Considerations for Integration of Perioperative Electronic Health Records Across Institutions for Research and Quality Improvement: The Approach Taken by the Multicenter Perioperative Outcomes Group

Airway driving pressure is associated with postoperative pulmonary complications after major abdominal surgery: a multicentre retrospective observational cohort study

Background

High airway driving pressure is associated with adverse outcomes in critically ill patients receiving mechanical ventilation, but large multicentre studies investigating airway driving pressure during major surgery are lacking. We hypothesised that increased driving pressure is associated with postoperative pulmonary complications in patients undergoing major abdominal surgery.

Methods

In this preregistered multicentre retrospective observational cohort study, the authors reviewed major abdominal surgical procedures in 11 hospitals from 2004 to 2018. The primary outcome was a composite of postoperative pulmonary complications, defined as postoperative pneumonia, unplanned tracheal intubation, or prolonged mechanical ventilation for more than 48 h. Associations between intraoperative dynamic driving pressure and outcomes, adjusted for patient and procedural factors, were evaluated.

Results

Among 14 218 qualifying cases, 389 (2.7%) experienced postoperative pulmonary complications. After adjustment, the mean dynamic driving pressure was associated with postoperative pulmonary complications (adjusted odds ratio for every 1 cm H₂O increase: 1.04; 95% confidence interval [CI], 1.02-1.06; P<0.001). Neither tidal volume nor PEEP was associated with postoperative pulmonary complications. Increased BMI, shorter height, and female sex were predictors for higher dynamic driving pressure (β=0.35, 95% CI 0.32-0.39, P<0.001; β=-0.01, 95% CI -0.02 to 0.00, P=0.005; and β=0.74, 95% CI 0.63-0.86, P<0.001, respectively).

Conclusions

Dynamic airway driving pressure, but not tidal volume or PEEP, is associated with postoperative pulmonary complications in models controlling for a large number of risk predictors and covariates. Such models are capable of risk prediction applicable to individual patients.

Preoperative clinical diagnostic accuracy of heart failure among patients undergoing major noncardiac surgery: a single-centre prospective observational analysis

Background

Reliable diagnosis of heart failure during preoperative evaluation is important for perioperative management and long-term care. We aimed to quantify preoperative heart failure diagnostic accuracy and explore characteristics of patients with heart failure misdiagnoses.

Methods

We performed an observational cohort study of adults undergoing major noncardiac surgery at an academic hospital between 2015 and 2019. A preoperative clinical diagnosis of heart failure was defined using keywords from the history and clinical examination or administrative documentation. Across stratified subsamples of cases with and without clinically diagnosed heart failure, health records were intensively reviewed by an expert panel to develop an adjudicated heart failure reference standard using diagnostic criteria congruent with consensus guidelines. We calculated agreement among experts, and analysed performance of clinically diagnosed heart failure compared with the adjudicated reference standard.

Results

Across 40 555 major noncardiac procedures, a stratified subsample of 511 patients was reviewed by the expert panel. The prevalence of heart failure was 9.1% based on clinically diagnosed compared with 13.3% (95% confidence interval [CI], 10.3-16.2%) estimated by the expert panel. Overall agreement and inter-rater reliability (kappa) among heart failure experts were 95% and 0.79, respectively. Based upon expert adjudication, heart failure was clinically diagnosed with an accuracy of 92.8% (90.6-95.1%), sensitivity 57.4% (53.1-61.7%), specificity 98.3% (97.1-99.4%), positive predictive value 83.5% (80.3-86.8%), and negative predictive value 93.8% (91.7-95.9%).

Conclusions

Limitations exist to the preoperative clinical diagnosis of heart failure, with nearly half of cases undiagnosed preoperatively. Considering the risks of undiagnosed heart failure, efforts to improve preoperative heart failure diagnoses are warranted.

Oxygen administration during surgery and postoperative organ injury: observational cohort study

OBJECTIVE

To examine whether supraphysiological oxygen administration during surgery is associated with lower or higher postoperative kidney, heart, and lung injury.

DESIGN

Observational cohort study.

SETTING

42 medical centers across the United States participating in the Multicenter Perioperative Outcomes Group data registry.

PARTICIPANTS

Adult patients undergoing surgical procedures ≥120 minutes' duration with general anesthesia and endotracheal intubation who were admitted to hospital after surgery between January 2016 and November 2018.

INTERVENTION

Supraphysiological oxygen administration, defined as the area under the curve of the fraction of inspired oxygen above air (21%) during minutes when the hemoglobin oxygen saturation was greater than 92%.

MAIN OUTCOMES

Primary endpoints were acute kidney injury defined using Kidney Disease Improving Global Outcomes criteria, myocardial injury defined as serum troponin >0.04 ng/mL within 72 hours of surgery, and lung injury defined using international classification of diseases hospital discharge diagnosis codes.

RESULTS

The cohort comprised 350 647 patients with median age 59 years (interquartile range 46-69 years), 180 546 women (51.5%), and median duration of surgery 205 minutes (interquartile range 158-279 minutes). Acute kidney injury was diagnosed in 19 207 of 297 554 patients (6.5%), myocardial injury in 8972 of 320 527 (2.8%), and lung injury in 13 789 of 312 161 (4.4%). The median fraction of inspired oxygen was 54.0% (interquartile range 47.5%-60.0%), and the area under the curve of supraphysiological inspired oxygen was 7951% min (5870-11 107% min), equivalent to an 80% fraction of inspired oxygen throughout a 135 minute procedure, for example. After accounting for baseline covariates and other potential confounding variables, increased oxygen exposure was associated with a higher risk of acute kidney injury, myocardial injury, and lung injury. Patients at the 75th centile for the area under the curve of the fraction of inspired oxygen had 26% greater odds of acute kidney injury (95% confidence interval 22% to 30%), 12% greater odds of myocardial injury (7% to 17%), and 14% greater odds of lung injury (12% to 16%) compared with patients at the 25th centile. Sensitivity analyses evaluating alternative definitions of the exposure, restricting the cohort, and conducting an instrumental variable analysis confirmed these observations.

CONCLUSIONS

Increased supraphysiological oxygen administration during surgery was associated with a higher incidence of kidney, myocardial, and lung injury. Residual confounding of these associations cannot be excluded.

TRIAL REGISTRATION

Open Science Framework osf.io/cfd2m.

Time-of-day dependent effects of midazolam administration on myocardial injury in non-cardiac surgery

Background

Animal studies have shown that midazolam can increase vulnerability to cardiac ischemia, potentially via circadian-mediated mechanisms. We hypothesized that perioperative midazolam administration is associated with an increased incidence of myocardial injury in patients undergoing non-cardiac surgery (MINS) and that circadian biology may underlie this relationship.

