The impact of a medically directed student registered nurse anesthesia staffing model on Postprocedural patient outcomes

STUDY OBJECTIVE

In 2018, the American Society of Anesthesiologists stated that student registered nurse anesthetists (SRNAs) "are not yet fully qualified anesthesia personnel." It remains unclear, however, whether postprocedural outcomes are affected by SRNAs providing anesthesia care under the medical direction of anesthesiologists, as compared with medically directed anesthesiology fellows or residents, or certified registered nurse anesthetists (CRNAs). We therefore aimed to examine whether medically directed SRNAs serving as in-room anesthesia providers impact surgical outcomes.

DESIGN

Retrospective, matched-cohort analysis.

SETTING

Adult patients (≥18 years old) undergoing inpatient surgery between 2000 and 2017 at a tertiary academic medical center.

PATIENTS

15,365 patients exclusively cared for by medically directed SRNAs were matched to 15,365 cared for by medically directed CRNAs, anesthesiology residents, and/or fellows.

INTERVENTIONS

None.

MEASUREMENTS

The primary composite outcome was postoperative occurrence of in-hospital mortality and six categories of major morbidities (infectious, bleeding, serious cardiac, gastrointestinal, respiratory, and urinary complications). In-hospital mortality was analyzed as the secondary outcome.

MAIN RESULTS

In all, 30,730 cases were matched using propensity score matching to control for potential confounding. The primary outcome was identified in 2295 (7.5%) cases (7.5% with exclusive medically directed SRNAs vs 7.4% with medically directed CRNAs, residents and/or fellows; relative risk, 1.02; 95% CI, 0.94-1.11). Thus, our effort to determine noninferiority (10% difference in relative risk) with other providers was inconclusive (P = .07). However, the medically directed SRNA group (0.8% [118]) was found to be noninferior (P < .001) to the matched group (1.0% [156]) on in-hospital mortality (relative risk, 0.75; 95% CI, 0.59-0.96).

CONCLUSIONS

Among 30,730 patients undergoing inpatient surgery at a single hospital, findings were inconclusive regarding whether exclusive medically directed SRNAs as in-room providers were noninferior to other providers. The use of medically directed SRNAs under this staffing model should be subject to further review. Clinical Trial and Registry URL: Not applicable.

Oxygen-Saturation Targets and Cognitive and Functional Outcomes in Mechanically Ventilated Adults

Rationale: Among mechanically ventilated critically ill adults, the PILOT (Pragmatic Investigation of Optimal Oxygen Targets) trial demonstrated no difference in ventilator-free days among lower, intermediate, and higher oxygen-saturation targets. The effects on long-term cognition and related outcomes are unknown.Objectives: To compare the effects of lower (90% [range, 88-92%]), intermediate (94% [range, 92-96%]), and higher (98% [range, 96-100%]) oxygen-saturation targets on long-term outcomes.Methods: Twelve months after enrollment in the PILOT trial, blinded neuropsychological raters conducted assessments of cognition, disability, employment status, and quality of life. The primary outcome was global cognition as measured using the Telephone Montreal Cognitive Assessment. In a subset of patients, an expanded neuropsychological battery measured executive function, attention, immediate and delayed memory, verbal fluency, and abstraction.Measurements and Main Results: A total of 501 patients completed follow-up, including 142 in the lower, 186 in the intermediate, and 173 in the higher oxygen target groups. Median (interquartile range) peripheral oxygen saturation values in the lower, intermediate, and higher target groups were 94% (91-96%), 95% (93-97%), and 97% (95-99%), respectively. Telephone Montreal Cognitive Assessment score did not differ between lower and intermediate (adjusted odds ratio [OR], 1.36 [95% confidence interval (CI), 0.92-2.00]), intermediate and higher (adjusted OR, 0.90 [95% CI, 0.62-1.29]), or higher and lower (adjusted OR, 1.22 [95% CI, 0.83-1.79]) target groups. There was also no difference in individual cognitive domains, disability, employment, or quality of life.Conclusions: Among mechanically ventilated critically ill adults who completed follow-up at 12 months, oxygen-saturation targets were not associated with cognition or related outcomes.

The Association between Preoperative Blood Pressures and Postoperative Adverse Events

BACKGROUND

The relationship between postoperative adverse events and blood pressures in the preoperative period remains poorly understood. This study tested the hypothesis that day-of-surgery preoperative blood pressures are associated with postoperative adverse events.

METHODS

We conducted a retrospective, observational study of adult patients having elective procedures requiring an inpatient stay between November 2017 and July 2021 at Vanderbilt University Medical Center to examine the independent associations between preoperative systolic and diastolic blood pressures (SBP, DBP) recorded immediately before anesthesia care and number of postoperative adverse events - myocardial injury, stroke, acute kidney injury (AKI), and mortality, while adjusting for potential confounders. We used multivariable ordinal logistic regression to model the relationship.

RESULTS

The analysis included 57,389 cases. The overall incidence of myocardial injury, stroke, AKI, and mortality within 30 days of surgery was 3.4% (1,967 events), 0.4% (223), 10.2% (5,871), and 2.1% (1,223), respectively. The independent associations between both SBP and DBP measurements and number of postoperative adverse events were found to be U-shaped, with greater risk both above and below SBP 143 mmHg and DBP 86 mmHg - the troughs of the curves. The associations were strongest at SBP 173 mmHg (adjusted odds ratio [aOR] 1.212 versus 143 mmHg; 95% CI, 1.021 to 1.439; p = 0.028), SBP 93 mmHg (aOR 1.339 versus 143 mmHg; 95% CI, 1.211 to 1.479; p < 0.001), DBP 106 mmHg (aOR 1.294 versus 86 mmHg; 95% CI, 1.003 to 1.17671; p = 0.048), and DBP 46 mmHg (aOR 1.399 versus 86 mmHg; 95% CI, 1.244 to 1.558; p < 0.001).

CONCLUSIONS

Preoperative blood pressures both below and above a specific threshold were independently associated with a higher number of postoperative adverse events, but the data do not support specific strategies for managing patients with low or high blood pressure on the day of surgery.

Effectiveness of Oral Iron Therapy in Anemic Inpatient Pregnant Women: A Single Center Retrospective Cohort Study

Background and aim Oral iron therapy is effective in treating iron deficiency anemia in outpatient pregnant women but has not been studied in inpatient pregnant women. We aimed to evaluate the effect of oral iron therapy versus no therapy during hospitalization on maternal and neonatal outcomes in women with anemia who are hospitalized for pregnancy-related morbidities (i.e., preterm premature rupture of membranes, preterm labor, pre-eclampsia, abnormal placentation, or fetal monitoring). Methods A retrospective, single-center study was conducted in hospitalized pregnant women (2018 to 2020) with inpatient stays of more than three days. The primary outcome was a change in hemoglobin level from admission to delivery in women treated with oral iron compared with those left untreated. Secondary outcomes included the total amount of iron administered before delivery, the time interval from admission to delivery, and neonatal effects. Results Two hundred sixty-three women were admitted, 79 women had anemia, and 29 (36.7%) received at least one dose of oral iron. Baseline patient characteristics were similar between groups. The median (interquartile range) dose of iron in the oral iron group was 1185.0 (477.0, 1874.0) mg. Neither absolute hemoglobin before delivery (control group: 10.0±1.2 g/dL; iron group: 10.1±1.1 g/dL; p=0.774) nor change in hemoglobin from admission to delivery (control group: -0.1±1.1 g/dL vs. iron group: 0.4±1.1 g/dL; p=0.232) differed between groups. Women in the control group had shorter length of stay (LOS) median (IQR) than women in the iron group (control group: 7.1 (5.0, 13.7) days; iron group: 11.4 (7.4, 25.9) days; p=0.03). There were no differences in maternal mode of delivery, though each group had high rates of cesarean delivery (control group: 53.7%; iron group: 72.4%; p=0.181). There were no differences in estimated blood loss at delivery (control group: 559±401; iron group: 662.1±337.4;p=0.264) in either group. Neonatal birthweight (control group: 1.9±0.7 kg; iron group: 1.9±0.7 kg; p=0.901), birth hemoglobin (control group: 16.3±2.2 g/dL; iron group: 16±2.2 g/dL; p=0.569), neonatal intensive care unit (NICU) admission (control group: 93.3%; iron group: 84.8%;p=0.272 ), or neonatal death (control group: 8.9%; iron group: 3%; p=0.394) were not different between groups. Conclusions Oral iron administered to anemic inpatient pregnant women was not associated with higher hemoglobin concentrations before delivery. Lack of standardized iron regimens and short hospital stays may contribute to the inefficacy of oral iron for this inpatient pregnant population. The small sample size and retrospective nature of this study are limiting factors in drawing conclusive evidence from this study.

Improving Neuromuscular Monitoring Through Education-Based Interventions and Studying Its Association With Adverse Postoperative Outcomes: A Retrospective Observational Study

BACKGROUND

We assessed the association between education-based interventions, the frequency of train-of-four (TOF) monitoring, and postoperative outcomes.

METHODS

We studied adults undergoing noncardiac surgery from February 1, 2020 through October 31, 2021. Our education-based interventions consisted of 3 phases. An interrupted time-series analysis, adjusting for patient- and procedure-related characteristics and secular trends over time, was used to assess the associations between education-based interventions and the frequency of TOF monitoring, postoperative pulmonary complications (PPCs), 90-day mortality, and sugammadex dosage. For each outcome and intervention phase, we tested whether the intervention at that phase was associated with an immediate change in the outcome or its trend (weekly rate of change) over time. In a sensitivity analysis, the association between education-based interventions and postoperative outcomes was adjusted for TOF monitoring.

