Erik Lehman, MS

Patients experience acute illness at all hours of the day. In acute care hospitals, over 60% of patient admissions occur outside of normal business hours, or the off hours.[1, 2] Similarly, the acute decompensation of patients already admitted to hospital‐based units is frequent, with 90% of rapid responses occurring between 9 _pm and 6 _am.[3] Research suggests worse hospital performance during off hours, including increased patient falls, in‐hospital cardiac arrest mortality, and severity of hospital employee injuries.[2, 4, 5, 6, 7]

Although hospital‐based services should match care demand, the disparity between patient acuity and hospital capability at night is significant. Off hours typically have lower staffing of nurses, and attending and housestaff physicians, and ancillary staff as well as limited availability of consultative and supportive services.[8] Additionally, off‐hours providers are subject to the physiological effects of imbalanced circadian rhythms, including fatigue, attenuating their abilities to provide high‐quality care. The significant patient care needs mandate continuous patient care delivery without compromising quality or safety. To achieve this, further defining the barriers to delivering quality care during off hours is essential to improvement efforts in medicine‐based units.

Previous investigations have found increased occurrence and severity of worker accidents, increased potential for higher occurrence of preventable adverse patient events, and decreased performance during off hours.[4, 9, 10] Additionally, detrimental effects of off‐hours care may be further magnified by rotating employees through both day and night shifts, a common practice in academic hospitals.[11, 12] Potentially modifiable outcomes, such as patient fall rate and in‐hospital cardiac arrest survival differ markedly between day and night shifts.[6, 13] These studies primarily report on specific diseases, such as myocardial infarction and stroke, and are investigated from the perspective of hospital‐level outcomes.

To our knowledge, no study has reported provider‐perceived quality and safety issues occurring during off hours in an academic setting. Likewise, although off‐hours collaborative care requires shared, interprofessional conceptualization regarding care delivery, this perspective has not been reported. Understanding the similarities and differences between provider perceptions will allow the construction of an interprofessional team mental model, facilitating the design of future quality improvement initiatives.[14, 15] Our objectives were to: (1) identify off‐hours quality and safety issues, (2) assess which issues are perceived as most significant, and (3) evaluate differences in perceptions of these issues between nurses, and attending and housestaff physicians.

METHODS

RESULTS

Perceived Highest Quality of Care Time Period During Off Hours

Compared with other time periods, all providers ranked 4 to 7 _am as the period with the lowest quality of care delivery (mean rank 3.2, P0.001) (Figure 1). Nursing staff and attending physicians both ranked the 10 _pm to 1 _am time period as the best period (mean of 2.0 and 1.5, respectively), whereas housestaff physicians ranked the 7 to 10 _pm as the best time period (mean 1.62). The only statistical difference between provider groups for any given time period was the 7 to 10 _pm time period (P=0.002).

Figure 1

DISCUSSION

In this prospective, mixed‐methods study evaluating perceived off‐hours quality and safety issues, several themes were identified, including perceived mismanagement, insufficient quality of delivery processes, communication/coordination breakdowns, and staffing and supervision issues. In the quantitative analysis, lowest‐rated items (lowest quality) related to timeliness/safety/communication involved with ED transfers, number of attending physicians, and timeliness of consults and blood draws. Highest‐rated items (highest quality) related to timeliness of lab reporting and identification of deteriorating patients, medication ordering/processing, communication between physicians, and safety/communication during intraservice transfers. In general, day providers reported lower ratings than night providers on nearly all quality‐related items. Nursing staff reported the lowest ratings regarding communication between physicians and consults, whereas housestaff physicians reported the lowest ratings regarding documentation in the medical record and timely blood draws. These between‐group differences reveal the lack of shared conceptual understanding regarding off‐hours care delivery.

Our qualitative results reveal several significant issues related to care delivery during off hours, many of which are not obtainable by hospital‐level data or chart review.[18] For hospital‐based medicine units, an understanding of the structure‐ and process‐related factors associated with events is required for quality improvement efforts. Although the primary focus for this work was the off hours, it is plausible that providers may have identified similar issues as important issues during daytime hours. Our study was not designed to investigate if these perceived issues are specific to off hours, or if these issues are an accurate reflection of objective events occurring during this time period. We believe this topic deserves further investigation, as understanding if these off‐hours perceptions are unique to this time period would change the scope of future quality improvement initiatives.

The most significant finding in the quantitative results was the vulnerability in quality and safety during patient admissions from the ED, specifically in relation to communication and timeliness of transfer. Between‐unit handoffs for patients admitted from the ED to medicine units have been identified as particularly vulnerable to breakdowns in the communication process.[19, 20, 21, 22] There are multiple etiologies, including clinical uncertainty, higher acuity in patient illness early in hospitalization, and cultural differences between services.[23] Additionally, patterns of communication and standardized handoff processes are often insufficient. In our hospital system, the transfer process relies primarily upon synchronous communication methods without standardized, asynchronous information exchange. We hypothesize front‐line providers perceive this lack of standardization as a primary threat to quality. Because approximately 60% of new patient admissions from the ED to medicine service (both in our hospital and in prior studies) occur during off hours, these findings highlight a need for subsequent study and quality improvement efforts.[24]

During the time of this study, our medicine units were staffed at night by 5 medicine housestaff physicians and 1 academic hospitalist, or nocturnist. In efforts to improve quality and safety during off hours, our hospital, as well as other health systems, implemented the nocturnist position, a faculty‐level attending physician to provide off‐hours clinical care and housestaff supervision.[25] Although participants reported a moderate rating of housestaff supervision, participants provided lower scores for staffing numbers of nurses, and housestaff and attending physicians, despite nocturnist presence. With both increased off‐hours supervision in our hospital and increasing use of faculty‐level physicians in other academic programs, these results provide context for the anticipated level of overnight housestaff supervision.[26, 27] To our knowledge, this is the first study to investigate perceived overnight quality issues on medicine units following such staffing models. Although this model of direct, on‐site supervision in academic medicine programs may help offset staffing and supervisory issues during off hours, the nocturnist role is insufficient to offset threats to quality/safety already inherent within the system. Furthermore, prospective trials following implementation of nocturnist systems have shown mixed results in improving patient outcomes.[28] These findings have led some to question whether resources dedicated to nocturnist staffing may be better allocated to other overnight initiatives, highlighting the need for a more subtle understanding of quality issues to design targeted interventions.[29]

A notable finding from this work is that providers without night experience reported lower scores for 20 of 24 items, highlighting their perceptions of the quality of care delivery during off hours are lower than those who experience this environment. Although day providers are not directly experiencing off‐hours delivery processes, these providers receive and detect the results from care delivery at night.[17] Most nurse, physician, and hospital leaders are present in the hospital only during day hours, requiring these individuals to account for differences in perceived and actual care delivered overnight.[1] These individuals make critical decisions pertaining to process changes and quality improvement efforts in these units. We believe these results raise awareness for leadership decisions and quality improvement efforts in medicine service units, specifically to focus on overnight issues beyond staffing issues alone.

All respondent groups ranked the latter half of the shift (17 _am) as lower in quality compared to the first 6 hours (7 _pm1 _am). This finding is contrary to our hypothesis that earlier time periods, during the majority of patient admissions (and presumed higher workload for all providers), would be perceived as lower quality. Reasons for this finding are unknown, but may relate to end‐of‐shift tasks, sign‐out preparation, provider fatigue, or disease‐related concerns (eg, increased incidence of stroke and myocardial infarction) during the latter portions of night shifts. One study identified a decrease in nursing clinical judgments from the beginning to end of 12‐hour shifts, with a potential suggested mechanism of decrease in ability to maintain attention during judgments.[30] Additionally, in a study by Folkard et al., risk was highest within the first several hours and fell substantially thereafter during a shift.[9] To our knowledge, no work has investigated perceived or objective quality outcomes by time period during the off‐hours shift in medicine units. Further work could help delineate why provider‐perceived compromises in quality occur late in off‐hours shifts and whether this correlates to safety events.