Methods

We analyzed intraoperative data from the Multicenter Perioperative Outcomes Group for the occurrence of MINS across 50 institutions from 2014 to 2019. The primary outcome was the occurrence of MINS. MINS was defined as having at least one troponin-I lab value ≥0.03 ng/ml from anesthesia start to 72 h after anesthesia end. To account for bias, propensity scores and inverse probability of treatment weighting were applied.

Results

A total of 1,773,118 cases were available for analysis. Of these subjects, 951,345 (53.7%) received midazolam perioperatively, and 16,404 (0.93%) met criteria for perioperative MINS. There was no association between perioperative midazolam administration and risk of MINS in the study population as a whole (odds ratio (OR) 0.98, confidence interval (CI) [0.94, 1.01]). However, we found a strong association between midazolam administration and risk of MINS when surgery occurred overnight (OR 3.52, CI [3.10, 4.00]) or when surgery occurred in ASA 1 or 2 patients (OR 1.25, CI [1.13, 1.39]).

Conclusion

Perioperative midazolam administration may not pose a significant risk for MINS occurrence. However, midazolam administration at night and in healthier patients could increase MINS, which warrants further clinical investigation with an emphasis on circadian biology.

Carbon Dioxide, Blood Pressure, and Perioperative Stroke: A Retrospective Case-Control Study

BACKGROUND

The relationship between intraoperative physiology and postoperative stroke is incompletely understood. Preliminary data suggest that either hypo- or hypercapnia coupled with reduced cerebrovascular inflow (e.g., due to hypotension) can lead to ischemia. This study tested the hypothesis that the combination of intraoperative hypotension and either hypo- or hypercarbia is associated with postoperative ischemic stroke.

METHODS

We conducted a retrospective, case-control study via the Multicenter Perioperative Outcomes Group. Noncardiac, nonintracranial, and nonmajor vascular surgical cases (18 yr or older) were extracted from five major academic centers between January 2004 and December 2015. Ischemic stroke cases were identified via manual chart review and matched to controls (1:4). Time and reduction below key mean arterial blood pressure thresholds (less than 55 mmHg, less than 60 mmHg, less than 65 mmHg) and outside of specific end-tidal carbon dioxide thresholds (30 mmHg or less, 35 mmHg or less, 45 mmHg or greater) were calculated based on total area under the curve. The association between stroke and total area under the curve values was then tested while adjusting for relevant confounders.

RESULTS

In total, 1,244,881 cases were analyzed. Among the cases that screened positive for stroke (n = 1,702), 126 were confirmed and successfully matched with 500 corresponding controls. Total area under the curve was significantly associated with stroke for all thresholds tested, with the strongest combination observed with mean arterial pressure less than 55 mmHg (adjusted odds ratio per 10 mmHg-min, 1.17 [95% CI, 1.10 to 1.23], P < 0.0001) and end-tidal carbon dioxide 45 mmHg or greater (adjusted odds ratio per 10 mmHg-min, 1.11 [95% CI, 1.10 to 1.11], P < 0.0001). There was no interaction effect observed between blood pressure and carbon dioxide.

CONCLUSIONS

Intraoperative hypotension and carbon dioxide dysregulation may each independently increase postoperative stroke risk.

EDITOR’S PERSPECTIVE

Association of propofol induction dose and severe pre-incision hypotension among surgical patients over age 65

STUDY OBJECTIVE

We aimed to study the association between propofol induction dose (mg/kg) and pre-incision severe hypotension (Mean Arterial Pressure (MAP) ≤ 55 mmHg) among patients ≥65 years of age.

DESIGN

Retrospective Observational.

SETTING

40 centers participating in the Multicenter Perioperative Outcomes Group consortium.

PATIENTS

Patients ≥65 years of age undergoing non-cardiac, non-vascular surgery who received propofol for general anesthetic induction prior to endotracheal intubation between January 2014 and December 2018.

INTERVENTIONS

None.

MEASUREMENTS

The primary exposure was total propofol induction dose in mg/kg, and the primary outcome was occurrence of severe hypotension (MAP≤55 mmHg) prior to surgical incision, stratified by non-invasive vs. invasive blood pressure monitoring type.

MAIN RESULTS

Among 320,585 total patients, 22.6% experienced the outcome of pre-incision severe hypotension (MAP≤55 mmHg). When stratified by blood pressure monitoring type, 20.7% with non-invasive blood pressure measurements, and 35.0% with invasive blood pressure measurements had the outcome. After controlling for a variety of patient and procedural factors, there was a significant independent association between propofol induction dose and pre-incision hypotension (Non-invasive blood pressure cohort odds ratio (OR) 1.10; 95% confidence interval (CI) 1.07 to 1.13; p < 0.001; and Invasive blood pressure cohort OR 1.15; 95%CI 1.10 to 1.21; adjusted p < 0.001). The association was robust to alternative definitions of the outcome, including less severe hypotension (MAP≤65 mmHg) and blood pressure drop from baseline as a continuous measure. Although no threshold safe induction dose was identified at which hypotension was avoided, an analysis of propofol dose greater or less than 1.5 mg/kg (i.e. the maximum FDA-defined typical induction dose) demonstrated that doses in excess of the FDAs threshold were positively associated with odds of severe hypotension (Non-invasive cohort: OR 1.05; 95% CI 1.02 to 1.08; p < 0.001; Invasive cohort: OR 1.11; 95%CI 1.05 to 1.17; adjusted p < 0.001).

CONCLUSIONS

In a multicenter cohort of geriatric surgical patients receiving propofol for general anesthetic induction and endotracheal intubation, severe pre-incision hypotension (MAP ≤55 mmHg) that has previously been associated with postoperative morbidity was common. The dose of propofol used was significantly associated with increased odds of this outcome after controlling for a number of clinically relevant factors. Future studies that are designed to test different approaches to anesthesia induction for reducing severe post induction pre-incision hypotension are warranted.

Fluids, vasopressors, and acute kidney injury after major abdominal surgery between 2015 and 2019: a multicentre retrospective analysis

BACKGROUND

Practice patterns related to intraoperative fluid administration and vasopressor use have potentially evolved over recent years. However, the extent of such changes and their association with perioperative outcomes, such as the development of acute kidney injury (AKI), have not been studied.

METHODS

We performed a retrospective analysis of major abdominal surgeries in adults across 26 US hospitals between 2015 and 2019. The primary outcome was AKI as defined by the Kidney Disease Improving Global Outcomes definition (KDIGO) using only serum creatinine criteria. Univariable linear predictive additive models were used to describe the dose-dependent risk of AKI given fluid administration or vasopressor use.