RESULTS

Of 19,422 cases, 11,636 (59.9%) had documented TOF monitoring. Monitoring frequency increased from 44.2% in the first week of preintervention stage to 83.4% in the final week of the postintervention phase. During the preintervention phase, the odds of TOF monitoring trended upward by 0.5% per week (odds ratio [OR], 1.005; 95% confidence interval [CI], 1.002-1.007). Phase 1 saw an immediate 54% increase (OR, 1.54; 95% CI, 1.33-1.79) in the odds, and the trend OR increased by 3% (OR, 1.03; 95% CI, 1.01-1.05) to 1.035, or 3.5% per week (joint Wald test, P < .001). Phase 2 was associated with a further immediate 29% increase (OR, 1.29; 95% CI, 1.02-1.64) but no significant association with trend (OR, 0.96; 95% CI, 0.93-1.01) of TOF monitoring (joint test, P = .04). Phase 3 and postintervention phase were not significantly associated with the frequency of TOF monitoring (joint test, P = .16 and P = .61). The study phases were not significantly associated with PPCs or sugammadex administration. The trend OR for 90-day mortality was larger by 24% (OR, 1.24; 95% CI, 1.06-1.45; joint test, P = .03) in phase 2 versus phase 1, from a weekly decrease of 8% to a weekly increase of 14%. However, this trend reversed again at the transition from phase 3 to the postintervention phase (OR, 0.82; 95% CI, 0.68-0.99; joint test, P = .05), from a 14% weekly increase to a 6.2% weekly decrease in the odds of 90-day mortality. In sensitivity analyses, adjusting for TOF monitoring, we found similar associations between study initiatives and postoperative outcomes. TOF monitoring was associated with lower odds of PPCs (OR, 0.69; 95% CI, 0.55-0.86) and 90-day mortality (OR, 0.79; 95% CI, 0.63-0.98), but not sugammadex dosing (mean difference, -0.02; 95% CI, -0.04 to 0.01).

CONCLUSIONS

Our education-based interventions were associated with both TOF utilization and 90-day mortality but were not associated with either the odds of PPCs or sugammadex dosing. TOF monitoring was associated with reduced odds of PPCs and 90-day mortality.

External validation of a predictive model for reintubation after cardiac surgery: A retrospective, observational study

STUDY OBJECTIVE

Explore validation of a model to predict patients' risk of failing extubation, to help providers make informed, data-driven decisions regarding the optimal timing of extubation.

DESIGN

We performed temporal, geographic, and domain validations of a model for the risk of reintubation after cardiac surgery by assessing its performance on data sets from three academic medical centers, with temporal validation using data from the institution where the model was developed.

SETTING

Three academic medical centers in the United States.

PATIENTS

Adult patients arriving in the cardiac intensive care unit with an endotracheal tube in place after cardiac surgery.

INTERVENTIONS

Receiver operating characteristic (ROC) curves and concordance statistics were used as measures of discriminative ability, and calibration curves and Brier scores were used to assess the model's predictive ability.

MEASUREMENTS

Temporal validation was performed in 1642 patients with a reintubation rate of 4.8%, with the model demonstrating strong discrimination (optimism-corrected c-statistic 0.77) and low predictive error (Brier score 0.044) but poor model precision and recall (Optimal F1 score 0.29). Combined domain and geographic validation were performed in 2041 patients with a reintubation rate of 1.5%. The model displayed solid discriminative ability (optimism-corrected c-statistic = 0.73) and low predictive error (Brier score = 0.0149) but low precision and recall (Optimal F1 score = 0.13). Geographic validation was performed in 2489 patients with a reintubation rate of 1.6%, with the model displaying good discrimination (optimism-corrected c-statistic = 0.71) and predictive error (Brier score = 0.0152) but poor precision and recall (Optimal F1 score = 0.13).

MAIN RESULTS

The reintubation model displayed strong discriminative ability and low predictive error within each validation cohort.

CONCLUSIONS

Future work is needed to explore how to optimize models before local implementation.

Public Health Informatics and the Perioperative Physician: Looking to the Future

The role of informatics in public health has increased over the past few decades, and the coronavirus disease 2019 (COVID-19) pandemic has underscored the critical importance of aggregated, multicenter, high-quality, near-real-time data to inform decision-making by physicians, hospital systems, and governments. Given the impact of the pandemic on perioperative and critical care services (eg, elective procedure delays; information sharing related to interventions in critically ill patients; regional bed-management under crisis conditions), anesthesiologists must recognize and advocate for improved informatic frameworks in their local environments. Most anesthesiologists receive little formal training in public health informatics (PHI) during clinical residency or through continuing medical education. The COVID-19 pandemic demonstrated that this knowledge gap represents a missed opportunity for our specialty to participate in informatics-related, public health-oriented clinical care and policy decision-making. This article briefly outlines the background of PHI, its relevance to perioperative care, and conceives intersections with PHI that could evolve over the next quarter century.

Analysis of the factors contributing to residual weakness after sugammadex administration in pediatric patients under 2 years of age

BACKGROUND

Sugammadex reverses the neuromuscular blockade induced by rocuronium and vecuronium and is approved by the U.S. Food and Drug Administration for use in patients aged over 2 years. There is, however, a paucity of data regarding its dosing profile in infants and children younger than 2 years.

AIMS

The aim of this study was to assess the risk of recurarization, or re-paralysis, in children under 2 years of age to increase awareness on the importance of appropriate neuromuscular blocked monitoring and reversal.

METHODS

All patients aged ≤24 months who underwent an operative procedure at a tertiary medical center between January 1, 2018, and December 31, 2021, and received both rocuronium for neuromuscular blockade and sugammadex for neuromuscular blockade reversal, were identified in the electronic medical record. Patients were excluded from analysis if they (1) received vecuronium, cisatracurium, atracurium, or succinylcholine for neuromuscular blockade, (2) received neostigmine for reversal, or (3) underwent more than one operation within 24 h. We performed a survival analysis of sugammadex redose using a Cox proportional hazards model.

RESULTS

We reviewed 2923 records. Sugammadex was redosed in 123 (4.2%) cases. The median [IQR] time to redose was 7 [4-17] min, and the median [IQR] amount of redose administered was 2.74 [1.96-3.99] mg/kg. Increasing patient age (p < .01) and weight (p < .01) were associated with reduced hazard rate of sugammadex redose. For a patient of median weight, increasing age from 3 to 13 months was associated with a 53% risk reduction (HR: 0.47; 95% CI: 0.24-0.91). For a patient of median age, increasing weight from 4.7 to 9.2 kg was associated with 41% risk reduction (HR: 0.59; 95% CI: 0.32-1.07). We failed to detect any other associations.

CONCLUSIONS

In this single-center, retrospective cohort study of pediatric surgery patients, there was an association between the hazard of sugammadex redose with both increased age and weight.

Development of a machine learning model to predict intraoperative transfusion and guide type and screen ordering

STUDY OBJECTIVE

To develop an algorithm to predict intraoperative Red Blood Cell (RBC) transfusion from preoperative variables contained in the electronic medical record of our institution, with the goal of guiding type and screen ordering.

DESIGN

Machine Learning model development on retrospective single-center hospital data.

SETTING

Preoperative period and operating room.

PATIENTS

The study included patients ≥18 years old who underwent surgery during 2019-2022 and excluded those who refused transfusion, underwent emergency surgery, or surgery for organ donation after cardiac or brain death.

INTERVENTION

Prediction of intraoperative transfusion vs. no intraoperative transfusion.

MEASUREMENTS

The outcome variable was intraoperative transfusion of RBCs. Predictive variables were surgery, surgeon, anesthesiologist, age, sex, body mass index, race or ethnicity, preoperative hemoglobin (g/dL), partial thromboplastin time (s), platelet count x 109 per liter, and prothrombin time. We compared the performances of seven machine learning algorithms. After training and optimization on the 2019-2021 dataset, model thresholds were set to the current institutional performance level of sensitivity (93%). To qualify for comparison, models had to maintain clinically relevant sensitivity (>90%) when predicting on 2022 data; overall accuracy was the comparative metric.

MAIN RESULTS

Out of 100,813 cases that met study criteria from 2019 to 2021, intraoperative transfusion occurred in 5488 (5.4%) of cases. The LightGBM model was the highest performing algorithm in external temporal validity experiments, with overall accuracy of (76.1%) [95% confidence interval (CI), 75.6-76.5], while maintaining clinically relevant sensitivity of (91.2%) [95% CI, 89.8-92.5]. If type and screens were ordered based upon the LightGBM model, the predicted type and screen to transfusion ratio would improve from 8.4 to 5.1.

CONCLUSIONS

Machine learning approaches are feasible in predicting intraoperative transfusion from preoperative variables and may improve preoperative type and screen ordering practices when incorporated into the electronic health record.

Postdischarge Survival After Sepsis: A Cohort Study

BACKGROUND

After hospital discharge, patients who had sepsis have increased mortality. We sought to estimate factors associated with postdischarge mortality and how they vary with time after discharge.

