion

• “Thunderclap” headache (ie, instantly peaking pain)

• Limited neck flexion on examination.⁵

This decision rule has nearly 100% sensitivity for aneurysmal subarachnoid hemorrhage in clinical practice.⁵ All patients require brain imaging if they have a severe headache plus either abnormal neurologic findings (eg, a focal neurologic deficit) or a history of cerebral aneurysm.

Emergency physicians should have a low threshold for ordering noncontrast computed tomography (CT) of the head in patients with even mild symptoms suggesting aneurysmal subarachnoid hemorrhage. Failure to order CT is the most common diagnostic error in this situation.⁶ CT performed within 6 hours of headache onset is nearly 100% sensitive for this condition,⁷ but the sensitivity falls to 93% after the first 24 hours and to less than 60% after 5 days.⁸ In patients who have symptoms highly suggestive of aneurysmal subarachnoid hemorrhage but a normal CT, lumbar puncture is the next diagnostic step.

There are two alternatives to CT followed by lumbar puncture: ie, noncontrast CT followed by CT angiography,^9,10 and magnetic resonance imaging followed by magnetic resonance angiography. In patients with suspicious clinical symptoms but negative CT results, CT followed by CT angiography can rule out aneurysmal subarachnoid hemorrhage with a 99% probability.^9,10 However, CT followed by lumbar puncture remains the standard of care and carries a class I recommendation in the American Heart Association guidelines for ruling out subarachnoid hemorrhage.⁵

GRADING THE SEVERITY OF SUBARACHNOID HEMORRHAGE

Age, the thickness of the blood layer in the subarachnoid space, intraventricular hemorrhage and the findings of the neurologic examination at presentation are predictors of long-term outcomes in aneurysmal subarachnoid hemorrhage (Figure 1).

Different grading systems used in clinical practice are based on the findings on the initial neurologic examination and on the initial noncontrast CT (ie, the thickness of the blood, and whether intraventricular hemorrhage is present). Among the most widely used are those developed by Hunt and Hess¹² and by the World Federation of Neurological Surgeons¹¹ (WFNS), and the CT grading scales (Fisher¹³ or its modified version¹⁴)  (Tables 1 and 2). With either the Hunt and Hess scale or the WFNS scale, the higher the score, the worse the patient’s probable outcome. Scores on both Fisher scales correlate with the risk of angiographic vasospasm. The higher the grade, the higher the risk of angiographic vasospasm.

The VASOGRADE score—a combination of the WFNS score and the modified Fisher scale—stratifies patients at risk of delayed cerebral ischemia, allowing for a tailored monitoring strategy.¹⁵ There are three variations:

• VASOGRADE green—Modified Fisher 1 or 2 and WFNS 1 or 2

• VASOGRADE yellow—Modified Fisher 3 or 4 and WFNS 1, 2, or 3

• VASOGRADE red—WFNS 4 or 5. 

After the initial bleeding event, patients with aneurysmal subarachnoid hemorrhage are at high risk of delayed systemic and neurologic complications, with poor functional outcomes. Delayed cerebral ischemia holds the greatest risk of an unfavorable outcome and ultimately can lead to cerebral infarction, disability, and death.^6,7

INITIAL MANAGEMENT

After aneurysmal subarachnoid hemorrhage is diagnosed, the initial management (Figure 2) includes appropriate medical prevention of rebleeding (which includes supportive care, blood pressure management, and, perhaps, the early use of a short course of an antifibrinolytic drug) and early transfer to a high-volume center for securing the aneurysm. The reported incidence of rebleeding varies from 5% to 22% in the first 72 hours. “Ultra-early” rebleeding (within 24 hours of hemorrhage) has been reported, with an incidence as high as 15% and a fatality rate around 70%. Patients with poor-grade aneurysmal subarachnoid hemorrhage, larger aneurysms, and “sentinel bleeds” are at higher risk of rebleeding.16

Outcomes are much better when patients are managed in a high-volume center, with a specialized neurointensive care unit¹⁷ and access to an interdisciplinary team.¹⁸ Regardless of the initial grade, patients with aneurysmal subarachnoid hemorrhage should be quickly transferred to a high-volume center, defined as one treating at least 35 cases per year, and the benefit is greater in centers treating more than 60 cases per year.¹⁹ The higher the caseload in any given hospital, the better the clinical outcomes in this population.²⁰

Treating cerebral aneurysm: Clipping or coiling

Early aneurysm repair is generally considered the standard of care and the best strategy to reduce the risk of rebleeding. Further, early treatment may be associated with a lower risk of delayed cerebral ischemia²¹ and better outcomes.²²

Three randomized clinical trials have compared surgical clipping and endovascular repair (placement of small metal coils within the aneurysm to promote clotting).

The International Subarachnoid Aneurysm Trial²³ showed a reduction of 23% in relative risk and of 7% in absolute risk in patients who underwent endovascular treatment compared with surgery. The survival benefit persisted at a mean of 9 years (range 6–14 years), but with a higher annual rate of aneurysm recurrence in the coiling group (2.9% vs 0.9%).²⁴ Of note, this trial included only patients with aneurysms deemed suitable for both coiling and clipping, so that the exclusion rate was high. Most of the patients presented with good-grade (WFNS score 1–3), small aneurysms (< 5 mm) in the anterior circulation.