RESULTS

Over the study period, we observed a decrease in the volume of crystalloid administered, a decrease in the proportion of patients receiving more than 10 ml kg^-1 h^-1 of crystalloid, an increase in the amount of norepinephrine equivalents administered, and a decreased duration of hypotension. The incidence of AKI increased between 2016 and 2019. An increase of crystalloid administration from 1 to 10 ml kg^-1 h^-1 was associated with a 58% decreased risk of AKI.

CONCLUSIONS

Despite decreased duration of hypotension during the study period, decreased fluid administration and increased vasopressor use were associated with increased incidence of AKI. Crystalloid administration below 10 ml kg^-1 h^-1 was associated with an increased risk of AKI. Although no causality can be concluded, these data suggest that prevention and treatment of hypotension during abdominal surgery with liberal use of vasopressors at the expense of fluid administration is associated with an increased risk of postoperative AKI.

Translating evidence into practice: still a way to go

Chiu and colleagues report a retrospective analysis describing the 5-yr trend in both intraoperative fluid and vasopressor administration in 32 250 patients undergoing elective abdominal surgery within the Multicenter Perioperative Outcomes Group (MPOG) database from 2015 to 2019, and exploring the association between these two factors and acute kidney injury. Modelling predicted the lowest risk for acute kidney injury when the administered crystalloid volume was 15-20 ml kg^-1 h^-1, and an 80% increase in risk for acute kidney injury as intraoperative vasopressor use increased from 0 to 0.04 μg kg^-1 min^-1 of norepinephrine equivalents. Although these results are consistent with those of a large, randomised trial (REstrictive Versus LIbEral Fluid Therapy in Major Abdominal Surgery [RELIEF]) published in 2018, the mean intraoperative volume of crystalloid administered in the current study declined monotonically through every year included, from 6.4 ml kg^-1 h^-1 in 2015 to 5.5 ml kg^-1 h^-1 in 2019. These new findings support the broad generalisability of the RELIEF trial; highlight the complexity of the relationship between intravenous crystalloid volume infused, arterial pressure, and acute kidney injury; and demonstrate the ongoing challenge of translating high-quality evidence into clinical practice.

Optimizing the Design and Analysis of Future AKI Trials

AKI is a complex clinical syndrome associated with an increased risk of morbidity and mortality, particularly in critically ill and perioperative patient populations. Most AKI clinical trials have been inconclusive, failing to detect clinically important treatment effects at predetermined statistical thresholds. Heterogeneity in the pathobiology, etiology, presentation, and clinical course of AKI remains a key challenge in successfully testing new approaches for AKI prevention and treatment. This article, derived from the "AKI" session of the "Kidney Disease Clinical Trialists" virtual workshop held in October 2021, reviews barriers to and strategies for improving the design and implementation of clinical trials in patients with, or at risk of, developing AKI. The novel approaches to trial design included in this review span adaptive trial designs that increase the knowledge gained from each trial participant; pragmatic trial designs that allow for the efficient enrollment of sufficiently large numbers of patients to detect small, but clinically significant, treatment effects; and platform trial designs that use one trial infrastructure to answer multiple clinical questions simultaneously. This review also covers novel approaches to clinical trial analysis, such as Bayesian analysis and assessing heterogeneity in the response to therapies among trial participants. We also propose a road map and actionable recommendations to facilitate the adoption of the reviewed approaches. We hope that the resulting road map will help guide future clinical trial planning, maximize learning from AKI trials, and reduce the risk of missing important signals of benefit (or harm) from trial interventions.

A Century of Technology in Anesthesia & Analgesia

Technological innovation has been closely intertwined with the growth of modern anesthesiology as a medical and scientific discipline. Anesthesia & Analgesia, the longest-running physician anesthesiology journal in the world, has documented key technological developments in the specialty over the past 100 years. What began as a focus on the fundamental tools needed for effective anesthetic delivery has evolved over the century into an increasing emphasis on automation, portability, and machine intelligence to improve the quality, safety, and efficiency of patient care.

Association of Anesthesiologist Staffing Ratio With Surgical Patient Morbidity and Mortality

Importance

Recent studies have investigated the effect of overlapping surgeon responsibilities or nurse to patient staffing ratios on patient outcomes, but the association of overlapping anesthesiologist responsibilities with patient outcomes remains unexplored to our knowledge.

Objective

To examine the association between different levels of anesthesiologist staffing ratios and surgical patient morbidity and mortality.

Design, Setting, and Participants

A retrospective, matched cohort study consisting of major noncardiac inpatient surgical procedures performed from January 1, 2010, to October 31, 2017, was conducted in 23 US academic and private hospitals. A total of 866 453 adult patients (aged ≥18 years) undergoing major inpatient surgery within the Multicenter Perioperative Outcomes Group electronic health record registry were included. Anesthesiologist sign-in and sign-out times were used to calculate a continuous time-weighted average staffing ratio variable for each operation. Propensity score-matching methods were applied to create balanced sample groups with respect to patient-, operative-, and hospital-level confounders and resulted in 4 groups based on anesthesiologist staffing ratio. Groups consisted of patients receiving care from an anesthesiologist covering 1 operation (group 1), more than 1 to no more than 2 overlapping operations (group 1-2), more than 2 to no more than 3 overlapping operations (group 2-3), and more than 3 to no more than 4 overlapping operations (group 3-4). Data analysis was performed from October 2019 to October 2021.

Exposure

Undergoing a major inpatient surgical operation that involved an anesthesiologist providing care for up to 4 overlapping operations.

Main Outcomes and Measures

The primary composite outcome was 30-day mortality and 6 major surgical morbidities (cardiac, respiratory, gastrointestinal, urinary, bleeding, and infectious complications) derived from International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision discharge diagnosis codes.

Results

In all, 578 815 adult patients (mean [SD] age, 55.7 [16.2] years; 55.1% female) were analyzed. After matching operations according to anesthesiologist staffing ratio, 48 555 patients were in group 1; 247 057, group 1-2; 216 193, group 2-3; and 67 010, group 3-4. Increasing anesthesiologist coverage responsibilities was associated with an increase in risk-adjusted surgical patient morbidity and mortality. Compared with patients in group 1-2, those in group 2-3 had a 4% relative increase in risk-adjusted mortality and morbidity (5.06% vs 5.25%; adjusted odds ratio [AOR], 1.04; 95% CI, 1.01-1.08; P = .02) and those in group 3-4 had a 14% increase in risk-adjusted mortality and morbidity (5.06% vs 5.75%; AOR, 1.15; 95% CI, 1.09-1.21; P < .001).

Conclusions and Relevance

This study's findings suggest that increasing overlapping coverage by anesthesiologists is associated with increased surgical patient morbidity and mortality. Therefore, the potential effects of staffing ratios in perioperative team models should be considered in clinical coverage efforts.

