Imaging

VIENNA – Rapid echocardiographic assessment has become routine for many patients who arrive at an emergency department with suspected acute heart failure, and experts consider these examinations critical for quickly getting patients on the right treatment.

Growing use and the important role for emergency echo exams prompted the European echocardiography community to issue in 2014 both recommendations and a position statement on the practice.

With their actions, European echocardiographers joined their U.S. colleagues who had earlier endorsed rapid, focused echocardiography exams. The European position also highlighted the limitations and pitfalls of emergency echo and the need for proper training.

Mitchel L. Zoler/Frontline Medical News

Use of limited, directed, ultrasound heart examinations on an emergency basis by physicians who are not cardiologists is “an irreversible process, but without appropriate training it may become dangerous,” Dr. Nuno Cardim said at the annual meeting of the European Association of Cardiovascular Imaging (EACVI).

A focused cardiac ultrasound (FoCUS) examination for patients with an emergency cardiac condition such as acute heart failure is not a new concept. In 2010, the American Society of Echocardiography and the American College of Emergency Physicians jointly issued a consensus statement on emergency FoCUS (J. Am. Soc. Echocardiogr. 2010;23:1225-30), and the American Society of Echocardiography followed with additional recommendations in 2013 that also dealt with nonemergency uses for FoCUS (J. Am. Soc. Echocardiogr. 2013;26:567-81).

In its 2014 position statement released last May, the EACVI directly addressed FoCUS for the first time (Eur. Heart J. Cardiovasc. Imaging 2014:15;956-60). The statement acknowledged the important role for a circumscribed, point-of-care ultrasound exam in patients undergoing cardiopulmonary resuscitation and in other critical cardiac conditions, but highlighted that a FoCUS exam does not substitute for a comprehensive echocardiographic exam, and that FoCUS should only be done by properly trained clinicians who appreciate the limits of a FoCUS exam.

The EASVI recommendations, which came out a few months later in collaboration with the Acute Cardiovascular Care Association, said that “echocardiography is now recommended (where appropriately trained practitioners are available) in the management of cardiac arrest. However, FoCUS should always be used and interpreted thoughtfully, since this fundamentally limited approach may lead to missing/misinterpretation of important findings unless the practitioner is aware of its (and their) limitations” (Eur. Heart J. Cardiovasc. Imaging 2014 [doi:10.1093/ehjci/jeu210]).

“Of course all patients with suspected acute heart failure in the emergency department should undergo an echo exam. The question is, who will do it? These are patients who are the most difficult to assess,” said Dr. Susanna Price, a member of the EACVI recommendations panel and a specialist in critical care cardiology at Royal Brompton Hospital in London.

“Without proper training, the person doing FoCUS could make a false positive diagnosis, or might miss something and make a false negative diagnosis,” said Dr. Cardim, professor and director of echocardiography and cardiac imaging at Hospital da Luz in Lisbon, and another member of the EACVI panel.

To avoid this, emergency-medicine physicians and others who often triage patients with acute heart disorders should be trained in echocardiography and especially the FoCUS exam, which aims to quickly evaluate several important abnormalities of cardiac function: pericardial effusion, cardiac tamponade, left and right ventricular size and function, and intravascular volume status. A FoCUS exam also screens for pulmonary embolism. FoCUS assesses each of these in a yes-or-no or present-or-absent way, information critical for guiding emergency management but lacking the quantitative and detailed information available with a comprehensive echocardiography exam.

“FoCUS must never substitute” for the comprehensive exam, which should always also be done, he said. FoCUS “should be used wisely and cautiously because of its limitations.”

The FoCUS exam also has equipment specifications. Ideally, clinicians should use a portable, hand-held ultrasound machine, which is larger than “pocket-sized” ultrasound devices and hence gives much better image quality compared with pocket-sized devices, Dr. Cardim said in an interview.

Dr. Cardim and Dr. Price had no disclosures.

[email protected]

On Twitter @mitchelzoler

VIENNA – Rapid echocardiographic assessment has become routine for many patients who arrive at an emergency department with suspected acute heart failure, and experts consider these examinations critical for quickly getting patients on the right treatment.

Growing use and the important role for emergency echo exams prompted the European echocardiography community to issue in 2014 both recommendations and a position statement on the practice.

With their actions, European echocardiographers joined their U.S. colleagues who had earlier endorsed rapid, focused echocardiography exams. The European position also highlighted the limitations and pitfalls of emergency echo and the need for proper training.

Mitchel L. Zoler/Frontline Medical News

Use of limited, directed, ultrasound heart examinations on an emergency basis by physicians who are not cardiologists is “an irreversible process, but without appropriate training it may become dangerous,” Dr. Nuno Cardim said at the annual meeting of the European Association of Cardiovascular Imaging (EACVI).

A focused cardiac ultrasound (FoCUS) examination for patients with an emergency cardiac condition such as acute heart failure is not a new concept. In 2010, the American Society of Echocardiography and the American College of Emergency Physicians jointly issued a consensus statement on emergency FoCUS (J. Am. Soc. Echocardiogr. 2010;23:1225-30), and the American Society of Echocardiography followed with additional recommendations in 2013 that also dealt with nonemergency uses for FoCUS (J. Am. Soc. Echocardiogr. 2013;26:567-81).

In its 2014 position statement released last May, the EACVI directly addressed FoCUS for the first time (Eur. Heart J. Cardiovasc. Imaging 2014:15;956-60). The statement acknowledged the important role for a circumscribed, point-of-care ultrasound exam in patients undergoing cardiopulmonary resuscitation and in other critical cardiac conditions, but highlighted that a FoCUS exam does not substitute for a comprehensive echocardiographic exam, and that FoCUS should only be done by properly trained clinicians who appreciate the limits of a FoCUS exam.

The EASVI recommendations, which came out a few months later in collaboration with the Acute Cardiovascular Care Association, said that “echocardiography is now recommended (where appropriately trained practitioners are available) in the management of cardiac arrest. However, FoCUS should always be used and interpreted thoughtfully, since this fundamentally limited approach may lead to missing/misinterpretation of important findings unless the practitioner is aware of its (and their) limitations” (Eur. Heart J. Cardiovasc. Imaging 2014 [doi:10.1093/ehjci/jeu210]).

“Of course all patients with suspected acute heart failure in the emergency department should undergo an echo exam. The question is, who will do it? These are patients who are the most difficult to assess,” said Dr. Susanna Price, a member of the EACVI recommendations panel and a specialist in critical care cardiology at Royal Brompton Hospital in London.

“Without proper training, the person doing FoCUS could make a false positive diagnosis, or might miss something and make a false negative diagnosis,” said Dr. Cardim, professor and director of echocardiography and cardiac imaging at Hospital da Luz in Lisbon, and another member of the EACVI panel.

To avoid this, emergency-medicine physicians and others who often triage patients with acute heart disorders should be trained in echocardiography and especially the FoCUS exam, which aims to quickly evaluate several important abnormalities of cardiac function: pericardial effusion, cardiac tamponade, left and right ventricular size and function, and intravascular volume status. A FoCUS exam also screens for pulmonary embolism. FoCUS assesses each of these in a yes-or-no or present-or-absent way, information critical for guiding emergency management but lacking the quantitative and detailed information available with a comprehensive echocardiography exam.

“FoCUS must never substitute” for the comprehensive exam, which should always also be done, he said. FoCUS “should be used wisely and cautiously because of its limitations.”

The FoCUS exam also has equipment specifications. Ideally, clinicians should use a portable, hand-held ultrasound machine, which is larger than “pocket-sized” ultrasound devices and hence gives much better image quality compared with pocket-sized devices, Dr. Cardim said in an interview.

Dr. Cardim and Dr. Price had no disclosures.

[email protected]

On Twitter @mitchelzoler

VIENNA – Rapid echocardiographic assessment has become routine for many patients who arrive at an emergency department with suspected acute heart failure, and experts consider these examinations critical for quickly getting patients on the right treatment.

Growing use and the important role for emergency echo exams prompted the European echocardiography community to issue in 2014 both recommendations and a position statement on the practice.

With their actions, European echocardiographers joined their U.S. colleagues who had earlier endorsed rapid, focused echocardiography exams. The European position also highlighted the limitations and pitfalls of emergency echo and the need for proper training.

Mitchel L. Zoler/Frontline Medical News

Use of limited, directed, ultrasound heart examinations on an emergency basis by physicians who are not cardiologists is “an irreversible process, but without appropriate training it may become dangerous,” Dr. Nuno Cardim said at the annual meeting of the European Association of Cardiovascular Imaging (EACVI).

A focused cardiac ultrasound (FoCUS) examination for patients with an emergency cardiac condition such as acute heart failure is not a new concept. In 2010, the American Society of Echocardiography and the American College of Emergency Physicians jointly issued a consensus statement on emergency FoCUS (J. Am. Soc. Echocardiogr. 2010;23:1225-30), and the American Society of Echocardiography followed with additional recommendations in 2013 that also dealt with nonemergency uses for FoCUS (J. Am. Soc. Echocardiogr. 2013;26:567-81).

In its 2014 position statement released last May, the EACVI directly addressed FoCUS for the first time (Eur. Heart J. Cardiovasc. Imaging 2014:15;956-60). The statement acknowledged the important role for a circumscribed, point-of-care ultrasound exam in patients undergoing cardiopulmonary resuscitation and in other critical cardiac conditions, but highlighted that a FoCUS exam does not substitute for a comprehensive echocardiographic exam, and that FoCUS should only be done by properly trained clinicians who appreciate the limits of a FoCUS exam.

The EASVI recommendations, which came out a few months later in collaboration with the Acute Cardiovascular Care Association, said that “echocardiography is now recommended (where appropriately trained practitioners are available) in the management of cardiac arrest. However, FoCUS should always be used and interpreted thoughtfully, since this fundamentally limited approach may lead to missing/misinterpretation of important findings unless the practitioner is aware of its (and their) limitations” (Eur. Heart J. Cardiovasc. Imaging 2014 [doi:10.1093/ehjci/jeu210]).

“Of course all patients with suspected acute heart failure in the emergency department should undergo an echo exam. The question is, who will do it? These are patients who are the most difficult to assess,” said Dr. Susanna Price, a member of the EACVI recommendations panel and a specialist in critical care cardiology at Royal Brompton Hospital in London.

“Without proper training, the person doing FoCUS could make a false positive diagnosis, or might miss something and make a false negative diagnosis,” said Dr. Cardim, professor and director of echocardiography and cardiac imaging at Hospital da Luz in Lisbon, and another member of the EACVI panel.

To avoid this, emergency-medicine physicians and others who often triage patients with acute heart disorders should be trained in echocardiography and especially the FoCUS exam, which aims to quickly evaluate several important abnormalities of cardiac function: pericardial effusion, cardiac tamponade, left and right ventricular size and function, and intravascular volume status. A FoCUS exam also screens for pulmonary embolism. FoCUS assesses each of these in a yes-or-no or present-or-absent way, information critical for guiding emergency management but lacking the quantitative and detailed information available with a comprehensive echocardiography exam.

“FoCUS must never substitute” for the comprehensive exam, which should always also be done, he said. FoCUS “should be used wisely and cautiously because of its limitations.”

The FoCUS exam also has equipment specifications. Ideally, clinicians should use a portable, hand-held ultrasound machine, which is larger than “pocket-sized” ultrasound devices and hence gives much better image quality compared with pocket-sized devices, Dr. Cardim said in an interview.

Dr. Cardim and Dr. Price had no disclosures.

[email protected]

On Twitter @mitchelzoler

CHICAGO – Coronary artery calcium testing has established itself as a true “game changer” in primary cardiovascular prevention, proponents of the risk-stratification tool said at the American Heart Association scientific sessions.

Knowing a patient’s coronary artery calcium score facilitates a more informed physician-patient discussion and shared decision making regarding whether to go on decades-long statin therapy, according to Dr. Khurram Nasir of the center for prevention and wellness research at Baptist Health Medical Center in Miami Beach.

“In our view, a much underappreciated value of coronary artery calcium testing lies in the power of zero. Roughly half of adults have a coronary artery calcium score of 0, and this results in a very low cardiovascular event rate,” the cardiologist said.

He presented an analysis of 4,758 nondiabetic participants in the prospective, population-based MESA (Multi-Ethnic Study of Atherosclerosis) in which he examined how they fared in terms of cardiovascular events over a median 10.3 years of follow-up. All were free of known cardiovascular disease at baseline. With the risk estimator included in the 2013 AHA/ACC cholesterol management guidelines, 2,377 subjects would be recommended for high-intensity statin therapy at baseline on the basis of a 10-year atherosclerotic cardiovascular disease risk estimate of at least 7.5%. Another 589 participants were recommended for consideration of a moderate-intensity statin based on an estimated 10-year risk of 5%-7.4%.

Forty-one percent of MESA subjects recommended for a high-intensity statin according to the AHA/ACC risk estimator had a coronary artery calcium (CAC) score of 0, and their 10-year composite rate of MI, stroke, or cardiovascular death was just 4.9% – well below the 7.5% threshold recommended for statin therapy. In contrast, if any CAC was present, the event rate was 10.5%.

 

With a relative risk reduction with statin therapy of 30%, the number needed to treat for 5 years to prevent one cardiovascular event in the group with a CAC of 0 would be 128. In the presence of any CAC, the number needed to treat fell to a far more reasonable 56, Dr. Nasir said.

Similarly, among the group recommended for consideration of statin therapy on the basis of a 10-year risk of 5%-7.4%, the actual event rate in the 57% of subjects with a CAC of 0 was just 1.5%. If any CAC was present, the event rate shot up to 7.2%. The number needed to treat in this cohort was 445 among those with a CAC of 0 and 90 with any CAC present.

“I think coronary artery calcium is a game changer in primary prevention,” Dr. Michael J. Blaha commented. “It sufficiently moves the needle to make you think differently about a patient. I’m not sure some of the other tests have sufficient evidence to say, ‘I’m going to think about not treating you if it’s negative and treating you if it’s positive,’ but coronary artery calcium has that evidence.”

In his own cardiology practice at Johns Hopkins University, Baltimore, Dr. Blaha finds himself using CAC testing often, especially in his many statin-reluctant patients.

“I have a lot of patients who would fit under a recommendation for statin therapy under the 2013 AHA/ACC cholesterol management guidelines, but who really don’t want to take medications. I know you see these patients in your practices, too. This is lifelong therapy, and they want a really good reason to take it or not to take it. If a patient is reluctant to take a statin and has a CAC score of 0, I will sometimes emphasize lifestyle therapy. It certainly redoubles my interest in lifestyle therapy. But if the CAC score is elevated, then I can make a specific case that the number needed to treat is very favorable, compared to the number needed to harm,” explained Dr. Blaha, a coinvestigator with Dr. Nasir in the MESA study.

 

Other situations where he finds CAC testing useful in daily practice include uncertainty as to a patient’s true risk level because the individual’s situation isn’t adequately captured by the AHA/ACC risk estimator. A patient with rheumatologic disease would be one example; another would be an individual who is neither white nor African American. He said he also utilizes CAC testing in statin-intolerant patients, where the results are useful in deciding how many different statins to try before saying “enough.”

Audience members asked what it’s going to take to get insurers to cover CAC testing for risk stratification. Dr. Blaha replied that more long-term outcomes and cost-effectiveness data are coming. In the meantime, at an out-of-pocket cost of $75-$100, a lot of his statin-reluctant patients consider CAC testing a good buy.

“They say, ‘I’ll take this test to help me decide whether to take a pill for the rest of my life,’” according to Dr. Blaha.

Dr. Nasir said the evidence in support of CAC testing is now so strong that he believes physicians have an obligation to mention it as an option during the statin treatment decision discussion.

“At this moment, most patients are making their decision based on the guesstimate of their risk we are giving them using the risk calculator. If they have the ability through a $75-$100 test that costs about the same as 18 months of statin therapy to know that their true risk is not, say, 10%, but actually 5%, they’re less likely to choose therapy. Is it even ethical to withhold from our patients that there is a test out there that can reduce their estimated risk to a point that they can avoid statin therapy?” the cardiologist asked.

Dr. Nasir reported serving on an advisory board for Quest Diagnostics. Dr. Blaha reported having no financial conflicts.

[email protected]

CHICAGO – Coronary artery calcium testing has established itself as a true “game changer” in primary cardiovascular prevention, proponents of the risk-stratification tool said at the American Heart Association scientific sessions.

Knowing a patient’s coronary artery calcium score facilitates a more informed physician-patient discussion and shared decision making regarding whether to go on decades-long statin therapy, according to Dr. Khurram Nasir of the center for prevention and wellness research at Baptist Health Medical Center in Miami Beach.

“In our view, a much underappreciated value of coronary artery calcium testing lies in the power of zero. Roughly half of adults have a coronary artery calcium score of 0, and this results in a very low cardiovascular event rate,” the cardiologist said.

He presented an analysis of 4,758 nondiabetic participants in the prospective, population-based MESA (Multi-Ethnic Study of Atherosclerosis) in which he examined how they fared in terms of cardiovascular events over a median 10.3 years of follow-up. All were free of known cardiovascular disease at baseline. With the risk estimator included in the 2013 AHA/ACC cholesterol management guidelines, 2,377 subjects would be recommended for high-intensity statin therapy at baseline on the basis of a 10-year atherosclerotic cardiovascular disease risk estimate of at least 7.5%. Another 589 participants were recommended for consideration of a moderate-intensity statin based on an estimated 10-year risk of 5%-7.4%.

Forty-one percent of MESA subjects recommended for a high-intensity statin according to the AHA/ACC risk estimator had a coronary artery calcium (CAC) score of 0, and their 10-year composite rate of MI, stroke, or cardiovascular death was just 4.9% – well below the 7.5% threshold recommended for statin therapy. In contrast, if any CAC was present, the event rate was 10.5%.

 

With a relative risk reduction with statin therapy of 30%, the number needed to treat for 5 years to prevent one cardiovascular event in the group with a CAC of 0 would be 128. In the presence of any CAC, the number needed to treat fell to a far more reasonable 56, Dr. Nasir said.

Similarly, among the group recommended for consideration of statin therapy on the basis of a 10-year risk of 5%-7.4%, the actual event rate in the 57% of subjects with a CAC of 0 was just 1.5%. If any CAC was present, the event rate shot up to 7.2%. The number needed to treat in this cohort was 445 among those with a CAC of 0 and 90 with any CAC present.

“I think coronary artery calcium is a game changer in primary prevention,” Dr. Michael J. Blaha commented. “It sufficiently moves the needle to make you think differently about a patient. I’m not sure some of the other tests have sufficient evidence to say, ‘I’m going to think about not treating you if it’s negative and treating you if it’s positive,’ but coronary artery calcium has that evidence.”

In his own cardiology practice at Johns Hopkins University, Baltimore, Dr. Blaha finds himself using CAC testing often, especially in his many statin-reluctant patients.

“I have a lot of patients who would fit under a recommendation for statin therapy under the 2013 AHA/ACC cholesterol management guidelines, but who really don’t want to take medications. I know you see these patients in your practices, too. This is lifelong therapy, and they want a really good reason to take it or not to take it. If a patient is reluctant to take a statin and has a CAC score of 0, I will sometimes emphasize lifestyle therapy. It certainly redoubles my interest in lifestyle therapy. But if the CAC score is elevated, then I can make a specific case that the number needed to treat is very favorable, compared to the number needed to harm,” explained Dr. Blaha, a coinvestigator with Dr. Nasir in the MESA study.

 

Other situations where he finds CAC testing useful in daily practice include uncertainty as to a patient’s true risk level because the individual’s situation isn’t adequately captured by the AHA/ACC risk estimator. A patient with rheumatologic disease would be one example; another would be an individual who is neither white nor African American. He said he also utilizes CAC testing in statin-intolerant patients, where the results are useful in deciding how many different statins to try before saying “enough.”