A single-center Finnish study²⁵ found no differences in rates of recovery, disability, and  death at 1 year, comparing surgery and endovascular treatment. Additionally, survival rates at a mean follow-up of 39 months were similar, with no late recurrences or aneurysmal bleeding.

Lastly, the Barrow Ruptured Aneurysm Trial26,27 found that patients assigned to endovascular treatment had better 1-year neurologic outcomes, defined as a modified Rankin score of 2 or less. Importantly, 37.7% of patients originally assigned to endovascular treatment crossed over to surgical treatment. The authors then performed intention-to-treat and as-treated analyses. Either way, patients treated by endovascular means had better neurologic outcomes at 1 year. However, no difference in the relative risk reduction in worse outcome was found on 3-year follow-up, and patients treated surgically had higher rates of aneurysm obliteration and required less aneurysm retreatment, both of which were statistically significant.

The question that remains is not whether to clip or whether to coil, but whom to clip and whom to coil.²⁸ That question must be answered on a patient-to-patient basis and requires the expertise of an interventional neuroradiologist and a vascular neurosurgeon—one of the reasons these patients are best cared for in high-volume centers providing such expertise.

MEDICAL PREVENTION OF REBLEEDING

Blood pressure management

There are no systematic data on the optimal blood pressure before securing an aneurysm. Early studies of hemodynamic augmentation in cases of ruptured untreated aneurysm reported rebleeding when the systolic blood pressure was allowed to rise above 160 mm Hg.^29,30 A recent study evaluating hypertensive intracerebral hemorrhage revealed better functional outcomes with intensive lowering of blood pressure (defined as systolic blood pressure < 140 mm Hg) but no significant reduction in the combined rate of death or severe disability.³¹ It is difficult to know if these results can be extrapolated to patients with aneurysmal subarachnoid hemorrhage. Current guidelines^3,32 say that before the aneurysm is treated, the systolic pressure should be lower than 160 mm Hg.

There is no specific drug of choice, but a short-acting, titratable medication is preferable. Nicardipine is a very good option, and labetalol might be an appropriate alternative.³³ Once the aneurysm is secured, all antihypertensive drugs should be held. Hypertension should not be treated unless the patient has clinical signs of a hypertensive crisis, such as flash pulmonary edema, myocardial infarction, or hypertensive encephalopathy.

Antifibrinolytic therapy

Risk factors: Family history, hypertension, smoking, heavy drinking

The role of antifibrinolytic therapy in aneurysmal subarachnoid hemorrhage is controversial and has been studied in 10 clinical trials. In a Swedish study,³⁴ early use of tranexamic acid (1 g intravenously over 10 minutes followed by 1 g every 6 hours for a maximum of 24 hours) reduced the rebleeding rate substantially, from 10.8% to 2.4%, with an 80% reduction in the mortality rate from ultra-early rebleeding. However, a recent Cochrane review that included this study found no overall benefit.³⁵

An ongoing multicenter randomized trial in the Netherlands will, we hope, answer this question in the near future.³⁶ At present, some centers would consider a short course of tranexamic acid before aneurysm treatment.

DIAGNOSIS AND TREATMENT OF COMPLICATIONS

Medical complications are extremely common after aneurysmal subarachnoid hemorrhage. Between 75% and 100% of patients develop some type of systemic or further neurologic derangement, which in turn has a negative impact on the long-term outcome.^37,38 In the first 72 hours, rebleeding is the most feared complication, and as mentioned previously, appropriate blood pressure management and early securing of the aneurysm minimize its risk.

NEUROLOGIC COMPLICATIONS

Hydrocephalus

Hydrocephalus is the most common early neurologic complication after aneurysmal subarachnoid hemorrhage, with an overall incidence of 50%.³⁹ Many patients with poor-grade aneurysmal subarachnoid hemorrhage and patients whose condition deteriorates due to worsening of hydrocephalus require the insertion of an external ventricular drain (Figure 1).

Up to 30% of patients who have a poor-grade aneurysmal subarachnoid hemorrhage improve neurologically with cerebrospinal fluid drainage.⁴⁰ An external ventricular drain can be safely placed, even before aneurysm treatment, and placement does not appear to increase the risk of rebleeding.^39,41 After placement, rapid weaning from the drain (clamping within 24 hours of insertion) is safe, decreases length of stay in the intensive care unit and hospital, and may be more cost-effective than gradual weaning over 96 hours.⁴²

Increased intracranial pressure

Intracranial hypertension is another potential early complication, and is frequently due to the development of hydrocephalus, cerebral edema, or rebleeding. The treatment of increased intracranial pressure does not differ from the approach used in managing severe traumatic brain injury, which includes elevating the head of the bed, sedation, analgesia, normoventilation, and cerebrospinal fluid drainage.

Hypertonic saline has been tested in several studies that were very small but nevertheless consistently showed control of intracranial pressure levels and improvement in cerebral blood flow measured by xenon CT.^43–47 Two of these studies even showed better outcomes at discharge.^43,44 However, the small number of patients prevents any meaningful conclusion regarding the use of hypertonic saline and functional outcomes.