Intraoperative risk factors of acute kidney injury after liver transplantation

Acute kidney injury (AKI) is one of the most common complications of liver transplantation (LT). We examined the impact of intraoperative management on risk for AKI following LT. In this retrospective observational study, we linked data from the electronic health record with standardized transplant outcomes. Our primary outcome was stage 2 or 3 AKI as defined by Kidney Disease Improving Global Outcomes guidelines within the first 7 days of LT. We used logistic regression models to test the hypothesis that the addition of intraoperative variables, including inotropic/vasopressor administration, transfusion requirements, and hemodynamic markers improves our ability to predict AKI following LT. We also examined the impact of postoperative AKI on mortality. Of the 598 adult primary LT recipients included in our study, 43% (n = 255) were diagnosed with AKI within the first 7 postoperative days. Several preoperative and intraoperative variables including (1) electrolyte/acid-base balance disorder (International Classification of Diseases, Ninth Revision codes 253.6 or 276.x and International Classification of Diseases, Tenth Revision codes E22.2 or E87.x, where x is any digit; adjusted odds ratio [aOR], 1.917, 95% confidence interval [CI], 1.280-2.869; p = 0.002); (2) preoperative anemia (aOR, 2.612; 95% CI, 1.405-4.854; p = 0.002); (3) low serum albumin (aOR, 0.576; 95% CI, 0.410-0.808; p = 0.001), increased potassium value during reperfusion (aOR, 1.513; 95% CI, 1.103-2.077; p = 0.01), and lactate during reperfusion (aOR, 1.081; 95% CI, 1.003-1.166; p = 0.04) were associated with posttransplant AKI. New dialysis requirement within the first 7 days postoperatively predicted the posttransplant mortality. Our study identified significant association between several potentially modifiable variables with posttransplant AKI. The addition of intraoperative data did not improve overall model discrimination.

Assessment of Perioperative Outcomes Among Surgeons Who Operated the Night Before

IMPORTANCE

The association between physician fatigue and patient outcomes is important to understand but has been difficult to examine given methodological and data limitations. Surgeons frequently perform urgent procedures overnight and perform additional procedures the following day, which could adversely affect outcomes for those daytime operations.

OBJECTIVE

To examine the association between an attending surgeon operating overnight and outcomes for operations performed by that surgeon the next day.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study, a retrospective analysis of a large multicenter registry of surgical procedures was done using a within-surgeon analysis to address confounding, with data from 20 high-volume US institutions. This study included 498 234 patients who underwent a surgical procedure during the day (between 7 am and 5 pm) between January 1, 2010, and August 30, 2020.

EXPOSURES

Whether the attending surgeon for the current day's procedures operated between 11 pm and 7 am the previous night. Two exposure measures were examined: whether the surgeon operated at all the previous night and the number of hours spent operating the previous night (including having performed no work at all).

MAIN OUTCOMES AND MEASURES

The primary composite outcome was in-hospital death or major complication (sepsis, pneumonia, myocardial infarction, thromboembolic event, or stroke). Secondary outcomes included operation length and individual outcomes of death, major complications, and minor complications (surgical site infection or urinary tract infection).

RESULTS

Among 498 234 daytime operations performed by 1131 surgeons, 13 098 (2.6%) involved an attending surgeon who operated the night before. The mean (SD) age of the patients who underwent an operation was 55.3 (16.4) years, and 264 740 (53.1%) were female. After adjusting for operation type, surgeon fixed effects, and observable patient characteristics (ie, age and comorbidities), the adjusted incidence of in-hospital death or major complications was 5.89% (95% CI, 5.41%-6.36%) among daytime operations when the attending surgeon operated the night before compared with 5.87% (95% CI, 5.85%-5.89%) among daytime operations when the same surgeon did not (absolute adjusted difference, 0.02%; 95% CI, -0.47% to 0.51%; P = .93). No significant associations were found between overnight work and secondary outcomes except for operation length. Operating the previous night was associated with a statistically significant decrease in length of daytime operations (adjusted length, 112.7 vs 117.4 minutes; adjusted difference, -4.7 minutes; 95% CI, -8.7 to -0.8, P = .02), although this difference is unlikely to be meaningful.

CONCLUSIONS AND RELEVANCE

The findings of this cross-sectional study suggest that operating overnight was not associated with worse outcomes for operations performed by surgeons the subsequent day. These results provide reassurance concerning the practice of having attending surgeons take overnight call and still perform operations the following morning.

Health equity research in obstetric anesthesia

PURPOSE OF REVIEW

Health equity is an important priority for obstetric anesthesia, but describing disparities in perinatal care process and health outcome is insufficient to achieve this goal. Conceptualizing and framing disparity is a prerequisite to pose meaningful research questions. We emphasize the need to hypothesize and test which mechanisms and drivers are instrumental for disparities in perinatal processes and outcomes, in order to target, test and refine effective countermeasures.

RECENT FINDINGS

With an emphasis on methodology and measurement, we sketch how health systems and disparity research may advance maternal health equity by narrating, conceptualizing, and investigating social determinants of health as key drivers of perinatal disparity, by identifying the granular mechanism of this disparity, by making the economic case to address them, and by testing specific interventions to advance obstetric health equity.

SUMMARY

Measuring social determinants of health and meaningful perinatal processes and outcomes precisely and accurately at the individual, family, community/neighborhood level is a prerequisite for healthcare disparity research. A focus on elucidating the precise mechanism driving disparity in processes of obstetric care would inform a more rational effort to promote health equity. Implementation scientists should rigorously investigate in prospective trials, which countermeasures are most efficient and effective in mitigating perinatal outcome disparities.

A Scalable Service to Improve Health Care Quality Through Precision Audit and Feedback: Proposal for a Randomized Controlled Trial

BACKGROUND

Health care delivery organizations lack evidence-based strategies for using quality measurement data to improve performance. Audit and feedback (A&F), the delivery of clinical performance summaries to providers, demonstrates the potential for large effects on clinical practice but is currently implemented as a blunt one size fits most intervention. Each provider in a care setting typically receives a performance summary of identical metrics in a common format despite the growing recognition that precisionizing interventions hold significant promise in improving their impact. A precision approach to A&F prioritizes the display of information in a single metric that, for each recipient, carries the highest value for performance improvement, such as when the metric's level drops below a peer benchmark or minimum standard for the first time, thereby revealing an actionable performance gap. Furthermore, precision A&F uses an optimal message format (including framing and visual displays) based on what is known about the recipient and the intended gist meaning being communicated to improve message interpretation while reducing the cognitive processing burden. Well-established psychological principles, frameworks, and theories form a feedback intervention knowledge base to achieve precision A&F. From an informatics perspective, precision A&F requires a knowledge-based system that enables mass customization by representing knowledge configurable at the group and individual levels.