There are several limitations to our study. First, although all surveys were pilot tested for content validity, the construct validity was not rigorously assessed. Second, although data were collected from all participant groups, the collection methods were unbalanced, favoring attending‐level physician perspectives. Although the relative incidence of vulnerabilities in quality and safety should be interpreted with caution, our methods and general taxonomy provide a framework for developing and monitoring the perceptions of future interventions. Due to limitations in infrastructure, our findings could not be independently validated through review of reported adverse events, but previous investigations have found the vast majority of adverse events are not detected by standard anonymous reporting.[31, 32, 33] Our methodology (used in our prior work) may provide an independent means of detecting causes of poor quality not easily observed through routine surveillance.[22] Although many survey items showed statistical differences between provider groups, the clinical significance is subject to interpretation. Last, the perceptions and events related to our institution may not be fully generalizable to other academic programs or service lines, particularly in community‐based, nonteaching hospitals.

In conclusion, our results suggest a significant discrepancy between the concerns of day and night providers regarding the quality of care delivered to inpatients during the off hours, specifically with issues related to communication, quality‐of‐care delivery processes, and patient transfers from the ED. Although specific concerns may be institution‐ (and service line‐) dependent, appropriately designing initiatives to improve the quality of care delivered overnight will need to take the perspectives of both provider groups into account. Additionally, educational initiatives should focus on achieving a shared mental model among all providers to improve collaboration and performance.

Patients experience acute illness at all hours of the day. In acute care hospitals, over 60% of patient admissions occur outside of normal business hours, or the off hours.[1, 2] Similarly, the acute decompensation of patients already admitted to hospital‐based units is frequent, with 90% of rapid responses occurring between 9 _pm and 6 _am.[3] Research suggests worse hospital performance during off hours, including increased patient falls, in‐hospital cardiac arrest mortality, and severity of hospital employee injuries.[2, 4, 5, 6, 7]

Although hospital‐based services should match care demand, the disparity between patient acuity and hospital capability at night is significant. Off hours typically have lower staffing of nurses, and attending and housestaff physicians, and ancillary staff as well as limited availability of consultative and supportive services.[8] Additionally, off‐hours providers are subject to the physiological effects of imbalanced circadian rhythms, including fatigue, attenuating their abilities to provide high‐quality care. The significant patient care needs mandate continuous patient care delivery without compromising quality or safety. To achieve this, further defining the barriers to delivering quality care during off hours is essential to improvement efforts in medicine‐based units.

Previous investigations have found increased occurrence and severity of worker accidents, increased potential for higher occurrence of preventable adverse patient events, and decreased performance during off hours.[4, 9, 10] Additionally, detrimental effects of off‐hours care may be further magnified by rotating employees through both day and night shifts, a common practice in academic hospitals.[11, 12] Potentially modifiable outcomes, such as patient fall rate and in‐hospital cardiac arrest survival differ markedly between day and night shifts.[6, 13] These studies primarily report on specific diseases, such as myocardial infarction and stroke, and are investigated from the perspective of hospital‐level outcomes.

To our knowledge, no study has reported provider‐perceived quality and safety issues occurring during off hours in an academic setting. Likewise, although off‐hours collaborative care requires shared, interprofessional conceptualization regarding care delivery, this perspective has not been reported. Understanding the similarities and differences between provider perceptions will allow the construction of an interprofessional team mental model, facilitating the design of future quality improvement initiatives.[14, 15] Our objectives were to: (1) identify off‐hours quality and safety issues, (2) assess which issues are perceived as most significant, and (3) evaluate differences in perceptions of these issues between nurses, and attending and housestaff physicians.

METHODS

RESULTS

Perceived Highest Quality of Care Time Period During Off Hours

Compared with other time periods, all providers ranked 4 to 7 _am as the period with the lowest quality of care delivery (mean rank 3.2, P0.001) (Figure 1). Nursing staff and attending physicians both ranked the 10 _pm to 1 _am time period as the best period (mean of 2.0 and 1.5, respectively), whereas housestaff physicians ranked the 7 to 10 _pm as the best time period (mean 1.62). The only statistical difference between provider groups for any given time period was the 7 to 10 _pm time period (P=0.002).

Figure 1

DISCUSSION

In this prospective, mixed‐methods study evaluating perceived off‐hours quality and safety issues, several themes were identified, including perceived mismanagement, insufficient quality of delivery processes, communication/coordination breakdowns, and staffing and supervision issues. In the quantitative analysis, lowest‐rated items (lowest quality) related to timeliness/safety/communication involved with ED transfers, number of attending physicians, and timeliness of consults and blood draws. Highest‐rated items (highest quality) related to timeliness of lab reporting and identification of deteriorating patients, medication ordering/processing, communication between physicians, and safety/communication during intraservice transfers. In general, day providers reported lower ratings than night providers on nearly all quality‐related items. Nursing staff reported the lowest ratings regarding communication between physicians and consults, whereas housestaff physicians reported the lowest ratings regarding documentation in the medical record and timely blood draws. These between‐group differences reveal the lack of shared conceptual understanding regarding off‐hours care delivery.

Our qualitative results reveal several significant issues related to care delivery during off hours, many of which are not obtainable by hospital‐level data or chart review.[18] For hospital‐based medicine units, an understanding of the structure‐ and process‐related factors associated with events is required for quality improvement efforts. Although the primary focus for this work was the off hours, it is plausible that providers may have identified similar issues as important issues during daytime hours. Our study was not designed to investigate if these perceived issues are specific to off hours, or if these issues are an accurate reflection of objective events occurring during this time period. We believe this topic deserves further investigation, as understanding if these off‐hours perceptions are unique to this time period would change the scope of future quality improvement initiatives.

The most significant finding in the quantitative results was the vulnerability in quality and safety during patient admissions from the ED, specifically in relation to communication and timeliness of transfer. Between‐unit handoffs for patients admitted from the ED to medicine units have been identified as particularly vulnerable to breakdowns in the communication process.[19, 20, 21, 22] There are multiple etiologies, including clinical uncertainty, higher acuity in patient illness early in hospitalization, and cultural differences between services.[23] Additionally, patterns of communication and standardized handoff processes are often insufficient. In our hospital system, the transfer process relies primarily upon synchronous communication methods without standardized, asynchronous information exchange. We hypothesize front‐line providers perceive this lack of standardization as a primary threat to quality. Because approximately 60% of new patient admissions from the ED to medicine service (both in our hospital and in prior studies) occur during off hours, these findings highlight a need for subsequent study and quality improvement efforts.[24]

During the time of this study, our medicine units were staffed at night by 5 medicine housestaff physicians and 1 academic hospitalist, or nocturnist. In efforts to improve quality and safety during off hours, our hospital, as well as other health systems, implemented the nocturnist position, a faculty‐level attending physician to provide off‐hours clinical care and housestaff supervision.[25] Although participants reported a moderate rating of housestaff supervision, participants provided lower scores for staffing numbers of nurses, and housestaff and attending physicians, despite nocturnist presence. With both increased off‐hours supervision in our hospital and increasing use of faculty‐level physicians in other academic programs, these results provide context for the anticipated level of overnight housestaff supervision.[26, 27] To our knowledge, this is the first study to investigate perceived overnight quality issues on medicine units following such staffing models. Although this model of direct, on‐site supervision in academic medicine programs may help offset staffing and supervisory issues during off hours, the nocturnist role is insufficient to offset threats to quality/safety already inherent within the system. Furthermore, prospective trials following implementation of nocturnist systems have shown mixed results in improving patient outcomes.[28] These findings have led some to question whether resources dedicated to nocturnist staffing may be better allocated to other overnight initiatives, highlighting the need for a more subtle understanding of quality issues to design targeted interventions.[29]

A notable finding from this work is that providers without night experience reported lower scores for 20 of 24 items, highlighting their perceptions of the quality of care delivery during off hours are lower than those who experience this environment. Although day providers are not directly experiencing off‐hours delivery processes, these providers receive and detect the results from care delivery at night.[17] Most nurse, physician, and hospital leaders are present in the hospital only during day hours, requiring these individuals to account for differences in perceived and actual care delivered overnight.[1] These individuals make critical decisions pertaining to process changes and quality improvement efforts in these units. We believe these results raise awareness for leadership decisions and quality improvement efforts in medicine service units, specifically to focus on overnight issues beyond staffing issues alone.