Audience members asked what it’s going to take to get insurers to cover CAC testing for risk stratification. Dr. Blaha replied that more long-term outcomes and cost-effectiveness data are coming. In the meantime, at an out-of-pocket cost of $75-$100, a lot of his statin-reluctant patients consider CAC testing a good buy.

“They say, ‘I’ll take this test to help me decide whether to take a pill for the rest of my life,’” according to Dr. Blaha.

Dr. Nasir said the evidence in support of CAC testing is now so strong that he believes physicians have an obligation to mention it as an option during the statin treatment decision discussion.

“At this moment, most patients are making their decision based on the guesstimate of their risk we are giving them using the risk calculator. If they have the ability through a $75-$100 test that costs about the same as 18 months of statin therapy to know that their true risk is not, say, 10%, but actually 5%, they’re less likely to choose therapy. Is it even ethical to withhold from our patients that there is a test out there that can reduce their estimated risk to a point that they can avoid statin therapy?” the cardiologist asked.

Dr. Nasir reported serving on an advisory board for Quest Diagnostics. Dr. Blaha reported having no financial conflicts.

[email protected]

CHICAGO – Coronary artery calcium testing has established itself as a true “game changer” in primary cardiovascular prevention, proponents of the risk-stratification tool said at the American Heart Association scientific sessions.

Knowing a patient’s coronary artery calcium score facilitates a more informed physician-patient discussion and shared decision making regarding whether to go on decades-long statin therapy, according to Dr. Khurram Nasir of the center for prevention and wellness research at Baptist Health Medical Center in Miami Beach.

“In our view, a much underappreciated value of coronary artery calcium testing lies in the power of zero. Roughly half of adults have a coronary artery calcium score of 0, and this results in a very low cardiovascular event rate,” the cardiologist said.

He presented an analysis of 4,758 nondiabetic participants in the prospective, population-based MESA (Multi-Ethnic Study of Atherosclerosis) in which he examined how they fared in terms of cardiovascular events over a median 10.3 years of follow-up. All were free of known cardiovascular disease at baseline. With the risk estimator included in the 2013 AHA/ACC cholesterol management guidelines, 2,377 subjects would be recommended for high-intensity statin therapy at baseline on the basis of a 10-year atherosclerotic cardiovascular disease risk estimate of at least 7.5%. Another 589 participants were recommended for consideration of a moderate-intensity statin based on an estimated 10-year risk of 5%-7.4%.

Forty-one percent of MESA subjects recommended for a high-intensity statin according to the AHA/ACC risk estimator had a coronary artery calcium (CAC) score of 0, and their 10-year composite rate of MI, stroke, or cardiovascular death was just 4.9% – well below the 7.5% threshold recommended for statin therapy. In contrast, if any CAC was present, the event rate was 10.5%.

 

With a relative risk reduction with statin therapy of 30%, the number needed to treat for 5 years to prevent one cardiovascular event in the group with a CAC of 0 would be 128. In the presence of any CAC, the number needed to treat fell to a far more reasonable 56, Dr. Nasir said.

Similarly, among the group recommended for consideration of statin therapy on the basis of a 10-year risk of 5%-7.4%, the actual event rate in the 57% of subjects with a CAC of 0 was just 1.5%. If any CAC was present, the event rate shot up to 7.2%. The number needed to treat in this cohort was 445 among those with a CAC of 0 and 90 with any CAC present.

“I think coronary artery calcium is a game changer in primary prevention,” Dr. Michael J. Blaha commented. “It sufficiently moves the needle to make you think differently about a patient. I’m not sure some of the other tests have sufficient evidence to say, ‘I’m going to think about not treating you if it’s negative and treating you if it’s positive,’ but coronary artery calcium has that evidence.”

In his own cardiology practice at Johns Hopkins University, Baltimore, Dr. Blaha finds himself using CAC testing often, especially in his many statin-reluctant patients.

“I have a lot of patients who would fit under a recommendation for statin therapy under the 2013 AHA/ACC cholesterol management guidelines, but who really don’t want to take medications. I know you see these patients in your practices, too. This is lifelong therapy, and they want a really good reason to take it or not to take it. If a patient is reluctant to take a statin and has a CAC score of 0, I will sometimes emphasize lifestyle therapy. It certainly redoubles my interest in lifestyle therapy. But if the CAC score is elevated, then I can make a specific case that the number needed to treat is very favorable, compared to the number needed to harm,” explained Dr. Blaha, a coinvestigator with Dr. Nasir in the MESA study.

 

Other situations where he finds CAC testing useful in daily practice include uncertainty as to a patient’s true risk level because the individual’s situation isn’t adequately captured by the AHA/ACC risk estimator. A patient with rheumatologic disease would be one example; another would be an individual who is neither white nor African American. He said he also utilizes CAC testing in statin-intolerant patients, where the results are useful in deciding how many different statins to try before saying “enough.”

Audience members asked what it’s going to take to get insurers to cover CAC testing for risk stratification. Dr. Blaha replied that more long-term outcomes and cost-effectiveness data are coming. In the meantime, at an out-of-pocket cost of $75-$100, a lot of his statin-reluctant patients consider CAC testing a good buy.

“They say, ‘I’ll take this test to help me decide whether to take a pill for the rest of my life,’” according to Dr. Blaha.

Dr. Nasir said the evidence in support of CAC testing is now so strong that he believes physicians have an obligation to mention it as an option during the statin treatment decision discussion.

“At this moment, most patients are making their decision based on the guesstimate of their risk we are giving them using the risk calculator. If they have the ability through a $75-$100 test that costs about the same as 18 months of statin therapy to know that their true risk is not, say, 10%, but actually 5%, they’re less likely to choose therapy. Is it even ethical to withhold from our patients that there is a test out there that can reduce their estimated risk to a point that they can avoid statin therapy?” the cardiologist asked.

Dr. Nasir reported serving on an advisory board for Quest Diagnostics. Dr. Blaha reported having no financial conflicts.

[email protected]

VIENNA – One of the best ways to prevent advanced tricuspid-valve regurgitation and need for tricuspid-valve repair may be a more aggressive approach to mitral valve repair.

“If you operate on the mitral valve early, then tricuspid regurgitation does not tend to progress,” Dr. Sunil V. Mankad said at the annual meeting of the European Association of Cardiovascular Imaging. “If you wait until the mitral valve remodels and the atrium enlarges and remodels or there is pulmonary hypertension, then tricuspid regurgitation will progress,” said Dr. Mankad, a echocardiographer at the Mayo Clinic in Rochester, Minn.

Mitchel L. Zoler/Frontline Medical News

Early intervention on mitral valve prolapse has other benefits as well, he said. Mitral disease causes atrial remodeling, which can then progress to atrial fibrillation, “and once that happens it’s a game changer for the patient, even if they later undergo valve repair,” because of atrial fibrillation’s long-term risks and consequences, Dr. Mankad said in an interview.

“We believe there is also subclinical left ventricular dysfunction” in patients with mitral-valve prolapse “even if their ejection fraction is normal.” Once that happens, even if the mitral valve is repaired “the heart is not normal anymore and there is subtle left ventricular dysfunction that is not captured by just looking at ejection fraction.”

To document the impact a more aggressive approach to mitral-valve repair can have on the tricuspid valve, Dr. Mankad cited a 2011 Mayo Clinic analysis of 699 patients who underwent mitral-valve repair at Mayo for severe mitral-valve prolapse and also had some amount of tricuspid regurgitation at the time of their surgery, including 115 patients (16%) with grade 3 or higher tricuspid regurgitation. One year after surgery, the severity of tricuspid regurgitation in these patients had decreased significantly overall, and throughout follow-up only one patient required surgery for tricuspid-valve repair, 4.5 years after that patient’s mitral-valve repair (J. Thoracic Cardiovasc. Surgery 2011;142:608-13).

 

Dr. Mankad also cited a recent editorial written by several of his Mayo Clinic colleagues that synthesized results from the 2011 report as well as from a second Mayo report published in 2014, and a third report from a different group also published in 2014. The authors of the editorial concluded that results from all three studies showed “the performance of early correction of mitral regurgitation is important not only for its own well known benefits (preservation of survival and minimization of late heart failure risk) but also to diminish the late occurrence of functional tricuspid regurgitation (J. Thoracic Cardiovasc. Surgery 2014;148:2810-2).

Because mitral-valve repair often improves tricuspid-valve function and durability, the editorialists suggested “strongly considering” tricuspid repair for a carefully defined, select subgroup of patients. Their list included patients with tricuspid regurgitation that is worse than moderate, right-heart dysfunction, symptoms of right-heart failure, pulmonary hypertension, reduced left ventricular systolic function, cardiomyopathy, or organic tricuspid pathology.

Existing evidence supports leaving the valve alone when patients have a tricuspid regurgitation that is less than moderate when they have also undergone effective correction of degenerative mitral regurgitation. Patients like these are “unlikely ever to have difficulty with the tricuspid valve or the right ventricle,” wrote the authors of the editorial.

Dr. Mankad offered his own suggestions for identifying patients with a tricuspid valve that requires repair at the time of mitral-valve surgery.

“The evidence supports tricuspid-valve repair at the time of mitral-valve surgery if there is tricuspid annular dilatation of more than 4.0 cm measured by three-dimensional echo or greater than moderate tricuspid regurgitation. This is based on observational data and not on results from randomized control trials, but it is what I recommend,” Dr. Mankad said. “I suggest measuring the tricuspid annulus; it is quite easy to do. Directly measuring the annulus size with three-dimensional echo is pretty basic, and I think it is ready for prime time.”

Dr. Mankad had no disclosures.

[email protected]

On Twitter @mitchelzoler

VIENNA – One of the best ways to prevent advanced tricuspid-valve regurgitation and need for tricuspid-valve repair may be a more aggressive approach to mitral valve repair.

“If you operate on the mitral valve early, then tricuspid regurgitation does not tend to progress,” Dr. Sunil V. Mankad said at the annual meeting of the European Association of Cardiovascular Imaging. “If you wait until the mitral valve remodels and the atrium enlarges and remodels or there is pulmonary hypertension, then tricuspid regurgitation will progress,” said Dr. Mankad, a echocardiographer at the Mayo Clinic in Rochester, Minn.

Mitchel L. Zoler/Frontline Medical News

Early intervention on mitral valve prolapse has other benefits as well, he said. Mitral disease causes atrial remodeling, which can then progress to atrial fibrillation, “and once that happens it’s a game changer for the patient, even if they later undergo valve repair,” because of atrial fibrillation’s long-term risks and consequences, Dr. Mankad said in an interview.

“We believe there is also subclinical left ventricular dysfunction” in patients with mitral-valve prolapse “even if their ejection fraction is normal.” Once that happens, even if the mitral valve is repaired “the heart is not normal anymore and there is subtle left ventricular dysfunction that is not captured by just looking at ejection fraction.”

To document the impact a more aggressive approach to mitral-valve repair can have on the tricuspid valve, Dr. Mankad cited a 2011 Mayo Clinic analysis of 699 patients who underwent mitral-valve repair at Mayo for severe mitral-valve prolapse and also had some amount of tricuspid regurgitation at the time of their surgery, including 115 patients (16%) with grade 3 or higher tricuspid regurgitation. One year after surgery, the severity of tricuspid regurgitation in these patients had decreased significantly overall, and throughout follow-up only one patient required surgery for tricuspid-valve repair, 4.5 years after that patient’s mitral-valve repair (J. Thoracic Cardiovasc. Surgery 2011;142:608-13).

 

Dr. Mankad also cited a recent editorial written by several of his Mayo Clinic colleagues that synthesized results from the 2011 report as well as from a second Mayo report published in 2014, and a third report from a different group also published in 2014. The authors of the editorial concluded that results from all three studies showed “the performance of early correction of mitral regurgitation is important not only for its own well known benefits (preservation of survival and minimization of late heart failure risk) but also to diminish the late occurrence of functional tricuspid regurgitation (J. Thoracic Cardiovasc. Surgery 2014;148:2810-2).

Because mitral-valve repair often improves tricuspid-valve function and durability, the editorialists suggested “strongly considering” tricuspid repair for a carefully defined, select subgroup of patients. Their list included patients with tricuspid regurgitation that is worse than moderate, right-heart dysfunction, symptoms of right-heart failure, pulmonary hypertension, reduced left ventricular systolic function, cardiomyopathy, or organic tricuspid pathology.

Existing evidence supports leaving the valve alone when patients have a tricuspid regurgitation that is less than moderate when they have also undergone effective correction of degenerative mitral regurgitation. Patients like these are “unlikely ever to have difficulty with the tricuspid valve or the right ventricle,” wrote the authors of the editorial.

Dr. Mankad offered his own suggestions for identifying patients with a tricuspid valve that requires repair at the time of mitral-valve surgery.

“The evidence supports tricuspid-valve repair at the time of mitral-valve surgery if there is tricuspid annular dilatation of more than 4.0 cm measured by three-dimensional echo or greater than moderate tricuspid regurgitation. This is based on observational data and not on results from randomized control trials, but it is what I recommend,” Dr. Mankad said. “I suggest measuring the tricuspid annulus; it is quite easy to do. Directly measuring the annulus size with three-dimensional echo is pretty basic, and I think it is ready for prime time.”

Dr. Mankad had no disclosures.

[email protected]

On Twitter @mitchelzoler

VIENNA – One of the best ways to prevent advanced tricuspid-valve regurgitation and need for tricuspid-valve repair may be a more aggressive approach to mitral valve repair.

“If you operate on the mitral valve early, then tricuspid regurgitation does not tend to progress,” Dr. Sunil V. Mankad said at the annual meeting of the European Association of Cardiovascular Imaging. “If you wait until the mitral valve remodels and the atrium enlarges and remodels or there is pulmonary hypertension, then tricuspid regurgitation will progress,” said Dr. Mankad, a echocardiographer at the Mayo Clinic in Rochester, Minn.

Mitchel L. Zoler/Frontline Medical News

Early intervention on mitral valve prolapse has other benefits as well, he said. Mitral disease causes atrial remodeling, which can then progress to atrial fibrillation, “and once that happens it’s a game changer for the patient, even if they later undergo valve repair,” because of atrial fibrillation’s long-term risks and consequences, Dr. Mankad said in an interview.

“We believe there is also subclinical left ventricular dysfunction” in patients with mitral-valve prolapse “even if their ejection fraction is normal.” Once that happens, even if the mitral valve is repaired “the heart is not normal anymore and there is subtle left ventricular dysfunction that is not captured by just looking at ejection fraction.”

To document the impact a more aggressive approach to mitral-valve repair can have on the tricuspid valve, Dr. Mankad cited a 2011 Mayo Clinic analysis of 699 patients who underwent mitral-valve repair at Mayo for severe mitral-valve prolapse and also had some amount of tricuspid regurgitation at the time of their surgery, including 115 patients (16%) with grade 3 or higher tricuspid regurgitation. One year after surgery, the severity of tricuspid regurgitation in these patients had decreased significantly overall, and throughout follow-up only one patient required surgery for tricuspid-valve repair, 4.5 years after that patient’s mitral-valve repair (J. Thoracic Cardiovasc. Surgery 2011;142:608-13).

 

Dr. Mankad also cited a recent editorial written by several of his Mayo Clinic colleagues that synthesized results from the 2011 report as well as from a second Mayo report published in 2014, and a third report from a different group also published in 2014. The authors of the editorial concluded that results from all three studies showed “the performance of early correction of mitral regurgitation is important not only for its own well known benefits (preservation of survival and minimization of late heart failure risk) but also to diminish the late occurrence of functional tricuspid regurgitation (J. Thoracic Cardiovasc. Surgery 2014;148:2810-2).

Because mitral-valve repair often improves tricuspid-valve function and durability, the editorialists suggested “strongly considering” tricuspid repair for a carefully defined, select subgroup of patients. Their list included patients with tricuspid regurgitation that is worse than moderate, right-heart dysfunction, symptoms of right-heart failure, pulmonary hypertension, reduced left ventricular systolic function, cardiomyopathy, or organic tricuspid pathology.

Existing evidence supports leaving the valve alone when patients have a tricuspid regurgitation that is less than moderate when they have also undergone effective correction of degenerative mitral regurgitation. Patients like these are “unlikely ever to have difficulty with the tricuspid valve or the right ventricle,” wrote the authors of the editorial.

Dr. Mankad offered his own suggestions for identifying patients with a tricuspid valve that requires repair at the time of mitral-valve surgery.

“The evidence supports tricuspid-valve repair at the time of mitral-valve surgery if there is tricuspid annular dilatation of more than 4.0 cm measured by three-dimensional echo or greater than moderate tricuspid regurgitation. This is based on observational data and not on results from randomized control trials, but it is what I recommend,” Dr. Mankad said. “I suggest measuring the tricuspid annulus; it is quite easy to do. Directly measuring the annulus size with three-dimensional echo is pretty basic, and I think it is ready for prime time.”

Dr. Mankad had no disclosures.

[email protected]

On Twitter @mitchelzoler

CHICAGO – Insulin glargine showed no effects on left ventricular mass or function during 3 years of follow-up in dysglycemic patients at high cardiovascular risk in the ORIGIN echocardiographic substudy.

This echocardiographic study of the ORIGIN (Outcome Reduction With an Initial Glargine Intervention) trial, the largest reported study of the effects of exogenous insulin on left ventricular mass and LV systolic and diastolic function, provides reassuring new evidence that insulin glargine is safe from a cardiac standpoint, Dr. Michelle Haroun said at the American Heart Association scientific sessions.

“The key here is that we didn’t see any signal whatsoever to suggest that insulin is putting patients at increased risk. We think that this finding is important. While you need to follow patients for a very long time to detect changes in clinical heart failure outcomes, we think we’d be able to detect subtle changes in endpoints like LV mass over a 3-year period if insulin was of harm to patients,” said Dr. Haroun of the Population Health Research Institute at McMaster University in Hamilton, Ont.

ORIGIN-ECHO involved 564 dysglycemic patients at high cardiovascular risk who were randomized to insulin glargine (Lantus) or standard therapy. All had echocardiograms at baseline and after 3 years of therapy. Participants had to have impaired fasting blood glucose, impaired glucose tolerance, or early type 2 diabetes managed with no more than one oral antiglycemic drug at baseline. This was a group at high cardiovascular risk: 32% had a prior MI, 84% had a history of hypertension, obesity was common, and the average age was 64. However, none of the participants had heart failure at baseline.

The study was undertaken because some of the medications used to treat hyperglycemia are associated with increased risk of heart failure. Regulatory agencies, physicians, and patients want to see evidence of cardiovascular safety, and until ORIGIN-ECHO, the effects of exogenous insulin on LV mass and function hadn’t been well studied.

Baseline LV mass and function values were within normal range and did not change significantly over 3 years of follow-up in either treatment arm. For example, left ventricular mass/height averaged 116 g/m at baseline and 115 g/m after 3 years on insulin glargine, and was comparable at 113 and 114 g/m, respectively, with standard therapy. This was an unexpected finding, according to Dr. Haroun.

“We thought patients with diabetes on standard therapy were going to develop left ventricular hypertrophy over a 3-year follow-up period, and they didn’t. That came as a bit of a surprise to us. We expected to see a lower rate of LVH in the patients on insulin glargine. This patient population was relatively early in their course of diabetes, and we believe our findings suggest that adequate management of cardiovascular risk factors – especially hypertension– and the use of cardioprotective drugs in this population may prevent or delay abnormalities in LV structure and function,” she said.

The primary outcomes of the full ORIGIN study involving more than 12,000 patients have previously been published (N. Engl. J. Med. 2012; 367:319-28). ORIGIN was sponsored by Sanofi. Dr. Haroun reported having no financial conflicts.