Outcomes are much better when patients are managed in a high-volume center

Barbiturates, hypothermia, and decompressive craniectomy could be tried in refractory cases.⁴⁸ Seule et al⁴⁹ evaluated the role of therapeutic hypothermia with or without barbiturate coma in 100 patients with refractory intracranial hypertension. Only 13 patients received hypothermia by itself. At 1 year, 32 patients had achieved a good functional outcome (Glasgow Outcome Scale score 4 or 5). The remaining patients were severely disabled or had died. Of interest, the median duration of hypothermia was 7 days, and 93% of patients developed some medical complication such as electrolyte disorders (77%), pneumonia (52%), thrombocytopenia (47%), or septic shock syndrome (40%). Six patients died as a consequence of one of these complications.

Decompressive craniectomy can be life-saving in patients with refractory intracranial hypertension. However, most of these patients will die or remain severely disabled or comatose.⁵⁰

Seizure prophylaxis is controversial

Seizures can occur at the onset of intracranial hemorrhage, perioperatively, or later (ie, after the first week). The incidence varied considerably in different reports, ranging from 4% to 26%.⁵¹ Seizures occurring perioperatively, ie, after hospital admission, are less frequent and are usually the manifestation of aneurysm rebleeding.²⁴

The question is not whether to clip or coil, but whom to clip and whom to coil

Seizure prophylaxis remains controversial, especially because the use of phenytoin is associated with increased incidence of cerebral vasospasm, infarction, and worse cognitive outcomes after aneurysmal subarachnoid hemorrhage.^52,53 Therefore, routine prophylactic use of phenytoin is not recommended in these patients,³ although the effect of other antiepileptic drugs is less studied and less clear. Patients may be considered for this therapy if they have multiple risk factors for seizures, such as intraparenchymal hematoma, advanced age (> 65), middle cerebral artery aneurysm, craniotomy for aneurysm clipping, and a short course (≤ 72 hours) of an antiepileptic drug other than phenytoin, especially while the aneurysm is unsecured.³

Levetiracetam may be an alternative to phenytoin, having better pharmacodynamic and kinetic profiles, minimal protein binding, and absence of hepatic metabolism, resulting in a very low risk of drug interaction and better tolerability.^54,55 Because of these advantages, levetiracetam has become the drug of choice in several centers treating aneurysmal subarachnoid hemorrhage in the United States.

Addressing this question, a survey was sent to 25 high-volume aneurysmal subarachnoid hemorrhage academic centers in the United States. All 25 institutions answered the survey, and interestingly, levetiracetam was the first-line agent for 16 (94%) of the 17 responders that used prophylaxis, while only 1 used phenytoin as the agent of choice.⁵⁶

A retrospective cohort study by Murphy-Human et al⁵⁷ showed that a short course of levetiracetam (≤ 72 hours) was associated with higher rates of in-hospital seizures compared with an extended course of phenytoin (eg, entire hospital stay). However, the study did not address functional outcomes.⁵⁷

Continuous electroencephalographic monitoring may be considered in comatose patients, in patients requiring controlled ventilation and sedation, or in patients with unexplained alteration in consciousness. In one series of patients with aneurysmal subarachnoid hemorrhage who received continuous monitoring, the incidence of nonconvulsive status epilepticus was 19%, with an associated mortality rate of 100%.⁵⁸

Continuous quantitative electroencephalography is useful to monitor and to detect angiographic vasospasm and delayed cerebral ischemia. Relative alpha variability and the alpha-delta ratio decrease with ischemia, and this effect can precede angiographic vasospasm by 3 days.^59,60

Delayed cerebral ischemia

Delayed cerebral ischemia is defined as the occurrence of focal neurologic impairment, or a decrease of at least 2 points on the Glasgow Coma Scale that lasts for at least 1 hour, is not apparent immediately after aneurysm occlusion, and not attributable to other causes (eg, hyponatremia, fever).⁶¹

Classically, neurologic deficits that occurred within 2 weeks of aneurysm rupture were ascribed to reduced cerebral blood flow caused by delayed large-vessel vasospasm causing cerebral ischemia.⁶² However, perfusion abnormalities have also been observed with either mild or no demonstrable vasospasm.⁶³ Almost 70% of patients who survive the initial hemorrhage develop some degree of angiographic vasospasm. However, only 30% of those patients will experience symptoms.

In addition to vasospasm of large cerebral arteries, impaired autoregulation and early brain injury within the first 72 hours following subarachnoid hemorrhage may play important roles in the development of delayed cerebral ischemia.⁶⁴ Therefore, the modern concept of delayed cerebral ischemia monitoring should focus on cerebral perfusion rather than vessel diameter measurements. This underscores the importance of comprehensive, standardized monitoring techniques that provide information not only on microvasculature, but also at the level of the microcirculation, with information on perfusion, oxygen utilization and extraction, and autoregulation.

Although transcranial Doppler has been the most commonly applied tool to monitor for angiographic vasospasm, it has a low sensitivity and negative predictive value.³⁷ It is nevertheless a useful technique to monitor good-grade aneurysmal subarachnoid hemorrhage patients (WFNS score 1–3) combined with frequent neurologic examinations (Figure 3).

CT angiography is a good noninvasive alternative to digital subtraction angiography. However, it tends to overestimate the degree of vasoconstriction and does not provide information about perfusion and autoregulation.⁶⁵ Nevertheless, CT angiography combined with a CT perfusion scan can add information about autoregulation and cerebral perfusion and has been shown to be more sensitive for the diagnosis of angiographic vasospasm than transcranial Doppler and digital subtraction angiography (Figure 4).