METHODS

This was a retrospective study of hospital survivors of sepsis using time-varying Cox proportional hazard models, which produce a baseline hazard ratio (HR) and a second number (δHR) that reflects the amount by which the baseline HR changes with time.

RESULTS

Of the 32,244 patients who survived sepsis at hospital discharge, 13,565 patients (42%) died (mean ± standard deviation: 1.41 ± 1.87 years) after discharge from the index hospitalization, while 18,679 patients were still alive at follow-up (4.98 ± 2.86 years). The mortality rate decreased with time after discharge: approximately 8.7% of patients died during the first month after discharge, 1.1% of patients died during the 12th month after discharge, and 0.3%% died during the 60th month; after Kaplan-Meier analysis, survival was 91% (95% confidence interval [CI], 91%-92%) at 1 month, 76% (95% CI, 76%-77%) at 1 year, 57% (95% CI, 56%-58%) at 5 years, and 48% (95% CI, 47%-48%) at 10 years after discharge. Organ dysfunction at discharge was associated with worse survival. In particular, elevated urea nitrogen at discharge (HR, 1.10 per 10 mg/dL, 95% CI, 1.08-1.12, P < .001) was associated with increased mortality, but the HR decreased with time from discharge (δHR, 0.98 per 10 mg/dL per year, 95% CI, 0.98-0.99, P < .001). Higher hemoglobin levels were associated with lower mortality (HR, 0.92 per g/dL, 95% CI, 0.91-0.93, P < .001), but this association increased with increasing time after discharge (δHR, 1.02 per g/dL per year, 95% CI, 1.01-1.02, P < .001). Older age was associated with an increased risk of mortality (HR, 1.29 per decade of age, 95% CI, 1.27-1.31, P < .001) that grew with increasing time after discharge (δHR, 1.01 per year of follow-up per decade of age, 95% CI, 1.00-1.02, P < .001). Compared to private insurances Medicaid as primary insurance was associated with an increased risk of mortality (HR, 1.17, 95% CI, 1.10-1.25, P < .001) that did not change with time after discharge. In contrast, Medicare status was initially associated with a similar risk of mortality as private insurance at discharge (HR, 1), but was associated with greater risk as time after discharge increased (δHR, 1.04 per year of follow-up, 95% CI, 1.03-1.05, P < .001).

CONCLUSIONS

Acute physiologic derangements and organ dysfunction were associated with postdischarge mortality with the associations decreasing over time.

Development and Validation of an Automated Tool to Retrieve and Curate Faculty Publications of Academic Departments

Introduction Academic departments need to monitor their faculty's academic productivity for various purposes, such as reporting to the medical school dean, assessing the allocation of non-clinical research time, evaluating for rank promotion, and reporting to the Accreditation Council for Graduate Medical Education (ACGME). Our objective was to develop and validate a simple method that automatically generates query strings to identify and process distinct department faculty publications listed in PubMed and Scopus. Methods We created a macro-enabled Excel workbook (Microsoft, Redmond, WA) to automate the retrieval of faculty publications from the PubMed and Scopus bibliometric databases (available at https://bit.ly/get-pubs). Where the returned reference includes the digital object identifier (doi), a link is provided in the workbook. Duplicate publications are removed automatically, and false attributions are managed. Results At the University of Miami, between 2020 and 2021, there were 143 anesthesiology faculty-authored publications with a PubMed identifier (PMID), 95.8% identified by the query and 4.2% missed. At Vanderbilt University Medical Center, between 2019 and 2021, there were 760 anesthesiology faculty-authored publications with a PMID, 94.3% identified by the query and 5.7% missed. Recall, precision, and the F1 score were all above 93% at both medical centers. Conclusions We developed a highly accurate, simple, transportable, scalable method to identify publications in PubMed and Scopus authored by anesthesiology faculty. Manual checking and faculty feedback are required because not all names can be disambiguated, and some references are missed. This process can greatly reduce the burden of curating a list of faculty publications. The methodology applies to other academic departments that track faculty publications.

Factors Associated With Initiation of Mechanical Ventilation in Patients With Sepsis: Retrospective Observational Study

BACKGROUND

Patients with sepsis are at risk for mechanical ventilation. This study aimed to identify risk factors for initiation of mechanical ventilation in patients with sepsis and assess whether these factors varied with time.

METHODS

Data from the electronic health record were used to model risk factors for initiation of mechanical ventilation after the onset of sepsis. A time-varying Cox model was used to study factors that varied with time.

RESULTS

Of 35 020 patients who met sepsis criteria, 28 747 were eligible for inclusion. Mechanical ventilation was initiated within 30 days after sepsis onset in 3891 patients (13.5%). Factors that were independently associated with increased likelihood of receipt of mechanical ventilation were race (White: adjusted hazard ratio [HR], 1.59; 95% CI, 1.39-1.83; other/unknown: adjusted HR, 1.97; 95% CI, 1.54-2.52), systemic inflammatory response syndrome (adjusted HR [per point], 1.23; 95% CI, 1.17-1.28), Sequential Organ Failure Assessment score (adjusted HR [per point], 1.28; 95% CI, 1.26-1.31), and congestive heart failure (adjusted HR, 1.30; 95% CI, 1.17-1.45). Hazard ratios decreased with time for Sequential Organ Failure Assessment score and congestive heart failure and varied with time for 4 comorbidities and 3 culture results.

CONCLUSIONS

The risk for mechanical ventilation associated with different factors varied with time after sepsis onset, increasing for some factors and decreasing for others. Through a better understanding of risk factors for initiation of mechanical ventilation in patients with sepsis, targeted interventions may be tailored to high-risk patients.

Effects of Postoperative Blood Pressure Management on Delirium Among Patients in the Intensive Care Unit After Cardiac Surgery: An Observational Cohort Study

OBJECTIVES

This study aimed to determine whether blood pressure control in the early postoperative period was associated with postoperative delirium in the cardiovascular intensive care unit (ICU).

DESIGN

Observational cohort study.

SETTING

Single large academic institution with a high volume of cardiac surgery.

PARTICIPANTS

Cardiac surgery patients admitted to the cardiovascular ICU after surgery.

INTERVENTIONS

Observational study.

MEASUREMENTS AND MAIN RESULTS

A total of 517 cardiac surgery patients had mean arterial pressure (MAP) data recorded minute-by-minute for 12 postoperative hours. The time spent in each of the 7 prespecified blood pressure bands was calculated, and the development of delirium was recorded in the ICU. A multivariate Cox regression model was developed using the least absolute shrinkage and selection operator approach to identify associations between time spent in each MAP range band and delirium. Compared with the reference band of 60-to-69 mmHg, longer durations spent in 3 bands were independently associated with a lower risk of delirium: 50-to-59 mmHg band (adjusted hazard ratio [HR] 0.907 [per 10 minutes]; 95% CI 0.861-0.955); 70-to-79 mmHg band (adjusted HR 0.923 [per 10 minutes]; 95% CI 0.902-0.944); 90-to-99 mmHg band (adjusted HR 0.898 [per 10 minutes]; 95% CI 0.853-0.945).

CONCLUSIONS

The MAP range bands above and below the authors' reference band of 60-to- 69 mmHg were associated with decreased risk of ICU delirium development; however, this was difficult to reconcile with a plausible biologic mechanism. Therefore, the authors did not find a correlation between early postoperative MAP control and increased risk of the development of ICU delirium after cardiac surgery.

PeRiOperative Glucose PRAgMatic (PROGRAM) trial protocol and statistical analysis plan for comparing automated intraoperative reminders to standardise insulin administration in surgical patients at high risk of hyperglycaemia

INTRODUCTION

Studies finding perioperative hyperglycaemia is associated with adverse patient outcomes in surgical procedures spurred the development of blood glucose guidelines at many institutions. In this trial, we will assess the implementation of a clinical decision support tool that is integrated into the intraoperative portion of our electronic health record and provides real-time best practice recommendations for intraoperative insulin dosing in surgical patients at high risk for hyperglycaemia.

METHODS AND DESIGN

We will assess this intervention using a sequential and repeated cross-over design at the institutional level with periods of time for wash-out, control and study intervention. The unit of analysis will be the surgical case. The primary outcome will be the frequency of hyperglycaemia (>180 mg/dL (10 mmol/L)) at first postoperative anaesthesia care unit measurement. There are several prespecified secondary analyses focused on perioperative glycaemic control.

DISCUSSION

This protocol and statistical analysis plan describes the methodology, primary and secondary analyses. The PeRiOperative Glucose PRAgMatic (PROGRAM) trial was approved by the Vanderbilt University Institutional Review Board (IRB), Vanderbilt University Medical Center, Nashville, Tennessee, USA (IRB, 220991). The study results will be disseminated via publication in a peer-reviewed journal and presented at national scientific conferences. The results of PROGRAM trial will inform best practice for perioperative standardised insulin administration in surgical patients at high risk of hyperglycaemia.

TRIAL REGISTRATION NUMBER

NCT05426096.

The IMpact of PerioperAtive KeTamine on Enhanced Recovery after Abdominal Surgery (IMPAKT ERAS): protocol for a pragmatic, randomized, double-blinded, placebo-controlled trial

BACKGROUND

Multimodal analgesic strategies that reduce perioperative opioid consumption are well-supported in Enhanced Recovery After Surgery (ERAS) literature. However, the optimal analgesic regimen has not been established, as the contributions of each individual agent to the overall analgesic efficacy with opioid reduction remains unknown. Perioperative ketamine infusions can decrease opioid consumption and opioid-related side effects. However, as opioid requirements are drastically minimized within ERAS models, the differential effects of ketamine within an ERAS pathway remain unknown. We aim to pragmatically investigate through a learning healthcare system infrastructure how the addition of a perioperative ketamine infusion to mature ERAS pathways affects functional recovery.