OBJECTIVE

This study aims to implement and evaluate a demonstration system for precision A&F in anesthesia care and to assess the effect of precision feedback emails on care quality and outcomes in a national quality improvement consortium.

METHODS

We propose to achieve our aims by conducting 3 studies: a requirements analysis and preferences elicitation study using human-centered design and conjoint analysis methods, a software service development and implementation study, and a cluster randomized controlled trial of a precision A&F service with a concurrent process evaluation. This study will be conducted with the Multicenter Perioperative Outcomes Group, a national anesthesia quality improvement consortium with >60 member hospitals in >20 US states. This study will extend the Multicenter Perioperative Outcomes Group quality improvement infrastructure by using existing data and performance measurement processes.

RESULTS

The proposal was funded in September 2021 with a 4-year timeline. Data collection for Aim 1 began in March 2022. We plan for a 24-month trial timeline, with the intervention period of the trial beginning in March 2024.

CONCLUSIONS

The proposed aims will collectively demonstrate a precision feedback service developed using an open-source technical infrastructure for computable knowledge management. By implementing and evaluating a demonstration system for precision feedback, we create the potential to observe the conditions under which feedback interventions are effective.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/34990.

Multi-Site Observational Study to Assess Biomarkers for Susceptibility or Resilience to Chronic Pain: The Acute to Chronic Pain Signatures (A2CPS) Study Protocol

Chronic pain has become a global health problem contributing to years lived with disability and reduced quality of life. Advances in the clinical management of chronic pain have been limited due to incomplete understanding of the multiple risk factors and molecular mechanisms that contribute to the development of chronic pain. The Acute to Chronic Pain Signatures (A2CPS) Program aims to characterize the predictive nature of biomarkers (brain imaging, high-throughput molecular screening techniques, or "omics," quantitative sensory testing, patient-reported outcome assessments and functional assessments) to identify individuals who will develop chronic pain following surgical intervention. The A2CPS is a multisite observational study investigating biomarkers and collective biosignatures (a combination of several individual biomarkers) that predict susceptibility or resilience to the development of chronic pain following knee arthroplasty and thoracic surgery. This manuscript provides an overview of data collection methods and procedures designed to standardize data collection across multiple clinical sites and institutions. Pain-related biomarkers are evaluated before surgery and up to 3 months after surgery for use as predictors of patient reported outcomes 6 months after surgery. The dataset from this prospective observational study will be available for researchers internal and external to the A2CPS Consortium to advance understanding of the transition from acute to chronic postsurgical pain.

Frequency and Risk Factors for Difficult Intubation in Women Undergoing General Anesthesia for Cesarean Delivery: A Multicenter Retrospective Cohort Analysis

BACKGROUND

Estimates for the incidence of difficult intubation in the obstetric population vary widely, though prior studies reporting rates of difficult intubation in obstetrics are older and limited by smaller samples. The goals of this study were to provide a contemporary estimate of the frequency of difficult and failed intubation in women undergoing general anesthesia for cesarean delivery and to elucidate risk factors for difficult intubation in women undergoing general anesthesia for cesarean delivery.

METHODS

This is a multicenter, retrospective cohort study utilizing the Multicenter Perioperative Outcomes Group database. The study population included women aged 15-44 undergoing general anesthesia for cesarean delivery between 2004 and 2019 at one of 45 medical centers. Co-primary outcomes included the frequencies of difficult and failed intubation. Difficult intubation was defined as Cormack-Lehane view ≥3, intubation attempts ≥3, rescue fiberoptic intubation, rescue supraglottic airway, or surgical airway. Failed intubation was defined as any attempt at intubation without successful endotracheal tube placement. Rates of difficult and failed intubation were assessed. Several patient demographic, anatomical, and obstetric factors were evaluated for potential associations with difficult intubation.

RESULTS

We identified 14,748 cases of cesarean delivery performed under general anesthesia. There were 295 cases of difficult intubation, with a frequency of 1:49 (95% CI: 1:55, 1:44) (n=14,531). There were 18 cases of failed intubation, with a frequency of 1:808 (95% CI: 1:1,276, 1:511) (n=14,537). Factors with the highest point estimates for the odds of difficult intubation included increased body mass index, Mallampati score III or IV, small hyoid to mentum distance, limited jaw protrusion, limited mouth opening, and cervical spine limitations.

CONCLUSIONS

In this large, multi-center, contemporary study of over 14,000 general anesthetics for cesarean delivery, we observed an overall risk of difficult intubation of 1:49 and a risk of failed intubation of 1:808. Most risk factors for difficult intubation were non-obstetric in nature. These data demonstrate that difficult intubation in obstetrics remains an ongoing concern.

Towards a national perioperative outcomes registry: A survey of perioperative electronic medical record utilisation to support quality assurance and research at Australian and New Zealand College of Anaesthetists Clinical Trials Network hospitals in Australia

In Australia, 2.7 million surgical procedures are performed annually. Historically, a lack of perioperative data standardisation and infrastructure has limited pooling of routinely collected data across institutions. We surveyed Australian and New Zealand College of Anaesthetists (ANZCA) Clinical Trials Network hospitals to investigate current and potential uses of perioperative electronic medical record data for research and quality assurance.A targeted survey was sent to 131 ANZCA Clinical Trials Network-affiliated hospitals in Australia. The primary aim was to map current electronic data collection methods and data utilisation in six domains of the perioperative pathway.The survey response rate was 32%. Electronic data recording in the six domains ranged from 19% to 85%. Where electronic data exist, the ability of anaesthesiology departments to export them for analysis ranged from 27% to 100%. The proportion of departments with access to data exports that are regularly exporting the data for quality assurance or research ranged from 13% to 58%.The existence of a perioperative electronic medical record does not automatically lead to the data being used to measure and improve clinical outcomes. The first barrier is clinician access to data exports. Even when this barrier is overcome, a large gap remains between the proportion of departments able to access data exports and those using the data regularly to inform and improve clinical practice. We believe this gap can be addressed by establishing a national perioperative outcomes registry to lead high-quality multicentre registry research and quality assurance in Australia.

Multicentre analysis of practice patterns regarding benzodiazepine use in cardiac surgery

BACKGROUND

There is controversy regarding optimal use of benzodiazepines during cardiac surgery, and it is unknown whether and to what extent there is variation in practice. We sought to describe benzodiazepine use and sources of variation during cardiac surgeries across patients, clinicians, and institutions.

METHODS

We conducted an analysis of adult cardiac surgeries across a multicentre consortium of USA academic and private hospitals from 2014 to 2019. The primary outcome was administration of a benzodiazepine from 2 h before anaesthesia start until anaesthesia end. Institutional-, clinician-, and patient-level variables were analysed via multilevel mixed-effects models.