Patients with a poor clinical condition (WFNS score 4 or 5) or receiving continuous sedation constitute a challenge in monitoring for delayed neurologic deterioration. Neurologic examination is not sensitive enough in this setting to detect subtle changes. In these specific and challenging circumstances, multimodality neuromonitoring may be useful in the early detection of delayed cerebral ischemia and may help guide therapy.⁶⁷

Several noninvasive and invasive techniques have been studied to monitor patients at risk of delayed cerebral ischemia after subarachnoid hemorrhage.⁶⁶ These include continuous electroencephalography, brain tissue oxygenation monitoring (Ptio₂), cerebral microdialysis, thermal diffusion flowmetry, and near-infrared spectroscopy. Of these techniques, Ptio₂, cerebral microdialysis, and continuous electroencephalography (see discussion of seizure prophylaxis above) have been more extensively studied. However, most of the studies were observational and very small, limiting any recommendations for using these techniques in routine clinical practice.⁶⁸

Ptio₂ is measured by inserting an intraparenchymal oxygen-sensitive microelectrode, and microdialysis requires a microcatheter with a semipermeable membrane that allows small soluble substances to cross it into the dialysate. These substances, which include markers of ischemia (ie, glucose, lactate, and pyruvate), excitotoxins (ie, glutamate and aspartate), and membrane cell damage products (ie, glycerol), can be measured. Low Ptio₂ values (< 15 mm Hg) and abnormal mycrodialysate findings (eg, glucose < 0.8 mmol/L, lactate-to-pyruvate ratio > 40) have both been associated with cerebral ischemic events and poor outcome.⁶⁸

Preventing delayed cerebral ischemia

Oral nimodipine 60 mg every 4 hours for 21 days, started on admission, carries a class I, level of evidence A recommendation in the management of aneurysmal subarachnoid hemorrhage.^3,32,69 It improves clinical outcome despite having no effect on the risk of angiographic vasospasm. The mechanism of improved outcome is unclear, but the effect may be a neuroprotective phenomenon limiting the extension of delayed cerebral ischemia.⁷⁰

If hypotension occurs, the dose can be lowered to 30 mg every 2 hours. Whether to discontinue nimodipine in this situation is controversial. Of note, the clinical benefits of nimodipine have not been replicated with other calcium channel blockers (eg, nicardipine).⁷¹

Prophylactic hyperdynamic fluid therapy, known as “triple-H” (hypervolemia, hemodilution, and hypertension) was for years the mainstay of treatment in preventing delayed cerebral ischemia due to vasospasm. However, the clinical data supporting this intervention have been called into question, as analysis of two trials found that hypervolemia did not improve outcomes or reduce the incidence of delayed cerebral ischemia, and in fact increased the rate of complications.^72,73 Based on these findings, current guidelines recommend maintaining euvolemia rather than prophylactic hypervolemia in patients with aneurysmal subarachnoid hemorrhage.^3,32,69

TREATING DELAYED CEREBRAL ISCHEMIA

Hemodynamic augmentation

In patients with neurologic deterioration due to delayed cerebral ischemia, hemodynamic augmentation is the cornerstone of treatment. This is done according to a protocol, started early, involving specific physiologic goals, clinical improvement, and escalation to invasive therapies in a timely fashion in patients at high risk of further neurologic insult (Figure 5).

The physiologic goal is to increase the delivery of oxygen and glucose to the ischemic brain. Hypertension seems to be the most effective component of hemodynamic augmentation regardless of volume status, increasing cerebral blood flow and brain tissue oxygenation, with reversal of delayed cerebral ischemic symptoms in up to two-thirds of treated patients.^74,75 However, this information comes from very small studies, with no randomized trials of induced hypertension available.

The effect of a normal saline fluid bolus in patients suspected of having delayed cerebral ischemia has been shown to increase cerebral blood flow in areas of cerebral ischemia.⁷⁴ If volume augmentation fails to improve the neurologic status, the next step is to artificially induce hypertension using vasopressors. The blood pressure target should be based on clinical improvement. A stepwise approach is reasonable in this situation, and the lowest level of blood pressure at which there is a complete reversal of the new focal neurologic deficit should be maintained.^3,29

Inotropic agents such as dobutamine or milrinone can be considered as alternatives in patients who have new neurologic deficits that are refractory to fluid boluses and vasopressors, or in a setting of subarachnoid hemorrhage-induced cardiomyopathy.^76,77

Once the neurologic deficit is reversed by hemodynamic augmentation, the blood pressure should be maintained for 48 to 72 hours at the level that reversed the deficit completely, carefully reassessed thereafter, and the patient weaned slowly. Unruptured unsecured aneurysms should not prevent blood pressure augmentation in a setting of delayed cerebral ischemia if the culprit aneurysm is treated.^3,32 If the ruptured aneurysm has not been secured, careful blood pressure augmentation can be attempted, keeping in mind that hypertension (> 160/95 mm Hg) is a risk factor for fatal aneurysm rupture.