METHODS

The IMPAKT ERAS trial (IMpact of PerioperAtive KeTamine on Enhanced Recovery after Abdominal Surgery) is a single center, pragmatic, randomized, blinded, placebo-controlled trial. 1544 patients undergoing major abdominal surgery will be randomly allocated to receive intraoperative and postoperative (up to 48 h) ketamine versus placebo infusions as part of a perioperative multimodal analgesic regimen. The primary outcome is length of stay, defined as surgical start time until hospital discharge. Secondary outcomes will include a variety of in-hospital clinical end points derived from the electronic health record.

DISCUSSION

We aimed to launch a large-scale, pragmatic trial that would easily integrate into routine clinical workflow. Implementation of a modified consent process was critical to preserving our pragmatic design, permitting an efficient, low-cost model without reliance on external study personnel. Therefore, we partnered with leaders of our Investigational Review Board to develop a novel, modified consent process and shortened written consent form that would meet all standard elements of informed consent, yet also allow clinical providers the ability to recruit and enroll patients during their clinical workflow. Our trial design has created a platform for subsequent pragmatic studies at our institution.

TRIAL REGISTRATION

NCT04625283, Pre-results.

Antibiotic clinical decision support for pneumonia in the ED: A randomized trial

BACKGROUND

Electronic health record-based clinical decision support (CDS) is a promising antibiotic stewardship strategy. Few studies have evaluated the effectiveness of antibiotic CDS in the pediatric emergency department (ED).

OBJECTIVE

To compare the effectiveness of antibiotic CDS vs. usual care for promoting guideline-concordant antibiotic prescribing for pneumonia in the pediatric ED.

DESIGN

Pragmatic randomized clinical trial.

SETTING AND PARTICIPANTS

Encounters for children (6 months-18 years) with pneumonia presenting to two tertiary care children s hospital EDs in the United States.

INTERVENTION

CDS or usual care was randomly assigned during 4-week periods within each site. The CDS intervention provided antibiotic recommendations tailored to each encounter and in accordance with national guidelines.

MAIN OUTCOME AND MEASURES

The primary outcome was exclusive guideline-concordant antibiotic prescribing within the first 24 h of care. Safety outcomes included time to first antibiotic order, encounter length of stay, delayed intensive care, and 3- and 7-day revisits.

RESULTS

1027 encounters were included, encompassing 478 randomized to usual care and 549 to CDS. Exclusive guideline-concordant prescribing did not differ at 24 h (CDS, 51.7% vs. usual care, 53.3%; odds ratio [OR] 0.94 [95% confidence interval [CI]: 0.73, 1.20]). In pre-specified stratified analyses, CDS was associated with guideline-concordant prescribing among encounters discharged from the ED (74.9% vs. 66.0%; OR 1.53 [95% CI: 1.01, 2.33]), but not among hospitalized encounters. Mean time to first antibiotic was shorter in the CDS group (3.0 vs 3.4 h; p = .024). There were no differences in safety outcomes.

CONCLUSIONS

Effectiveness of ED-based antibiotic CDS was greatest among those discharged from the ED. Longitudinal interventions designed to target both ED and inpatient clinicians and to address common implementation challenges may enhance the effectiveness of CDS as a stewardship tool.

The Association Between Enhanced Recovery After Cardiac Surgery-Guided Analgesics and Postoperative Delirium

OBJECTIVES

Delirium is a common postoperative complication associated with death and long-term cognitive impairment. The authors studied the association between opioid-sparing anesthetics, incorporating Enhanced Recovery After Cardiac Surgery (ERACS)-guided analgesics and postoperative delirium.

DESIGN

The authors performed a retrospective review of nonemergent coronary, valve, or ascending aorta surgery patients.

SETTING

A tertiary academic medical institution.

PARTICIPANTS

The study authors analyzed a dataset of elective adult cardiac surgical patients. All patients ≥18 years undergoing elective cardiac surgery from November 2, 2017 until February 2, 2021 were eligible for inclusion.

INTERVENTIONS

The ERACS-guided multimodal pain regimen included preoperative oral acetaminophen and gabapentin, and intraoperative intravenous lidocaine, ketamine, and dexmedetomidine.

MEASUREMENTS AND MAIN RESULTS

Delirium was measured by bedside nurses using the Confusion Assessment Method for the intensive care unit (ICU). Delirium occurred in 220 of the 1,675 patients (13.7%). The use of any component of the multimodal pain regimen was not associated with delirium (odds ratio [OR]: 0.85 [95% CI: 0.63-1.16]). Individually, acetaminophen was associated with reduced odds of delirium (OR: 0.60 [95% CI: 0.37-0.95]). Gabapentin (OR: 1.36 [95% CI: 0.97-2.21]), lidocaine (OR: 0.86 [95% CI: 0.53-1.37]), ketamine (OR: 1.15 [95% CI: 0.72-1.83]), and dexmedetomidine (OR: 0.79 [95% CI: 0.46-1.31]) were not individually associated with postoperative delirium. Individual ERACS elements were associated with secondary outcomes of hospital length of stay, ICU duration, postoperative opioid administration, and postoperative intubation duration.

CONCLUSIONS

The use of an opioid-sparing perioperative ERACS pain regimen was not associated with reduced postoperative delirium, opioid consumption, or additional poor outcomes. Individually, acetaminophen was associated with reduced delirium.

The IMpact of PerioperAtive KeTamine on Enhanced Recovery after Abdominal Surgery (IMPAKT ERAS): protocol for a pragmatic, randomized, double-blinded, placebo-controlled trial

BACKGROUND

Multimodal analgesic strategies that reduce perioperative opioid consumption are well-supported in Enhanced Recovery After Surgery (ERAS) literature. However, the optimal analgesic regimen has not been established, as the contributions of each individual agent to the overall analgesic efficacy with opioid reduction remains unknown. Perioperative ketamine infusions can decrease opioid consumption and opioid-related side effects. However, as opioid requirements are drastically minimized within ERAS models, the differential effects of ketamine within an ERAS pathway remain unknown. We aim to pragmatically investigate through a learning healthcare system infrastructure how the addition of a perioperative ketamine infusion to mature ERAS pathways affects functional recovery.

METHODS

The IMPAKT ERAS trial (IMpact of PerioperAtive KeTamine on Enhanced Recovery after Abdominal Surgery) is a single center, pragmatic, randomized, blinded, placebo-controlled trial. 1544 patients undergoing major abdominal surgery will be randomly allocated to receive intraoperative and postoperative (up to 48 hours) ketamine versus placebo infusions as part of a perioperative multimodal analgesic regimen. The primary outcome is length of stay, defined as surgical start time until hospital discharge. Secondary outcomes will include a variety of in-hospital clinical end points derived from the electronic health record.

DISCUSSION

We aimed to launch a large-scale, pragmatic trial that would easily integrate into routine clinical workflow. Implementation of a modified consent process was critical to preserving our pragmatic design, permitting an efficient, low-cost model without reliance on external study personnel. Therefore, we partnered with leaders of our Investigational Review Board to develop a novel, modified consent process and shortened written consent form that would meet all standard elements of informed consent, yet also allow clinical providers the ability to recruit and enroll patients during their clinical workflow. Our trial design has created a platform for subsequent pragmatic studies at our institution.

TRIAL REGISTRATION NUMBER

NCT04625283, Pre-results Protocol Version 1.0, 2021.

Patient and Operative Factors Predict Risk of Discretionary Prolonged Postoperative Mechanical Ventilation in a Broad Surgical Cohort

BACKGROUND

Patients undergoing surgery with general anesthesia and endotracheal intubation are ideally extubated upon case completion, as prolonged postoperative mechanical ventilation (PPMV) has been associated with poor outcomes. However, some patients require PPMV for surgical reasons, such as airway compromise, while others remain intubated at the discretion of the anesthesia provider. Incidence and risk factors for discretionary PPMV (DPPMV) have been described in individual surgical subspecialties and intensive care unit (ICU) populations, but are relatively understudied in a broad surgical cohort. The present study seeks to fill this gap and identify the perioperative risk factors that predict DPPMV.

METHODS

After obtaining institutional review board (IRB) exemption, existing electronic health record databases at our large referral center were retrospectively queried for adult surgeries performed between January 2018 and December 2020 with general anesthesia, endotracheal intubation, and by surgical services that do not routinely leave patients intubated for surgical reasons. Patients who arrived to the ICU intubated after surgery were identified as experiencing DPPMV. Selection of candidate risk factors was performed with LASSO-regularized logistic regression, and surviving variables were used to generate a multivariable logistic regression model of DPPMV risk.