[email protected]

CHICAGO – Insulin glargine showed no effects on left ventricular mass or function during 3 years of follow-up in dysglycemic patients at high cardiovascular risk in the ORIGIN echocardiographic substudy.

This echocardiographic study of the ORIGIN (Outcome Reduction With an Initial Glargine Intervention) trial, the largest reported study of the effects of exogenous insulin on left ventricular mass and LV systolic and diastolic function, provides reassuring new evidence that insulin glargine is safe from a cardiac standpoint, Dr. Michelle Haroun said at the American Heart Association scientific sessions.

“The key here is that we didn’t see any signal whatsoever to suggest that insulin is putting patients at increased risk. We think that this finding is important. While you need to follow patients for a very long time to detect changes in clinical heart failure outcomes, we think we’d be able to detect subtle changes in endpoints like LV mass over a 3-year period if insulin was of harm to patients,” said Dr. Haroun of the Population Health Research Institute at McMaster University in Hamilton, Ont.

ORIGIN-ECHO involved 564 dysglycemic patients at high cardiovascular risk who were randomized to insulin glargine (Lantus) or standard therapy. All had echocardiograms at baseline and after 3 years of therapy. Participants had to have impaired fasting blood glucose, impaired glucose tolerance, or early type 2 diabetes managed with no more than one oral antiglycemic drug at baseline. This was a group at high cardiovascular risk: 32% had a prior MI, 84% had a history of hypertension, obesity was common, and the average age was 64. However, none of the participants had heart failure at baseline.

The study was undertaken because some of the medications used to treat hyperglycemia are associated with increased risk of heart failure. Regulatory agencies, physicians, and patients want to see evidence of cardiovascular safety, and until ORIGIN-ECHO, the effects of exogenous insulin on LV mass and function hadn’t been well studied.

Baseline LV mass and function values were within normal range and did not change significantly over 3 years of follow-up in either treatment arm. For example, left ventricular mass/height averaged 116 g/m at baseline and 115 g/m after 3 years on insulin glargine, and was comparable at 113 and 114 g/m, respectively, with standard therapy. This was an unexpected finding, according to Dr. Haroun.

“We thought patients with diabetes on standard therapy were going to develop left ventricular hypertrophy over a 3-year follow-up period, and they didn’t. That came as a bit of a surprise to us. We expected to see a lower rate of LVH in the patients on insulin glargine. This patient population was relatively early in their course of diabetes, and we believe our findings suggest that adequate management of cardiovascular risk factors – especially hypertension– and the use of cardioprotective drugs in this population may prevent or delay abnormalities in LV structure and function,” she said.

The primary outcomes of the full ORIGIN study involving more than 12,000 patients have previously been published (N. Engl. J. Med. 2012; 367:319-28). ORIGIN was sponsored by Sanofi. Dr. Haroun reported having no financial conflicts.

[email protected]

CHICAGO – Insulin glargine showed no effects on left ventricular mass or function during 3 years of follow-up in dysglycemic patients at high cardiovascular risk in the ORIGIN echocardiographic substudy.

This echocardiographic study of the ORIGIN (Outcome Reduction With an Initial Glargine Intervention) trial, the largest reported study of the effects of exogenous insulin on left ventricular mass and LV systolic and diastolic function, provides reassuring new evidence that insulin glargine is safe from a cardiac standpoint, Dr. Michelle Haroun said at the American Heart Association scientific sessions.

“The key here is that we didn’t see any signal whatsoever to suggest that insulin is putting patients at increased risk. We think that this finding is important. While you need to follow patients for a very long time to detect changes in clinical heart failure outcomes, we think we’d be able to detect subtle changes in endpoints like LV mass over a 3-year period if insulin was of harm to patients,” said Dr. Haroun of the Population Health Research Institute at McMaster University in Hamilton, Ont.

ORIGIN-ECHO involved 564 dysglycemic patients at high cardiovascular risk who were randomized to insulin glargine (Lantus) or standard therapy. All had echocardiograms at baseline and after 3 years of therapy. Participants had to have impaired fasting blood glucose, impaired glucose tolerance, or early type 2 diabetes managed with no more than one oral antiglycemic drug at baseline. This was a group at high cardiovascular risk: 32% had a prior MI, 84% had a history of hypertension, obesity was common, and the average age was 64. However, none of the participants had heart failure at baseline.

The study was undertaken because some of the medications used to treat hyperglycemia are associated with increased risk of heart failure. Regulatory agencies, physicians, and patients want to see evidence of cardiovascular safety, and until ORIGIN-ECHO, the effects of exogenous insulin on LV mass and function hadn’t been well studied.

Baseline LV mass and function values were within normal range and did not change significantly over 3 years of follow-up in either treatment arm. For example, left ventricular mass/height averaged 116 g/m at baseline and 115 g/m after 3 years on insulin glargine, and was comparable at 113 and 114 g/m, respectively, with standard therapy. This was an unexpected finding, according to Dr. Haroun.

“We thought patients with diabetes on standard therapy were going to develop left ventricular hypertrophy over a 3-year follow-up period, and they didn’t. That came as a bit of a surprise to us. We expected to see a lower rate of LVH in the patients on insulin glargine. This patient population was relatively early in their course of diabetes, and we believe our findings suggest that adequate management of cardiovascular risk factors – especially hypertension– and the use of cardioprotective drugs in this population may prevent or delay abnormalities in LV structure and function,” she said.

The primary outcomes of the full ORIGIN study involving more than 12,000 patients have previously been published (N. Engl. J. Med. 2012; 367:319-28). ORIGIN was sponsored by Sanofi. Dr. Haroun reported having no financial conflicts.

[email protected]

Case

A 46-year-old white woman with sudden onset of numbness in her lower extremities and inability to ambulate was transported to the ED via emergency medical services. At the onset of symptoms, the patient reported a feeling of “heaviness” in her lower extremities, which was greater on the left side than the right. After an unsuccessful attempt at ambulation, she subsequently presented to a community hospital where she could no longer move her left lower extremity. Upon evaluation, the patient was found to have progressive neurological deficits and was transferred by ambulance to the authors’ tertiary medical center for definitive management. 

A review of the patient’s recent symptoms indicated that she had also experienced lower abdominal paresthesias of 5 days’ duration. She described this sensation as sharp, numb, and constant since its onset and unrelieved with the use of a muscle relaxant at home. She further noted that the pain became worse with movement, having no palliative modifying factors. Upon further questioning, the patient acknowledged recent urinary incontinence of unknown duration, nausea, and current menstruation. She denied any recent injury or illness.

Her past medical history was unknown, and she stated that she had not seen a physician in several years. The patient’s surgical history included a tonsillectomy and an appendectomy at a young age. She had no known drug allergies. Although she denied the use of medications, electronic medical records show that the patient had been prescribed baclofen, hydrochlorothiazide, metoprolol, and tramadol. She was unaware of her family’s medical history and denied use of tobacco, alcohol, or illicit drugs.

Upon physical examination, the patient’s vital signs were: blood pressure, 161/99 mm Hg; heart rate, 103 beats/minute; respiratory rate, 16 breaths/minute; oxygen saturation, 97% on room air; and temperature, 97.0°F. She appeared to be a middle-aged obese woman in no apparent distress and was alert with normal mentation, lying comfortably on the gurney.

The head and neck examinations were normal. Lung auscultation demonstrated equal and unlabored breath sounds bilaterally with no adventitious sounds. Incidentally, it was noted at this time that the left breast had a significantly large fungating mass about the areola and within the deep tissue that was visually evidenced by prominent erythema and classic peau d’orange skin. The right breast had minimal skin involvement with a smaller palpable mass below the dermal surface. Both breast masses and enlarged axillary lymph nodes on the left were nontender. The cardiovascular examination demonstrated mild tachycardia with normal heart sounds, no extremity edema, and normal pulses throughout. The gastrointestinal examination had normal borborygmus with mild infraabdominal tenderness to palpation superficially over a nondistended abdomen. Neither organomegaly, hernia, nor masses were appreciated. In addition to urinary incontinence, the patient also had fecal incontinence, which correlated with diminished tone on digital rectal examination.

 Neurological sensation was intact in all extremities and no deficits were noted in the cranial nerves. Patellar and ankle tendon-testing demonstrated left-sided hyperreflexia with ipsilateral Babinski reflex exhibiting up-going toes. Musculoskeletal weakness was grossly noted in the left lower extremity to be +2/5, whereas the right lower limb had +4/5 strength. Palpation of the thoracic and lumbar spines did not elicit tenderness. Aside from the aforementioned observations, no additional integumentary findings were noted. 

The patient was given oxygen by nasal cannula, connected to cardiac monitoring and pulse oximetry. A urinary catheter was inserted, and she was given parenteral dexamethasone,³ morphine sulfate, ondansetron, and normal saline. An electrocardiogram showed a normal sinus rhythm. A chest X-ray and basic blood analysis were ordered in preparation for the likelihood of surgical management. Neurosurgery and radiology were consulted. Emergent magnetic resonance imaging (MRI) of the cervical, thoracic, and lumbar spine with and without contrast was obtained to rule out SCC.

The MRI of the spine revealed pathologic fractures leading to cord compression at T9 and spinal stenosis at the L2 segment (Figure 1); diffuse bone metastasis of the spine was also observed. Subsequent surgical decompressive laminectomy from T7 to L3 was performed without complication. Despite the reportedly poor outcome in CMS,^2,4-6 the patient demonstrated a moderate return of strength, sensation, and function within the first month of postoperative follow-up. At 3 months, she had minimal subjective and objective deficits and was ambulating without difficulty. She denied urinary and fecal incontinence during these periods. The biopsied breast mass was determined to be stage IV infiltrating ductal carcinoma mucinous type, for which she was followed by an oncologist and received radiation and chemotherapy.

 

Discussion

The patient’s chief complaint of lower extremity muscle weakness was a clinical emergency that merited thorough investigation in a timely manner to preserve limb function. Since her medical history did not provide pathologic insight concerning her condition, physical examination by emergency personnel served as the founding evidence for this patient’s diagnosis. Decreased muscle tone of the lower extremities and rectal sphincter raised suspicion for a neurological etiology. These symptoms, along with hyperreflexia, the presence of a Babinski sign, and dual-system incontinence, were suggestive of an underlying central nervous system lesion. Of note, urinary complaints commonly result from retention leading to overflow incontinence, a time-dependent symptom that may not be experienced before presentation to medical personnel. Urinary retention is one of the most consistent findings in patients with CMS and SCC, with a relative prevalence of 90%.^4,7,8

For providers not familiar with CMS presentation, preserved tactile sensation, normoreflexia, and lack of a Babinski sign and/or incontinence are not sufficient indicators to discontinue the consideration of spinal cord lesions in the differential diagnosis and may in fact be misleading.^6,9,10 Although the patient’s deficits were not symmetrical as is commonly reported, this did not rule out the diagnosis. 

Appropriate diagnosis and treatment of such a rare entity in the emergency setting consists of a high clinical suspicion, MRI of the spine, urgent consultations, and early treatment with parenteral corticosteroids.^3,4 The patient did not have a previous diagnosis of breast carcinoma; however, once discovered on examination, the condition became suspect as approximately 80% of patients with SCC have a preexisting cancer. The peak incidence of SCC is in the sixth and seventh decades of life. The most common primary cancers metastasizing to bone are breast, prostate, and lung. When found to affect the spine, roughly 60% will be located in the thoracic spine, 30% at the lumbosacral level, and 10% in the cervical spine.

As demonstrated in this case presentation, a thorough examination cannot be stressed enough in emergent situations. The patient’s dermatological findings and nontender lymphadenopathy were adequately significant to consider the possibility of a metastatic process as the underlying etiology. Although discouraged due to the fast-paced environment of the ED, patients are frequently assessed and examined in street clothing, which in this case, may have masked the underlying cause of the patient’s neurological deficits. As a result, imaging studies, corticosteroid treatment, consultations, and surgical management may have been delayed, leading to a nonreversible outcome for the patient.

Central and Peripheral Nervous System Structures and Deficits

Central and peripheral nervous system structures animate the body through coordinated signaling of upper and lower motor neurons respectively. In most adults, the distal spinal cord terminates at the level of the first or second lumbar vertebrae where the conus medullaris is found, giving rise to S2, S3 and S4 functionality. Lesions at this level exhibit lower motor neuron deficits of the bladder and rectum resulting in incontinence and sexual dysfunction. Deficits of sensorium such as saddle anesthesia or upper motor neuron lesions as evidenced by increased motor tone and abnormal reflexes are not uncommon.¹ Branches of the cauda equina extend caudally from the epiconus, a structure proximal to the conus medullaris, as peripheral nervous system branches that innervate spinal cord segments L4 through S1 (Figure 2). Lesions of the epiconus are clinically distinguished by lower motor neuron deficits wherein muscles of the lower extremities are often weakened with potential sparing of the bulbocavernosus and micturition reflexes.²

Among the many etiologies of CMS, the most common are due to compressive lesions. These include spinal trauma, neoplasm, nucleus pulposus herniation, and spinal infection. When the spinal foramen becomes either stenotic or space-occupying lesions compress, neurological function at the affected level may be compromised. In the case of CMS, neurological deficits may present as lower extremity weakness, perineal pain, or altered deep tendon reflexes (hyperreflexia or areflexia). Tactile sensation is usually spared and incontinence is frequently present. Pure lesions of the conus medullaris are uncommon and are often combined with cauda equina symptoms¹ (Table).

Conclusion

While many EPs are cognizant of cauda equina syndrome and its presentation, CMS is less well known and not commonly documented. Due to symptomatic overlap and epidemiological rarity of these conditions, most of the literature describing these entities combines their discussion. This case contributes to the growing body of literature to assist clinicians in the evaluation and management of CMS.

Dr Batt is an emergency medicine resident, Arrowhead Regional Medical Center, Colton, California. Dr Stone is the emergency medical services director, Travis Air Force Base, Fairfield, California.

Case

A 46-year-old white woman with sudden onset of numbness in her lower extremities and inability to ambulate was transported to the ED via emergency medical services. At the onset of symptoms, the patient reported a feeling of “heaviness” in her lower extremities, which was greater on the left side than the right. After an unsuccessful attempt at ambulation, she subsequently presented to a community hospital where she could no longer move her left lower extremity. Upon evaluation, the patient was found to have progressive neurological deficits and was transferred by ambulance to the authors’ tertiary medical center for definitive management. 

A review of the patient’s recent symptoms indicated that she had also experienced lower abdominal paresthesias of 5 days’ duration. She described this sensation as sharp, numb, and constant since its onset and unrelieved with the use of a muscle relaxant at home. She further noted that the pain became worse with movement, having no palliative modifying factors. Upon further questioning, the patient acknowledged recent urinary incontinence of unknown duration, nausea, and current menstruation. She denied any recent injury or illness.

Her past medical history was unknown, and she stated that she had not seen a physician in several years. The patient’s surgical history included a tonsillectomy and an appendectomy at a young age. She had no known drug allergies. Although she denied the use of medications, electronic medical records show that the patient had been prescribed baclofen, hydrochlorothiazide, metoprolol, and tramadol. She was unaware of her family’s medical history and denied use of tobacco, alcohol, or illicit drugs.

Upon physical examination, the patient’s vital signs were: blood pressure, 161/99 mm Hg; heart rate, 103 beats/minute; respiratory rate, 16 breaths/minute; oxygen saturation, 97% on room air; and temperature, 97.0°F. She appeared to be a middle-aged obese woman in no apparent distress and was alert with normal mentation, lying comfortably on the gurney.

The head and neck examinations were normal. Lung auscultation demonstrated equal and unlabored breath sounds bilaterally with no adventitious sounds. Incidentally, it was noted at this time that the left breast had a significantly large fungating mass about the areola and within the deep tissue that was visually evidenced by prominent erythema and classic peau d’orange skin. The right breast had minimal skin involvement with a smaller palpable mass below the dermal surface. Both breast masses and enlarged axillary lymph nodes on the left were nontender. The cardiovascular examination demonstrated mild tachycardia with normal heart sounds, no extremity edema, and normal pulses throughout. The gastrointestinal examination had normal borborygmus with mild infraabdominal tenderness to palpation superficially over a nondistended abdomen. Neither organomegaly, hernia, nor masses were appreciated. In addition to urinary incontinence, the patient also had fecal incontinence, which correlated with diminished tone on digital rectal examination.

 Neurological sensation was intact in all extremities and no deficits were noted in the cranial nerves. Patellar and ankle tendon-testing demonstrated left-sided hyperreflexia with ipsilateral Babinski reflex exhibiting up-going toes. Musculoskeletal weakness was grossly noted in the left lower extremity to be +2/5, whereas the right lower limb had +4/5 strength. Palpation of the thoracic and lumbar spines did not elicit tenderness. Aside from the aforementioned observations, no additional integumentary findings were noted. 

The patient was given oxygen by nasal cannula, connected to cardiac monitoring and pulse oximetry. A urinary catheter was inserted, and she was given parenteral dexamethasone,³ morphine sulfate, ondansetron, and normal saline. An electrocardiogram showed a normal sinus rhythm. A chest X-ray and basic blood analysis were ordered in preparation for the likelihood of surgical management. Neurosurgery and radiology were consulted. Emergent magnetic resonance imaging (MRI) of the cervical, thoracic, and lumbar spine with and without contrast was obtained to rule out SCC.

The MRI of the spine revealed pathologic fractures leading to cord compression at T9 and spinal stenosis at the L2 segment (Figure 1); diffuse bone metastasis of the spine was also observed. Subsequent surgical decompressive laminectomy from T7 to L3 was performed without complication. Despite the reportedly poor outcome in CMS,^2,4-6 the patient demonstrated a moderate return of strength, sensation, and function within the first month of postoperative follow-up. At 3 months, she had minimal subjective and objective deficits and was ambulating without difficulty. She denied urinary and fecal incontinence during these periods. The biopsied breast mass was determined to be stage IV infiltrating ductal carcinoma mucinous type, for which she was followed by an oncologist and received radiation and chemotherapy.

 

Discussion

The patient’s chief complaint of lower extremity muscle weakness was a clinical emergency that merited thorough investigation in a timely manner to preserve limb function. Since her medical history did not provide pathologic insight concerning her condition, physical examination by emergency personnel served as the founding evidence for this patient’s diagnosis. Decreased muscle tone of the lower extremities and rectal sphincter raised suspicion for a neurological etiology. These symptoms, along with hyperreflexia, the presence of a Babinski sign, and dual-system incontinence, were suggestive of an underlying central nervous system lesion. Of note, urinary complaints commonly result from retention leading to overflow incontinence, a time-dependent symptom that may not be experienced before presentation to medical personnel. Urinary retention is one of the most consistent findings in patients with CMS and SCC, with a relative prevalence of 90%.^4,7,8

For providers not familiar with CMS presentation, preserved tactile sensation, normoreflexia, and lack of a Babinski sign and/or incontinence are not sufficient indicators to discontinue the consideration of spinal cord lesions in the differential diagnosis and may in fact be misleading.^6,9,10 Although the patient’s deficits were not symmetrical as is commonly reported, this did not rule out the diagnosis. 

Appropriate diagnosis and treatment of such a rare entity in the emergency setting consists of a high clinical suspicion, MRI of the spine, urgent consultations, and early treatment with parenteral corticosteroids.^3,4 The patient did not have a previous diagnosis of breast carcinoma; however, once discovered on examination, the condition became suspect as approximately 80% of patients with SCC have a preexisting cancer. The peak incidence of SCC is in the sixth and seventh decades of life. The most common primary cancers metastasizing to bone are breast, prostate, and lung. When found to affect the spine, roughly 60% will be located in the thoracic spine, 30% at the lumbosacral level, and 10% in the cervical spine.