Endovascular management of delayed cerebral ischemia

When medical augmentation fails to completely reverse the neurologic deficits, endovascular treatment can be considered. Although patients treated early in the course of delayed cerebral ischemia have better neurologic recovery, prophylactic endovascular treatment in asymptomatic patients, even if angiographic signs of spasm are present, does not improve clinical outcomes and carries the risk of fatal arterial rupture.⁷⁸

SYSTEMIC COMPLICATIONS

Hyponatremia and hypovolemia

Aneurysmal subarachnoid hemorrhage is commonly associated with abnormalities of fluid balance and electrolyte derangements. Hyponatremia (serum sodium < 135 mmol/L) occurs in 30% to 50% of patients, while the rate of hypovolemia (decreased circulating blood volume) ranges from 17% to 30%.⁷⁹ Both can negatively affect long-term outcomes.^80,81

Decreased circulating blood volume is a well-described contributor to delayed cerebral ischemia and cerebral infarction after aneurysmal subarachnoid hemorrhage.^80–82 Clinical variables such as heart rate, blood pressure, fluid balance, and serum sodium concentration are usually the cornerstones of intravascular volume status assessment. However, these variables correlate poorly with measured circulating blood volumes in those with aneurysmal subarachnoid hemorrhage.^83,84

The mechanisms responsible for the development of hyponatremia and hypovolemia after aneurysmal subarachnoid hemorrhage are not completely understood. Several factors have been described and may contribute to the increased natriuresis and, hence, to a reduction in circulating blood volume: increased circulating natriuretic peptide concentrations,^85–87 sympathetic nervous system hyperactivation,⁸⁸ and hyperreninemic hypo-
aldosteronism syndrome.^89,90

Guidelines: Before treating the aneurysm, the systolic pressure should be < 160 mm Hg

Lastly, the cerebral salt wasting syndrome, described in the 1950s,⁹¹ was thought to be a key mechanism in the development of hyponatremia and hypovolemia after aneurysmal subarachnoid hemorrhage. In contrast to the syndrome of inappropriate antidiuretic hormone, which is characterized by hyponatremia with a normal or slightly elevated intravascular volume, the characteristic feature of cerebral salt wasting syndrome is the development of hyponatremia in a setting of intravascular volume depletion.⁹² In critically ill neurologic and neurosurgical patients, this differential diagnosis is very difficult, especially in those with aneurysmal subarachnoid hemorrhage in whom the clinical assessment of fluid status is not reliable. These two syndromes might coexist and contribute to the development of hyponatremia after aneurysmal subarachnoid hemorrhage.^92,93

Hoff et al^83,84 prospectively compared the clinical assessment of fluid status by critical and intermediate care nurses and direct measurements of blood volume using pulse dye densitometry. The clinical assessment failed to accurately assess patients’ volume status. Using the same technique to measure circulating blood volume, this group showed that calculation of fluid balance does not provide adequate assessment of fluid status.^83,84

Hemodynamic monitoring tools can help guide fluid replacement in this population. Mutoh et al⁹⁴ randomized 160 patients within 24 hours of hemorrhage to receive early goal-directed fluid therapy (ie, preload volume and cardiac output monitored by transpulmonary thermodilution) vs standard therapy (ie, fluid balance or central venous pressure). Overall, no difference was found in the rates of delayed cerebral ischemia (33% vs 42%; P = .33) or favorable outcome (67% vs 57%; P = .22). However, in the subgroup of poor-grade patients (WFNS score 4 or 5), early goal-directed therapy was associated with a lower rate of delayed cerebral ischemia (5% vs 14%; P = .036) and with better functional outcomes at 3 months (52% vs 36%; P = .026).

Fluid restriction to treat hyponatremia in aneurysmal subarachnoid hemorrhage is no longer recommended because of the increased risk of cerebral infarction due to hypovolemic hypoperfusion.⁸²

Prophylactic use of mineralocorticoids (eg, fludrocortisone, hydrocortisone) has been shown to limit natriuresis, hyponatremia, and the amount of fluid required to maintain euvolemia.^95,96 Higher rates of hypokalemia and hyperglycemia, which can be easily treated, are the most common complications associated with this approach. Additionally, hypertonic saline (eg, 3% saline) can be used to correct hyponatremia in a setting of aneurysmal subarachnoid hemorrhage.⁷⁹

Cardiac complications

Cardiac complications after subarachnoid hemorrhage are most likely related to sympathetic hyperactivity and catecholamine-induced myocyte dysfunction. The pathophysiology is complex, but cardiac complications have a significant negative impact on long-term outcome in these patients.⁹⁷

Electrocardiographic changes and positive cardiac enzymes associated with aneurysmal subarachnoid hemorrhage have been extensively reported. More recently, data from studies of two-dimensional echocardiography have shown that subarachnoid hemorrhage can also be associated with significant wall-motion abnormalities and even overt cardiogenic shock.^98–100

There is no specific curative therapy; the treatment is mainly supportive. Vasopressors and inotropes may be used for hemodynamic augmentation.

Pulmonary complications

Pulmonary complications occur in 20% to 30% of all aneurysmal subarachnoid hemorrhage patients and are associated with a higher risk of delayed cerebral ischemia and death. Common pulmonary complications in this population are mild acute respiratory distress syndrome (27%), hospital-acquired pneumonia (9%), cardiogenic pulmonary edema (8%), aspiration pneumonia (6%), neurogenic pulmonary edema (2%), and pulmonary embolism (1%).^101–103

SUPPORTIVE CARE

Hyperthermia, hyperglycemia, and liberal use of transfusions have all been associated with longer stays in the intensive care unit and hospital, poorer neurologic outcomes, and higher mortality rates in patients with acute brain injury.¹⁰⁴ Noninfectious fever is the most common systemic complication after subarachnoid hemorrhage.