All respondent groups ranked the latter half of the shift (17 _am) as lower in quality compared to the first 6 hours (7 _pm1 _am). This finding is contrary to our hypothesis that earlier time periods, during the majority of patient admissions (and presumed higher workload for all providers), would be perceived as lower quality. Reasons for this finding are unknown, but may relate to end‐of‐shift tasks, sign‐out preparation, provider fatigue, or disease‐related concerns (eg, increased incidence of stroke and myocardial infarction) during the latter portions of night shifts. One study identified a decrease in nursing clinical judgments from the beginning to end of 12‐hour shifts, with a potential suggested mechanism of decrease in ability to maintain attention during judgments.[30] Additionally, in a study by Folkard et al., risk was highest within the first several hours and fell substantially thereafter during a shift.[9] To our knowledge, no work has investigated perceived or objective quality outcomes by time period during the off‐hours shift in medicine units. Further work could help delineate why provider‐perceived compromises in quality occur late in off‐hours shifts and whether this correlates to safety events.

There are several limitations to our study. First, although all surveys were pilot tested for content validity, the construct validity was not rigorously assessed. Second, although data were collected from all participant groups, the collection methods were unbalanced, favoring attending‐level physician perspectives. Although the relative incidence of vulnerabilities in quality and safety should be interpreted with caution, our methods and general taxonomy provide a framework for developing and monitoring the perceptions of future interventions. Due to limitations in infrastructure, our findings could not be independently validated through review of reported adverse events, but previous investigations have found the vast majority of adverse events are not detected by standard anonymous reporting.[31, 32, 33] Our methodology (used in our prior work) may provide an independent means of detecting causes of poor quality not easily observed through routine surveillance.[22] Although many survey items showed statistical differences between provider groups, the clinical significance is subject to interpretation. Last, the perceptions and events related to our institution may not be fully generalizable to other academic programs or service lines, particularly in community‐based, nonteaching hospitals.

In conclusion, our results suggest a significant discrepancy between the concerns of day and night providers regarding the quality of care delivered to inpatients during the off hours, specifically with issues related to communication, quality‐of‐care delivery processes, and patient transfers from the ED. Although specific concerns may be institution‐ (and service line‐) dependent, appropriately designing initiatives to improve the quality of care delivered overnight will need to take the perspectives of both provider groups into account. Additionally, educational initiatives should focus on achieving a shared mental model among all providers to improve collaboration and performance.

Patients experience acute illness at all hours of the day. In acute care hospitals, over 60% of patient admissions occur outside of normal business hours, or the off hours.[1, 2] Similarly, the acute decompensation of patients already admitted to hospital‐based units is frequent, with 90% of rapid responses occurring between 9 _pm and 6 _am.[3] Research suggests worse hospital performance during off hours, including increased patient falls, in‐hospital cardiac arrest mortality, and severity of hospital employee injuries.[2, 4, 5, 6, 7]

Although hospital‐based services should match care demand, the disparity between patient acuity and hospital capability at night is significant. Off hours typically have lower staffing of nurses, and attending and housestaff physicians, and ancillary staff as well as limited availability of consultative and supportive services.[8] Additionally, off‐hours providers are subject to the physiological effects of imbalanced circadian rhythms, including fatigue, attenuating their abilities to provide high‐quality care. The significant patient care needs mandate continuous patient care delivery without compromising quality or safety. To achieve this, further defining the barriers to delivering quality care during off hours is essential to improvement efforts in medicine‐based units.

Previous investigations have found increased occurrence and severity of worker accidents, increased potential for higher occurrence of preventable adverse patient events, and decreased performance during off hours.[4, 9, 10] Additionally, detrimental effects of off‐hours care may be further magnified by rotating employees through both day and night shifts, a common practice in academic hospitals.[11, 12] Potentially modifiable outcomes, such as patient fall rate and in‐hospital cardiac arrest survival differ markedly between day and night shifts.[6, 13] These studies primarily report on specific diseases, such as myocardial infarction and stroke, and are investigated from the perspective of hospital‐level outcomes.

To our knowledge, no study has reported provider‐perceived quality and safety issues occurring during off hours in an academic setting. Likewise, although off‐hours collaborative care requires shared, interprofessional conceptualization regarding care delivery, this perspective has not been reported. Understanding the similarities and differences between provider perceptions will allow the construction of an interprofessional team mental model, facilitating the design of future quality improvement initiatives.[14, 15] Our objectives were to: (1) identify off‐hours quality and safety issues, (2) assess which issues are perceived as most significant, and (3) evaluate differences in perceptions of these issues between nurses, and attending and housestaff physicians.

METHODS

RESULTS

Perceived Highest Quality of Care Time Period During Off Hours

Compared with other time periods, all providers ranked 4 to 7 _am as the period with the lowest quality of care delivery (mean rank 3.2, P0.001) (Figure 1). Nursing staff and attending physicians both ranked the 10 _pm to 1 _am time period as the best period (mean of 2.0 and 1.5, respectively), whereas housestaff physicians ranked the 7 to 10 _pm as the best time period (mean 1.62). The only statistical difference between provider groups for any given time period was the 7 to 10 _pm time period (P=0.002).

Figure 1

DISCUSSION

In this prospective, mixed‐methods study evaluating perceived off‐hours quality and safety issues, several themes were identified, including perceived mismanagement, insufficient quality of delivery processes, communication/coordination breakdowns, and staffing and supervision issues. In the quantitative analysis, lowest‐rated items (lowest quality) related to timeliness/safety/communication involved with ED transfers, number of attending physicians, and timeliness of consults and blood draws. Highest‐rated items (highest quality) related to timeliness of lab reporting and identification of deteriorating patients, medication ordering/processing, communication between physicians, and safety/communication during intraservice transfers. In general, day providers reported lower ratings than night providers on nearly all quality‐related items. Nursing staff reported the lowest ratings regarding communication between physicians and consults, whereas housestaff physicians reported the lowest ratings regarding documentation in the medical record and timely blood draws. These between‐group differences reveal the lack of shared conceptual understanding regarding off‐hours care delivery.

Our qualitative results reveal several significant issues related to care delivery during off hours, many of which are not obtainable by hospital‐level data or chart review.[18] For hospital‐based medicine units, an understanding of the structure‐ and process‐related factors associated with events is required for quality improvement efforts. Although the primary focus for this work was the off hours, it is plausible that providers may have identified similar issues as important issues during daytime hours. Our study was not designed to investigate if these perceived issues are specific to off hours, or if these issues are an accurate reflection of objective events occurring during this time period. We believe this topic deserves further investigation, as understanding if these off‐hours perceptions are unique to this time period would change the scope of future quality improvement initiatives.