RESULTS

A total of 32,915 cases met inclusion criteria, of which 415 (1.26%) experienced DPPMV. Compared to extubated patients, those with DPPMV were more likely to have undergone emergency surgery (42.9% versus 3.4%; P < .001), surgery during an existing ICU stay (30.8% versus 2.8%; P < 0.001), and have 20 of the 31 elixhauser comorbidities ( P < .05 for each comparison), among other differences. A risk model with 12 variables, including American Society of Anesthesiologists (ASA) physical classification status, emergency surgery designation, four Elixhauser comorbidities, surgery during an existing ICU stay, surgery duration, estimated number of intraoperative handoffs, and vasopressor, sodium bicarbonate, and albuterol administration, yielded an area under the receiver operating characteristic curve of 0.97 (95% confidence interval, 0.96-0.97) for prediction of DPPMV.

CONCLUSIONS

DPPMV was uncommon in this broad surgical cohort but could be accurately predicted using readily available patient-specific and operative factors. These results may be useful for preoperative risk stratification, postoperative resource allocation, and clinical trial planning.

Automated Emails to Improve Evening Staffing for Anesthesiologists

Scheduling flexibility and predictability to the end of a clinical workday are strategies aimed at addressing physician burnout. A voluntary relief shift was created to increase the pool of anesthesiologists providing end of the day relief. We hypothesized that an automated email reminder would improve the number of evening relief shifts filled and increase the number of anesthesiologists participating in the program. An automated email reminder was implemented, which selectively emailed anesthesiologists without a clinical assignment one day in advance when the voluntary relief shifts were not filled, and anticipated case volume past 4:00 PM was expected to exceed the capacity of the on-call team. After implementation of the automated email reminder, the median number of providers who worked the relief shift on a typical day was 2.6, compared to 1.75 prior to the intervention. After the initial increase in the number of volunteers post-intervention, the trend in the weekly average number of volunteers tended to decrease but remained higher than before the intervention. A total of 22 unique anesthesiologists chose to participate in this program after the intervention. An automated email reminder increased the number of anesthesiologists volunteering for a relief shift. Leveraging automation to match staffing needs with case volume allows for recruitment of additional personnel on the days when volunteers are most needed. Increasing the pool of anesthesiologists available to provide relief is one strategy to improve end of the day predictability and work-life balance.

Association of Time to Surgery After COVID-19 Infection With Risk of Postoperative Cardiovascular Morbidity

IMPORTANCE

The time interval between COVID-19 infection and surgery is a potentially modifiable but understudied risk factor for postoperative complications.

OBJECTIVE

To examine the association between time to surgery after COVID-19 diagnosis and the risk of a composite of major postoperative cardiovascular morbidity events within 30 days of surgery.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, retrospective cohort study was conducted among 3997 adult patients (aged ≥18 years) with a previous diagnosis of COVID-19, as documented by a positive polymerase chain reaction test result, who were undergoing surgery from January 1, 2020, to December 6, 2021. Data were obtained through Structured Query Language access of an existing perioperative data warehouse. Statistical analysis was performed March 29, 2022.

EXPOSURE

The time interval between COVID-19 diagnosis and surgery.

MAIN OUTCOMES AND MEASURES

The primary outcome was the composite occurrence of major cardiovascular comorbidity, defined as deep vein thrombosis, pulmonary embolism, cerebrovascular accident, myocardial injury, acute kidney injury, and death within 30 days after surgery, using multivariable logistic regression.

RESULTS

A total of 3997 patients (2223 [55.6%]; median age, 51.3 years [IQR, 35.1-64.4 years]; 667 [16.7%] African American or Black; 2990 [74.8%] White; and 340 [8.5%] other race) were included in the study. The median time from COVID-19 diagnosis to surgery was 98 days (IQR, 30-225 days). Major postoperative adverse cardiovascular events were identified in 485 patients (12.1%). Increased time from COVID-19 diagnosis to surgery was associated with a decreased rate of the composite outcome (adjusted odds ratio, 0.99 [per 10 days]; 95% CI, 0.98-1.00; P = .006). This trend persisted for the 1552 patients who had received at least 1 dose of COVID-19 vaccine (adjusted odds ratio, 0.98 [per 10 days]; 95% CI, 0.97-1.00; P = .04).

CONCLUSIONS AND RELEVANCE

This study suggests that increased time from COVID-19 diagnosis to surgery was associated with a decreased odds of experiencing major postoperative cardiovascular morbidity. This information should be used to better inform risk-benefit discussions concerning optimal surgical timing and perioperative outcomes for patients with a history of COVID-19 infection.

Protocol for a randomised controlled trial: reducing reintubation among high-risk cardiac surgery patients with high-flow nasal cannula (I-CAN)

INTRODUCTION

Heated, humidified, high-flow nasal cannula oxygen therapy has been used as a therapy for hypoxic respiratory failure in numerous clinical settings. To date, limited data exist to guide appropriate use following cardiac surgery, particularly among patients at risk for experiencing reintubation. We hypothesised that postextubation treatment with high-flow nasal cannula would decrease the all-cause reintubation rate within the 48 hours following initial extubation, compared with usual care.

METHODS AND ANALYSIS

Adult patients undergoing cardiac surgery (open surgery on the heart or thoracic aorta) will be automatically enrolled, randomised and allocated to one of two treatment arms in a pragmatic randomised controlled trial at the time of initial extubation. The two treatment arms are administration of heated, humidified, high-flow nasal cannula oxygen postextubation and usual care (treatment at the discretion of the treating provider). The primary outcome will be all-cause reintubation within 48 hours of initial extubation. Secondary outcomes include all-cause 30-day mortality, hospital length of stay, intensive care unit length of stay and ventilator-free days. Interaction analyses will be conducted to assess the differential impact of the intervention within strata of predicted risk of reintubation, calculated according to our previously published and validated prognostic model.

ETHICS AND DISSEMINATION

Vanderbilt University Medical Center IRB approval, 15 March 2021 with waiver of written informed consent. Plan for publication of study protocol prior to study completion, as well as publication of results.

TRIAL REGISTRATION NUMBER

clinicaltrials.gov, NCT04782817 submitted 25 February 2021.

DATE OF PROTOCOL

29 August 2022. Version 2.0.

Oxygen-Saturation Targets for Critically Ill Adults Receiving Mechanical Ventilation

BACKGROUND

Invasive mechanical ventilation in critically ill adults involves adjusting the fraction of inspired oxygen to maintain arterial oxygen saturation. The oxygen-saturation target that will optimize clinical outcomes in this patient population remains unknown.

METHODS

In a pragmatic, cluster-randomized, cluster-crossover trial conducted in the emergency department and medical intensive care unit at an academic center, we assigned adults who were receiving mechanical ventilation to a lower target for oxygen saturation as measured by pulse oximetry (Spo₂) (90%; goal range, 88 to 92%), an intermediate target (94%; goal range, 92 to 96%), or a higher target (98%; goal range, 96 to 100%). The primary outcome was the number of days alive and free of mechanical ventilation (ventilator-free days) through day 28. The secondary outcome was death by day 28, with data censored at hospital discharge.

RESULTS

A total of 2541 patients were included in the primary analysis. The median number of ventilator-free days was 20 (interquartile range, 0 to 25) in the lower-target group, 21 (interquartile range, 0 to 25) in the intermediate-target group, and 21 (interquartile range, 0 to 26) in the higher-target group (P = 0.81). In-hospital death by day 28 occurred in 281 of the 808 patients (34.8%) in the lower-target group, 292 of the 859 patients (34.0%) in the intermediate-target group, and 290 of the 874 patients (33.2%) in the higher-target group. The incidences of cardiac arrest, arrhythmia, myocardial infarction, stroke, and pneumothorax were similar in the three groups.

CONCLUSIONS

Among critically ill adults receiving invasive mechanical ventilation, the number of ventilator-free days did not differ among groups in which a lower, intermediate, or higher Spo₂ target was used. (Supported by the National Heart, Lung, and Blood Institute and others; PILOT ClinicalTrials.gov number, NCT03537937.).

Validation of an Intensive Care Unit Data Mart for Research and Quality Improvement

Data derived from the electronic health record (EHR) is frequently extracted using undefined approaches that may affect the accuracy of collected variables. Further, efforts to assess data accuracy often suffer from limited collaboration between clinicians and data analysts who perform the extraction. In this manuscript, we describe the methodology behind creation of a structured, rigorously derived intensive care unit (ICU) data mart based on data automatically and routinely derived from the EHR. This ICU data mart includes high-quality data elements commonly used for quality improvement and research purposes. These data elements were identified by physicians working closely with data analysts to iteratively develop and refine algorithmic definitions for complex outcomes and risk factors. We contend that this methodology can be reproduced and applied across other institution or to other clinical domains to create high quality data marts, inclusive of complex outcomes data.

Balanced Crystalloid versus Saline in Adults with Traumatic Brain Injury: Secondary Analysis of a Clinical Trial

Balanced crystalloids may improve outcomes compared with saline for some critically ill adults. Lower tonicity of balanced crystalloids could worsen cerebral edema in patients with intracranial pathology. The effect of balanced crystalloids versus saline on clinical outcomes in patients with traumatic brain injury (TBI) requires further study. We planned an a priori subgroup analysis of TBI patients enrolled in the pragmatic, cluster-randomized, multiple-crossover Isotonic Solutions and Major Adverse Renal Events Trial (SMART) (ClinicalTrials.gov: NCT02444988, NCT02547779). Primary outcome was 30-day in-hospital mortality. Secondary outcomes included hospital discharge disposition (home, facility, death). Regression models adjusted for pre-specified baseline covariates compared outcomes. TBI patients assigned to balanced crystalloids (n = 588) and saline (n = 569) had similar baseline characteristics including Injury Severity Score 19 (10); mean maximum head/neck Abbreviated Injury Score, 3.4 (1.0). Isotonic crystalloid volume administered between intensive care unit admission and first of hospital discharge or 30 days was 2037 (3470) mL and 1723 (2923) mL in the balanced crystalloids and saline groups, respectively (p = 0.18). During the study period, 94 (16%) and 82 (14%) patients (16%) died in the balanced crystalloid and saline groups, respectively (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 0.60 to 1.75; p = 0.913). Patients in the balanced crystalloid group were more likely to die or be discharged to another medical facility (aOR 1.38 [1.02-1.86]; p = 0.04). Overall, balanced crystalloids were associated with worse discharge disposition in critically injured patients with TBI compared with saline. The confidence intervals cannot exclude a clinically relevant increase in mortality when balanced crystalloids are used for patients with TBI.