As demonstrated in this case presentation, a thorough examination cannot be stressed enough in emergent situations. The patient’s dermatological findings and nontender lymphadenopathy were adequately significant to consider the possibility of a metastatic process as the underlying etiology. Although discouraged due to the fast-paced environment of the ED, patients are frequently assessed and examined in street clothing, which in this case, may have masked the underlying cause of the patient’s neurological deficits. As a result, imaging studies, corticosteroid treatment, consultations, and surgical management may have been delayed, leading to a nonreversible outcome for the patient.

Central and Peripheral Nervous System Structures and Deficits

Central and peripheral nervous system structures animate the body through coordinated signaling of upper and lower motor neurons respectively. In most adults, the distal spinal cord terminates at the level of the first or second lumbar vertebrae where the conus medullaris is found, giving rise to S2, S3 and S4 functionality. Lesions at this level exhibit lower motor neuron deficits of the bladder and rectum resulting in incontinence and sexual dysfunction. Deficits of sensorium such as saddle anesthesia or upper motor neuron lesions as evidenced by increased motor tone and abnormal reflexes are not uncommon.¹ Branches of the cauda equina extend caudally from the epiconus, a structure proximal to the conus medullaris, as peripheral nervous system branches that innervate spinal cord segments L4 through S1 (Figure 2). Lesions of the epiconus are clinically distinguished by lower motor neuron deficits wherein muscles of the lower extremities are often weakened with potential sparing of the bulbocavernosus and micturition reflexes.²

Among the many etiologies of CMS, the most common are due to compressive lesions. These include spinal trauma, neoplasm, nucleus pulposus herniation, and spinal infection. When the spinal foramen becomes either stenotic or space-occupying lesions compress, neurological function at the affected level may be compromised. In the case of CMS, neurological deficits may present as lower extremity weakness, perineal pain, or altered deep tendon reflexes (hyperreflexia or areflexia). Tactile sensation is usually spared and incontinence is frequently present. Pure lesions of the conus medullaris are uncommon and are often combined with cauda equina symptoms¹ (Table).

Conclusion

While many EPs are cognizant of cauda equina syndrome and its presentation, CMS is less well known and not commonly documented. Due to symptomatic overlap and epidemiological rarity of these conditions, most of the literature describing these entities combines their discussion. This case contributes to the growing body of literature to assist clinicians in the evaluation and management of CMS.

Dr Batt is an emergency medicine resident, Arrowhead Regional Medical Center, Colton, California. Dr Stone is the emergency medical services director, Travis Air Force Base, Fairfield, California.

Case

A 46-year-old white woman with sudden onset of numbness in her lower extremities and inability to ambulate was transported to the ED via emergency medical services. At the onset of symptoms, the patient reported a feeling of “heaviness” in her lower extremities, which was greater on the left side than the right. After an unsuccessful attempt at ambulation, she subsequently presented to a community hospital where she could no longer move her left lower extremity. Upon evaluation, the patient was found to have progressive neurological deficits and was transferred by ambulance to the authors’ tertiary medical center for definitive management. 

A review of the patient’s recent symptoms indicated that she had also experienced lower abdominal paresthesias of 5 days’ duration. She described this sensation as sharp, numb, and constant since its onset and unrelieved with the use of a muscle relaxant at home. She further noted that the pain became worse with movement, having no palliative modifying factors. Upon further questioning, the patient acknowledged recent urinary incontinence of unknown duration, nausea, and current menstruation. She denied any recent injury or illness.

Her past medical history was unknown, and she stated that she had not seen a physician in several years. The patient’s surgical history included a tonsillectomy and an appendectomy at a young age. She had no known drug allergies. Although she denied the use of medications, electronic medical records show that the patient had been prescribed baclofen, hydrochlorothiazide, metoprolol, and tramadol. She was unaware of her family’s medical history and denied use of tobacco, alcohol, or illicit drugs.

Upon physical examination, the patient’s vital signs were: blood pressure, 161/99 mm Hg; heart rate, 103 beats/minute; respiratory rate, 16 breaths/minute; oxygen saturation, 97% on room air; and temperature, 97.0°F. She appeared to be a middle-aged obese woman in no apparent distress and was alert with normal mentation, lying comfortably on the gurney.

The head and neck examinations were normal. Lung auscultation demonstrated equal and unlabored breath sounds bilaterally with no adventitious sounds. Incidentally, it was noted at this time that the left breast had a significantly large fungating mass about the areola and within the deep tissue that was visually evidenced by prominent erythema and classic peau d’orange skin. The right breast had minimal skin involvement with a smaller palpable mass below the dermal surface. Both breast masses and enlarged axillary lymph nodes on the left were nontender. The cardiovascular examination demonstrated mild tachycardia with normal heart sounds, no extremity edema, and normal pulses throughout. The gastrointestinal examination had normal borborygmus with mild infraabdominal tenderness to palpation superficially over a nondistended abdomen. Neither organomegaly, hernia, nor masses were appreciated. In addition to urinary incontinence, the patient also had fecal incontinence, which correlated with diminished tone on digital rectal examination.

 Neurological sensation was intact in all extremities and no deficits were noted in the cranial nerves. Patellar and ankle tendon-testing demonstrated left-sided hyperreflexia with ipsilateral Babinski reflex exhibiting up-going toes. Musculoskeletal weakness was grossly noted in the left lower extremity to be +2/5, whereas the right lower limb had +4/5 strength. Palpation of the thoracic and lumbar spines did not elicit tenderness. Aside from the aforementioned observations, no additional integumentary findings were noted. 

The patient was given oxygen by nasal cannula, connected to cardiac monitoring and pulse oximetry. A urinary catheter was inserted, and she was given parenteral dexamethasone,³ morphine sulfate, ondansetron, and normal saline. An electrocardiogram showed a normal sinus rhythm. A chest X-ray and basic blood analysis were ordered in preparation for the likelihood of surgical management. Neurosurgery and radiology were consulted. Emergent magnetic resonance imaging (MRI) of the cervical, thoracic, and lumbar spine with and without contrast was obtained to rule out SCC.

The MRI of the spine revealed pathologic fractures leading to cord compression at T9 and spinal stenosis at the L2 segment (Figure 1); diffuse bone metastasis of the spine was also observed. Subsequent surgical decompressive laminectomy from T7 to L3 was performed without complication. Despite the reportedly poor outcome in CMS,^2,4-6 the patient demonstrated a moderate return of strength, sensation, and function within the first month of postoperative follow-up. At 3 months, she had minimal subjective and objective deficits and was ambulating without difficulty. She denied urinary and fecal incontinence during these periods. The biopsied breast mass was determined to be stage IV infiltrating ductal carcinoma mucinous type, for which she was followed by an oncologist and received radiation and chemotherapy.

 

Discussion

The patient’s chief complaint of lower extremity muscle weakness was a clinical emergency that merited thorough investigation in a timely manner to preserve limb function. Since her medical history did not provide pathologic insight concerning her condition, physical examination by emergency personnel served as the founding evidence for this patient’s diagnosis. Decreased muscle tone of the lower extremities and rectal sphincter raised suspicion for a neurological etiology. These symptoms, along with hyperreflexia, the presence of a Babinski sign, and dual-system incontinence, were suggestive of an underlying central nervous system lesion. Of note, urinary complaints commonly result from retention leading to overflow incontinence, a time-dependent symptom that may not be experienced before presentation to medical personnel. Urinary retention is one of the most consistent findings in patients with CMS and SCC, with a relative prevalence of 90%.^4,7,8

For providers not familiar with CMS presentation, preserved tactile sensation, normoreflexia, and lack of a Babinski sign and/or incontinence are not sufficient indicators to discontinue the consideration of spinal cord lesions in the differential diagnosis and may in fact be misleading.^6,9,10 Although the patient’s deficits were not symmetrical as is commonly reported, this did not rule out the diagnosis. 

Appropriate diagnosis and treatment of such a rare entity in the emergency setting consists of a high clinical suspicion, MRI of the spine, urgent consultations, and early treatment with parenteral corticosteroids.^3,4 The patient did not have a previous diagnosis of breast carcinoma; however, once discovered on examination, the condition became suspect as approximately 80% of patients with SCC have a preexisting cancer. The peak incidence of SCC is in the sixth and seventh decades of life. The most common primary cancers metastasizing to bone are breast, prostate, and lung. When found to affect the spine, roughly 60% will be located in the thoracic spine, 30% at the lumbosacral level, and 10% in the cervical spine.

As demonstrated in this case presentation, a thorough examination cannot be stressed enough in emergent situations. The patient’s dermatological findings and nontender lymphadenopathy were adequately significant to consider the possibility of a metastatic process as the underlying etiology. Although discouraged due to the fast-paced environment of the ED, patients are frequently assessed and examined in street clothing, which in this case, may have masked the underlying cause of the patient’s neurological deficits. As a result, imaging studies, corticosteroid treatment, consultations, and surgical management may have been delayed, leading to a nonreversible outcome for the patient.

Central and Peripheral Nervous System Structures and Deficits

Central and peripheral nervous system structures animate the body through coordinated signaling of upper and lower motor neurons respectively. In most adults, the distal spinal cord terminates at the level of the first or second lumbar vertebrae where the conus medullaris is found, giving rise to S2, S3 and S4 functionality. Lesions at this level exhibit lower motor neuron deficits of the bladder and rectum resulting in incontinence and sexual dysfunction. Deficits of sensorium such as saddle anesthesia or upper motor neuron lesions as evidenced by increased motor tone and abnormal reflexes are not uncommon.¹ Branches of the cauda equina extend caudally from the epiconus, a structure proximal to the conus medullaris, as peripheral nervous system branches that innervate spinal cord segments L4 through S1 (Figure 2). Lesions of the epiconus are clinically distinguished by lower motor neuron deficits wherein muscles of the lower extremities are often weakened with potential sparing of the bulbocavernosus and micturition reflexes.²

Among the many etiologies of CMS, the most common are due to compressive lesions. These include spinal trauma, neoplasm, nucleus pulposus herniation, and spinal infection. When the spinal foramen becomes either stenotic or space-occupying lesions compress, neurological function at the affected level may be compromised. In the case of CMS, neurological deficits may present as lower extremity weakness, perineal pain, or altered deep tendon reflexes (hyperreflexia or areflexia). Tactile sensation is usually spared and incontinence is frequently present. Pure lesions of the conus medullaris are uncommon and are often combined with cauda equina symptoms¹ (Table).

Conclusion

While many EPs are cognizant of cauda equina syndrome and its presentation, CMS is less well known and not commonly documented. Due to symptomatic overlap and epidemiological rarity of these conditions, most of the literature describing these entities combines their discussion. This case contributes to the growing body of literature to assist clinicians in the evaluation and management of CMS.

Dr Batt is an emergency medicine resident, Arrowhead Regional Medical Center, Colton, California. Dr Stone is the emergency medical services director, Travis Air Force Base, Fairfield, California.

Lung ultrasound can be a valuable addition to the emergency physician’s (EP’s) diagnostic armamentarium. This article reviews how this modality may be used to differentiate between chronic obstructive pulmonary disease (COPD) and coronary heart failure (CHF) exacerbations. As patients often have a history of both of these diseases, it is difficult to distinguish which condition is the cause of a patient’s dyspnea. This examination is easy to learn and in most cases, it can be performed within 3 to 4 minutes. Most importantly, lung ultrasound can assist in making clinical decisions in real time at the bedside. Although the following is not a comprehensive review, it does provide the basic essentials, allowing the clinician to begin using this modality in the ED.

Getting Started

The curvilinear probe is required to perform ultrasound of the lungs. Most studies divide the lung into regions, though consensus on exactly how many regions are required remains unclear. The blue protocol, which is probably the most well-known study, divides the lung into the anterior, lateral, and posterolateral sections.¹ The superior and inferior aspects of each zone are evaluated with a total of six ultrasound views
per lung.

Artifacts

An understanding of artifacts is essential to correct interpretation of the ultrasound images. Two ultrasound findings of normal lungs are “A lines” and “lung sliding.” However, these patterns are seen in normal lungs and in the lungs of patients with asthma and COPD.

Lung sliding is movement of the parietal pleura sliding against the visceral pleura. A lines are a repetitive reverberation artifact of the pleura (Figure 1).  Occasional comet-tail artifacts—short hyperechoic artifacts that arise from the pleural line and descend in a vertical orientation partially down the screen (Figure 2).

B lines are the ultrasound equivalent of the Kerley B lines found on chest X-ray. Bilateral B lines are commonly present in lungs with interstitial edema. For an examination to be considered positive, there must be a minimum three B lines per view (Figure 3). Ultrasonographic B lines are long wide bands of hyperechoic artifact that have been likened to the beam of a flashlight. They originate at the pleural line and traverse the entire ultrasound screen vertically to the bottom of the screen. Causes of unilateral B lines can include pneumonia and pulmonary contusion. As the EP becomes more familiar in performing lung ultrasound, he or she will become more adept at identifying A and B lines.

Differential Diagnosis

When using ultrasound to differentiate between CHF and COPD, this examination has been shown to have a sensitivity of 100% and a specificity of 92%.² By performing lung ultrasound immediately upon a patient’s arrival to the ED, the clinician can obtain quick and accurate insight into whether a patient would benefit from albuterol or nitroglycerin. In the acutely dyspneic patient, combining lung ultrasound with focused echocardiogram and sonographic inferior vena cava assessment will provide additional information to support the diagnosis.

Conclusion

As with other bedside imaging techniques, lung ultrasound in the ED can help to quickly assess the dyspneic patient and facilitate initiation of appropriate treatment.

Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia.

Lung ultrasound can be a valuable addition to the emergency physician’s (EP’s) diagnostic armamentarium. This article reviews how this modality may be used to differentiate between chronic obstructive pulmonary disease (COPD) and coronary heart failure (CHF) exacerbations. As patients often have a history of both of these diseases, it is difficult to distinguish which condition is the cause of a patient’s dyspnea. This examination is easy to learn and in most cases, it can be performed within 3 to 4 minutes. Most importantly, lung ultrasound can assist in making clinical decisions in real time at the bedside. Although the following is not a comprehensive review, it does provide the basic essentials, allowing the clinician to begin using this modality in the ED.

Getting Started

The curvilinear probe is required to perform ultrasound of the lungs. Most studies divide the lung into regions, though consensus on exactly how many regions are required remains unclear. The blue protocol, which is probably the most well-known study, divides the lung into the anterior, lateral, and posterolateral sections.¹ The superior and inferior aspects of each zone are evaluated with a total of six ultrasound views
per lung.

Artifacts

An understanding of artifacts is essential to correct interpretation of the ultrasound images. Two ultrasound findings of normal lungs are “A lines” and “lung sliding.” However, these patterns are seen in normal lungs and in the lungs of patients with asthma and COPD.

Lung sliding is movement of the parietal pleura sliding against the visceral pleura. A lines are a repetitive reverberation artifact of the pleura (Figure 1).  Occasional comet-tail artifacts—short hyperechoic artifacts that arise from the pleural line and descend in a vertical orientation partially down the screen (Figure 2).

B lines are the ultrasound equivalent of the Kerley B lines found on chest X-ray. Bilateral B lines are commonly present in lungs with interstitial edema. For an examination to be considered positive, there must be a minimum three B lines per view (Figure 3). Ultrasonographic B lines are long wide bands of hyperechoic artifact that have been likened to the beam of a flashlight. They originate at the pleural line and traverse the entire ultrasound screen vertically to the bottom of the screen. Causes of unilateral B lines can include pneumonia and pulmonary contusion. As the EP becomes more familiar in performing lung ultrasound, he or she will become more adept at identifying A and B lines.

Differential Diagnosis

When using ultrasound to differentiate between CHF and COPD, this examination has been shown to have a sensitivity of 100% and a specificity of 92%.² By performing lung ultrasound immediately upon a patient’s arrival to the ED, the clinician can obtain quick and accurate insight into whether a patient would benefit from albuterol or nitroglycerin. In the acutely dyspneic patient, combining lung ultrasound with focused echocardiogram and sonographic inferior vena cava assessment will provide additional information to support the diagnosis.

Conclusion

As with other bedside imaging techniques, lung ultrasound in the ED can help to quickly assess the dyspneic patient and facilitate initiation of appropriate treatment.

Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia.

Lung ultrasound can be a valuable addition to the emergency physician’s (EP’s) diagnostic armamentarium. This article reviews how this modality may be used to differentiate between chronic obstructive pulmonary disease (COPD) and coronary heart failure (CHF) exacerbations. As patients often have a history of both of these diseases, it is difficult to distinguish which condition is the cause of a patient’s dyspnea. This examination is easy to learn and in most cases, it can be performed within 3 to 4 minutes. Most importantly, lung ultrasound can assist in making clinical decisions in real time at the bedside. Although the following is not a comprehensive review, it does provide the basic essentials, allowing the clinician to begin using this modality in the ED.

Getting Started

The curvilinear probe is required to perform ultrasound of the lungs. Most studies divide the lung into regions, though consensus on exactly how many regions are required remains unclear. The blue protocol, which is probably the most well-known study, divides the lung into the anterior, lateral, and posterolateral sections.¹ The superior and inferior aspects of each zone are evaluated with a total of six ultrasound views
per lung.

Artifacts

An understanding of artifacts is essential to correct interpretation of the ultrasound images. Two ultrasound findings of normal lungs are “A lines” and “lung sliding.” However, these patterns are seen in normal lungs and in the lungs of patients with asthma and COPD.

Lung sliding is movement of the parietal pleura sliding against the visceral pleura. A lines are a repetitive reverberation artifact of the pleura (Figure 1).  Occasional comet-tail artifacts—short hyperechoic artifacts that arise from the pleural line and descend in a vertical orientation partially down the screen (Figure 2).

B lines are the ultrasound equivalent of the Kerley B lines found on chest X-ray. Bilateral B lines are commonly present in lungs with interstitial edema. For an examination to be considered positive, there must be a minimum three B lines per view (Figure 3). Ultrasonographic B lines are long wide bands of hyperechoic artifact that have been likened to the beam of a flashlight. They originate at the pleural line and traverse the entire ultrasound screen vertically to the bottom of the screen. Causes of unilateral B lines can include pneumonia and pulmonary contusion. As the EP becomes more familiar in performing lung ultrasound, he or she will become more adept at identifying A and B lines.

Differential Diagnosis

When using ultrasound to differentiate between CHF and COPD, this examination has been shown to have a sensitivity of 100% and a specificity of 92%.² By performing lung ultrasound immediately upon a patient’s arrival to the ED, the clinician can obtain quick and accurate insight into whether a patient would benefit from albuterol or nitroglycerin. In the acutely dyspneic patient, combining lung ultrasound with focused echocardiogram and sonographic inferior vena cava assessment will provide additional information to support the diagnosis.

Conclusion

As with other bedside imaging techniques, lung ultrasound in the ED can help to quickly assess the dyspneic patient and facilitate initiation of appropriate treatment.

Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia.

Overview

Candidates for noninvasive ventilation (NIV) most commonly present to the ED with acute respiratory failure (ARF) secondary to chronic obstructive pulmonary disease (COPD) or congestive heart-failure (CHF) exacerbations. The emergency physician (EP) must select patients appropriately, recognizing which would benefit most from NIV, as well as those with contraindications to this therapy. When indicated, early application confers benefit to the patient and can help avoid endotracheal intubation. Once therapy is initiated, clinical deterioration is still possible, and close monitoring and troubleshooting are imperative. Frequently, the clinician must make adjustments in ventilatory parameters to support the patient.

In this article, the author discusses the evidence supporting the use of NIV in appropriately selected patients with ARF, as well as review the types of NIV commonly used in the ED, the physiologic effects of positive-pressure ventilation (PPV), and how to identify and avoid common pitfalls.