The most significant finding in the quantitative results was the vulnerability in quality and safety during patient admissions from the ED, specifically in relation to communication and timeliness of transfer. Between‐unit handoffs for patients admitted from the ED to medicine units have been identified as particularly vulnerable to breakdowns in the communication process.[19, 20, 21, 22] There are multiple etiologies, including clinical uncertainty, higher acuity in patient illness early in hospitalization, and cultural differences between services.[23] Additionally, patterns of communication and standardized handoff processes are often insufficient. In our hospital system, the transfer process relies primarily upon synchronous communication methods without standardized, asynchronous information exchange. We hypothesize front‐line providers perceive this lack of standardization as a primary threat to quality. Because approximately 60% of new patient admissions from the ED to medicine service (both in our hospital and in prior studies) occur during off hours, these findings highlight a need for subsequent study and quality improvement efforts.[24]

During the time of this study, our medicine units were staffed at night by 5 medicine housestaff physicians and 1 academic hospitalist, or nocturnist. In efforts to improve quality and safety during off hours, our hospital, as well as other health systems, implemented the nocturnist position, a faculty‐level attending physician to provide off‐hours clinical care and housestaff supervision.[25] Although participants reported a moderate rating of housestaff supervision, participants provided lower scores for staffing numbers of nurses, and housestaff and attending physicians, despite nocturnist presence. With both increased off‐hours supervision in our hospital and increasing use of faculty‐level physicians in other academic programs, these results provide context for the anticipated level of overnight housestaff supervision.[26, 27] To our knowledge, this is the first study to investigate perceived overnight quality issues on medicine units following such staffing models. Although this model of direct, on‐site supervision in academic medicine programs may help offset staffing and supervisory issues during off hours, the nocturnist role is insufficient to offset threats to quality/safety already inherent within the system. Furthermore, prospective trials following implementation of nocturnist systems have shown mixed results in improving patient outcomes.[28] These findings have led some to question whether resources dedicated to nocturnist staffing may be better allocated to other overnight initiatives, highlighting the need for a more subtle understanding of quality issues to design targeted interventions.[29]

A notable finding from this work is that providers without night experience reported lower scores for 20 of 24 items, highlighting their perceptions of the quality of care delivery during off hours are lower than those who experience this environment. Although day providers are not directly experiencing off‐hours delivery processes, these providers receive and detect the results from care delivery at night.[17] Most nurse, physician, and hospital leaders are present in the hospital only during day hours, requiring these individuals to account for differences in perceived and actual care delivered overnight.[1] These individuals make critical decisions pertaining to process changes and quality improvement efforts in these units. We believe these results raise awareness for leadership decisions and quality improvement efforts in medicine service units, specifically to focus on overnight issues beyond staffing issues alone.

All respondent groups ranked the latter half of the shift (17 _am) as lower in quality compared to the first 6 hours (7 _pm1 _am). This finding is contrary to our hypothesis that earlier time periods, during the majority of patient admissions (and presumed higher workload for all providers), would be perceived as lower quality. Reasons for this finding are unknown, but may relate to end‐of‐shift tasks, sign‐out preparation, provider fatigue, or disease‐related concerns (eg, increased incidence of stroke and myocardial infarction) during the latter portions of night shifts. One study identified a decrease in nursing clinical judgments from the beginning to end of 12‐hour shifts, with a potential suggested mechanism of decrease in ability to maintain attention during judgments.[30] Additionally, in a study by Folkard et al., risk was highest within the first several hours and fell substantially thereafter during a shift.[9] To our knowledge, no work has investigated perceived or objective quality outcomes by time period during the off‐hours shift in medicine units. Further work could help delineate why provider‐perceived compromises in quality occur late in off‐hours shifts and whether this correlates to safety events.

There are several limitations to our study. First, although all surveys were pilot tested for content validity, the construct validity was not rigorously assessed. Second, although data were collected from all participant groups, the collection methods were unbalanced, favoring attending‐level physician perspectives. Although the relative incidence of vulnerabilities in quality and safety should be interpreted with caution, our methods and general taxonomy provide a framework for developing and monitoring the perceptions of future interventions. Due to limitations in infrastructure, our findings could not be independently validated through review of reported adverse events, but previous investigations have found the vast majority of adverse events are not detected by standard anonymous reporting.[31, 32, 33] Our methodology (used in our prior work) may provide an independent means of detecting causes of poor quality not easily observed through routine surveillance.[22] Although many survey items showed statistical differences between provider groups, the clinical significance is subject to interpretation. Last, the perceptions and events related to our institution may not be fully generalizable to other academic programs or service lines, particularly in community‐based, nonteaching hospitals.

In conclusion, our results suggest a significant discrepancy between the concerns of day and night providers regarding the quality of care delivered to inpatients during the off hours, specifically with issues related to communication, quality‐of‐care delivery processes, and patient transfers from the ED. Although specific concerns may be institution‐ (and service line‐) dependent, appropriately designing initiatives to improve the quality of care delivered overnight will need to take the perspectives of both provider groups into account. Additionally, educational initiatives should focus on achieving a shared mental model among all providers to improve collaboration and performance.

Interprofessional collaborative care (IPCC) involves members from different professions working together to enhance communication, coordination, and healthcare quality.[1, 2, 3] Because several current healthcare policy initiatives include financial incentives for increased quality of care, there has been resultant interest in the implementation of IPCC in healthcare systems.[4, 5] Unfortunately, many hospitals have found IPCC difficult to achieve. Hospital‐based medicine units are complex, time‐constrained environments requiring a high degree of collaboration and mutual decision‐making between nurses, physicians, therapists, pharmacists, care coordinators, and patients. In addition, despite recommendations for interprofessional collaborative care, the implementation and assessment of IPCC within this environment has not been well studied.[6, 7]

On academic internal medicine services, the majority of care decisions occur during rounds. Although rounds provide a common structure, the participants, length, location, and agenda of rounds tend to vary by institution and individual physician preference.[8, 9, 10, 11] Traditionally, ward rounds occur mostly in hallways and conference rooms rather than the patient's bedside.[12] Additionally, during rounds, nurse‐physician collaboration occurs infrequently, estimated at <10% of rounding time.[13] Recently, an increased focus on quality, safety, and collaboration has inspired the investigation and implementation of new methods to increase interprofessional collaboration during rounds, but many of these interventions occurred away from the patient's bedside.[14, 15] One trial of bedside interprofessional rounds (BIRs) by Curley et al. suggested improvements in patient‐level outcomes (cost and length of stay) versus traditional physician‐based rounds.[16] Although interprofessional nurse‐physician rounds at patients' bedsides may represent an ideal process, limited work has investigated this activity.[17]

A prerequisite for successful and sustained integration of BIRs is a shared conceptualization among physicians and nurses regarding the process. Such a shared conceptualization would include perceptions of benefits and barriers to implementation.[18] Currently, such perceptions have not been measured. In this study, we sought to evaluate perceptions of front‐line care providers on inpatient units, specifically nursing staff, attending physicians, and housestaff physicians, regarding the benefits and barriers to BIRs.

METHODS

RESULTS

Of the 171 surveys sent, 149 participants completed surveys (response rate 87%). Responses were received from 53/58 nursing staff (91% response), 21/28 attending physicians (75% response), and 75/85 housestaff physicians (88% response). Table 1 describes the participant response demographics.

DISCUSSION

In this study, we sought to compare perceptions of nurses and physicians on the benefits and barriers to BIRs. Nursing staff ranked each benefit higher than physicians, though rank orders of specific benefits were highly correlated. Highest‐ranked benefits related to coordination and communication more than quality or process benefits. Across groups, the highest‐ranked barriers to BIRs were related to time, whereas the lowest‐ranked factors were related to provider and patient discomfort. These results highlight important similarities and differences in perceptions between front‐line providers.

The highest‐ranked benefits were related to improved interprofessional communication and coordination. Combining interprofessional team members during care delivery allows for integrated understanding of daily care plans and clinical issues, and fosters collaboration and a team‐based atmosphere.[1, 20, 26] The lowest‐ranked benefits were related to more tangible measures, including length of stay, timely consultations, and judicious laboratory ordering. This finding contrasts with the limited literature demonstrating increased efficiency in general medicine units practicing IPCC.[16] These rankings may reflect a poor understanding or self‐assessment of outcome measures by healthcare providers, representing a potential focus for educational initiatives. Future investigations using objective assessment methods of outcomes and collaboration will provide a more accurate understanding of these findings.

The highest‐ranked barriers were related to time and systems issues. Several studies of physician‐based bedside rounds have identified systems‐ and time‐related issues as primary limiting barriers.[22, 24] In units without colocalization of patients and providers, finding receptive times for BIRs can be difficult. Although time‐related issues could be addressed by decreasing patient‐provider ratios, these changes require substantial investment in resources. A reasonable degree of improvement in efficiency and coordination is expected following acclimation to BIRs or by addressing modifiable systems factors to increase this activity. Less costly interventions, such as tailoring provider schedules, prescheduling patient rounding times, and geographic colocalization of patients and providers may be more feasible. However, the clinical microsystems within which medicine patients are cared for are often chaotic and disorganized at the infrastructural and cultural levels, which may be less influenced by surface‐level interventions. Such interventions may be ward specific and require customization to individual team needs.