Antipyretic drugs such as acetaminophen and ibuprofen are not very effective in reducing fever in the subarachnoid hemorrhage population, but should still be used as first-line therapy. The use of surface and intravascular devices can be considered when fevers do not respond to nonsteroidal anti-inflammatory drugs.

Fluid restriction to treat hyponatremia in aneurysmal subarachnoid hemorrhage is no longer recommended

Although no prospective randomized trial has addressed the impact of induced normothermia on long-term outcome and mortality in aneurysmal subarachnoid hemorrhage patients, fever control has been shown to reduce cerebral metabolic distress, irrespective of intracranial pressure.¹⁰⁵ Maintenance of normothermia (< 37.5°C) seems reasonable, especially in aneurysmal subarachnoid hemorrhage patients at risk of or with active delayed cerebral ischemia.¹⁰⁶

Current guidelines^3,32,69 strongly recommend avoiding hypoglycemia, defined as a serum glucose level less than 80 mg/dL, but suggest keeping the blood sugar level below 180 or 200 mg/dL.

At the moment, there is no clear threshold for transfusion in patients with aneurysmal subarachnoid hemorrhage. Current guidelines suggest keeping hemoglobin levels between 8 and 10 g/dL.³

Preventing venous thromboembolism

The incidence of venous thromboembolism after aneurysmal subarachnoid hemorrhage varies widely, from 1.5% to 18%.¹⁰⁷ Active surveillance with venous Doppler ultrasonography has found asymptomatic deep vein thrombosis in up to 3.4% of poor-grade aneurysmal subarachnoid hemorrhage patients receiving pharmacologic thromboprophylaxis.¹⁰⁸

In a retrospective study of 170 patients, our group showed that giving drugs to prevent venous thromboembolism (unfractionated heparin 5,000 IU subcutaneously every 12 hours or dalteparin 5,000 IU subcutaneously daily), starting within 24 hours of aneurysm treatment, could be safe.¹⁰⁹ Fifty-eight percent of these patients had an external ventricular drain in place. One patient developed a major cerebral hemorrhagic complication and died while on unfractionated heparin; however, the patient was also on dual antiplatelet therapy with aspirin and clopidogrel.¹⁰⁹

Current guidelines suggest that intermittent compression devices be applied in all patients before aneurysm treatment. Pharmacologic thromboprophylaxis with a heparinoid can be started 12 to 24 hours after aneurysm treatment.^3,109

A TEAM APPROACH

Patients with subarachnoid hemorrhage need integrated care from different medical and nursing specialties. The best outcomes are achieved by systems that can focus as a team on the collective goal of quick intervention to secure the aneurysm, followed by measures to minimize secondary brain injury.

The modern concept of cerebral monitoring in a setting of subarachnoid hemorrhage should focus on brain perfusion rather than vascular diameter. Although the search continues for new diagnostic, prognostic, and therapeutic tools, there is no “silver bullet” that will help all patients. Instead, it is the systematic integration and application of many small advances that will ultimately lead to better outcomes.

ACKNOWLEDGMENT

This work was supported by research funding provided by the Bitove Foundation, which has been supportive of our clinical and research work for several years.

A 48-year-old woman presented to the emergency department after 2 days of nonproductive cough, chest discomfort, worsening shortness of breath, and subjective fever. She had a history of systemic sclerosis. She was currently taking prednisone 20 mg daily and aspirin 81 mg daily.

Physical examination revealed tachypnea (28 breaths per minute), and bronchial breath sounds in the left lower chest posteriorly.

The initial laboratory workup revealed:

• Hemoglobin 106 g/L (reference range 115–155)
• Mean corpuscular volume 84 fL (80–100)
• White blood cell count 29.4 × 10⁹/L (3.70–11.0), with 85% neutrophils
• Platelet count 180 × 10⁹/L (150–350)
• Lactate dehydrogenase 312 U/L (100–220).

Chest radiography showed opacification of the lower lobe of the left lung.

She was admitted to the hospital and started treatment with intravenous azithromycin and ceftriaxone for presumed community-acquired pneumonia, based on the clinical presentation and findings on chest radiography. Because of her immunosuppression (due to chronic prednisone therapy) and her high lactate dehydrogenase level, Pneumocystis jirovecii pneumonia was suspected, and because she had a history of allergy to trimethoprim-sulfamethoxazole and pentamidine, she was started on dapsone.

During the next 24 hours, she developed worsening dyspnea, hypoxia, and cyanosis. She was placed on an air-entrainment mask, with a fraction of inspired oxygen of 0.5. Pulse oximetry showed an oxygen saturation of 85%, but arterial blood gas analysis indicated an oxyhemoglobin concentration of 95%.

THE ‘SATURATION GAP’

1. Which is most likely to have caused the discrepancy between the oxyhemoglobin concentration and the oxygen saturation by pulse oximetry in this patient?

• Methemoglobinemia
• Carbon monoxide poisoning
• Inappropriate placement of the pulse oximeter probe
• Pulmonary embolism

Methemoglobinemia is the most likely cause of the discrepancy between the oxyhemoglobin levels and the oxygen saturation by pulse oximetry, a phenomenon also known as the “saturation gap.” Other common causes are cyanide poisoning and carbon monoxide poisoning.