Case Presentation Examples

Case 1

A 72-year-old man with a past medical history of COPD was brought to the ED by emergency medical services for evaluation of shortness of breath and wheezing. The patient’s initial oxygen (O₂) saturation was 84%, which responded to bronchodilators and supplemental O₂. At the time of arrival, he was somewhat somnolent, but aroused to verbal stimuli. A nonrebreather mask was placed delivering 15 L/minute of O₂ with a saturation of 96%. His vital signs were: blood pressure (BP), 142/76 mm Hg, heart rate, 108 beats/minute; and respiratory rate (RR), 13 breaths/minute. A cardiac monitor revealed sinus tachycardia, and a portable chest X-ray was obtained (Figure 1). On lung examination, the patient’s breath sounds were diminished in the bases with suboptimal respiratory effort and expiratory wheezes in all lung fields. Venous blood gas measurement revealed a pH of 7.25; end-tidal carbon dioxide (CO₂) was 77.

After the initial assessment, the EP considered NIV as an adjunct to improve ventilation as he suspected the patient was experiencing significant respiratory acidosis secondary to CO₂ retention. The respiratory therapist suggested NIV at 12/5 before titrating down the fraction of inspired O₂ (FiO₂) and sought approval from the EP. 

Discussion Questions: Is the above recommendation from the respiratory therapist the most appropriate therapy for this patient? What are the contraindications to this treatment and how should he be monitored to measure improvement?

Case 2

A 54-year-old woman presented to the ED for shortness of breath. On examination, she was diaphoretic and in severe distress with one- to two-word dyspnea and gasping respirations with pink-tinged sputum. Her BP was 236/158 mm Hg. A portable chest X-ray was obtained (Figure 2); rales were present with significant jugular venous distension. An electrocardiogram revealed a left-ventricular hypertrophy strain pattern but no evidence of ST-segment elevation.

During the assessment, the EP considered hypertensive emergency with resulting flash pulmonary edema as the cause of the patient’s condition; as such, he contemplated NIV to decrease the work of breathing and improve oxygenation. However, the EP had concerns regarding the preload and afterload ramifications. Although there was no respiratory therapist in the ED, the EP was able to set up the machine, but was not certain which mode of NIV or initial settings would be appropriate.

Discussion Questions: What is the protocol for proper set up to ensure a good mask fit? Once therapy is initiated, how should the EP monitor the patient? How should the EP explain this therapy to the patient and instruct her on how to work with the ventilator?

Acute-Care Application

Noninvasive ventilation refers to PPV delivered through a device such as a facemask, nasal mask, nasal plugs, or helmet. This modality was first used in the 1940s to treat respiratory failure, and its use has since grown to parallel that of mechanical ventilation.^1-3 Although the application of NIV does not represent definitive airway management, this therapy has dramatically changed the care and treatment of both chronic and ARF. It serves as a significant intervention to prevent further respiratory compromise; to reverse either existing physiologic, hemodynamic, or ventilatory derangements; and to avoid endotracheal intubation.

Modes of Delivery

In the acute setting, NIV is typically delivered via two modes. Continuous positive-airway pressure (CPAP) is delivered regardless of the phase of respiration, and noninvasive positive-pressure ventilation (NIPPV; typically referred to as bi-level positive-airway pressure [BiPAP] or BPPV) is delivered in the inspiratory and expiratory phases of the respiratory cycle. Inspiratory positive-airway pressure (IPAP) refers to an inspiratory boost that is triggered by the negative airway pressure on inspiration in a synchronous fashion. This inspiratory pressure is fixed, but the volume delivered fluctuates based on the patient’s inspiratory effort. Expiratory positive-airway pressure (EPAP) is the delivery of constant pressure during exhalation. The difference between the IPAP and EPAP is referred to as pressure support, which serves to decrease the work of breathing and improve ventilation. (A list of commonly used abbreviations, terms, and definitions are outlined in Table 1.)

 

Etiology of Respiratory Failure and Treatment Decisions
At the time of initial presentation, the exact etiology of a patient’s respiratory failure may not be known, and treatment decisions will be necessary before all relevant data are present. Patients presenting in acute respiratory distress (ARD) are often suffering from shunt physiology, in which alveoli are perfused but not ventilated due to the presence of fluid or collapse, as in pulmonary edema or COPD.⁴ Regardless of the etiology, patients will benefit from early application of NIV.⁵ Thus, the clinician must be aggressive in the application of this therapy to identify those patients who will benefit the most from treatment. All patients receiving NIV must be monitored closely as failure of therapy is still a possibility.

Patient Selection

The utilization of NIV has increased in the hospital and ED setting and it is now often initiated in the prehospital setting^6-8 with observed improvement in dyspnea scores and oxygenation with early intervention.⁹ Regarding patient selection, in the absence of contraindications (Table 2), all dyspneic patients should be considered eligible for a trial of NIV. ¹³ For some patients, this may be their first use of the therapy; as such, they are in effect learning to “swim while drowning.” The agitated and anxious patient will require coaching to provide reassurance and instruction while he or she learns to synchronize and work with the ventilator. The presence and quality of this instruction, though not previously measured, would intuitively be very helpful and an important determinant of success in the application of NIV in the naïve patient.

Common Conditions and NIV

In the ED, NIV is commonly utilized for the treatment of COPD and acute decompensated heart failure. These two conditions have been extensively studied and a robust amount of literature supports the routine use of NIV in these patients.

Chronic Obstructive Pulmonary Disease
For COPD, BiPAP has been shown and is widely accepted as the modality that confers the most benefit, with one study demonstrating a 462% increase in its use and a 42% decline in mechanical intubation rates from 1998 to 2008.¹⁴ Multiple studies have demonstrated a reduction in the intubation rate, improvement in the work of breathing, and a more rapid improvement in RR and symptoms.^15,16

Acute Decompensated Heart Failure and Pulmonary Edema
Noninvasive ventilation is used commonly for decompensated heart failure and acute cardiogenic pulmonary edema (ACPE). The rapid patient improvement with its use when compared to standard O₂ therapy is well documented. A successful trial and application of NIV demonstrated benefit in a recent retrospective analysis of 2,430 acutely decompensated heart-failure patients in the United States. The study found that the patients who were treated with NIV, but not immediately intubated, had better outcomes.¹⁷ (In these types of patients, pulmonary edema is typically not related to volume overload, but the result of imbalanced hemodynamics with markedly increased cardiac afterload and systemic vascular resistance.)

With respect to type of NIV, the use of CPAP is widely accepted as the primary modality of choice to confer the most benefit in ACPE.¹⁸ Although theoretical advantages do exist for the use of BiPAP over CPAP, this benefit has been noted in smaller studies¹⁹ but not clearly demonstrated in large reviews.^20,21 In addition, patients suffering from long-term CHF develop the syndrome of cardiac cachexia, characterized by the loss of quantity and quality of skeletal muscle.²² This reduction in muscle mass can produce a significant deficit in inspiratory muscle strength and ability, providing an opportunity for benefit with the use of BiPAP.

Previously, BiPAP was considered unsafe in the setting of ACPE due to an increase in myocardial infarction.²³ These results have not been reproduced in larger studies, and it is widely accepted that although BiPAP may not confer any benefit, it also does not increase harm.

Asthma
Because the underlying pathology of asthma differs from COPD, the current evidence for NIV use in patients presenting with an asthmatic episode is not very strong. Chronic obstructive pulmonary disease is characterized by collapse of terminal airways, with destruction of pulmonary architecture, and decreased compliance of the chest wall. In contrast, the airway obstruction in asthma progresses as the severity of the attack increases, and NIV may offer potential benefit in high-risk patients to avoid intubation.²⁴ Several small studies suggest the application of NIV for severe asthma exacerbations is reasonable, with some demonstration of improvement in the work of breathing and ventilatory status.^25-27

The Critically Ill Patient

Critically ill patients represent a high-risk group for desaturation during endotracheal intubation, and NIV should be considered for preoxygenation unless contraindications exist (Table 2). If standard high-flow O₂ without positive pressure does not improve oxygenation, the application of NIV may overcome shunt physiology, improve oxygenation, and lessen peri-intubation time with dangerous desaturation events.^4,28-30

 

Interfaces, Mask Leaks, Patient-Ventilator Interaction, and Respiratory Failure

Interfaces
Patient interfaces (mask types) for NIV include nasal prongs, full facial mask, or most commonly, an oronasal mask.³¹ For successful delivery of positive pressure, there must be an adequate fit or seal with minimal air leak to establish a ventilator circuit. Even though there is no perfect interface, patient comfort and treatment efficacy should be balanced. The interface chosen should minimize skin damage, maximize seal, and optimize patient-ventilator interface. The interfaces have straps that are used to secure the mask in place and balance the tension and stress on the skin to ensure a good seal and to avoid excess focal pressure that may result in complications such as skin breakdown, necrosis, or discomfort. Multiple interfaces and mask types have been evaluated in different acute-care situations, and it is important the clinician be familiar with the various options available for NIV interface and delivery. 

Mask Leaks
Unintentional leaks are an unavoidable reality with NIV use. The ventilators designed for NIV typically use a single-limb circuit with an intentional leak port close to the patient. This port provides resistance and, as the ventilator produces airflow, it can subsequently generate pressure. Because this leak port is incorporated into the interface, it is important to utilize the same manufacturer of the ventilator and interface to avoid interface-ventilator mismatch.³²

In some cases, unintentional leaks have been linked to asynchrony leading to increased work of breathing, ineffective delivery of breaths, and missed triggering events.³³ The goal of any chosen interface is the lowest measurable unintentional leak rate as higher values demonstrate significant variability (and inaccuracy) of measured tidal volumes (V_T).³⁴ Overtightening the mask should be avoided since it can compromise both patient comfort and increase the chance of skin necrosis or breakdown.

Patient-Ventilator Interaction
The importance of the patient-ventilator interaction and the development of synchrony between the two cannot be overstated. After initial application, the patient should be closely monitored as he or she begins to work with the ventilator. This is especially important in BiPAP.

Optimal patient-ventilator synchrony can be difficult to achieve, especially in the NIV-naïve patient with critical respiratory distress. Of note, approximately 20% to 30% of patients with ARD cannot be managed by NIV,¹¹ and asynchrony, though difficult to quantify in the acute-care setting, may contribute to this number. 

Respiratory Failure
Acute respiratory failure is caused by a change in the patient’s baseline gas exchange, resulting in an inability to provide sufficient levels of O₂ or to ventilate adequately. The etiologies of ARF are characterized into four types. 

Type I. Also referred to as hypoxemic respiratory failure, type I is the most common and is characterized by an arterial oxygen tension (PaO₂) of less than 60 mm Hg, with either normal or low levels of arterial CO₂ that is not responsive to supplemental O₂.

Type II. This type of respiratory failure is characterized by alveolar hypoventilation, with a PaCO₂ level greater than 45 mm Hg, although hypoxemia may also be present due to concomitant loss of central nervous system drive.

Type III. Failure primarily occurs in the perioperative setting where the functional residual capacity is reduced in combination with increasing atelectasis.

Type IV. Type IV ARF is secondary to circulatory failure and resolves when shock is corrected.^35,36

Regardless of the respiratory failure etiology, the patient is at risk of further deterioration and the need for endotracheal intubation.

Physiologic effects of NIV

Once the interface is secured, NIV has several important effects on both the cardiac and pulmonary systems. For this discussion, intrathoracic pressure (P_IT) is considered synonymous with mean airway pressure (P_aw).

Noninvasive ventilation improves airflow, lung volumes, and subsequent V_T while overcoming pulmonary atelectasis. The increase in lung volume is directly proportional to an increase in P_aw. This effect is only seen after overcoming airway resistance and chest wall and lung compliance. There is also an improvement in alveolar recruitment and redistribution of pulmonary blood flow³⁷ with decreased work of breathing.

With the increase in P_IT, there is decreased venous return to the right heart and a resulting decrease in cardiac preload.³⁸ In the setting of acute cardiogenic pulmonary edema (ACPE), this effect is highly favorable. However, in the volume-depleted or hemodynamically unstable patient, this may result in a drop in cardiac output and hypotension. The “normal” heart is more sensitive to preload, and the application of positive pressure can cause a significant decrease in cardiac output. Cardiac afterload is reduced through multiple mechanisms, including directly from a decreased left-ventricular (LV) preload and also from a decrease in the LV transmural pressure (referred to as P_TM).

 

The effects of positive pressure on the ventricles are opposite in the normal heart, with a decrease in both right and LV preload, increased right ventricular afterload and decreased LV afterload,^39,40 as well as an overall decrease in cardiac chamber size that is directly proportional to the level of PPV.⁴¹ For the decompensated CHF patient, this can produce an increase in cardiac output simply by shifting the patient to a more favorable (leftward) position on the Frank-Starling curve.^42-44 

Troubleshooting

Once NIV is initiated, it is imperative, at least initially, to remain at bedside to monitor progress and improvement. Even though NIV is beneficial in the acute setting, it should always be viewed as a temporary bridging measure. With improvement, NIV may be discontinued, but in cases of failure, it is necessary to proceed with endotracheal intubation.

As the patient synchronizes with the ventilator, changes should be seen rather quickly, including improvement in the work of breathing, a restoration of mental status (if significant hypercapnia is present), and improved oxygenation. In the patient with severe uncontrolled hypertension and resulting flash pulmonary edema, the reduction in preload and afterload should contribute to a decrease in systolic BP (in addition to medical therapy). There should be a low threshold for obtaining an initial arterial blood gas (or a venous sample coupled with end-tidal CO₂ data) as it may be helpful to guide therapy. 

Noninvasive ventilation is similar to mechanical ventilation in that the clinician should not view it is as a static therapy, but rather as a dynamic process. For application of NIV in the acute setting, it should be recognized that the patient’s physiology is deranged (albeit transiently); as physiology eventually returns to preexisting levels, changes in NIV-pressure levels (or modes) are therefore necessary. Moreover, initial starting pressures may not be adequate to either overcome deficits in oxygenation, ventilation, or provide significant preload/afterload reduction. Knowledge of which parameters or values to adjust contribute to increased patient comfort, patient safety, improved cardiopulmonary dynamics, and a faster restoration of ventilatory status. In essence, the EP at the bedside should always ask himself or herself “what am I trying to fix?”  

When the patient begins to develop synchrony with the ventilator, improvement and stabilization in the measured V_T should be observed. The goal of delivered V_T should be 6 to 10 mg/kg of ideal body weight.  An increase in the IPAP value will improve the V_T and decrease the work of breathing, and it should be the first value increased to reduce PaCO₂. The use of EPAP will help to reduce intrinsic positive-end expiratory pressure and atelectasis and reduce upper airway obstruction. Increasing EPAP will improve oxygenation. Table 3 lists the common starting values for both modes of NIV and provides troubleshooting suggestions.  

To date, no clinical trials have addressed the optimal initiation strategy or application settings for NIV. It should be understood, however, that the initial settings will typically be lower pressures to ensure patient comfort and development of familiarity with the device and interaction. For BiPAP, it is common to start with settings of 10/5 (IPAP/EPAP), and then titrate up (not exceeding 25 cm H₂O) and maintaining minimum pressure support of 4 to 5 cm H₂O. For CPAP, initial settings of 5 to 10 cm H₂O are reasonable. Increased pressures can lead to patient discomfort, unintentional leak, and the development of patient-ventilator associated asynchrony.¹² The goal is to balance therapeutic effect(s) with patient comfort. Higher pressures, even though they may be optimal, must be balanced with patient comfort as long as it is physiologically acceptable.

With increasing support, there may be an increase in mask leak; despite this, increasing levels of pressure or volume ventilation have been shown to increase minute ventilation (referred to as V_E).⁴⁵ In cases such as acute pulmonary edema or significant hypercapnia, initial higher-pressure settings may only be necessary for a brief time to reverse the pathology present and restore normal ventilation and hemodynamics. After the initial application, IPAP, EPAP, and FiO₂ all may require titration.

Patients who fail to show improvement (either clinically or based on ventilatory parameters) or those with persistent mental status abnormalities, agitation, excessive secretions, or ventilator asynchrony after 1 hour of NIV are at high risk for NIV failure.^46,47

Interpreting the Literature

Sizeable and sometimes conflicting literature exists on the subject of NIV.  Despite a lack of clear and consistently reproducible benefit in morbidity, NIV use continues to increase. There are multiple factors that make interpretation of the results difficult and at times seemingly contradictory. Careful examination of the literature therefore must be undertaken before applying NIV to daily practice. Inconsistency of therapy type delivered, NIV pressure settings, pressure adjustments, patient monitoring, differing mask types, ventilator designs, endpoints, patient populations and the influence of cotreatments can all influence outcomes and potential benefit. To further complicate the data, unmeasured factors such as patient tolerance, interface fit, mask leak, and patient-ventilator asynchrony may be grouped as “NIV failure.”

 

For a patient suffering from ARF, the point in time of NIV application may have more to do with study enrollment and study group assignment (NIV or intubation) than the underlying pathology. Specifically, in some cases if NIV had been initiated hours prior, a clear benefit may have been demonstrated. One must also remember that at many institutions, the threshold for intubation (or intensive care unit admission) may be different, as well as the treating provider’s expertise and experience with NIV. In addition, well-established and consistent criteria for NIV failure have not been clearly defined and vary significantly study to study, making generalizations difficult. A comparison of patient groups with equal possible clinical outcomes is necessary to compare the findings “on a level playing field” and determine external validity. 

Conclusion

Noninvasive ventilation represents a critically important intervention—one that should be applied early and aggressively in the ED to patients presenting with ARD in whom there are no contraindications to treatment. The EP should recognize the patient at high risk and, at the time of application, continue to closely monitor him or her for signs of improvement or deterioration.

As NIV use continues to increase, it is important that the clinician have a good working knowledge of its setup, modes of operation, and potential complications. A comfort level should exist for troubleshooting at the bedside. As provider competence increases, standardized quality of care is improved.

Dr Burns is an associate professor, residency director, and vice chair of academic affairs, department of emergency medicine, The University of Oklahoma School of Community Medicine, Tulsa.

Overview

Candidates for noninvasive ventilation (NIV) most commonly present to the ED with acute respiratory failure (ARF) secondary to chronic obstructive pulmonary disease (COPD) or congestive heart-failure (CHF) exacerbations. The emergency physician (EP) must select patients appropriately, recognizing which would benefit most from NIV, as well as those with contraindications to this therapy. When indicated, early application confers benefit to the patient and can help avoid endotracheal intubation. Once therapy is initiated, clinical deterioration is still possible, and close monitoring and troubleshooting are imperative. Frequently, the clinician must make adjustments in ventilatory parameters to support the patient.

In this article, the author discusses the evidence supporting the use of NIV in appropriately selected patients with ARF, as well as review the types of NIV commonly used in the ED, the physiologic effects of positive-pressure ventilation (PPV), and how to identify and avoid common pitfalls.

Case Presentation Examples

Case 1

A 72-year-old man with a past medical history of COPD was brought to the ED by emergency medical services for evaluation of shortness of breath and wheezing. The patient’s initial oxygen (O₂) saturation was 84%, which responded to bronchodilators and supplemental O₂. At the time of arrival, he was somewhat somnolent, but aroused to verbal stimuli. A nonrebreather mask was placed delivering 15 L/minute of O₂ with a saturation of 96%. His vital signs were: blood pressure (BP), 142/76 mm Hg, heart rate, 108 beats/minute; and respiratory rate (RR), 13 breaths/minute. A cardiac monitor revealed sinus tachycardia, and a portable chest X-ray was obtained (Figure 1). On lung examination, the patient’s breath sounds were diminished in the bases with suboptimal respiratory effort and expiratory wheezes in all lung fields. Venous blood gas measurement revealed a pH of 7.25; end-tidal carbon dioxide (CO₂) was 77.

After the initial assessment, the EP considered NIV as an adjunct to improve ventilation as he suspected the patient was experiencing significant respiratory acidosis secondary to CO₂ retention. The respiratory therapist suggested NIV at 12/5 before titrating down the fraction of inspired O₂ (FiO₂) and sought approval from the EP. 