The lowest‐ranked barriers to BIRs were related to provider‐ and patient‐related factors, including comfort level of patients and providers. Prior work on bedside rounds has identified physicians who are apprehensive about performing bedside rounds, but those who experience this activity are more likely to be comfortable with it.[12, 28] Our results from a culture where BIRs occur on nearly two‐thirds of patients suggest provider discomfort is not a predominant barrier.[22, 29] Additionally, educators have raised concerns about patient discomfort with bedside rounds, but nearly all studies evaluating patients' perspectives reveal patient preference for bedside case presentations over activities occurring in alternative locations.[30, 31, 32] Little work has investigated patient preference for BIRs as per our definition; our participants do not believe patients are discomforted by BIRs, building upon evidence in the literature for patient preferences regarding bedside activities.

Nursing staff perceptions of the benefits and culture related to BIRs were more positive than physicians. We hypothesize several reasons for this disparity. First, nursing staff may have more experience with observing and understanding the positive impact of BIRs and therefore are more likely to understand the positive ramifications. Alternatively, nursing staff may be satisfied with active integration into traditional physician‐centric decisions. Additionally, the professional culture and educational foundation of the nursing culture is based upon a patient‐centered approach and therefore may be more aligned with the goals of BIRs. Last, physicians may have competing priorities, favoring productivity and didactic learning rather than interprofessional collaboration. Further investigation is required to understand differences between nurses and physicians, in addition to other providers integral to BIRs (eg, care coordinators, pharmacists). Regardless, during the implementation of interprofessional collaborative care models, our findings suggest initial challenges, and the focus of educational initiatives may necessitate acclimating physician groups to benefits identified by front‐line nursing staff.

There are several limitations to our study. We investigated the perceptions of medicine nurses and physicians in 1 teaching hospital, limiting generalizability to other specialties, other vital professional groups, and nonteaching hospitals. Additionally, BIRs has been a focus of our hospital for several years. Therefore, perceived barriers may differ in BIRs‐nave hospitals. Second, although pilot‐tested for content, the construct validity of the instrument was not rigorously assessed, and the instrument was not designed to measure benefits and barriers not explicitly identified during pilot testing. Last, although surveys were anonymous, the possibility of social desirability bias exists, thereby limiting accuracy.

For over a century, physician‐led rounds have been the preferred modality for point‐of‐care decision making.[10, 15, 32, 33] BIRs address our growing understanding of patient‐centered care. Future efforts should address the quality of collaboration and current hospital and unit structures hindering patient‐centered IPCC and patient outcomes.

Interprofessional collaborative care (IPCC) involves members from different professions working together to enhance communication, coordination, and healthcare quality.[1, 2, 3] Because several current healthcare policy initiatives include financial incentives for increased quality of care, there has been resultant interest in the implementation of IPCC in healthcare systems.[4, 5] Unfortunately, many hospitals have found IPCC difficult to achieve. Hospital‐based medicine units are complex, time‐constrained environments requiring a high degree of collaboration and mutual decision‐making between nurses, physicians, therapists, pharmacists, care coordinators, and patients. In addition, despite recommendations for interprofessional collaborative care, the implementation and assessment of IPCC within this environment has not been well studied.[6, 7]

On academic internal medicine services, the majority of care decisions occur during rounds. Although rounds provide a common structure, the participants, length, location, and agenda of rounds tend to vary by institution and individual physician preference.[8, 9, 10, 11] Traditionally, ward rounds occur mostly in hallways and conference rooms rather than the patient's bedside.[12] Additionally, during rounds, nurse‐physician collaboration occurs infrequently, estimated at <10% of rounding time.[13] Recently, an increased focus on quality, safety, and collaboration has inspired the investigation and implementation of new methods to increase interprofessional collaboration during rounds, but many of these interventions occurred away from the patient's bedside.[14, 15] One trial of bedside interprofessional rounds (BIRs) by Curley et al. suggested improvements in patient‐level outcomes (cost and length of stay) versus traditional physician‐based rounds.[16] Although interprofessional nurse‐physician rounds at patients' bedsides may represent an ideal process, limited work has investigated this activity.[17]

A prerequisite for successful and sustained integration of BIRs is a shared conceptualization among physicians and nurses regarding the process. Such a shared conceptualization would include perceptions of benefits and barriers to implementation.[18] Currently, such perceptions have not been measured. In this study, we sought to evaluate perceptions of front‐line care providers on inpatient units, specifically nursing staff, attending physicians, and housestaff physicians, regarding the benefits and barriers to BIRs.

METHODS

RESULTS

Of the 171 surveys sent, 149 participants completed surveys (response rate 87%). Responses were received from 53/58 nursing staff (91% response), 21/28 attending physicians (75% response), and 75/85 housestaff physicians (88% response). Table 1 describes the participant response demographics.

DISCUSSION

In this study, we sought to compare perceptions of nurses and physicians on the benefits and barriers to BIRs. Nursing staff ranked each benefit higher than physicians, though rank orders of specific benefits were highly correlated. Highest‐ranked benefits related to coordination and communication more than quality or process benefits. Across groups, the highest‐ranked barriers to BIRs were related to time, whereas the lowest‐ranked factors were related to provider and patient discomfort. These results highlight important similarities and differences in perceptions between front‐line providers.

The highest‐ranked benefits were related to improved interprofessional communication and coordination. Combining interprofessional team members during care delivery allows for integrated understanding of daily care plans and clinical issues, and fosters collaboration and a team‐based atmosphere.[1, 20, 26] The lowest‐ranked benefits were related to more tangible measures, including length of stay, timely consultations, and judicious laboratory ordering. This finding contrasts with the limited literature demonstrating increased efficiency in general medicine units practicing IPCC.[16] These rankings may reflect a poor understanding or self‐assessment of outcome measures by healthcare providers, representing a potential focus for educational initiatives. Future investigations using objective assessment methods of outcomes and collaboration will provide a more accurate understanding of these findings.

The highest‐ranked barriers were related to time and systems issues. Several studies of physician‐based bedside rounds have identified systems‐ and time‐related issues as primary limiting barriers.[22, 24] In units without colocalization of patients and providers, finding receptive times for BIRs can be difficult. Although time‐related issues could be addressed by decreasing patient‐provider ratios, these changes require substantial investment in resources. A reasonable degree of improvement in efficiency and coordination is expected following acclimation to BIRs or by addressing modifiable systems factors to increase this activity. Less costly interventions, such as tailoring provider schedules, prescheduling patient rounding times, and geographic colocalization of patients and providers may be more feasible. However, the clinical microsystems within which medicine patients are cared for are often chaotic and disorganized at the infrastructural and cultural levels, which may be less influenced by surface‐level interventions. Such interventions may be ward specific and require customization to individual team needs.

The lowest‐ranked barriers to BIRs were related to provider‐ and patient‐related factors, including comfort level of patients and providers. Prior work on bedside rounds has identified physicians who are apprehensive about performing bedside rounds, but those who experience this activity are more likely to be comfortable with it.[12, 28] Our results from a culture where BIRs occur on nearly two‐thirds of patients suggest provider discomfort is not a predominant barrier.[22, 29] Additionally, educators have raised concerns about patient discomfort with bedside rounds, but nearly all studies evaluating patients' perspectives reveal patient preference for bedside case presentations over activities occurring in alternative locations.[30, 31, 32] Little work has investigated patient preference for BIRs as per our definition; our participants do not believe patients are discomforted by BIRs, building upon evidence in the literature for patient preferences regarding bedside activities.

Nursing staff perceptions of the benefits and culture related to BIRs were more positive than physicians. We hypothesize several reasons for this disparity. First, nursing staff may have more experience with observing and understanding the positive impact of BIRs and therefore are more likely to understand the positive ramifications. Alternatively, nursing staff may be satisfied with active integration into traditional physician‐centric decisions. Additionally, the professional culture and educational foundation of the nursing culture is based upon a patient‐centered approach and therefore may be more aligned with the goals of BIRs. Last, physicians may have competing priorities, favoring productivity and didactic learning rather than interprofessional collaboration. Further investigation is required to understand differences between nurses and physicians, in addition to other providers integral to BIRs (eg, care coordinators, pharmacists). Regardless, during the implementation of interprofessional collaborative care models, our findings suggest initial challenges, and the focus of educational initiatives may necessitate acclimating physician groups to benefits identified by front‐line nursing staff.