Assessment of Awake Prone Positioning in Hospitalized Adults With COVID-19: A Nonrandomized Controlled Trial

IMPORTANCE

Awake prone positioning may improve hypoxemia among patients with COVID-19, but whether it is associated with improved clinical outcomes remains unknown.

OBJECTIVE

To determine whether the recommendation of awake prone positioning is associated with improved outcomes among patients with COVID-19-related hypoxemia who have not received mechanical ventilation.

DESIGN, SETTING, AND PARTICIPANTS

This pragmatic nonrandomized controlled trial was conducted at 2 academic medical centers (Vanderbilt University Medical Center and NorthShore University HealthSystem) during the COVID-19 pandemic. A total of 501 adult patients with COVID-19-associated hypoxemia who had not received mechanical ventilation were enrolled from May 13 to December 11, 2020.

INTERVENTIONS

Patients were assigned 1:1 to receive either the practitioner-recommended awake prone positioning intervention (intervention group) or usual care (usual care group).

MAIN OUTCOMES AND MEASURES

Primary outcome analyses were performed using a bayesian proportional odds model with covariate adjustment for clinical severity ranking based on the World Health Organization ordinal outcome scale, which was modified to highlight the worst level of hypoxemia on study day 5.

RESULTS

A total of 501 patients (mean [SD] age, 61.0 [15.3] years; 284 [56.7%] were male; and most [417 (83.2%)] were self-reported non-Hispanic or non-Latinx) were included. Baseline severity was comparable between the intervention vs usual care groups, with 170 patients (65.9%) vs 162 patients (66.7%) receiving oxygen via standard low-flow nasal cannula, 71 patients (27.5%) vs 62 patients (25.5%) receiving oxygen via high-flow nasal cannula, and 16 patients (6.2%) vs 19 patients (7.8%) receiving noninvasive positive-pressure ventilation. Nursing observations estimated that patients in the intervention group spent a median of 4.2 hours (IQR, 1.8-6.7 hours) in the prone position per day compared with 0 hours (IQR, 0-0.7 hours) per day in the usual care group. On study day 5, the bayesian posterior probability of the intervention group having worse outcomes than the usual care group on the modified World Health Organization ordinal outcome scale was 0.998 (posterior median adjusted odds ratio [aOR], 1.63; 95% credibility interval [CrI], 1.16-2.31). However, on study days 14 and 28, the posterior probabilities of harm were 0.874 (aOR, 1.29; 95% CrI, 0.84-1.99) and 0.673 (aOR, 1.12; 95% CrI, 0.67-1.86), respectively. Exploratory outcomes (progression to mechanical ventilation, length of stay, and 28-day mortality) did not differ between groups.

CONCLUSIONS AND RELEVANCE

In this nonrandomized controlled trial, prone positioning offered no observed clinical benefit among patients with COVID-19-associated hypoxemia who had not received mechanical ventilation. Moreover, there was substantial evidence of worsened clinical outcomes at study day 5 among patients recommended to receive the awake prone positioning intervention, suggesting potential harm.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04359797.

Impact of Intraoperative Data on Risk Prediction for Mortality After Intra-Abdominal Surgery

BACKGROUND

Risk prediction models for postoperative mortality after intra-abdominal surgery have typically been developed using preoperative variables. It is unclear if intraoperative data add significant value to these risk prediction models.

METHODS

With IRB approval, an institutional retrospective cohort of intra-abdominal surgery patients in the 2005 to 2015 American College of Surgeons National Surgical Quality Improvement Program was identified. Intraoperative data were obtained from the electronic health record. The primary outcome was 30-day mortality. We evaluated the performance of machine learning algorithms to predict 30-day mortality using: 1) baseline variables and 2) baseline + intraoperative variables. Algorithms evaluated were: 1) logistic regression with elastic net selection, 2) random forest (RF), 3) gradient boosting machine (GBM), 4) support vector machine (SVM), and 5) convolutional neural networks (CNNs). Model performance was evaluated using the area under the receiver operator characteristic curve (AUROC). The sample was randomly divided into a training/testing split with 80%/20% probabilities. Repeated 10-fold cross-validation identified the optimal model hyperparameters in the training dataset for each model, which were then applied to the entire training dataset to train the model. Trained models were applied to the test cohort to evaluate model performance. Statistical significance was evaluated using P < .05.

RESULTS

The training and testing cohorts contained 4322 and 1079 patients, respectively, with 62 (1.4%) and 15 (1.4%) experiencing 30-day mortality, respectively. When using only baseline variables to predict mortality, all algorithms except SVM (area under the receiver operator characteristic curve [AUROC], 0.83 [95% confidence interval {CI}, 0.69-0.97]) had AUROC >0.9: GBM (AUROC, 0.96 [0.94-1.0]), RF (AUROC, 0.96 [0.92-1.0]), CNN (AUROC, 0.96 [0.92-0.99]), and logistic regression (AUROC, 0.95 [0.91-0.99]). AUROC significantly increased with intraoperative variables with CNN (AUROC, 0.97 [0.96-0.99]; P = .047 versus baseline), but there was no improvement with GBM (AUROC, 0.97 [0.95-0.99]; P = .3 versus baseline), RF (AUROC, 0.96 [0.93-1.0]; P = .5 versus baseline), and logistic regression (AUROC, 0.94 [0.90-0.99]; P = .6 versus baseline).

CONCLUSIONS

Postoperative mortality is predicted with excellent discrimination in intra-abdominal surgery patients using only preoperative variables in various machine learning algorithms. The addition of intraoperative data to preoperative data also resulted in models with excellent discrimination, but model performance did not improve.

The Impact of Functional Dependence and Related Surgical Complications on Postoperative Mortality

PURPOSE

Functional dependency is a known determinant of surgical risk. To enhance our understanding of the relationship between dependency and adverse surgical outcomes, we studied how postoperative mortality following a surgical complication was impacted by preoperative functional dependency.

METHODS

We explored a historical cohort of 6,483,387 surgical patients within the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). All patients ≥ 18 years old within the ACS-NSQIP from 2007 to 2017 were included.

RESULTS

There were 6,222,611 (96.5%) functionally independent, 176,308 (2.7%) partially dependent, and 47,428 (0.7%) totally dependent patients. Within 30 days postoperatively, 57,652 (0.9%) independent, 15,075 (8.6%) partially dependent, and 10,168 (21.4%) totally dependent patients died. After adjusting for confounders, increasing functional dependency was associated with increased odds of mortality (Partially Dependent OR: 1.72, 99% CI: 1.66 to 1.77; Totally Dependent OR: 2.26, 99% CI: 2.15 to 2.37). Dependency also significantly impacted mortality following a complication; however, independent patients usually experienced much stronger increases in the odds of mortality. There were six complications not associated with increased odds of mortality. Model diagnostics show our model was able to distinguish between patients who did and did not suffer 30-day postoperative mortality nearly 96.7% of the time.

CONCLUSIONS

Within our cohort, dependent surgical patients had higher rates of comorbidities, complications, and odds of 30-day mortality. Preoperative functional status significantly impacted the level of postoperative mortality following a complication, but independent patients were most affected.

Understanding the Accuracy of Clinician Provided Estimated Discharge Dates

Discharge planning is a vital tool in managing hospital capacity, which is essential for maintaining hospital throughput for surgical postoperative admissions. Early discharge planning has been effective in reducing length of stay and hospital readmissions. Between 2014 and 2017, Vanderbilt University Medical Center (VUMC) implemented a tool in the electronic health record (EHR) requiring providers to input the patient's estimated discharge date on each hospital day. We hypothesized discharge estimates would be more accurate, on average, for surgical patients compared to non-surgical patients because treatment plans are known in advance of surgical admissions. We also analyzed the data to identify factors associated with more accurate discharge estimates. In this retrospective observational study, via an analysis of covariance (ANCOVA) approach, we identified factors associated with more accurate discharge estimates for admitted adult patients at VUMC. The primary outcome was the difference between estimated and actual discharge date, and the primary exposure of interest was whether the patient underwent surgery while admitted to the hospital. A total of 304,802 date of discharge estimate entries from 68,587 inpatient encounters met inclusion criteria. After controlling for measured confounding, we found the discharge estimates were more precise as the difference between estimated and actual discharge date narrowed; for each additional day closer to discharge, prediction accuracy improved by .67 days (95% confidence interval [CI], 0.66 to 0.67; p < 0.001), on average. No difference was observed on the primary outcome in patients undergoing surgery compared with non-surgical treatment (0.02 days; 95% CI, 0.00 to 0.03; p = 0.111). Faculty members were found to perform best among all clinicians in predicting estimated discharge date with a 0.24-day better accuracy (95% CI, 0.20 to 0.27; p < 0.001), on average, than other staff. Weekend and holiday, specific clinical teams, staff types, and discharge dispositions were associated with the variability in estimated versus actual discharge date (p < 0.001). Given the widespread variation in current efforts to improve discharge planning and the recommended approach of assigning a discharge date early in the hospital stay, understanding provider estimated discharge dates is an important tool in hospital capacity management. While we did not determine a difference in discharge estimates among surgical and non-surgical patients, we found estimates were more accurate as discharge came nearer and identified notable trends in provider inputs and patient factors. Assessing factors that impact variability in discharge accuracy can allow hospitals to design targeted interventions to improve discharge planning and reduce unnecessary hospital days.