RESULTS

Of 65 508 patients cared for by 825 anaesthesiology attending clinicians (consultants) at 33 institutions, 58 004 patients (88.5%) received benzodiazepines with a median midazolam-equivalent dose of 4.0 mg (inter-quartile range [IQR], 2.0-6.0 mg). Variation in benzodiazepine dosage administration was 54.7% attributable to institution, 14.7% to primary attending anaesthesiology clinician, and 30.5% to patient factors. The adjusted median odds ratio for two similar patients receiving a benzodiazepine was 2.68 between two randomly selected clinicians and 4.19 between two randomly selected institutions. Factors strongly associated (adjusted odds ratio, <0.75, or >1.25) with significantly decreased likelihoods of benzodiazepine administration included older age (>80 vs ≤50 yr; adjusted odds ratio=0.04; 95% CI, 0.04-0.05), university affiliation (0.08, 0.02-0.35), recent year of surgery (0.42, 0.37-0.49), and low clinician case volume (0.44, 0.25-0.75). Factors strongly associated with significantly increased likelihoods of benzodiazepine administration included cardiopulmonary bypass (2.26, 1.99-2.55), and drug use history (1.29, 1.02-1.65).

CONCLUSIONS

Two-thirds of the variation in benzodiazepine administration during cardiac surgery are associated with institutions and attending anaesthesiology clinicians (consultants). These data, showing wide variations in administration, suggest that rigorous research is needed to guide evidence-based and patient-centred benzodiazepine administration.

Adherence to Guidelines for the Administration of Intraoperative Antibiotics in a Nationwide US Sample

IMPORTANCE

Despite widespread adherence to Surgical Care Improvement Project antibiotic measures, prevention of surgical site infections (SSIs) remains a clinical challenge. Several components of perioperative antibiotic prophylaxis guidelines are incompletely monitored and reported within the Surgical Care Improvement Project program.

OBJECTIVES

To describe adherence to each component of perioperative antibiotic prophylaxis guidelines in regard to procedure-specific antibiotic choice, weight-adjusted dosing, and timing of first and subsequent administrations in a nationwide, multicenter cohort of patients undergoing noncardiac surgery.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included adult patients undergoing general, urological, orthopedic, and gynecological surgical procedures involving skin incision between January 1, 2014, and December 31, 2018, across 31 academic and community hospitals identified within the Multicenter Perioperative Outcomes Group registry. Data were analyzed between April 2 and April 21, 2021.

MAIN OUTCOMES AND MEASURES

The primary end point was overall adherence to Infectious Diseases Society of America guidelines, including (1) appropriateness of antibiotic choice, (2) weight-based dose adjustment, (3) timing of administration with respect to surgical incision, and (4) timing of redosing when indicated. Data were analyzed using mixed-effects regression to investigate patient, clinician, and institutional factors associated with guideline adherence.

RESULTS

In the final cohort of 414 851 encounters across 31 institutions, 51.8% of patients were women, the mean (SD) age was 57.5 (15.7) years, 1.2% of patients were of Hispanic ethnicity, and 10.2% were Black. In this cohort, 148 804 encounters (35.9%) did not adhere to guidelines: 19.7% for antibiotic choice, 17.1% for weight-adjusted dosing, 0.6% for timing of first dose, and 26.8% for redosing. In adjusted analyses, overall nonadherence was associated with emergency surgery (odds ratio [OR], 1.35; 95% CI, 1.29-1.41; P < .001), surgery requiring blood transfusions (OR, 1.30; 95% CI, 1.25-1.36; P < .001), off-hours procedures (OR, 1.08; 95% CI, 1.04-1.13; P < .001), and procedures staffed by a certified registered nurse anesthetist (OR, 1.14; 95% CI, 1.11-1.17; P < .001). Overall adherence to guidelines for antibiotic administration improved over the study period from 53.1% (95% CI, 52.7%-53.5%) in 2014 to 70.2% (95% CI, 69.8%-70.6%) in 2018 (P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study, although adherence to perioperative antibiotic administration guidelines improved over the study period, more than one-third of surgical encounters remained discordant with Infectious Diseases Society of America recommendations. Future quality improvement efforts targeting gaps in practice in relation to guidelines may lead to improved adherence and possibly decreased SSIs.

Leveraging the Tracking Operations and Outcomes for Plastic Surgeons Database for Plastic Surgery Research: A "How-To" Guide

SUMMARY

The Plastic Surgeries Registry Network supported by the American Society of Plastic Surgeons (ASPS) and the Plastic Surgery Foundation offers a variety of options for procedural data and outcomes assessment and research. The Tracking Operations and Outcomes for Plastic Surgeons (TOPS) database is a registry created for and used by active members of ASPS to monitor all types of procedural outcomes. It functions as a way for individual or group practices to follow surgical outcomes and constitutes a huge research registry available to ASPS members to access for registry-based projects. The TOPS registry was launched in 2002 and has undergone several iterations and improvements over the years and now includes more than 1 million procedure records. Although ASPS member surgeons have proven valuable assets in contributing their data to the TOPS registry, fewer have leveraged the database for registry-based research. This article overviews the authors' experience using the TOPS registry for a database research project to demonstrate the process, usefulness, and accessibility of TOPS data for ASPS member surgeons to conduct registry-based research. This article pairs with the report of the authors' TOPS registry investigation related to 30-day adverse events associated with incision location for augmentation mammaplasty.

Variation in propofol induction doses administered to surgical patients over age 65

BACKGROUND/OBJECTIVES

Advanced age is associated with increased susceptibility to acute adverse effects of propofol. The present study aimed to describe patterns of propofol dosing for induction of general anesthesia before endotracheal intubation in a nationwide sample of older adults presenting for surgery.

DESIGN

Retrospective observational study using the Multicenter Perioperative Outcomes Group data set.

SETTING

Thirty-six institutions across the United States.

PARTICIPANTS

A total of 350,766 patients aged over 65 years who received propofol for general anesthetic induction and endotracheal intubation between 2014 and 2018.

INTERVENTION

None.

MEASUREMENTS

Total induction bolus dose of propofol administered.

RESULTS

The mean (SD) weight-adjusted propofol dose was 1.7 (0.6) mg/kg. The mean prevalent propofol induction dose exceeded the upper bound of what has been described as the typical geriatric dose requirement across every age category examined. The percent of patients receiving propofol induction doses above the described typical geriatric range was 64.8% (95% CI 64.6-65.0), varying from 73.8% among patients aged 65-69 to 45.8% among patients aged 80 and older.