Discussion Questions: Is the above recommendation from the respiratory therapist the most appropriate therapy for this patient? What are the contraindications to this treatment and how should he be monitored to measure improvement?

Case 2

A 54-year-old woman presented to the ED for shortness of breath. On examination, she was diaphoretic and in severe distress with one- to two-word dyspnea and gasping respirations with pink-tinged sputum. Her BP was 236/158 mm Hg. A portable chest X-ray was obtained (Figure 2); rales were present with significant jugular venous distension. An electrocardiogram revealed a left-ventricular hypertrophy strain pattern but no evidence of ST-segment elevation.

During the assessment, the EP considered hypertensive emergency with resulting flash pulmonary edema as the cause of the patient’s condition; as such, he contemplated NIV to decrease the work of breathing and improve oxygenation. However, the EP had concerns regarding the preload and afterload ramifications. Although there was no respiratory therapist in the ED, the EP was able to set up the machine, but was not certain which mode of NIV or initial settings would be appropriate.

Discussion Questions: What is the protocol for proper set up to ensure a good mask fit? Once therapy is initiated, how should the EP monitor the patient? How should the EP explain this therapy to the patient and instruct her on how to work with the ventilator?

Acute-Care Application

Noninvasive ventilation refers to PPV delivered through a device such as a facemask, nasal mask, nasal plugs, or helmet. This modality was first used in the 1940s to treat respiratory failure, and its use has since grown to parallel that of mechanical ventilation.^1-3 Although the application of NIV does not represent definitive airway management, this therapy has dramatically changed the care and treatment of both chronic and ARF. It serves as a significant intervention to prevent further respiratory compromise; to reverse either existing physiologic, hemodynamic, or ventilatory derangements; and to avoid endotracheal intubation.

Modes of Delivery

In the acute setting, NIV is typically delivered via two modes. Continuous positive-airway pressure (CPAP) is delivered regardless of the phase of respiration, and noninvasive positive-pressure ventilation (NIPPV; typically referred to as bi-level positive-airway pressure [BiPAP] or BPPV) is delivered in the inspiratory and expiratory phases of the respiratory cycle. Inspiratory positive-airway pressure (IPAP) refers to an inspiratory boost that is triggered by the negative airway pressure on inspiration in a synchronous fashion. This inspiratory pressure is fixed, but the volume delivered fluctuates based on the patient’s inspiratory effort. Expiratory positive-airway pressure (EPAP) is the delivery of constant pressure during exhalation. The difference between the IPAP and EPAP is referred to as pressure support, which serves to decrease the work of breathing and improve ventilation. (A list of commonly used abbreviations, terms, and definitions are outlined in Table 1.)

 

Etiology of Respiratory Failure and Treatment Decisions
At the time of initial presentation, the exact etiology of a patient’s respiratory failure may not be known, and treatment decisions will be necessary before all relevant data are present. Patients presenting in acute respiratory distress (ARD) are often suffering from shunt physiology, in which alveoli are perfused but not ventilated due to the presence of fluid or collapse, as in pulmonary edema or COPD.⁴ Regardless of the etiology, patients will benefit from early application of NIV.⁵ Thus, the clinician must be aggressive in the application of this therapy to identify those patients who will benefit the most from treatment. All patients receiving NIV must be monitored closely as failure of therapy is still a possibility.

Patient Selection

The utilization of NIV has increased in the hospital and ED setting and it is now often initiated in the prehospital setting^6-8 with observed improvement in dyspnea scores and oxygenation with early intervention.⁹ Regarding patient selection, in the absence of contraindications (Table 2), all dyspneic patients should be considered eligible for a trial of NIV. ¹³ For some patients, this may be their first use of the therapy; as such, they are in effect learning to “swim while drowning.” The agitated and anxious patient will require coaching to provide reassurance and instruction while he or she learns to synchronize and work with the ventilator. The presence and quality of this instruction, though not previously measured, would intuitively be very helpful and an important determinant of success in the application of NIV in the naïve patient.

Common Conditions and NIV

In the ED, NIV is commonly utilized for the treatment of COPD and acute decompensated heart failure. These two conditions have been extensively studied and a robust amount of literature supports the routine use of NIV in these patients.

Chronic Obstructive Pulmonary Disease
For COPD, BiPAP has been shown and is widely accepted as the modality that confers the most benefit, with one study demonstrating a 462% increase in its use and a 42% decline in mechanical intubation rates from 1998 to 2008.¹⁴ Multiple studies have demonstrated a reduction in the intubation rate, improvement in the work of breathing, and a more rapid improvement in RR and symptoms.^15,16

Acute Decompensated Heart Failure and Pulmonary Edema
Noninvasive ventilation is used commonly for decompensated heart failure and acute cardiogenic pulmonary edema (ACPE). The rapid patient improvement with its use when compared to standard O₂ therapy is well documented. A successful trial and application of NIV demonstrated benefit in a recent retrospective analysis of 2,430 acutely decompensated heart-failure patients in the United States. The study found that the patients who were treated with NIV, but not immediately intubated, had better outcomes.¹⁷ (In these types of patients, pulmonary edema is typically not related to volume overload, but the result of imbalanced hemodynamics with markedly increased cardiac afterload and systemic vascular resistance.)

With respect to type of NIV, the use of CPAP is widely accepted as the primary modality of choice to confer the most benefit in ACPE.¹⁸ Although theoretical advantages do exist for the use of BiPAP over CPAP, this benefit has been noted in smaller studies¹⁹ but not clearly demonstrated in large reviews.^20,21 In addition, patients suffering from long-term CHF develop the syndrome of cardiac cachexia, characterized by the loss of quantity and quality of skeletal muscle.²² This reduction in muscle mass can produce a significant deficit in inspiratory muscle strength and ability, providing an opportunity for benefit with the use of BiPAP.

Previously, BiPAP was considered unsafe in the setting of ACPE due to an increase in myocardial infarction.²³ These results have not been reproduced in larger studies, and it is widely accepted that although BiPAP may not confer any benefit, it also does not increase harm.

Asthma
Because the underlying pathology of asthma differs from COPD, the current evidence for NIV use in patients presenting with an asthmatic episode is not very strong. Chronic obstructive pulmonary disease is characterized by collapse of terminal airways, with destruction of pulmonary architecture, and decreased compliance of the chest wall. In contrast, the airway obstruction in asthma progresses as the severity of the attack increases, and NIV may offer potential benefit in high-risk patients to avoid intubation.²⁴ Several small studies suggest the application of NIV for severe asthma exacerbations is reasonable, with some demonstration of improvement in the work of breathing and ventilatory status.^25-27

The Critically Ill Patient

Critically ill patients represent a high-risk group for desaturation during endotracheal intubation, and NIV should be considered for preoxygenation unless contraindications exist (Table 2). If standard high-flow O₂ without positive pressure does not improve oxygenation, the application of NIV may overcome shunt physiology, improve oxygenation, and lessen peri-intubation time with dangerous desaturation events.^4,28-30

 

Interfaces, Mask Leaks, Patient-Ventilator Interaction, and Respiratory Failure

Interfaces
Patient interfaces (mask types) for NIV include nasal prongs, full facial mask, or most commonly, an oronasal mask.³¹ For successful delivery of positive pressure, there must be an adequate fit or seal with minimal air leak to establish a ventilator circuit. Even though there is no perfect interface, patient comfort and treatment efficacy should be balanced. The interface chosen should minimize skin damage, maximize seal, and optimize patient-ventilator interface. The interfaces have straps that are used to secure the mask in place and balance the tension and stress on the skin to ensure a good seal and to avoid excess focal pressure that may result in complications such as skin breakdown, necrosis, or discomfort. Multiple interfaces and mask types have been evaluated in different acute-care situations, and it is important the clinician be familiar with the various options available for NIV interface and delivery. 

Mask Leaks
Unintentional leaks are an unavoidable reality with NIV use. The ventilators designed for NIV typically use a single-limb circuit with an intentional leak port close to the patient. This port provides resistance and, as the ventilator produces airflow, it can subsequently generate pressure. Because this leak port is incorporated into the interface, it is important to utilize the same manufacturer of the ventilator and interface to avoid interface-ventilator mismatch.³²

In some cases, unintentional leaks have been linked to asynchrony leading to increased work of breathing, ineffective delivery of breaths, and missed triggering events.³³ The goal of any chosen interface is the lowest measurable unintentional leak rate as higher values demonstrate significant variability (and inaccuracy) of measured tidal volumes (V_T).³⁴ Overtightening the mask should be avoided since it can compromise both patient comfort and increase the chance of skin necrosis or breakdown.

Patient-Ventilator Interaction
The importance of the patient-ventilator interaction and the development of synchrony between the two cannot be overstated. After initial application, the patient should be closely monitored as he or she begins to work with the ventilator. This is especially important in BiPAP.

Optimal patient-ventilator synchrony can be difficult to achieve, especially in the NIV-naïve patient with critical respiratory distress. Of note, approximately 20% to 30% of patients with ARD cannot be managed by NIV,¹¹ and asynchrony, though difficult to quantify in the acute-care setting, may contribute to this number. 

Respiratory Failure
Acute respiratory failure is caused by a change in the patient’s baseline gas exchange, resulting in an inability to provide sufficient levels of O₂ or to ventilate adequately. The etiologies of ARF are characterized into four types. 

Type I. Also referred to as hypoxemic respiratory failure, type I is the most common and is characterized by an arterial oxygen tension (PaO₂) of less than 60 mm Hg, with either normal or low levels of arterial CO₂ that is not responsive to supplemental O₂.

Type II. This type of respiratory failure is characterized by alveolar hypoventilation, with a PaCO₂ level greater than 45 mm Hg, although hypoxemia may also be present due to concomitant loss of central nervous system drive.

Type III. Failure primarily occurs in the perioperative setting where the functional residual capacity is reduced in combination with increasing atelectasis.

Type IV. Type IV ARF is secondary to circulatory failure and resolves when shock is corrected.^35,36

Regardless of the respiratory failure etiology, the patient is at risk of further deterioration and the need for endotracheal intubation.

Physiologic effects of NIV

Once the interface is secured, NIV has several important effects on both the cardiac and pulmonary systems. For this discussion, intrathoracic pressure (P_IT) is considered synonymous with mean airway pressure (P_aw).

Noninvasive ventilation improves airflow, lung volumes, and subsequent V_T while overcoming pulmonary atelectasis. The increase in lung volume is directly proportional to an increase in P_aw. This effect is only seen after overcoming airway resistance and chest wall and lung compliance. There is also an improvement in alveolar recruitment and redistribution of pulmonary blood flow³⁷ with decreased work of breathing.

With the increase in P_IT, there is decreased venous return to the right heart and a resulting decrease in cardiac preload.³⁸ In the setting of acute cardiogenic pulmonary edema (ACPE), this effect is highly favorable. However, in the volume-depleted or hemodynamically unstable patient, this may result in a drop in cardiac output and hypotension. The “normal” heart is more sensitive to preload, and the application of positive pressure can cause a significant decrease in cardiac output. Cardiac afterload is reduced through multiple mechanisms, including directly from a decreased left-ventricular (LV) preload and also from a decrease in the LV transmural pressure (referred to as P_TM).

 

The effects of positive pressure on the ventricles are opposite in the normal heart, with a decrease in both right and LV preload, increased right ventricular afterload and decreased LV afterload,^39,40 as well as an overall decrease in cardiac chamber size that is directly proportional to the level of PPV.⁴¹ For the decompensated CHF patient, this can produce an increase in cardiac output simply by shifting the patient to a more favorable (leftward) position on the Frank-Starling curve.^42-44 

Troubleshooting

Once NIV is initiated, it is imperative, at least initially, to remain at bedside to monitor progress and improvement. Even though NIV is beneficial in the acute setting, it should always be viewed as a temporary bridging measure. With improvement, NIV may be discontinued, but in cases of failure, it is necessary to proceed with endotracheal intubation.

As the patient synchronizes with the ventilator, changes should be seen rather quickly, including improvement in the work of breathing, a restoration of mental status (if significant hypercapnia is present), and improved oxygenation. In the patient with severe uncontrolled hypertension and resulting flash pulmonary edema, the reduction in preload and afterload should contribute to a decrease in systolic BP (in addition to medical therapy). There should be a low threshold for obtaining an initial arterial blood gas (or a venous sample coupled with end-tidal CO₂ data) as it may be helpful to guide therapy. 

Noninvasive ventilation is similar to mechanical ventilation in that the clinician should not view it is as a static therapy, but rather as a dynamic process. For application of NIV in the acute setting, it should be recognized that the patient’s physiology is deranged (albeit transiently); as physiology eventually returns to preexisting levels, changes in NIV-pressure levels (or modes) are therefore necessary. Moreover, initial starting pressures may not be adequate to either overcome deficits in oxygenation, ventilation, or provide significant preload/afterload reduction. Knowledge of which parameters or values to adjust contribute to increased patient comfort, patient safety, improved cardiopulmonary dynamics, and a faster restoration of ventilatory status. In essence, the EP at the bedside should always ask himself or herself “what am I trying to fix?”  

When the patient begins to develop synchrony with the ventilator, improvement and stabilization in the measured V_T should be observed. The goal of delivered V_T should be 6 to 10 mg/kg of ideal body weight.  An increase in the IPAP value will improve the V_T and decrease the work of breathing, and it should be the first value increased to reduce PaCO₂. The use of EPAP will help to reduce intrinsic positive-end expiratory pressure and atelectasis and reduce upper airway obstruction. Increasing EPAP will improve oxygenation. Table 3 lists the common starting values for both modes of NIV and provides troubleshooting suggestions.  

To date, no clinical trials have addressed the optimal initiation strategy or application settings for NIV. It should be understood, however, that the initial settings will typically be lower pressures to ensure patient comfort and development of familiarity with the device and interaction. For BiPAP, it is common to start with settings of 10/5 (IPAP/EPAP), and then titrate up (not exceeding 25 cm H₂O) and maintaining minimum pressure support of 4 to 5 cm H₂O. For CPAP, initial settings of 5 to 10 cm H₂O are reasonable. Increased pressures can lead to patient discomfort, unintentional leak, and the development of patient-ventilator associated asynchrony.¹² The goal is to balance therapeutic effect(s) with patient comfort. Higher pressures, even though they may be optimal, must be balanced with patient comfort as long as it is physiologically acceptable.

With increasing support, there may be an increase in mask leak; despite this, increasing levels of pressure or volume ventilation have been shown to increase minute ventilation (referred to as V_E).⁴⁵ In cases such as acute pulmonary edema or significant hypercapnia, initial higher-pressure settings may only be necessary for a brief time to reverse the pathology present and restore normal ventilation and hemodynamics. After the initial application, IPAP, EPAP, and FiO₂ all may require titration.

Patients who fail to show improvement (either clinically or based on ventilatory parameters) or those with persistent mental status abnormalities, agitation, excessive secretions, or ventilator asynchrony after 1 hour of NIV are at high risk for NIV failure.^46,47

Interpreting the Literature

Sizeable and sometimes conflicting literature exists on the subject of NIV.  Despite a lack of clear and consistently reproducible benefit in morbidity, NIV use continues to increase. There are multiple factors that make interpretation of the results difficult and at times seemingly contradictory. Careful examination of the literature therefore must be undertaken before applying NIV to daily practice. Inconsistency of therapy type delivered, NIV pressure settings, pressure adjustments, patient monitoring, differing mask types, ventilator designs, endpoints, patient populations and the influence of cotreatments can all influence outcomes and potential benefit. To further complicate the data, unmeasured factors such as patient tolerance, interface fit, mask leak, and patient-ventilator asynchrony may be grouped as “NIV failure.”

 

For a patient suffering from ARF, the point in time of NIV application may have more to do with study enrollment and study group assignment (NIV or intubation) than the underlying pathology. Specifically, in some cases if NIV had been initiated hours prior, a clear benefit may have been demonstrated. One must also remember that at many institutions, the threshold for intubation (or intensive care unit admission) may be different, as well as the treating provider’s expertise and experience with NIV. In addition, well-established and consistent criteria for NIV failure have not been clearly defined and vary significantly study to study, making generalizations difficult. A comparison of patient groups with equal possible clinical outcomes is necessary to compare the findings “on a level playing field” and determine external validity. 

Conclusion

Noninvasive ventilation represents a critically important intervention—one that should be applied early and aggressively in the ED to patients presenting with ARD in whom there are no contraindications to treatment. The EP should recognize the patient at high risk and, at the time of application, continue to closely monitor him or her for signs of improvement or deterioration.

As NIV use continues to increase, it is important that the clinician have a good working knowledge of its setup, modes of operation, and potential complications. A comfort level should exist for troubleshooting at the bedside. As provider competence increases, standardized quality of care is improved.

Dr Burns is an associate professor, residency director, and vice chair of academic affairs, department of emergency medicine, The University of Oklahoma School of Community Medicine, Tulsa.

Overview

Candidates for noninvasive ventilation (NIV) most commonly present to the ED with acute respiratory failure (ARF) secondary to chronic obstructive pulmonary disease (COPD) or congestive heart-failure (CHF) exacerbations. The emergency physician (EP) must select patients appropriately, recognizing which would benefit most from NIV, as well as those with contraindications to this therapy. When indicated, early application confers benefit to the patient and can help avoid endotracheal intubation. Once therapy is initiated, clinical deterioration is still possible, and close monitoring and troubleshooting are imperative. Frequently, the clinician must make adjustments in ventilatory parameters to support the patient.

In this article, the author discusses the evidence supporting the use of NIV in appropriately selected patients with ARF, as well as review the types of NIV commonly used in the ED, the physiologic effects of positive-pressure ventilation (PPV), and how to identify and avoid common pitfalls.

Case Presentation Examples

Case 1

A 72-year-old man with a past medical history of COPD was brought to the ED by emergency medical services for evaluation of shortness of breath and wheezing. The patient’s initial oxygen (O₂) saturation was 84%, which responded to bronchodilators and supplemental O₂. At the time of arrival, he was somewhat somnolent, but aroused to verbal stimuli. A nonrebreather mask was placed delivering 15 L/minute of O₂ with a saturation of 96%. His vital signs were: blood pressure (BP), 142/76 mm Hg, heart rate, 108 beats/minute; and respiratory rate (RR), 13 breaths/minute. A cardiac monitor revealed sinus tachycardia, and a portable chest X-ray was obtained (Figure 1). On lung examination, the patient’s breath sounds were diminished in the bases with suboptimal respiratory effort and expiratory wheezes in all lung fields. Venous blood gas measurement revealed a pH of 7.25; end-tidal carbon dioxide (CO₂) was 77.

After the initial assessment, the EP considered NIV as an adjunct to improve ventilation as he suspected the patient was experiencing significant respiratory acidosis secondary to CO₂ retention. The respiratory therapist suggested NIV at 12/5 before titrating down the fraction of inspired O₂ (FiO₂) and sought approval from the EP. 

Discussion Questions: Is the above recommendation from the respiratory therapist the most appropriate therapy for this patient? What are the contraindications to this treatment and how should he be monitored to measure improvement?

Case 2

A 54-year-old woman presented to the ED for shortness of breath. On examination, she was diaphoretic and in severe distress with one- to two-word dyspnea and gasping respirations with pink-tinged sputum. Her BP was 236/158 mm Hg. A portable chest X-ray was obtained (Figure 2); rales were present with significant jugular venous distension. An electrocardiogram revealed a left-ventricular hypertrophy strain pattern but no evidence of ST-segment elevation.

During the assessment, the EP considered hypertensive emergency with resulting flash pulmonary edema as the cause of the patient’s condition; as such, he contemplated NIV to decrease the work of breathing and improve oxygenation. However, the EP had concerns regarding the preload and afterload ramifications. Although there was no respiratory therapist in the ED, the EP was able to set up the machine, but was not certain which mode of NIV or initial settings would be appropriate.