Protocol and statistical analysis plan for the Pragmatic Investigation of optimaL Oxygen Targets (PILOT) clinical trial

INTRODUCTION

Mechanical ventilation of intensive care unit (ICU) patients universally involves titration of the fraction of inspired oxygen to maintain arterial oxygen saturation (SpO2). However, the optimal SpO2 target remains unknown.

METHODS AND ANALYSIS

The Pragmatic Investigation of optimaL Oxygen Targets (PILOT) trial is a prospective, unblinded, pragmatic, cluster-crossover trial being conducted in the emergency department (ED) and medical ICU at Vanderbilt University Medical Center in Nashville, Tennessee, USA. PILOT compares use of a lower SpO2 target (target 90% and goal range: 88%-92%), an intermediate SpO2 target (target 94% and goal range: 92%-96%) and a higher SpO2 target (target 98% and goal range: 96%-100%). The study units are assigned to a single SpO2 target (cluster-level allocation) for each 2-month study block, and the assigned SpO2 target switches every 2 months in a randomly generated sequence (cluster-level crossover). The primary outcome is ventilator-free days (VFDs) to study day 28, defined as the number of days alive and free of invasive mechanical ventilation from the final receipt of invasive mechanical ventilation through 28 days after enrolment.

ETHICS AND DISSEMINATION

The trial was approved by the Vanderbilt Institutional Review Board. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences.

TRIAL REGISTRATION NUMBER

The trial protocol was registered with ClinicalTrials.gov on 25 May 2018 prior to initiation of patient enrolment (ClinicalTrials.gov identifier: NCT03537937).

Natural Language Mapping of Electrocardiogram Interpretations to a Standardized Ontology

BACKGROUND

Interpretations of the electrocardiogram (ECG) are often prepared using software outside the electronic health record (EHR) and imported via an interface as a narrative note. Thus, natural language processing is required to create a computable representation of the findings. Challenges include misspellings, nonstandard abbreviations, jargon, and equivocation in diagnostic interpretations.

OBJECTIVES

Our objective was to develop an algorithm to reliably and efficiently extract such information and map it to the standardized ECG ontology developed jointly by the American Heart Association, the American College of Cardiology Foundation, and the Heart Rhythm Society. The algorithm was to be designed to be easily modifiable for use with EHRs and ECG reporting systems other than the ones studied.

METHODS

An algorithm using natural language processing techniques was developed in structured query language to extract and map quantitative and diagnostic information from ECG narrative reports to the cardiology societies' standardized ECG ontology. The algorithm was developed using a training dataset of 43,861 ECG reports and applied to a test dataset of 46,873 reports.

RESULTS

Accuracy, precision, recall, and the F1-measure were all 100% in the test dataset for the extraction of quantitative data (e.g., PR and QTc interval, atrial and ventricular heart rate). Performances for matches in each diagnostic category in the standardized ECG ontology were all above 99% in the test dataset. The processing speed was approximately 20,000 reports per minute. We externally validated the algorithm from another institution that used a different ECG reporting system and found similar performance.

CONCLUSION

The developed algorithm had high performance for creating a computable representation of ECG interpretations. Software and lookup tables are provided that can easily be modified for local customization and for use with other EHR and ECG reporting systems. This algorithm has utility for research and in clinical decision-support where incorporation of ECG findings is desired.

A Predictive Model of Reintubation after Cardiac Surgery Using the Electronic Health Record

BACKGROUND

Reintubation and prolonged intubation after cardiac surgery are associated with significant complications. Despite these competing risks, providers frequently extubate patients with limited insight into the risk of reintubation at the time of extubation. Achieving timely, successful extubation remains a significant clinical challenge.

METHODS

Based on an analysis of 2835 patients undergoing cardiac surgery at our institution between November 2017 and July 2020, we developed a model for an individual's risk of reintubation at the time of extubation. Predictors were screened for inclusion in the model based on clinical plausibility and availability at the time of extubation. Rigorous data reduction methods were used to create a model that could be easily integrated into clinical workflow at the time of extubation.

RESULTS

In total, 90 patients (3.2%) were reintubated within 48 hours of initial extubation. Number of inotropes [1 (adjusted odds ratio (OR), 15.4; 95% confidence interval (CI) 6.5-47.6; p <.001), ≥2 (OR, 62.7; 95% CI 14.3-279.5; p<.001)]; dexmedetomidine dose (OR, 3.0 [per mcg/kg/h]; 95% CI 1.9-4.7; p <.001), time to extubation (OR, 1.04 [per six hour increase]; 95% CI 1.02-1.05; p <.001), and respiratory rate (OR, 1.04 [per breath/min.]; 95% CI 1.01-1.07; p <.001) were the best predictors for the model, which displayed excellent discriminative capacity (the area under the receiver operating characteristic, 0.86; 95% CI 0.84-0.89).

CONCLUSIONS

An improved understanding of reintubation risk may lead to improved decision-making at extubation and targeted interventions to decrease reintubation in high-risk patients. Future studies are needed to optimize timing of extubation.

Reliability of the ASA Physical Status Classification System in Predicting Surgical Morbidity: a Retrospective Analysis

The American Society of Anesthesiologists (ASA) Physical Status Classification System has been used to assess pre-anesthesia comorbid conditions for over 60 years. However, the ASA Physical Status Classification System has been criticized for its subjective nature. In this study, we aimed to assess the correlation between the ASA physical status assignment and more objective measures of overall illness. This is a single medical center, retrospective cohort study of adult patients who underwent surgery between November 2, 2017 and April 22, 2020. A multivariable ordinal logistic regression model was developed to examine the relationship between the ASA physical status and Elixhauser comorbidity groups. A secondary analysis was then conducted to evaluate the capability of the model to predict 30-day postoperative mortality. A total of 56,820 cases meeting inclusion criteria were analyzed. Twenty-seven Elixhauser comorbidities were independently associated with ASA physical status. Older patient (adjusted odds ratio, 1.39 [per 10 years of age]; 95% CI 1.37 to 1.41), male patient (adjusted odds ratio, 1.24; 95% CI 1.20 to 1.29), higher body weight (adjusted odds ratio, 1.08 [per 10 kg]; 95% CI 1.07 to 1.09), and ASA emergency status (adjusted odds ratio, 2.11; 95% CI 2.00 to 2.23) were also independently associated with higher ASA physical status assignments. Furthermore, the model derived from the primary analysis was a better predictor of 30-day mortality than the models including either single ASA physical status or comorbidity indices in isolation (p < 0.001). We found significant correlation between ASA physical status and 27 of the 31 Elixhauser comorbidities, as well other demographic characteristics. This demonstrates the reliability of ASA scoring and its potential ability to predict postoperative outcomes. Additionally, compared to ASA physical status and individual comorbidity indices, the derived model offered better predictive power in terms of short-term postoperative mortality.

Etiology and Timing of Postoperative Rapid Response Team Activations

In this retrospective cohort study we sought to evaluate the association between the etiology and timing of rapid response team (RRT) activations in postoperative patients at a tertiary care hospital in the southeastern United States. From 2010 to 2016, there were 2,390 adult surgical inpatients with RRT activations within seven days of surgery. Using multivariable linear regression, we modeled the correlation between etiology of RRT and timing of the RRT call, as measured from the conclusion of the surgical procedure. We found that respiratory triggers were associated with an increase in time after surgical procedure to RRT of 10.6 h compared to activations due to general concern (95% CI 3.9 - 17.3) (p = 0.002). These findings may have an impact on monitoring of postoperative patients, as well as focusing interventions to better respond to clinically deteriorating patients.

Delirium Variability is Influenced by the Sound Environment (DEVISE Study): How Changes in the Intensive Care Unit soundscape affect delirium incidence

Quantitative data on the sensory environment of intensive care unit (ICU) patients and its potential link to increased risk of delirium is limited. We examined whether higher average sound and light levels in ICU environments are associated with delirium incidence. Over 111 million sound and light measurements from 143 patient stays in the surgical and trauma ICUs were collected using Quietyme® (Neshkoro, Wisconsin) sensors from May to July 2018 and analyzed. Sensory data were grouped into time of day, then normalized against their ICU environments, with Confusion Assessment Method (CAM-ICU) scores measured each shift. We then performed logistic regression analysis, adjusting for possible confounding variables. Lower morning sound averages (8 am-12 pm) (OR = 0.835, 95% OR CI = [0.746, 0.934], p = 0.002) and higher daytime sound averages (12 pm-6 pm) (OR = 1.157, 95% OR CI = [1.036, 1.292], p = 0.011) were associated with an increased odds of delirium incidence, while nighttime sound averages (10 pm-8 am) (OR = 0.990, 95% OR CI = [0.804, 1.221], p = 0.928) and the ICU light environment did not show statistical significance. Our results suggest an association between the ICU soundscape and the odds of developing delirium. This creates a future paradigm for studies of the ICU soundscape and lightscape.