CONCLUSION

The present study of a large multicenter cohort demonstrates that prevalent propofol dosing commonly falls above the published typically required dose range for patients aged ≥65 in nationwide anesthetic practice. Widespread variability in induction dose administration remains incompletely explained by known patient variables. The nature and clinical consequences of these unexplained dosing decisions remain important topics for further study. Observed discordance between expected and actual induction dosing raises the question of whether there should be reconsideration of widespread provider practice or, alternatively, whether what is published as the typical propofol induction dose range should be revisited.

Practice Patterns and Variability in Intraoperative Opioid Utilization: A Report From the Multicenter Perioperative Outcomes Group

BACKGROUND

Opioids remain the primary mode of analgesia intraoperatively. There are limited data on how patient, procedural, and institutional characteristics influence intraoperative opioid administration. The aim of this retrospective, longitudinal study from 2012 to 2016 was to assess how intraoperative opioid dosing varies by patient and clinical care factors and across multiple institutions over time.

METHODS

Demographic, surgical procedural, anesthetic technique, and intraoperative analgesia data as putative variables of intraoperative opioid utilization were collected from 10 institutions. Log parenteral morphine equivalents (PME) was modeled in a multivariable linear regression model as a function of 15 covariates: 3 continuous covariates (age, anesthesia duration, year) and 12 factor covariates (peripheral block, neuraxial block, general anesthesia, emergency status, race, sex, remifentanil infusion, major surgery, American Society of Anesthesiologists [ASA] physical status, non-opioid analgesic count, Multicenter Perioperative Outcomes Group [MPOG] institution, surgery category). One interaction (year by MPOG institution) was included in the model. The regression model adjusted simultaneously for all included variables. Comparison of levels within a factor were reported as a ratio of medians with 95% credible intervals (CrI).

RESULTS

A total of 1,104,324 cases between January 2012 and December 2016 were analyzed. The median (interquartile range) PME and standardized by weight PME per case for the study period were 15 (10-28) mg and 200 (111-347) μg/kg, respectively. As estimated in the multivariable model, there was a sustained decrease in opioid use (mean, 95% CrI) dropping from 152 (151-153) μg/kg in 2012 to 129 (129-130) μg/kg in 2016. The percent of variability in PME due to institution was 25.6% (24.8%-26.5%). Less opioids were prescribed in men (130 [129-130] μg/kg) than women (144 [143-145] μg/kg). The men to women PME ratio was 0.90 (0.89-0.90). There was substantial variability in PME administration among institutions, with the lowest being 80 (79-81) μg/kg and the highest being 186 (184-187) μg/kg; this is a PME ratio of 0.43 (0.42-0.43).

CONCLUSIONS

We observed a reduction in intraoperative opioid administration over time, with variability in dose ranging between sexes and by procedure type. Furthermore, there was substantial variability in opioid use between institutions even when adjusting for multiple variables.

A Lower Tidal Volume Regimen during One-lung Ventilation for Lung Resection Surgery Is Not Associated with Reduced Postoperative Pulmonary Complications

BACKGROUND

Protective ventilation may improve outcomes after major surgery. However, in the context of one-lung ventilation, such a strategy is incompletely defined. The authors hypothesized that a putative one-lung protective ventilation regimen would be independently associated with decreased odds of pulmonary complications after thoracic surgery.

METHODS

The authors merged Society of Thoracic Surgeons Database and Multicenter Perioperative Outcomes Group intraoperative data for lung resection procedures using one-lung ventilation across five institutions from 2012 to 2016. They defined one-lung protective ventilation as the combination of both median tidal volume 5 ml/kg or lower predicted body weight and positive end-expiratory pressure 5 cm H2O or greater. The primary outcome was a composite of 30-day major postoperative pulmonary complications.

RESULTS

A total of 3,232 cases were available for analysis. Tidal volumes decreased modestly during the study period (6.7 to 6.0 ml/kg; P < 0.001), and positive end-expiratory pressure increased from 4 to 5 cm H2O (P < 0.001). Despite increasing adoption of a "protective ventilation" strategy (5.7% in 2012 vs. 17.9% in 2016), the prevalence of pulmonary complications did not change significantly (11.4 to 15.7%; P = 0.147). In a propensity score matched cohort (381 matched pairs), protective ventilation (mean tidal volume 6.4 vs. 4.4 ml/kg) was not associated with a reduction in pulmonary complications (adjusted odds ratio, 0.86; 95% CI, 0.56 to 1.32). In an unmatched cohort, the authors were unable to define a specific alternative combination of positive end-expiratory pressure and tidal volume that was associated with decreased risk of pulmonary complications.

CONCLUSIONS

In this multicenter retrospective observational analysis of patients undergoing one-lung ventilation during thoracic surgery, the authors did not detect an independent association between a low tidal volume lung-protective ventilation regimen and a composite of postoperative pulmonary complications.

EDITOR’S PERSPECTIVE

Prevalence of aberrant blood pressure readings across two automated intraoperative blood pressure monitoring systems among patients undergoing caesarean delivery

OBJECTIVES

Aberrant automated blood pressure (BP) readings during caesarean delivery may lead to disruptions in monitoring. The present study compared the frequency of aberrant BP readings across two types of commercially available BP monitoring systems in use during caesarean delivery.

METHODS

This was a retrospective observational study using two comparable patient cohorts that resulted from simultaneous introduction of two types of monitors into a single obstetric surgical center in which similar patients were treated for the same surgical procedure by the same set of clinicians during the same year. Our primary hypothesis was that aberrant readings were significantly associated with the type of monitor being used for BP measurement, controlling for a variety of relevant covariates as specified in the analytic plan.

RESULTS

A total of 1418 cesarean delivery patients met inclusion criteria. Gaps of at least 6 min in machine-captured BP readings occurred in 159 (21.1%) of cases done in the operating room using a Datex-Ohmeda monitor vs. 183 (27.5%) of cases in the operating rooms using Phillips monitors (P = 0.005). In multivariable logistic regression analysis, the relative odds of the occurrence of monitoring gaps was 35% higher in rooms with the Phillips BP monitors as compared to the Datex-Ohmeda monitor while controlling for pre-specified covariates (odds ratio = 1.35, 95% confidence interval = 1.04-1.74, P = 0.02).

CONCLUSION

The present analysis suggests that aberrant BP readings for parturients undergoing caesarean delivery are significantly different between the two types of automated BP monitoring systems used in the operating rooms at our institution.

Reduced Echocardiographic Inotropy Index after Cardiopulmonary Bypass Is Associated With Complications After Cardiac Surgery: An Institutional Outcomes Study

OBJECTIVE

Despite advances in echocardiography and hemodynamic monitoring, limited progress has been made to effectively quantify left ventricular function during cardiac surgery. Traditional measures, including left ventricular ejection fraction (LVEF) and cardiac index, remain dependent on loading conditions; more complex measures remain impractical in a dynamic surgical setting. However, the Smith-Madigan Inotropy Index (SMII) and potential-to-kinetic energy ratio (PKR) offer promise as measures calculable during cardiac surgery and potentially predictive of outcomes. Using echocardiographic and hemodynamic monitoring data, the authors aimed to calculate SMII and PKR values after cardiopulmonary bypass and understand associations with postoperative outcomes, adjusting for previously identified risk factors.