P jirovecii pneumonia was suspected, and dapsone was started in light of her allergy to trimethoprim-sulfamethoxazole and pentamidine

Carbon monoxide poisoning, however, does not explain our patient’s cyanosis. On the contrary, carbon monoxide poisoning can actually cause the patient’s lips and mucous membranes to appear unnaturally bright pink. Also, carbon monoxide poisoning raises the blood concentration of carboxyhemoglobin (which has a high affinity for oxygen), and this usually causes pulse oximetry to read inappropriately high, whereas in our patient it read low.

Incorrect placement of the pulse oximeter probe can result in an inaccurate measurement of oxygen saturation. Visualization of the waveform on the plethysmograph or the signal quality index can be used to assess adequate placement of the pulse oximeter probe. However, inadequate probe placement does not explain our patient’s dyspnea and cyanosis.

Pulmonary embolism can lead to hypoxia as a result of ventilation-perfusion mismatch. However, pulmonary embolism leading to low oxygen saturation on pulse oximetry will also lead to concomitantly low oxyhemoglobin levels as measured by arterial blood gas analysis, and this was not seen in our patient.

BACK TO OUR PATIENT

Because there was a discrepancy between our patient’s pulse oximetry reading and oxyhemoglobin concentration by arterial blood gas measurement, her methemoglobin level was checked and was found to be 30%, thus confirming the diagnosis of methemoglobinemia.

WHAT IS METHEMOGLOBINEMIA, AND WHAT CAUSES IT?

Oxygen is normally bound to iron in its ferrous (Fe²⁺) form in hemoglobin to form oxyhemoglobin. Oxidative stress in the body can cause iron to change from the ferrous to the ferric (Fe³⁺) state, forming methemoglobin. Methemoglobin is normally present in the blood in low levels (< 1% of the total hemoglobin), and ferric iron is reduced and recycled back to the ferrous form by NADH-cytochrome b5 reductase, an enzyme present in red blood cells. This protective mechanism maintains methemoglobin levels within safe limits. But increased production can lead to accumulation of methemoglobin, resulting in dyspnea and hypoxia and the condition referred to as methemoglobinemia.¹

Increased levels of methemoglobin relative to normal hemoglobin cause tissue hypoxia by several mechanisms. Methemoglobin cannot efficiently carry oxygen; instead, it binds to water or to a hydroxide ion depending on the pH of the environment.² Therefore, the hemoglobin molecule does not carry its usual load of oxygen, and hypoxia results from the reduced delivery of oxygen to tissues. In addition, an increased concentration of methemoglobin causes a leftward shift in the oxygen-hemoglobin dissociation curve, representing an increased affinity to bound oxygen in the remaining heme groups. The tightly bound oxygen is not adequately released at the tissue level, thus causing cellular hypoxia.

Methemoglobinemia is most often caused by exposure to an oxidizing chemical or drug that increases production of methemoglobin. In rare cases, it is caused by a congenital deficiency of NADH-cytochrome b5 reductase.³

2. Which of the following drugs can cause methemoglobinemia?

• Acetaminophen
• Dapsone
• Benzocaine
• Primaquine

All four of these drugs are common culprits for causing acquired methemoglobinemia; others include chloroquine, nitroglycerin, and sulfonamides.^4–6

The increased production of methemoglobin caused by these drugs overwhelms the protective effect of reducing enzymes and can lead to an accumulation of methemoglobin. However, because of variability in cellular metabolism, not every person who takes these drugs develops dangerous levels of methemoglobin.

Dapsone and benzocaine are the most commonly encountered drugs known to cause methemoglobinemia (Table 1). Dapsone is an anti-inflammatory and antimicrobial agent most commonly used for treating lepromatous leprosy and dermatitis herpetiformis. It is also often prescribed for prophylaxis and treatment of P jirovecii pneumonia in immunosuppressed individuals.⁷ Benzocaine is a local anesthetic and was commonly used before procedures such as oral or dental surgery, transesophageal echocardiography, and endoscopy.^8–10 Even low doses of benzocaine can lead to high levels of methemoglobinemia. However, the availability of other, safer anesthetics now limits the use of benzocaine in major US centers. In addition, the topical anesthetic Emla (lidocaine plus prilocaine) has been recently reported as a cause of methemoglobinemia in infants and children.^11,12

Also, potentially fatal methemoglobinemia has been reported in patients with a deficiency of G-6-phosphate dehydrogenase (G6PD) who received rasburicase, a recombinant version of urate oxidase enzyme used to prevent and treat tumor lysis syndrome.^13,14

Lastly, methemoglobinemia has been reported in patients with inflammatory bowel disease treated with mesalamine.

Although this adverse reaction is rare, clinicians should be aware of it, since these agents are commonly used in everyday medical practice.¹⁵

RECOGNIZING THE DANGER SIGNS

The clinical manifestations of methemoglobinemia are directly proportional to the percentage of methemoglobin in red blood cells. Cyanosis generally becomes apparent at concentrations around 15%, at which point the patient may still have no symptoms. Anxiety, lightheadedness, tachycardia, and dizziness manifest at levels of 20% to 30%. Fatigue, confusion, dizziness, tachypnea, and worsening tachycardia occur at levels of 30% to 50%. Levels of 50% to 70% cause coma, seizures, arrhythmias, and acidosis, and levels over 70% are considered lethal.¹⁶

While these levels provide a general guideline of symptomatology in an otherwise healthy person, it is important to remember that patients with underlying conditions such as anemia, lung disease (both of which our patient had), sepsis, thalassemia, G6PD deficiency, and sickle cell disease can manifest symptoms at lower concentrations of methemoglobin.^1,17

Most patients who develop clinically significant levels of methemoglobin do so within the first few hours of starting one of the culprit drugs.