There are several limitations to our study. We investigated the perceptions of medicine nurses and physicians in 1 teaching hospital, limiting generalizability to other specialties, other vital professional groups, and nonteaching hospitals. Additionally, BIRs has been a focus of our hospital for several years. Therefore, perceived barriers may differ in BIRs‐nave hospitals. Second, although pilot‐tested for content, the construct validity of the instrument was not rigorously assessed, and the instrument was not designed to measure benefits and barriers not explicitly identified during pilot testing. Last, although surveys were anonymous, the possibility of social desirability bias exists, thereby limiting accuracy.

For over a century, physician‐led rounds have been the preferred modality for point‐of‐care decision making.[10, 15, 32, 33] BIRs address our growing understanding of patient‐centered care. Future efforts should address the quality of collaboration and current hospital and unit structures hindering patient‐centered IPCC and patient outcomes.

Interprofessional collaborative care (IPCC) involves members from different professions working together to enhance communication, coordination, and healthcare quality.[1, 2, 3] Because several current healthcare policy initiatives include financial incentives for increased quality of care, there has been resultant interest in the implementation of IPCC in healthcare systems.[4, 5] Unfortunately, many hospitals have found IPCC difficult to achieve. Hospital‐based medicine units are complex, time‐constrained environments requiring a high degree of collaboration and mutual decision‐making between nurses, physicians, therapists, pharmacists, care coordinators, and patients. In addition, despite recommendations for interprofessional collaborative care, the implementation and assessment of IPCC within this environment has not been well studied.[6, 7]

On academic internal medicine services, the majority of care decisions occur during rounds. Although rounds provide a common structure, the participants, length, location, and agenda of rounds tend to vary by institution and individual physician preference.[8, 9, 10, 11] Traditionally, ward rounds occur mostly in hallways and conference rooms rather than the patient's bedside.[12] Additionally, during rounds, nurse‐physician collaboration occurs infrequently, estimated at <10% of rounding time.[13] Recently, an increased focus on quality, safety, and collaboration has inspired the investigation and implementation of new methods to increase interprofessional collaboration during rounds, but many of these interventions occurred away from the patient's bedside.[14, 15] One trial of bedside interprofessional rounds (BIRs) by Curley et al. suggested improvements in patient‐level outcomes (cost and length of stay) versus traditional physician‐based rounds.[16] Although interprofessional nurse‐physician rounds at patients' bedsides may represent an ideal process, limited work has investigated this activity.[17]

A prerequisite for successful and sustained integration of BIRs is a shared conceptualization among physicians and nurses regarding the process. Such a shared conceptualization would include perceptions of benefits and barriers to implementation.[18] Currently, such perceptions have not been measured. In this study, we sought to evaluate perceptions of front‐line care providers on inpatient units, specifically nursing staff, attending physicians, and housestaff physicians, regarding the benefits and barriers to BIRs.

METHODS

RESULTS

Of the 171 surveys sent, 149 participants completed surveys (response rate 87%). Responses were received from 53/58 nursing staff (91% response), 21/28 attending physicians (75% response), and 75/85 housestaff physicians (88% response). Table 1 describes the participant response demographics.

DISCUSSION

In this study, we sought to compare perceptions of nurses and physicians on the benefits and barriers to BIRs. Nursing staff ranked each benefit higher than physicians, though rank orders of specific benefits were highly correlated. Highest‐ranked benefits related to coordination and communication more than quality or process benefits. Across groups, the highest‐ranked barriers to BIRs were related to time, whereas the lowest‐ranked factors were related to provider and patient discomfort. These results highlight important similarities and differences in perceptions between front‐line providers.

The highest‐ranked benefits were related to improved interprofessional communication and coordination. Combining interprofessional team members during care delivery allows for integrated understanding of daily care plans and clinical issues, and fosters collaboration and a team‐based atmosphere.[1, 20, 26] The lowest‐ranked benefits were related to more tangible measures, including length of stay, timely consultations, and judicious laboratory ordering. This finding contrasts with the limited literature demonstrating increased efficiency in general medicine units practicing IPCC.[16] These rankings may reflect a poor understanding or self‐assessment of outcome measures by healthcare providers, representing a potential focus for educational initiatives. Future investigations using objective assessment methods of outcomes and collaboration will provide a more accurate understanding of these findings.

The highest‐ranked barriers were related to time and systems issues. Several studies of physician‐based bedside rounds have identified systems‐ and time‐related issues as primary limiting barriers.[22, 24] In units without colocalization of patients and providers, finding receptive times for BIRs can be difficult. Although time‐related issues could be addressed by decreasing patient‐provider ratios, these changes require substantial investment in resources. A reasonable degree of improvement in efficiency and coordination is expected following acclimation to BIRs or by addressing modifiable systems factors to increase this activity. Less costly interventions, such as tailoring provider schedules, prescheduling patient rounding times, and geographic colocalization of patients and providers may be more feasible. However, the clinical microsystems within which medicine patients are cared for are often chaotic and disorganized at the infrastructural and cultural levels, which may be less influenced by surface‐level interventions. Such interventions may be ward specific and require customization to individual team needs.

The lowest‐ranked barriers to BIRs were related to provider‐ and patient‐related factors, including comfort level of patients and providers. Prior work on bedside rounds has identified physicians who are apprehensive about performing bedside rounds, but those who experience this activity are more likely to be comfortable with it.[12, 28] Our results from a culture where BIRs occur on nearly two‐thirds of patients suggest provider discomfort is not a predominant barrier.[22, 29] Additionally, educators have raised concerns about patient discomfort with bedside rounds, but nearly all studies evaluating patients' perspectives reveal patient preference for bedside case presentations over activities occurring in alternative locations.[30, 31, 32] Little work has investigated patient preference for BIRs as per our definition; our participants do not believe patients are discomforted by BIRs, building upon evidence in the literature for patient preferences regarding bedside activities.

Nursing staff perceptions of the benefits and culture related to BIRs were more positive than physicians. We hypothesize several reasons for this disparity. First, nursing staff may have more experience with observing and understanding the positive impact of BIRs and therefore are more likely to understand the positive ramifications. Alternatively, nursing staff may be satisfied with active integration into traditional physician‐centric decisions. Additionally, the professional culture and educational foundation of the nursing culture is based upon a patient‐centered approach and therefore may be more aligned with the goals of BIRs. Last, physicians may have competing priorities, favoring productivity and didactic learning rather than interprofessional collaboration. Further investigation is required to understand differences between nurses and physicians, in addition to other providers integral to BIRs (eg, care coordinators, pharmacists). Regardless, during the implementation of interprofessional collaborative care models, our findings suggest initial challenges, and the focus of educational initiatives may necessitate acclimating physician groups to benefits identified by front‐line nursing staff.

There are several limitations to our study. We investigated the perceptions of medicine nurses and physicians in 1 teaching hospital, limiting generalizability to other specialties, other vital professional groups, and nonteaching hospitals. Additionally, BIRs has been a focus of our hospital for several years. Therefore, perceived barriers may differ in BIRs‐nave hospitals. Second, although pilot‐tested for content, the construct validity of the instrument was not rigorously assessed, and the instrument was not designed to measure benefits and barriers not explicitly identified during pilot testing. Last, although surveys were anonymous, the possibility of social desirability bias exists, thereby limiting accuracy.

For over a century, physician‐led rounds have been the preferred modality for point‐of‐care decision making.[10, 15, 32, 33] BIRs address our growing understanding of patient‐centered care. Future efforts should address the quality of collaboration and current hospital and unit structures hindering patient‐centered IPCC and patient outcomes.