DESIGN

Observational cohort study.

SETTING

Tertiary care academic hospital.

PATIENTS

The study comprised 189 elective adult cardiac surgical procedures from 2015-2016.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was postoperative mortality or organ system complication (stroke, prolonged ventilation, reintubation, cardiac arrest, acute kidney injury, new-onset atrial fibrillation). After adjustment, SMII <0.83 W/m² independently predicted the primary outcome (adjusted odds ratio 2.19, 95% confidence interval 1.08-4.42); whereas PKR, LVEF, and cardiac index demonstrated no associations. When SMII and PKR were incorporated into a EuroSCORE II risk model, predictive performance improved (net reclassification index improvement 0.457; p = 0.001); whereas a model incorporating LVEF and cardiac index demonstrated no improvement (0.130; p = 0.318).

CONCLUSION

The present study demonstrated that SMII, but not PKR, as a measure of cardiac function was associated with major complications. The study's data may guide investigations of more suitable perioperative goal-directed therapies to reduce complications after cardiac surgery.

Novel Assessments of Technical and Nontechnical Cardiac Surgery Quality: Protocol for a Mixed Methods Study

BACKGROUND

Of the 150,000 patients annually undergoing coronary artery bypass grafting, 35% develop complications that increase mortality 5 fold and expenditure by 50%. Differences in patient risk and operative approach explain only 2% of hospital variations in some complications. The intraoperative phase remains understudied as a source of variation, despite its complexity and amenability to improvement.

OBJECTIVE

The objectives of this study are to (1) investigate the relationship between peer assessments of intraoperative technical skills and nontechnical practices with risk-adjusted complication rates and (2) evaluate the feasibility of using computer-based metrics to automate the assessment of important intraoperative technical skills and nontechnical practices.

METHODS

This multicenter study will use video recording, established peer assessment tools, electronic health record data, registry data, and a high-dimensional computer vision approach to (1) investigate the relationship between peer assessments of surgeon technical skills and variability in risk-adjusted patient adverse events; (2) investigate the relationship between peer assessments of intraoperative team-based nontechnical practices and variability in risk-adjusted patient adverse events; and (3) use quantitative and qualitative methods to explore the feasibility of using objective, data-driven, computer-based assessments to automate the measurement of important intraoperative determinants of risk-adjusted patient adverse events.

RESULTS

The project has been funded by the National Heart, Lung and Blood Institute in 2019 (R01HL146619). Preliminary Institutional Review Board review has been completed at the University of Michigan by the Institutional Review Boards of the University of Michigan Medical School.

CONCLUSIONS

We anticipate that this project will substantially increase our ability to assess determinants of variation in complication rates by specifically studying a surgeon's technical skills and operating room team member nontechnical practices. These findings may provide effective targets for future trials or quality improvement initiatives to enhance the quality and safety of cardiac surgical patient care.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/22536.

The incidence of intraoperative hypotension in moderate to high risk patients undergoing non-cardiac surgery: A retrospective multicenter observational analysis

STUDY OBJECTIVE

Intraoperative hypotension is associated with perioperative morbidity. We undertook this project to describe the incidence of hypotension (defined as mean arterial pressure <65 mmHg).

DESIGN

Retrospective, observational study.

SETTING

This study was in the intraoperative setting.

PATIENTS

We studied 22,109 adult patients ASA 3 and 4 patients, undergoing surgeries ≥180 min, with arterial line monitoring, from January 1, 2017, to December 31, 2017.

INTERVENTIONS

None.

MEASUREMENTS

Our primary measurement was the number of minutes of primarily invasive mean arterial blood pressure below 65 mmHg. Additionally, we collected patient medical history data as classified by the Elixhauser Comorbidity Enhanced ICD-9-CM/ICD-10 CM Algorithm. Additional study variables included age, gender, BMI, preoperative blood pressure, ASA physical status classification, presence of absence of vasopressor infusion (phenylephrine, norepinephrine, vasopressin), estimated blood loss, amount of PRBCs administered, and surgical procedure type, characterized by body region on the basis of primary anesthesiology Current Procedural Terminology (CPT) code.

MAIN RESULTS

The mean duration of MAP <65 mmHg was 28.2 min (SD 42.6). 88% of cases had at least one hypotensive event as defined as MAP <65 mmHg for 1 min. Across centers this varied from 83.2 to 91.6% of cases. The mean duration of hypotension ranged from 22.1 to 31.8 min.

CONCLUSION

There continues to be a significant burden of hypotension (defined as MAP <65 mmHg) across our multicenter cohort of hospitals.

An Electronic Medical Record-Derived Individualized Performance Metric to Measure Risk-Adjusted Adherence with Perioperative Prophylactic Bundles for Health Care Disparity Research and Implementation Science

BACKGROUND

Health care disparity persists despite vigorous countermeasures. Clinician performance is paramount for equitable care processes and outcomes. However, precise and valid individual performance measures remain elusive.

OBJECTIVES

We sought to develop a generalizable, rigorous, risk-adjusted metric for individual clinician performance (MIP) derived directly from the electronic medical record (EMR) to provide visual, personalized feedback.

METHODS

We conceptualized MIP as risk responsiveness, i.e., administering an increasing number of interventions contingent on patient risk. We embedded MIP in a hierarchical statistical model, reflecting contemporary nested health care delivery. We tested MIP by investigating the adherence with prophylactic bundles to reduce the risk of postoperative nausea and vomiting (PONV), retrieving PONV risk factors and prophylactic antiemetic interventions from the EMR. We explored the impact of social determinants of health on MIP.

RESULTS

We extracted data from the EMR on 25,980 elective anesthesia cases performed at Penn State Milton S. Hershey Medical Center between June 3, 2018 and March 31, 2019. Limiting the data by anesthesia Current Procedural Terminology code and to complete cases with PONV risk and antiemetic interventions, we evaluated the performance of 83 anesthesia clinicians on 2,211 anesthesia cases. Our metric demonstrated considerable variance between clinicians in the adherence to risk-adjusted utilization of antiemetic interventions. Risk seemed to drive utilization only in few clinicians. We demonstrated the impact of social determinants of health on MIP, illustrating its utility for health science and disparity research.

CONCLUSION

The strength of our novel measure of individual clinician performance is its generalizability, as well as its intuitive graphical representation of risk-adjusted individual performance. However, accuracy, precision and validity, stability over time, sensitivity to system perturbations, and acceptance among clinicians remain to be evaluated.