Discussion Questions: What is the protocol for proper set up to ensure a good mask fit? Once therapy is initiated, how should the EP monitor the patient? How should the EP explain this therapy to the patient and instruct her on how to work with the ventilator?

Acute-Care Application

Noninvasive ventilation refers to PPV delivered through a device such as a facemask, nasal mask, nasal plugs, or helmet. This modality was first used in the 1940s to treat respiratory failure, and its use has since grown to parallel that of mechanical ventilation.^1-3 Although the application of NIV does not represent definitive airway management, this therapy has dramatically changed the care and treatment of both chronic and ARF. It serves as a significant intervention to prevent further respiratory compromise; to reverse either existing physiologic, hemodynamic, or ventilatory derangements; and to avoid endotracheal intubation.

Modes of Delivery

In the acute setting, NIV is typically delivered via two modes. Continuous positive-airway pressure (CPAP) is delivered regardless of the phase of respiration, and noninvasive positive-pressure ventilation (NIPPV; typically referred to as bi-level positive-airway pressure [BiPAP] or BPPV) is delivered in the inspiratory and expiratory phases of the respiratory cycle. Inspiratory positive-airway pressure (IPAP) refers to an inspiratory boost that is triggered by the negative airway pressure on inspiration in a synchronous fashion. This inspiratory pressure is fixed, but the volume delivered fluctuates based on the patient’s inspiratory effort. Expiratory positive-airway pressure (EPAP) is the delivery of constant pressure during exhalation. The difference between the IPAP and EPAP is referred to as pressure support, which serves to decrease the work of breathing and improve ventilation. (A list of commonly used abbreviations, terms, and definitions are outlined in Table 1.)

 

Etiology of Respiratory Failure and Treatment Decisions
At the time of initial presentation, the exact etiology of a patient’s respiratory failure may not be known, and treatment decisions will be necessary before all relevant data are present. Patients presenting in acute respiratory distress (ARD) are often suffering from shunt physiology, in which alveoli are perfused but not ventilated due to the presence of fluid or collapse, as in pulmonary edema or COPD.⁴ Regardless of the etiology, patients will benefit from early application of NIV.⁵ Thus, the clinician must be aggressive in the application of this therapy to identify those patients who will benefit the most from treatment. All patients receiving NIV must be monitored closely as failure of therapy is still a possibility.

Patient Selection

The utilization of NIV has increased in the hospital and ED setting and it is now often initiated in the prehospital setting^6-8 with observed improvement in dyspnea scores and oxygenation with early intervention.⁹ Regarding patient selection, in the absence of contraindications (Table 2), all dyspneic patients should be considered eligible for a trial of NIV. ¹³ For some patients, this may be their first use of the therapy; as such, they are in effect learning to “swim while drowning.” The agitated and anxious patient will require coaching to provide reassurance and instruction while he or she learns to synchronize and work with the ventilator. The presence and quality of this instruction, though not previously measured, would intuitively be very helpful and an important determinant of success in the application of NIV in the naïve patient.

Common Conditions and NIV

In the ED, NIV is commonly utilized for the treatment of COPD and acute decompensated heart failure. These two conditions have been extensively studied and a robust amount of literature supports the routine use of NIV in these patients.

Chronic Obstructive Pulmonary Disease
For COPD, BiPAP has been shown and is widely accepted as the modality that confers the most benefit, with one study demonstrating a 462% increase in its use and a 42% decline in mechanical intubation rates from 1998 to 2008.¹⁴ Multiple studies have demonstrated a reduction in the intubation rate, improvement in the work of breathing, and a more rapid improvement in RR and symptoms.^15,16

Acute Decompensated Heart Failure and Pulmonary Edema
Noninvasive ventilation is used commonly for decompensated heart failure and acute cardiogenic pulmonary edema (ACPE). The rapid patient improvement with its use when compared to standard O₂ therapy is well documented. A successful trial and application of NIV demonstrated benefit in a recent retrospective analysis of 2,430 acutely decompensated heart-failure patients in the United States. The study found that the patients who were treated with NIV, but not immediately intubated, had better outcomes.¹⁷ (In these types of patients, pulmonary edema is typically not related to volume overload, but the result of imbalanced hemodynamics with markedly increased cardiac afterload and systemic vascular resistance.)

With respect to type of NIV, the use of CPAP is widely accepted as the primary modality of choice to confer the most benefit in ACPE.¹⁸ Although theoretical advantages do exist for the use of BiPAP over CPAP, this benefit has been noted in smaller studies¹⁹ but not clearly demonstrated in large reviews.^20,21 In addition, patients suffering from long-term CHF develop the syndrome of cardiac cachexia, characterized by the loss of quantity and quality of skeletal muscle.²² This reduction in muscle mass can produce a significant deficit in inspiratory muscle strength and ability, providing an opportunity for benefit with the use of BiPAP.

Previously, BiPAP was considered unsafe in the setting of ACPE due to an increase in myocardial infarction.²³ These results have not been reproduced in larger studies, and it is widely accepted that although BiPAP may not confer any benefit, it also does not increase harm.

Asthma
Because the underlying pathology of asthma differs from COPD, the current evidence for NIV use in patients presenting with an asthmatic episode is not very strong. Chronic obstructive pulmonary disease is characterized by collapse of terminal airways, with destruction of pulmonary architecture, and decreased compliance of the chest wall. In contrast, the airway obstruction in asthma progresses as the severity of the attack increases, and NIV may offer potential benefit in high-risk patients to avoid intubation.²⁴ Several small studies suggest the application of NIV for severe asthma exacerbations is reasonable, with some demonstration of improvement in the work of breathing and ventilatory status.^25-27

The Critically Ill Patient

Critically ill patients represent a high-risk group for desaturation during endotracheal intubation, and NIV should be considered for preoxygenation unless contraindications exist (Table 2). If standard high-flow O₂ without positive pressure does not improve oxygenation, the application of NIV may overcome shunt physiology, improve oxygenation, and lessen peri-intubation time with dangerous desaturation events.^4,28-30

 

Interfaces, Mask Leaks, Patient-Ventilator Interaction, and Respiratory Failure

Interfaces
Patient interfaces (mask types) for NIV include nasal prongs, full facial mask, or most commonly, an oronasal mask.³¹ For successful delivery of positive pressure, there must be an adequate fit or seal with minimal air leak to establish a ventilator circuit. Even though there is no perfect interface, patient comfort and treatment efficacy should be balanced. The interface chosen should minimize skin damage, maximize seal, and optimize patient-ventilator interface. The interfaces have straps that are used to secure the mask in place and balance the tension and stress on the skin to ensure a good seal and to avoid excess focal pressure that may result in complications such as skin breakdown, necrosis, or discomfort. Multiple interfaces and mask types have been evaluated in different acute-care situations, and it is important the clinician be familiar with the various options available for NIV interface and delivery. 

Mask Leaks
Unintentional leaks are an unavoidable reality with NIV use. The ventilators designed for NIV typically use a single-limb circuit with an intentional leak port close to the patient. This port provides resistance and, as the ventilator produces airflow, it can subsequently generate pressure. Because this leak port is incorporated into the interface, it is important to utilize the same manufacturer of the ventilator and interface to avoid interface-ventilator mismatch.³²

In some cases, unintentional leaks have been linked to asynchrony leading to increased work of breathing, ineffective delivery of breaths, and missed triggering events.³³ The goal of any chosen interface is the lowest measurable unintentional leak rate as higher values demonstrate significant variability (and inaccuracy) of measured tidal volumes (V_T).³⁴ Overtightening the mask should be avoided since it can compromise both patient comfort and increase the chance of skin necrosis or breakdown.

Patient-Ventilator Interaction
The importance of the patient-ventilator interaction and the development of synchrony between the two cannot be overstated. After initial application, the patient should be closely monitored as he or she begins to work with the ventilator. This is especially important in BiPAP.

Optimal patient-ventilator synchrony can be difficult to achieve, especially in the NIV-naïve patient with critical respiratory distress. Of note, approximately 20% to 30% of patients with ARD cannot be managed by NIV,¹¹ and asynchrony, though difficult to quantify in the acute-care setting, may contribute to this number. 

Respiratory Failure
Acute respiratory failure is caused by a change in the patient’s baseline gas exchange, resulting in an inability to provide sufficient levels of O₂ or to ventilate adequately. The etiologies of ARF are characterized into four types. 

Type I. Also referred to as hypoxemic respiratory failure, type I is the most common and is characterized by an arterial oxygen tension (PaO₂) of less than 60 mm Hg, with either normal or low levels of arterial CO₂ that is not responsive to supplemental O₂.

Type II. This type of respiratory failure is characterized by alveolar hypoventilation, with a PaCO₂ level greater than 45 mm Hg, although hypoxemia may also be present due to concomitant loss of central nervous system drive.

Type III. Failure primarily occurs in the perioperative setting where the functional residual capacity is reduced in combination with increasing atelectasis.

Type IV. Type IV ARF is secondary to circulatory failure and resolves when shock is corrected.^35,36

Regardless of the respiratory failure etiology, the patient is at risk of further deterioration and the need for endotracheal intubation.

Physiologic effects of NIV

Once the interface is secured, NIV has several important effects on both the cardiac and pulmonary systems. For this discussion, intrathoracic pressure (P_IT) is considered synonymous with mean airway pressure (P_aw).

Noninvasive ventilation improves airflow, lung volumes, and subsequent V_T while overcoming pulmonary atelectasis. The increase in lung volume is directly proportional to an increase in P_aw. This effect is only seen after overcoming airway resistance and chest wall and lung compliance. There is also an improvement in alveolar recruitment and redistribution of pulmonary blood flow³⁷ with decreased work of breathing.

With the increase in P_IT, there is decreased venous return to the right heart and a resulting decrease in cardiac preload.³⁸ In the setting of acute cardiogenic pulmonary edema (ACPE), this effect is highly favorable. However, in the volume-depleted or hemodynamically unstable patient, this may result in a drop in cardiac output and hypotension. The “normal” heart is more sensitive to preload, and the application of positive pressure can cause a significant decrease in cardiac output. Cardiac afterload is reduced through multiple mechanisms, including directly from a decreased left-ventricular (LV) preload and also from a decrease in the LV transmural pressure (referred to as P_TM).

 

The effects of positive pressure on the ventricles are opposite in the normal heart, with a decrease in both right and LV preload, increased right ventricular afterload and decreased LV afterload,^39,40 as well as an overall decrease in cardiac chamber size that is directly proportional to the level of PPV.⁴¹ For the decompensated CHF patient, this can produce an increase in cardiac output simply by shifting the patient to a more favorable (leftward) position on the Frank-Starling curve.^42-44 

Troubleshooting

Once NIV is initiated, it is imperative, at least initially, to remain at bedside to monitor progress and improvement. Even though NIV is beneficial in the acute setting, it should always be viewed as a temporary bridging measure. With improvement, NIV may be discontinued, but in cases of failure, it is necessary to proceed with endotracheal intubation.

As the patient synchronizes with the ventilator, changes should be seen rather quickly, including improvement in the work of breathing, a restoration of mental status (if significant hypercapnia is present), and improved oxygenation. In the patient with severe uncontrolled hypertension and resulting flash pulmonary edema, the reduction in preload and afterload should contribute to a decrease in systolic BP (in addition to medical therapy). There should be a low threshold for obtaining an initial arterial blood gas (or a venous sample coupled with end-tidal CO₂ data) as it may be helpful to guide therapy. 

Noninvasive ventilation is similar to mechanical ventilation in that the clinician should not view it is as a static therapy, but rather as a dynamic process. For application of NIV in the acute setting, it should be recognized that the patient’s physiology is deranged (albeit transiently); as physiology eventually returns to preexisting levels, changes in NIV-pressure levels (or modes) are therefore necessary. Moreover, initial starting pressures may not be adequate to either overcome deficits in oxygenation, ventilation, or provide significant preload/afterload reduction. Knowledge of which parameters or values to adjust contribute to increased patient comfort, patient safety, improved cardiopulmonary dynamics, and a faster restoration of ventilatory status. In essence, the EP at the bedside should always ask himself or herself “what am I trying to fix?”  

When the patient begins to develop synchrony with the ventilator, improvement and stabilization in the measured V_T should be observed. The goal of delivered V_T should be 6 to 10 mg/kg of ideal body weight.  An increase in the IPAP value will improve the V_T and decrease the work of breathing, and it should be the first value increased to reduce PaCO₂. The use of EPAP will help to reduce intrinsic positive-end expiratory pressure and atelectasis and reduce upper airway obstruction. Increasing EPAP will improve oxygenation. Table 3 lists the common starting values for both modes of NIV and provides troubleshooting suggestions.  

To date, no clinical trials have addressed the optimal initiation strategy or application settings for NIV. It should be understood, however, that the initial settings will typically be lower pressures to ensure patient comfort and development of familiarity with the device and interaction. For BiPAP, it is common to start with settings of 10/5 (IPAP/EPAP), and then titrate up (not exceeding 25 cm H₂O) and maintaining minimum pressure support of 4 to 5 cm H₂O. For CPAP, initial settings of 5 to 10 cm H₂O are reasonable. Increased pressures can lead to patient discomfort, unintentional leak, and the development of patient-ventilator associated asynchrony.¹² The goal is to balance therapeutic effect(s) with patient comfort. Higher pressures, even though they may be optimal, must be balanced with patient comfort as long as it is physiologically acceptable.

With increasing support, there may be an increase in mask leak; despite this, increasing levels of pressure or volume ventilation have been shown to increase minute ventilation (referred to as V_E).⁴⁵ In cases such as acute pulmonary edema or significant hypercapnia, initial higher-pressure settings may only be necessary for a brief time to reverse the pathology present and restore normal ventilation and hemodynamics. After the initial application, IPAP, EPAP, and FiO₂ all may require titration.

Patients who fail to show improvement (either clinically or based on ventilatory parameters) or those with persistent mental status abnormalities, agitation, excessive secretions, or ventilator asynchrony after 1 hour of NIV are at high risk for NIV failure.^46,47

Interpreting the Literature

Sizeable and sometimes conflicting literature exists on the subject of NIV.  Despite a lack of clear and consistently reproducible benefit in morbidity, NIV use continues to increase. There are multiple factors that make interpretation of the results difficult and at times seemingly contradictory. Careful examination of the literature therefore must be undertaken before applying NIV to daily practice. Inconsistency of therapy type delivered, NIV pressure settings, pressure adjustments, patient monitoring, differing mask types, ventilator designs, endpoints, patient populations and the influence of cotreatments can all influence outcomes and potential benefit. To further complicate the data, unmeasured factors such as patient tolerance, interface fit, mask leak, and patient-ventilator asynchrony may be grouped as “NIV failure.”

 

For a patient suffering from ARF, the point in time of NIV application may have more to do with study enrollment and study group assignment (NIV or intubation) than the underlying pathology. Specifically, in some cases if NIV had been initiated hours prior, a clear benefit may have been demonstrated. One must also remember that at many institutions, the threshold for intubation (or intensive care unit admission) may be different, as well as the treating provider’s expertise and experience with NIV. In addition, well-established and consistent criteria for NIV failure have not been clearly defined and vary significantly study to study, making generalizations difficult. A comparison of patient groups with equal possible clinical outcomes is necessary to compare the findings “on a level playing field” and determine external validity. 

Conclusion

Noninvasive ventilation represents a critically important intervention—one that should be applied early and aggressively in the ED to patients presenting with ARD in whom there are no contraindications to treatment. The EP should recognize the patient at high risk and, at the time of application, continue to closely monitor him or her for signs of improvement or deterioration.

As NIV use continues to increase, it is important that the clinician have a good working knowledge of its setup, modes of operation, and potential complications. A comfort level should exist for troubleshooting at the bedside. As provider competence increases, standardized quality of care is improved.

Dr Burns is an associate professor, residency director, and vice chair of academic affairs, department of emergency medicine, The University of Oklahoma School of Community Medicine, Tulsa.

Soft-tissue sarcomas are quite rare, with an annual incidence of 20 to 30 per 1,000,000 persons in the United States.¹ Because of their heterogeneous presentation, they remain a diagnostic challenge and are often initially confused for more common, benign disorders.² Chronic expanding hematoma, first described by Friedlander and colleagues³ in 1968, is a rare entity that is particularly difficult to distinguish from soft-tissue malignancy.^3-5 Chronic expanding hematoma is defined as a hematoma that gradually expands over 1 month or longer, is absent of neoplastic change on histologic sections, and does not occur in the setting of coagulopathy.⁶

Typically associated with remote trauma, these lesions often present as a slowly growing mass on the anterior or lateral thigh, calf, or buttock.^3-4,7-9 They have been reported to persist as long as 46 years, with sizes ranging from 3 to 55 cm in maximum diameter.⁷ On imaging, they have a cystic appearance with a dense fibrous capsule.^7-8 Most cases resolve uneventfully after drainage or marginal excision, although some cases require repeated intervention.⁷ This case report describes a morbidly obese patient with a chronic expanding hematoma in the distal posterior thigh whose definitive treatment was delayed 6 months because of her pregnancy status and inability to lie prone for open biopsy. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 27-year-old morbidly obese woman, who was pregnant at 12 weeks gestation, was seen in an orthopedic oncology clinic with a 1-month history of a slowly growing, painful posterior thigh mass. She had no history of cancer or bleeding disorder, and denied a history of trauma or constitutional symptoms consistent with malignancy. Coagulation studies were normal. Magnetic resonance imaging (MRI) obtained 2 weeks prior in the emergency room showed a cystic lesion with mass-like components in the posterior compartment of the distal right thigh, measuring 17 cm longitudinally. The lesion was located adjacent to, but not involving, the sciatic nerve and femoral vasculature. On initial examination, the large soft-tissue mass was evident and moderately painful to palpation; no skin changes were noted, and the patient had a normal sensorimotor examination. Fine-needle aspiration was performed, which resulted in amorphous debris consistent with hematoma.

Repeat MRI 2 months later showed increased size of the lesion (9.5×10.5 cm axial, 22.0 cm craniocaudal). Although most findings of a more extensive imaging protocol, including precontrast and postcontrast sequences, were consistent with hematoma, the lesion also had several characteristics that indicated soft-tissue sarcoma. Specifically, findings suggestive of chronic hematoma included the hyperintense short tau inversion recovery (STIR) T1/T2 signal of the cystic component consistent with proteinaceous fluid and the low STIR TI/T2 signal of the periphery consistent with a rim of hemosiderin (Figure 1). Additionally, the cystic component of the lesion had multiple fine septations that are atypical for a hematoma (Figure 1), and several lymph nodes greater than 1.7 cm in short axis were noted in the anterior thigh and hemipelvis that were suspicious of metastatic lymphadenopathy. The encapsulated appearance of the lesion with a sharply defined margin and short transition zone were also reassuring findings for a benign lesion (Figures 1, 2A, 2B). However, several findings were identified that suggested soft-tissue sarcoma, including a nodular soft-tissue component on the medial wall of the lesion that had heterogeneous enhancement with contrast (Figure 2B). We, therefore, proceeded with ultrasound-guided core needle biopsy of the mass and cytologic sampling of the fluid components, which were again consistent with hematoma; no evidence of internal vascular flow was noted on Doppler ultrasound. Ultrasound-guided right inguinal lymph node biopsy was also performed and was negative for malignancy. Because of her large body habitus and pregnancy status, it was agreed that open biopsy should be delayed until after delivery to avoid placing the patient in a prone position.