Patients presenting for surgery with angiotensin axis blockade (AAB) from therapy with either angiotensin‐converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) experience an increased incidence of perioperative hypotension.[1, 2, 3, 4] Debate continues as to whether this hypotension results in any significant clinical sequelae. Some authors found that the use of an ACEI decreased the incidence of acute kidney injury (AKI),[5] mortality, and septicemia in cardiac and vascular surgical patients.[6] However, others found that in vascular and cardiac surgery there is increased mortality[7] as well as increased incidence of postoperative AKI.[8, 9, 10] A retrospective study of 10,000 coronary artery bypass graft patients found that ACEI was associated with increased inotropic support, AKI, mortality, and new onset atrial fibrillation.[11] In a meta‐analysis of 69,000 cardiothoracic surgery patients, the use of ACEIs/ARBs was associated with an increase in AKI and mortality.[12] AKI has also been demonstrated after lung resection surgery in patients receiving preoperative therapy with an ARB.[13]

Studies on noncardiac general surgery patients demonstrate that the use of AAB results in postinduction hypotension, but they fail to show an increased incidence in postoperative AKI.[14, 15] We propose, however, that major orthopedic surgery patients are a specific surgical cohort, like cardiac, vascular, and lung, who can develop operative hypotension and postoperative AKI when AAB is taken on the morning of surgery. To address this question we performed a retrospective study of 1154 patients undergoing either spinal fusion, total knee arthroplasty (TKA), or total hip arthroplasty (THA) during the 2010 calendar year in our academic medical center. We measured the incidence of postanesthesia induction hypotension, intraoperative hypotension, and postoperative AKI as it relates to the administration of AAB preoperatively.

MATERIALS AND METHODS

This study was a retrospective, observational investigation at a single, large academic hospital. The study design for chart review was approved by the institutional review board prior to data collection. Informed patient consent was not required for this retrospective study.

RESULTS

DISCUSSION

In this retrospective review of 922 patients presenting for major orthopedic surgery, we found that 343(37%) were receiving therapy with either ACEIs or ARBs. In such patients, we demonstrated a higher incidence of postinduction hypotension and an increased incidence of AKI. We further demonstrated that the development of AKI associated with AAB therapy was independent of hypotension occurring either postinduction or intraoperatively after incision.

Postinduction hypotension in patients receiving AAB was demonstrated to be 12.2% compared to 7.7% in patients not receiving this therapy. Hypotension after general anesthesia induction in patients receiving AAB is widely reported,[1, 14, 15] and ranges from 22% to 100%[19, 20] based on varying definitions of what constitutes hypotension. We chose an absolute value of a systolic blood pressure of 80 mm Hg occurring for 5 minutes as constituting significant hypotension.[16] Monk et al. reported an increased one year postnon‐cardiac surgery mortality risk of 1.036 times per minute of intraoperative hypotension, defining hypotension as a systolic blood pressure of <80 mm Hg.[21]

We further demonstrated that AAB therapy resulted in an 8.3% incidence of AKI versus 1.7% in non‐AAB patients (P<0.001). AKI was defined as an increase in serum creatinine of 0.3 mg/dL or a 50% increase in creatinine when pre‐ and postoperative values were compared.[17] A number of other investigators have identified AKI associated with AAB use in patients undergoing cardiac,[6, 11] vascular,[7, 10] and lung[13] surgery. Similarly, in the present study, in orthopedic patients, AAB remained a significant risk factor for developing AKI (OR: 2.68, P=0.034) independent of patient comorbidities and adjunct therapy (Table 2).

ACEIs and ARBs are prescribed to treat HTN, CHF, and improve renal function in diabetic and proteinuric nephropathy.[22] AAB therapy is prescribed for nephropathy because these medications decrease glomerular pressure by selective inhibition of angiotensin II mediated vasoconstriction of the efferent glomerular arteriole.[23] Normally, this is beneficial to patients and is associated with a decrease in serum creatinine concentration. However, during hypotension, when there is decreased renal perfusion, further decreases in intraglomerular pressure may occur, precipitating renal failure.[23] In addition, other factors may contribute to the development of AKI, as AAB has both tissue and systemic effects that extend beyond simply dilating the efferent glomerular arteriole. These include effects on the sympathetic nervous system, oxidative stress, and altering the release and synthesis of vasodilators such as bradykinin, nitric oxide, and prostacyclins[24] as well as effects through the release of aldosterone and arginine‐vasopressin.[25] These other factors might help explain the present study's findings that, when eliminating the effect of both postinduction and intraoperative hypotension, AAB therapy continued to have a statistically significant independent effect (OR: 2.60, 95% CI: 1.046.51, P=0.042) on developing postoperative AKI.

Although we demonstrated an association of AAB therapy with the development of hypotension after induction, we demonstrated only a trend in the development of postincisional, intraoperative hypotension (P=0.078). We defined intraoperative hypotension as a systolic BP <80 mm Hg for 10 minutes occurring after skin incision.[16] One must take into consideration, however, that a significant number of AAB patients were hypotensive during induction and received higher doses of ephedrine and vasopressin during the operative period. These patients may have been rescued from intraoperative hypotension by receiving vasopressor treatment at the outset. We did find that intraoperative hypotension was a significant, independent risk factor for AKI (OR: 2.62, P=0.019).

We looked further at the consequences of developing AKI. Patients who developed AKI had a significant greater mean length of hospital stay (5.76 days vs 3.28 days, P<0.001), which is consistent with other investigators' findings.[25, 26, 27] Although 2‐year mortality was higher at 5.88% in the AKI group compared to 2.38% in the non‐AAB group, this was not statistically significant (P=0.211). Other studies have shown that the development of AKI results in greater mortality.[26, 28]

The American College of Physicians (ACP) recommendations as of 2013 regarding the use of ACEIs and ARBs preoperatively is: uncertain, continue with caution, avoid hypovolemia. Potential for hypotension with induction of anesthesia and increased vasoconstrictor requirements and decreased responsiveness to pressors.[29] The ACP acknowledges that preoperative ACEIs and ARBs have the potential for postinduction hypotension and increased requirements for vasopressors. We have implemented recommendations at our preoperative anesthesia clinic to hold ACEIs and ARBs on the morning of surgery in patients with controlled blood pressure scheduled for spine fusion, and hip and knee arthroplasties. In accordance with ACP guidelines, other antihypertensives such as ‐blockers, calcium channel blockers, nitrates, and sympatholytics should be continued preoperatively and can be used perioperatively.

CONCLUSIONS

Patients who receive preoperative ACEI or ARB therapy and undergo major orthopedic surgery such as spinal fusion, and hip or knee arthroplasties experience a higher incidence of postinduction hypotension and AKI than those not receiving such therapy. The development of AKI in such patients is associated with a significantly prolonged length of hospital stay. Our findings suggest an association between preoperative ACEI/ARB use and moderate kidney injury following major orthopedic surgeries. However, a prospective, multicentered, randomized trial needs to be performed to confirm that withdrawal of AAB therapy preoperatively will decrease the incidence of AKI in patients undergoing major orthopedic procedures under general anesthesia. Future studies also need to determine the optimal time duration of withholding AAB therapy and the consequences on cardiac outcomes.

Patients presenting for surgery with angiotensin axis blockade (AAB) from therapy with either angiotensin‐converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) experience an increased incidence of perioperative hypotension.[1, 2, 3, 4] Debate continues as to whether this hypotension results in any significant clinical sequelae. Some authors found that the use of an ACEI decreased the incidence of acute kidney injury (AKI),[5] mortality, and septicemia in cardiac and vascular surgical patients.[6] However, others found that in vascular and cardiac surgery there is increased mortality[7] as well as increased incidence of postoperative AKI.[8, 9, 10] A retrospective study of 10,000 coronary artery bypass graft patients found that ACEI was associated with increased inotropic support, AKI, mortality, and new onset atrial fibrillation.[11] In a meta‐analysis of 69,000 cardiothoracic surgery patients, the use of ACEIs/ARBs was associated with an increase in AKI and mortality.[12] AKI has also been demonstrated after lung resection surgery in patients receiving preoperative therapy with an ARB.[13]

Studies on noncardiac general surgery patients demonstrate that the use of AAB results in postinduction hypotension, but they fail to show an increased incidence in postoperative AKI.[14, 15] We propose, however, that major orthopedic surgery patients are a specific surgical cohort, like cardiac, vascular, and lung, who can develop operative hypotension and postoperative AKI when AAB is taken on the morning of surgery. To address this question we performed a retrospective study of 1154 patients undergoing either spinal fusion, total knee arthroplasty (TKA), or total hip arthroplasty (THA) during the 2010 calendar year in our academic medical center. We measured the incidence of postanesthesia induction hypotension, intraoperative hypotension, and postoperative AKI as it relates to the administration of AAB preoperatively.