DIAGNOSIS: METHEMOGLOBINEMIA AND THE SATURATION GAP

In patients with methemoglobinemia, pulse oximetry gives lower values than arterial blood gas oxygen measurements. Regular pulse oximetry works by measuring light absorbance at two distinct wavelengths (660 and 940 nm) to calculate the ratio of oxyhemoglobin to deoxyhemoglobin. Methemoglobin absorbs light at both these wavelengths, thus lowering the pulse oximetry values.¹

In contrast, oxygen saturation of arterial blood gas (oxyhemoglobin) is calculated indirectly from the concentration of dissolved oxygen in the blood and does not include oxygen bound to hemoglobin. Therefore, the measured arterial oxygen saturation is often normal in patients with methemoglobinemia since it relies only on inspired oxygen content and is independent of the methemoglobin concentration.¹⁸

Patients with clinically significant methemoglobinemia usually have a saturation gap > 10%

Oxygen supplementation can raise the level of oxyhemoglobin, which is a measure of dissolved oxygen, but the oxygen saturation as measured by pulse oximetry remains largely unchanged—ie, the saturation gap. A difference of more than 5% between the oxygen saturation by pulse oximetry and blood gas analysis is abnormal. Patients with clinically significant methemoglobinemia usually have a saturation gap greater than 10%.

Several other unique features should raise suspicion of methemoglobinemia. It should be considered in a patient presenting with cyanosis out of proportion to the oxygen saturation and in a patient with low oxygen saturation and a normal chest radiograph. Other clues include blood that is chocolate-colored on gross examination, rather than the dark red of deoxygenated blood.

Co-oximetry measures oxygen saturation using different wavelengths of light to distinguish between fractions of oxyhemoglobin, deoxyhemoglobin, and methemoglobin, but it is not widely available.

THE NEXT STEP

3. What is the next step in the management of our patient?

• Discontinue the dapsone
• Start methylene blue
• Start hyperbaric oxygen
• Give sodium thiosulfate
• Discontinue dapsone and start methylene blue

The next step in her management should be to stop the dapsone and start an infusion of methylene blue. Hyperbaric oxygen is used in treating carbon monoxide poisoning, and sodium thiosulfate is used in treating cyanide toxicity. They would not be appropriate in this patient’s care.

MANAGEMENT OF ACQUIRED METHEMOGLOBINEMIA

The first, most critical step in managing acquired methemoglobinemia is to immediately discontinue the suspected offending agent. In most patients without a concomitant condition such as anemia or lung disease and with a methemoglobin level below 20%, discontinuing the offending agent may suffice. Patients with a level of 20% or greater and patients with cardiac and pulmonary disease, who develop symptoms at lower concentrations of methemoglobin, require infusion of methylene blue.

Methylene blue is converted to its reduced form, leukomethylene blue, by NADPH-methemoglobin reductase. As it is oxidized, leukomethylene blue reduces methemoglobin to hemoglobin. A dose of 1 mg/kg intravenously is given at first. The response is usually dramatic, with a reduction in methemoglobin levels and improvement in symptoms often within 30 to 60 minutes. If levels remain high, the dose can be repeated 1 hour later.¹⁹

A caveat: methylene blue should be avoided in patients with complete G6PD deficiency

A caveat: methylene blue therapy should be avoided in patients with complete G6PD deficiency. Methylene blue works through the enzyme NADPH-methemoglobin reductase, and since patients with G6PD deficiency lack this enzyme, methylene blue is ineffective. In fact, since it cannot be reduced, excessive methylene blue can oxidize hemoglobin to methemoglobin, further exacerbating the condition. In patients with partial G6PD deficiency, methylene blue is still recommended as a first-line treatment, but at a lower initial dose (0.3–0.5 mg/kg). However, in patients with significant hemolysis, an exchange transfusion is the only treatment option.

CASE CONCLUDED

Since dapsone was identified as the likely cause of methemoglobinemia in our patient, it was immediately discontinued. Because she was symptomatic, 70 mg of methylene blue was given intravenously. Over the next 60 minutes, her clinical condition improved significantly. A repeat methemoglobin measurement was 3%.

She was discharged home the next day on oral antibiotics to complete treatment for community-acquired pneumonia.

TAKE-HOME POINTS

• Consider methemoglobinemia in a patient with unexplained cyanosis.
• Pulse oximetry gives lower values than arterial blood gas oxygen measurements in patients with methemoglobinemia, and pulse oximetry readings do not improve with supplemental oxygen.
• A saturation gap greater than 5% strongly suggests methemoglobinemia.
• The diagnosis of methemoglobinemia is confirmed by measuring the methemoglobin concentration.
• Most healthy patients develop symptoms at methemoglobin levels of 20%, but patients with comorbidities can develop symptoms at lower levels.
• A number of drugs can cause methemoglobinemia, even at therapeutic dosages.
• Treatment is generally indicated in patients who have symptoms or in healthy patients who have a methemoglobin level of 20% or greater.
• Identifying and promptly discontinuing the causative agent and initiating methylene blue infusion (1 mg/kg over 5 minutes) is the preferred treatment.