The patient visited the emergency room several times during the following months because of intermittent exacerbations of her lower extremity pain, swelling, and occasional paresthesias. About 6 months after initial presentation, repeat MRI again showed increased size of the mass (13.5×13.5 cm axial, 28 cm craniocaudal). There was also increased displacement of the adjacent neurovascular structures but no evidence of deep vein thrombosis. Because of concerns about the increased symptomatology of her thigh mass and possible sampling error of the previous biopsies, an elective cesarean section was performed at 35 weeks gestation. One week later, after clearance by her obstetrician, we proceeded with open biopsy of the mass in prone position. Initial sampling was negative for malignancy on frozen section; then, we expressed 1.75 L of brown fluid and solidified blood products, irrigated copiously, and placed a surgical drain. The permanent histologic specimens were again consistent with hematoma, and microbial cultures were negative. A week later, the patient accidentally removed her drain, and she presented with a fever (101°F) on postoperative day (POD) 15. Computed tomography showed reaccumulation of fluid; duplex ultrasound was negative. She was placed on cephalexin and underwent ultrasound-guided replacement of the drain with removal of an additional 750 mL fluid on POD 20. She drained an additional 150 to 200 mL/d for 1 month, with marked improvement in her leg swelling and knee range of motion. The drainage decreased during the next 3 weeks, and the drain was removed on POD 75.

 

Discussion

The presence of a hematoma in the extremities is usually a straightforward diagnosis. However, the unusual circumstances of this case highlight all the indications for investigation for possible soft-tissue sarcoma when a patient presents with what appears to be a benign condition.

Hematomas are rare in the absence of trauma or coagulopathy, with chronic expansion of hematomas rarer still.^4,7,10-11 The patient had no evidence of coagulopathy because of her ability to have an uncomplicated pregnancy and elective cesarean section. She denied a history of trauma, and the location of her hematoma at the posterior distal thigh is an uncommon site of injury. In this setting, fine-needle aspiration and serial imaging to assess for progressive increase in lesion size were indicated to rule out malignancy.²

MRI is the gold-standard imaging modality for distinguishing soft-tissue masses from hematomas.^5,12-14 Unlike the typical appearance of a hematoma, sarcomas of the soft-tissue extremities are often complex cystic lesions with multiple septations, internal soft-tissue components, and relatively ill-defined margins.^15-17 However, as a hematoma becomes chronic, it can develop a fibrinous capsule, and the contents can manifest an atypical, heterogeneous appearance from scattered, progressive accumulation of blood products that is essentially indistinguishable from sarcomas on imaging.⁵

Because of the expansion of the hematoma and the atypical appearance of the mass on imaging, repeated core biopsy and, eventually, open biopsy were indicated, despite a preliminary negative diagnosis based on fine-needle aspiration. This resulted from the possibility of sampling error that is particularly relevant to cystic sarcomas, because only portions of the mass may be composed of malignant cells.² An unusual aspect of this case is the regional lymphadenopathy noted on MRI, because regional lymphatic spread is a known mechanism of metastasis in soft-tissue sarcomas.¹⁸ However, the inguinal biopsies showed a chronic inflammatory infiltrate and were negative for malignancy, and enlarged nodes were not seen on imaging several months later. It is possible that the lymphadenopathy resulted from an unrelated process; alternatively, it may have been secondary to impaired lymphatic drainage because of mass effect from the hematoma, which also caused temporary lower extremity swelling.

The distal posterior thigh is an unreported location for a chronic expanding hematoma. Our patient developed slowly progressive lower-limb swelling and, eventually, paresthesias because of displacement of the neurovasculature, an unusual sequela that was recently reported in a similar case of an acute spontaneous hematoma in a patient on warfarin.¹⁹ Rupture of a Baker cyst is a possible inciting factor in our patient, although the proximal location of the lesion and the clearly defined tissue plane on MRI between the hematoma and the popliteal region make this unlikely. Finally, the patient’s lesion showed no evidence of vascular flow on Doppler ultrasonography, although giant hematomas secondary to popliteal aneurysm rupture have been reported.^20-22

Conclusion

This case highlights the features of a chronic expanding hematoma that can suggest soft-tissue sarcoma and shows the recommended diagnostic steps to differentiate the 2 conditions. This case also describes an unreported location for a chronic expanding hematoma with resulting progressive neurovascular displacement caused by mass effect. We recommend careful monitoring of patients with similarly expansile lesions in this region for signs of neurovascular compromise.

Soft-tissue sarcomas are quite rare, with an annual incidence of 20 to 30 per 1,000,000 persons in the United States.¹ Because of their heterogeneous presentation, they remain a diagnostic challenge and are often initially confused for more common, benign disorders.² Chronic expanding hematoma, first described by Friedlander and colleagues³ in 1968, is a rare entity that is particularly difficult to distinguish from soft-tissue malignancy.^3-5 Chronic expanding hematoma is defined as a hematoma that gradually expands over 1 month or longer, is absent of neoplastic change on histologic sections, and does not occur in the setting of coagulopathy.⁶

Typically associated with remote trauma, these lesions often present as a slowly growing mass on the anterior or lateral thigh, calf, or buttock.^3-4,7-9 They have been reported to persist as long as 46 years, with sizes ranging from 3 to 55 cm in maximum diameter.⁷ On imaging, they have a cystic appearance with a dense fibrous capsule.^7-8 Most cases resolve uneventfully after drainage or marginal excision, although some cases require repeated intervention.⁷ This case report describes a morbidly obese patient with a chronic expanding hematoma in the distal posterior thigh whose definitive treatment was delayed 6 months because of her pregnancy status and inability to lie prone for open biopsy. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 27-year-old morbidly obese woman, who was pregnant at 12 weeks gestation, was seen in an orthopedic oncology clinic with a 1-month history of a slowly growing, painful posterior thigh mass. She had no history of cancer or bleeding disorder, and denied a history of trauma or constitutional symptoms consistent with malignancy. Coagulation studies were normal. Magnetic resonance imaging (MRI) obtained 2 weeks prior in the emergency room showed a cystic lesion with mass-like components in the posterior compartment of the distal right thigh, measuring 17 cm longitudinally. The lesion was located adjacent to, but not involving, the sciatic nerve and femoral vasculature. On initial examination, the large soft-tissue mass was evident and moderately painful to palpation; no skin changes were noted, and the patient had a normal sensorimotor examination. Fine-needle aspiration was performed, which resulted in amorphous debris consistent with hematoma.

Repeat MRI 2 months later showed increased size of the lesion (9.5×10.5 cm axial, 22.0 cm craniocaudal). Although most findings of a more extensive imaging protocol, including precontrast and postcontrast sequences, were consistent with hematoma, the lesion also had several characteristics that indicated soft-tissue sarcoma. Specifically, findings suggestive of chronic hematoma included the hyperintense short tau inversion recovery (STIR) T1/T2 signal of the cystic component consistent with proteinaceous fluid and the low STIR TI/T2 signal of the periphery consistent with a rim of hemosiderin (Figure 1). Additionally, the cystic component of the lesion had multiple fine septations that are atypical for a hematoma (Figure 1), and several lymph nodes greater than 1.7 cm in short axis were noted in the anterior thigh and hemipelvis that were suspicious of metastatic lymphadenopathy. The encapsulated appearance of the lesion with a sharply defined margin and short transition zone were also reassuring findings for a benign lesion (Figures 1, 2A, 2B). However, several findings were identified that suggested soft-tissue sarcoma, including a nodular soft-tissue component on the medial wall of the lesion that had heterogeneous enhancement with contrast (Figure 2B). We, therefore, proceeded with ultrasound-guided core needle biopsy of the mass and cytologic sampling of the fluid components, which were again consistent with hematoma; no evidence of internal vascular flow was noted on Doppler ultrasound. Ultrasound-guided right inguinal lymph node biopsy was also performed and was negative for malignancy. Because of her large body habitus and pregnancy status, it was agreed that open biopsy should be delayed until after delivery to avoid placing the patient in a prone position.

The patient visited the emergency room several times during the following months because of intermittent exacerbations of her lower extremity pain, swelling, and occasional paresthesias. About 6 months after initial presentation, repeat MRI again showed increased size of the mass (13.5×13.5 cm axial, 28 cm craniocaudal). There was also increased displacement of the adjacent neurovascular structures but no evidence of deep vein thrombosis. Because of concerns about the increased symptomatology of her thigh mass and possible sampling error of the previous biopsies, an elective cesarean section was performed at 35 weeks gestation. One week later, after clearance by her obstetrician, we proceeded with open biopsy of the mass in prone position. Initial sampling was negative for malignancy on frozen section; then, we expressed 1.75 L of brown fluid and solidified blood products, irrigated copiously, and placed a surgical drain. The permanent histologic specimens were again consistent with hematoma, and microbial cultures were negative. A week later, the patient accidentally removed her drain, and she presented with a fever (101°F) on postoperative day (POD) 15. Computed tomography showed reaccumulation of fluid; duplex ultrasound was negative. She was placed on cephalexin and underwent ultrasound-guided replacement of the drain with removal of an additional 750 mL fluid on POD 20. She drained an additional 150 to 200 mL/d for 1 month, with marked improvement in her leg swelling and knee range of motion. The drainage decreased during the next 3 weeks, and the drain was removed on POD 75.

 

Discussion

The presence of a hematoma in the extremities is usually a straightforward diagnosis. However, the unusual circumstances of this case highlight all the indications for investigation for possible soft-tissue sarcoma when a patient presents with what appears to be a benign condition.

Hematomas are rare in the absence of trauma or coagulopathy, with chronic expansion of hematomas rarer still.^4,7,10-11 The patient had no evidence of coagulopathy because of her ability to have an uncomplicated pregnancy and elective cesarean section. She denied a history of trauma, and the location of her hematoma at the posterior distal thigh is an uncommon site of injury. In this setting, fine-needle aspiration and serial imaging to assess for progressive increase in lesion size were indicated to rule out malignancy.²

MRI is the gold-standard imaging modality for distinguishing soft-tissue masses from hematomas.^5,12-14 Unlike the typical appearance of a hematoma, sarcomas of the soft-tissue extremities are often complex cystic lesions with multiple septations, internal soft-tissue components, and relatively ill-defined margins.^15-17 However, as a hematoma becomes chronic, it can develop a fibrinous capsule, and the contents can manifest an atypical, heterogeneous appearance from scattered, progressive accumulation of blood products that is essentially indistinguishable from sarcomas on imaging.⁵

Because of the expansion of the hematoma and the atypical appearance of the mass on imaging, repeated core biopsy and, eventually, open biopsy were indicated, despite a preliminary negative diagnosis based on fine-needle aspiration. This resulted from the possibility of sampling error that is particularly relevant to cystic sarcomas, because only portions of the mass may be composed of malignant cells.² An unusual aspect of this case is the regional lymphadenopathy noted on MRI, because regional lymphatic spread is a known mechanism of metastasis in soft-tissue sarcomas.¹⁸ However, the inguinal biopsies showed a chronic inflammatory infiltrate and were negative for malignancy, and enlarged nodes were not seen on imaging several months later. It is possible that the lymphadenopathy resulted from an unrelated process; alternatively, it may have been secondary to impaired lymphatic drainage because of mass effect from the hematoma, which also caused temporary lower extremity swelling.

The distal posterior thigh is an unreported location for a chronic expanding hematoma. Our patient developed slowly progressive lower-limb swelling and, eventually, paresthesias because of displacement of the neurovasculature, an unusual sequela that was recently reported in a similar case of an acute spontaneous hematoma in a patient on warfarin.¹⁹ Rupture of a Baker cyst is a possible inciting factor in our patient, although the proximal location of the lesion and the clearly defined tissue plane on MRI between the hematoma and the popliteal region make this unlikely. Finally, the patient’s lesion showed no evidence of vascular flow on Doppler ultrasonography, although giant hematomas secondary to popliteal aneurysm rupture have been reported.^20-22

Conclusion

This case highlights the features of a chronic expanding hematoma that can suggest soft-tissue sarcoma and shows the recommended diagnostic steps to differentiate the 2 conditions. This case also describes an unreported location for a chronic expanding hematoma with resulting progressive neurovascular displacement caused by mass effect. We recommend careful monitoring of patients with similarly expansile lesions in this region for signs of neurovascular compromise.

Soft-tissue sarcomas are quite rare, with an annual incidence of 20 to 30 per 1,000,000 persons in the United States.¹ Because of their heterogeneous presentation, they remain a diagnostic challenge and are often initially confused for more common, benign disorders.² Chronic expanding hematoma, first described by Friedlander and colleagues³ in 1968, is a rare entity that is particularly difficult to distinguish from soft-tissue malignancy.^3-5 Chronic expanding hematoma is defined as a hematoma that gradually expands over 1 month or longer, is absent of neoplastic change on histologic sections, and does not occur in the setting of coagulopathy.⁶

Typically associated with remote trauma, these lesions often present as a slowly growing mass on the anterior or lateral thigh, calf, or buttock.^3-4,7-9 They have been reported to persist as long as 46 years, with sizes ranging from 3 to 55 cm in maximum diameter.⁷ On imaging, they have a cystic appearance with a dense fibrous capsule.^7-8 Most cases resolve uneventfully after drainage or marginal excision, although some cases require repeated intervention.⁷ This case report describes a morbidly obese patient with a chronic expanding hematoma in the distal posterior thigh whose definitive treatment was delayed 6 months because of her pregnancy status and inability to lie prone for open biopsy. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 27-year-old morbidly obese woman, who was pregnant at 12 weeks gestation, was seen in an orthopedic oncology clinic with a 1-month history of a slowly growing, painful posterior thigh mass. She had no history of cancer or bleeding disorder, and denied a history of trauma or constitutional symptoms consistent with malignancy. Coagulation studies were normal. Magnetic resonance imaging (MRI) obtained 2 weeks prior in the emergency room showed a cystic lesion with mass-like components in the posterior compartment of the distal right thigh, measuring 17 cm longitudinally. The lesion was located adjacent to, but not involving, the sciatic nerve and femoral vasculature. On initial examination, the large soft-tissue mass was evident and moderately painful to palpation; no skin changes were noted, and the patient had a normal sensorimotor examination. Fine-needle aspiration was performed, which resulted in amorphous debris consistent with hematoma.

Repeat MRI 2 months later showed increased size of the lesion (9.5×10.5 cm axial, 22.0 cm craniocaudal). Although most findings of a more extensive imaging protocol, including precontrast and postcontrast sequences, were consistent with hematoma, the lesion also had several characteristics that indicated soft-tissue sarcoma. Specifically, findings suggestive of chronic hematoma included the hyperintense short tau inversion recovery (STIR) T1/T2 signal of the cystic component consistent with proteinaceous fluid and the low STIR TI/T2 signal of the periphery consistent with a rim of hemosiderin (Figure 1). Additionally, the cystic component of the lesion had multiple fine septations that are atypical for a hematoma (Figure 1), and several lymph nodes greater than 1.7 cm in short axis were noted in the anterior thigh and hemipelvis that were suspicious of metastatic lymphadenopathy. The encapsulated appearance of the lesion with a sharply defined margin and short transition zone were also reassuring findings for a benign lesion (Figures 1, 2A, 2B). However, several findings were identified that suggested soft-tissue sarcoma, including a nodular soft-tissue component on the medial wall of the lesion that had heterogeneous enhancement with contrast (Figure 2B). We, therefore, proceeded with ultrasound-guided core needle biopsy of the mass and cytologic sampling of the fluid components, which were again consistent with hematoma; no evidence of internal vascular flow was noted on Doppler ultrasound. Ultrasound-guided right inguinal lymph node biopsy was also performed and was negative for malignancy. Because of her large body habitus and pregnancy status, it was agreed that open biopsy should be delayed until after delivery to avoid placing the patient in a prone position.

The patient visited the emergency room several times during the following months because of intermittent exacerbations of her lower extremity pain, swelling, and occasional paresthesias. About 6 months after initial presentation, repeat MRI again showed increased size of the mass (13.5×13.5 cm axial, 28 cm craniocaudal). There was also increased displacement of the adjacent neurovascular structures but no evidence of deep vein thrombosis. Because of concerns about the increased symptomatology of her thigh mass and possible sampling error of the previous biopsies, an elective cesarean section was performed at 35 weeks gestation. One week later, after clearance by her obstetrician, we proceeded with open biopsy of the mass in prone position. Initial sampling was negative for malignancy on frozen section; then, we expressed 1.75 L of brown fluid and solidified blood products, irrigated copiously, and placed a surgical drain. The permanent histologic specimens were again consistent with hematoma, and microbial cultures were negative. A week later, the patient accidentally removed her drain, and she presented with a fever (101°F) on postoperative day (POD) 15. Computed tomography showed reaccumulation of fluid; duplex ultrasound was negative. She was placed on cephalexin and underwent ultrasound-guided replacement of the drain with removal of an additional 750 mL fluid on POD 20. She drained an additional 150 to 200 mL/d for 1 month, with marked improvement in her leg swelling and knee range of motion. The drainage decreased during the next 3 weeks, and the drain was removed on POD 75.

 

Discussion

The presence of a hematoma in the extremities is usually a straightforward diagnosis. However, the unusual circumstances of this case highlight all the indications for investigation for possible soft-tissue sarcoma when a patient presents with what appears to be a benign condition.

Hematomas are rare in the absence of trauma or coagulopathy, with chronic expansion of hematomas rarer still.^4,7,10-11 The patient had no evidence of coagulopathy because of her ability to have an uncomplicated pregnancy and elective cesarean section. She denied a history of trauma, and the location of her hematoma at the posterior distal thigh is an uncommon site of injury. In this setting, fine-needle aspiration and serial imaging to assess for progressive increase in lesion size were indicated to rule out malignancy.²

MRI is the gold-standard imaging modality for distinguishing soft-tissue masses from hematomas.^5,12-14 Unlike the typical appearance of a hematoma, sarcomas of the soft-tissue extremities are often complex cystic lesions with multiple septations, internal soft-tissue components, and relatively ill-defined margins.^15-17 However, as a hematoma becomes chronic, it can develop a fibrinous capsule, and the contents can manifest an atypical, heterogeneous appearance from scattered, progressive accumulation of blood products that is essentially indistinguishable from sarcomas on imaging.⁵

Because of the expansion of the hematoma and the atypical appearance of the mass on imaging, repeated core biopsy and, eventually, open biopsy were indicated, despite a preliminary negative diagnosis based on fine-needle aspiration. This resulted from the possibility of sampling error that is particularly relevant to cystic sarcomas, because only portions of the mass may be composed of malignant cells.² An unusual aspect of this case is the regional lymphadenopathy noted on MRI, because regional lymphatic spread is a known mechanism of metastasis in soft-tissue sarcomas.¹⁸ However, the inguinal biopsies showed a chronic inflammatory infiltrate and were negative for malignancy, and enlarged nodes were not seen on imaging several months later. It is possible that the lymphadenopathy resulted from an unrelated process; alternatively, it may have been secondary to impaired lymphatic drainage because of mass effect from the hematoma, which also caused temporary lower extremity swelling.

The distal posterior thigh is an unreported location for a chronic expanding hematoma. Our patient developed slowly progressive lower-limb swelling and, eventually, paresthesias because of displacement of the neurovasculature, an unusual sequela that was recently reported in a similar case of an acute spontaneous hematoma in a patient on warfarin.¹⁹ Rupture of a Baker cyst is a possible inciting factor in our patient, although the proximal location of the lesion and the clearly defined tissue plane on MRI between the hematoma and the popliteal region make this unlikely. Finally, the patient’s lesion showed no evidence of vascular flow on Doppler ultrasonography, although giant hematomas secondary to popliteal aneurysm rupture have been reported.^20-22

Conclusion

This case highlights the features of a chronic expanding hematoma that can suggest soft-tissue sarcoma and shows the recommended diagnostic steps to differentiate the 2 conditions. This case also describes an unreported location for a chronic expanding hematoma with resulting progressive neurovascular displacement caused by mass effect. We recommend careful monitoring of patients with similarly expansile lesions in this region for signs of neurovascular compromise.