MATERIALS AND METHODS

This study was a retrospective, observational investigation at a single, large academic hospital. The study design for chart review was approved by the institutional review board prior to data collection. Informed patient consent was not required for this retrospective study.

RESULTS

DISCUSSION

In this retrospective review of 922 patients presenting for major orthopedic surgery, we found that 343(37%) were receiving therapy with either ACEIs or ARBs. In such patients, we demonstrated a higher incidence of postinduction hypotension and an increased incidence of AKI. We further demonstrated that the development of AKI associated with AAB therapy was independent of hypotension occurring either postinduction or intraoperatively after incision.

Postinduction hypotension in patients receiving AAB was demonstrated to be 12.2% compared to 7.7% in patients not receiving this therapy. Hypotension after general anesthesia induction in patients receiving AAB is widely reported,[1, 14, 15] and ranges from 22% to 100%[19, 20] based on varying definitions of what constitutes hypotension. We chose an absolute value of a systolic blood pressure of 80 mm Hg occurring for 5 minutes as constituting significant hypotension.[16] Monk et al. reported an increased one year postnon‐cardiac surgery mortality risk of 1.036 times per minute of intraoperative hypotension, defining hypotension as a systolic blood pressure of <80 mm Hg.[21]

We further demonstrated that AAB therapy resulted in an 8.3% incidence of AKI versus 1.7% in non‐AAB patients (P<0.001). AKI was defined as an increase in serum creatinine of 0.3 mg/dL or a 50% increase in creatinine when pre‐ and postoperative values were compared.[17] A number of other investigators have identified AKI associated with AAB use in patients undergoing cardiac,[6, 11] vascular,[7, 10] and lung[13] surgery. Similarly, in the present study, in orthopedic patients, AAB remained a significant risk factor for developing AKI (OR: 2.68, P=0.034) independent of patient comorbidities and adjunct therapy (Table 2).

ACEIs and ARBs are prescribed to treat HTN, CHF, and improve renal function in diabetic and proteinuric nephropathy.[22] AAB therapy is prescribed for nephropathy because these medications decrease glomerular pressure by selective inhibition of angiotensin II mediated vasoconstriction of the efferent glomerular arteriole.[23] Normally, this is beneficial to patients and is associated with a decrease in serum creatinine concentration. However, during hypotension, when there is decreased renal perfusion, further decreases in intraglomerular pressure may occur, precipitating renal failure.[23] In addition, other factors may contribute to the development of AKI, as AAB has both tissue and systemic effects that extend beyond simply dilating the efferent glomerular arteriole. These include effects on the sympathetic nervous system, oxidative stress, and altering the release and synthesis of vasodilators such as bradykinin, nitric oxide, and prostacyclins[24] as well as effects through the release of aldosterone and arginine‐vasopressin.[25] These other factors might help explain the present study's findings that, when eliminating the effect of both postinduction and intraoperative hypotension, AAB therapy continued to have a statistically significant independent effect (OR: 2.60, 95% CI: 1.046.51, P=0.042) on developing postoperative AKI.

Although we demonstrated an association of AAB therapy with the development of hypotension after induction, we demonstrated only a trend in the development of postincisional, intraoperative hypotension (P=0.078). We defined intraoperative hypotension as a systolic BP <80 mm Hg for 10 minutes occurring after skin incision.[16] One must take into consideration, however, that a significant number of AAB patients were hypotensive during induction and received higher doses of ephedrine and vasopressin during the operative period. These patients may have been rescued from intraoperative hypotension by receiving vasopressor treatment at the outset. We did find that intraoperative hypotension was a significant, independent risk factor for AKI (OR: 2.62, P=0.019).

We looked further at the consequences of developing AKI. Patients who developed AKI had a significant greater mean length of hospital stay (5.76 days vs 3.28 days, P<0.001), which is consistent with other investigators' findings.[25, 26, 27] Although 2‐year mortality was higher at 5.88% in the AKI group compared to 2.38% in the non‐AAB group, this was not statistically significant (P=0.211). Other studies have shown that the development of AKI results in greater mortality.[26, 28]

The American College of Physicians (ACP) recommendations as of 2013 regarding the use of ACEIs and ARBs preoperatively is: uncertain, continue with caution, avoid hypovolemia. Potential for hypotension with induction of anesthesia and increased vasoconstrictor requirements and decreased responsiveness to pressors.[29] The ACP acknowledges that preoperative ACEIs and ARBs have the potential for postinduction hypotension and increased requirements for vasopressors. We have implemented recommendations at our preoperative anesthesia clinic to hold ACEIs and ARBs on the morning of surgery in patients with controlled blood pressure scheduled for spine fusion, and hip and knee arthroplasties. In accordance with ACP guidelines, other antihypertensives such as ‐blockers, calcium channel blockers, nitrates, and sympatholytics should be continued preoperatively and can be used perioperatively.

CONCLUSIONS

Patients who receive preoperative ACEI or ARB therapy and undergo major orthopedic surgery such as spinal fusion, and hip or knee arthroplasties experience a higher incidence of postinduction hypotension and AKI than those not receiving such therapy. The development of AKI in such patients is associated with a significantly prolonged length of hospital stay. Our findings suggest an association between preoperative ACEI/ARB use and moderate kidney injury following major orthopedic surgeries. However, a prospective, multicentered, randomized trial needs to be performed to confirm that withdrawal of AAB therapy preoperatively will decrease the incidence of AKI in patients undergoing major orthopedic procedures under general anesthesia. Future studies also need to determine the optimal time duration of withholding AAB therapy and the consequences on cardiac outcomes.

Patients presenting for surgery with angiotensin axis blockade (AAB) from therapy with either angiotensin‐converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) experience an increased incidence of perioperative hypotension.[1, 2, 3, 4] Debate continues as to whether this hypotension results in any significant clinical sequelae. Some authors found that the use of an ACEI decreased the incidence of acute kidney injury (AKI),[5] mortality, and septicemia in cardiac and vascular surgical patients.[6] However, others found that in vascular and cardiac surgery there is increased mortality[7] as well as increased incidence of postoperative AKI.[8, 9, 10] A retrospective study of 10,000 coronary artery bypass graft patients found that ACEI was associated with increased inotropic support, AKI, mortality, and new onset atrial fibrillation.[11] In a meta‐analysis of 69,000 cardiothoracic surgery patients, the use of ACEIs/ARBs was associated with an increase in AKI and mortality.[12] AKI has also been demonstrated after lung resection surgery in patients receiving preoperative therapy with an ARB.[13]

Studies on noncardiac general surgery patients demonstrate that the use of AAB results in postinduction hypotension, but they fail to show an increased incidence in postoperative AKI.[14, 15] We propose, however, that major orthopedic surgery patients are a specific surgical cohort, like cardiac, vascular, and lung, who can develop operative hypotension and postoperative AKI when AAB is taken on the morning of surgery. To address this question we performed a retrospective study of 1154 patients undergoing either spinal fusion, total knee arthroplasty (TKA), or total hip arthroplasty (THA) during the 2010 calendar year in our academic medical center. We measured the incidence of postanesthesia induction hypotension, intraoperative hypotension, and postoperative AKI as it relates to the administration of AAB preoperatively.

MATERIALS AND METHODS

This study was a retrospective, observational investigation at a single, large academic hospital. The study design for chart review was approved by the institutional review board prior to data collection. Informed patient consent was not required for this retrospective study.

RESULTS