Quantifying the incidence of clinically significant respiratory depression in women with and without obesity class III receiving neuraxial morphine for post-cesarean analgesia: a retrospective cohort study

BACKGROUND

Obesity is a suspected risk factor for respiratory depression following neuraxial morphine for post-cesarean analgesia, however monitoring guidelines for obese obstetric patients are based on small, limited studies. We tested the hypothesis that clinically significant respiratory depression following neuraxial morphine occurs more commonly in women with body mass index (BMI) ≥40 kg/m² compared with BMI <40 kg/m².

METHODS

We conducted a single-center, retrospective chart review (2006-2017) of obstetric patients with clinically significant respiratory depression following neuraxial morphine, defined as: (1) opioid antagonist administration; (2) rapid response team activation (initiated in April 2010); or (3) tracheal intubation due to a respiratory event. The incidence of respiratory depression was compared between women with BMI ≥40 kg/m² and BMI <40 kg/m².

RESULTS

In total, 11 327 women received neuraxial morphine (n=1945 BMI ≥40 kg/m²; n=9382 BMI <40 kg/m²). Women with BMI ≥40 kg/m² had higher rates of sleep apnea, hypertensive disorders, and magnesium administration. Sixteen cases of clinically significant respiratory depression occurred within seven days postpartum. The incidence did not significantly differ between groups (odds ratio 2.2, 95% CI 0.6 to 6.9, P=0.174). Neuraxial morphine was not deemed causative in any case, however women with BMI ≥40 kg/m² had higher rates of tracheal intubation unrelated to neuraxial morphine (2/1945 vs. 0/9382, P=0.029).

CONCLUSIONS

Respiratory depression in this population is rare. A larger sample (∼75 000) is required to determine whether the incidence is higher with BMI ≥40 kg/m². Tracheal intubation was higher among the BMI ≥40 kg/m² cohort, likely due to more comorbidities.

An improved predictive model for postoperative pulmonary complications after free flap reconstructions in the head and neck

BACKGROUND

Commonly used predictive models for postoperative pulmonary complications (PPCs) do not perform when applied to head and neck cases. A head and neck-specific risk prediction tool is needed.

METHODS

Data on 794 free flap head and neck surgery cases at a single center were abstracted from the electronic medical record. Each case was reviewed for the development of PPCs. A predictive model was developed and was then compared to existing predictive models for PPCs.

RESULTS

The least absolute shrinkage and selection operator procedure identified age, alcohol use, history of congestive heart failure, preoperative packed cell volume, preoperative oxygen saturation, and preoperative metabolic equivalents as predictors of PPCs in the head and neck population. The model demonstrated an area under the receiving operating characteristic curve of 0.75 (0.69-0.80) with moderately good calibration. Comparisons to the performance of existing models demonstrate superior performance.

CONCLUSIONS

The model for the development of PPCs developed in this article displays superior performance to existing models.

The Attributable Mortality of Postoperative Bleeding Exceeds the Attributable Mortality of Postoperative Venous Thromboembolism

BACKGROUND

Bleeding and venous thromboembolic disease are considered important sources of postoperative morbidity and mortality. Clinically, treatment of these 2 disorders is often competing. We sought to better understand the relative contributions of bleeding and venous thromboembolic disease to postoperative attributable mortality in a national cohort.

METHODS

A retrospective analysis of the 2006-2017 American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database was performed to assess the adjusted odds ratio and attributable mortality for postoperative bleeding and venous thromboembolism, adjusted by year.

RESULTS

After adjustment for confounding variables, bleeding exhibited a high postoperative attributable mortality in every year studied. Venous thromboembolism appeared to contribute minimal attributable mortality.

CONCLUSIONS

Bleeding complications are a consistent source of attributable mortality in surgical patients, while the contribution of venous thromboembolic disease appears to be minimal in this analysis. Further studies are warranted to better understand the etiology of this disparity.

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

Use of the electronic health record (EHR) has become a routine part of perioperative care in the United States. Secondary use of EHR data includes research, quality, and educational initiatives. Fundamental to secondary use is a framework to ensure fidelity, transparency, and completeness of the source data. In developing this framework, competing priorities must be considered as to which data sources are used and how data are organized and incorporated into a useable format. In assembling perioperative data from diverse institutions across the United States and Europe, the Multicenter Perioperative Outcomes Group (MPOG) has developed methods to support such a framework. This special article outlines how MPOG has approached considerations of data structure, validation, and accessibility to support multicenter integration of perioperative EHRs. In this multicenter practice registry, MPOG has developed processes to extract data from the perioperative EHR; transform data into a standardized format; and validate, deidentify, and transfer data to a secure central Coordinating Center database. Participating institutions may obtain access to this central database, governed by quality and research committees, to inform clinical practice and contribute to the scientific and clinical communities. Through a rigorous and standardized approach to ensure data integrity, MPOG enables data to be usable for quality improvement and advancing scientific knowledge. As of March 2019, our collaboration of 46 hospitals has accrued 10.7 million anesthesia records with associated perioperative EHR data across heterogeneous vendors. Facilitated by MPOG, each site retains access to a local repository containing all site-specific perioperative data, distinct from source EHRs and readily available for local research, quality, and educational initiatives. Through committee approval processes, investigators at participating sites may additionally access multicenter data for similar initiatives. Emerging from this work are 4 considerations that our group has prioritized to improve data quality: (1) data should be available at the local level before Coordinating Center transfer; (2) data should be rigorously validated against standardized metrics before use; (3) data should be curated into computable phenotypes that are easily accessible; and (4) data should be collected for both research and quality improvement purposes because these complementary goals bolster the strength of each endeavor.

Prospective Investigation of the Operating Room Time-Out Process

BACKGROUND

Although the surgical pause or time-out is a required part of most hospitals' standard operating procedures, little is known about the quality of execution of the time-out in routine clinical practice. An interactive electronic time-out was implemented to increase surgical team compliance with the time-out procedure and to improve communication among team members in the operating room. We sought to identify nonroutine events that occur during the time-out procedure in the operating room, including distractions and interruptions, deviations from protocol, and the problem-solving strategies used by operating room team members to mitigate them.

METHODS

Direct observations of surgical time-outs were performed on 166 nonemergent surgeries in 2016. For each time-out, the observers recorded compliance with each step, any nonroutine events that may have occurred, and whether any operating room team members were distracted.

RESULTS

The time-out procedure was performed before the first incision in 100% of cases. An announcement was made to indicate the start of the time-out procedure in 163 of 166 observed surgeries. Most observed time-outs were completed in <1 minute. Most time-outs were completed without interruption (92.8%). The most common reason for an interruption was to verify patient information. Ten time-out procedures were stopped due to a safety concern. At least 1 member of the operating room team was actively distracted in 10.2% of the time-out procedures observed.

CONCLUSIONS

Compliance with preincision time-outs is high at our institution, and nonroutine events are a rare occurrence. It is common for ≥1 member of the operating room team to be actively distracted during time-out procedures, even though most time-outs are completed in under 1 minute. Despite distractions, there were no wrong-site or wrong-person surgeries reported at our hospital during the study period. We conclude that the simple act of performing a preprocedure checklist may be completed quickly, but that distractions are common.

Patient satisfaction survey scores are not an appropriate metric to differentiate performance among anesthesiologists

STUDY OBJECTIVE

With the focus of patient-centered care in healthcare organizations, patient satisfaction plays an increasingly important role in healthcare quality measurement. We sought to determine whether an automated patient satisfaction survey could be effectively used to identify outlying anesthesiologists.

DESIGN

Retrospective Observational Study.

SETTING

Vanderbilt University Medical Center (VUMC).

MEASUREMENTS

Patient satisfaction data were obtained between October 24, 2016 and November 1, 2017. A multivariable ordered probit regression was conducted to evaluate the relationship between the mean scores of responses to Likert-scale questions on SurveyVitals' Anesthesia Patient Satisfaction Questionnaire 2. Fixed effects included demographics, clinical variables, providers and surgeons. Hypothesis tests to compare each individual anesthesiologist with the median-performing anesthesiologist were conducted.

MAIN RESULTS

We analyzed 10,528 surveys, with a 49.5% overall response rate. Younger patient (odds ratio (OR) 1.011 [per year of age]; 95% confidence interval (CI) 1.008 to 1.014; p < 0.001), regional anesthesia (versus general anesthesia) (OR 1.695; 95% CI 1.186 to 2.422; p = 0.004) and daytime surgery (versus nighttime surgery) (OR 1.795; 95% CI 1.091 to 2.959; p = 0.035) were associated with higher satisfaction scores. Compared with the median-ranked anesthesiologist, we found the adjusted odds ratio for an increase in satisfaction score ranged from 0.346 (95% CI 0.158 to 0.762) to 1.649 (95% CI 0.687 to 3.956) for the lowest and highest scoring providers, respectively. Only 10.10% of anesthesiologists at our institution had an odds ratio for satisfaction with a 95% CI not inclusive of 1.

CONCLUSIONS

Patient satisfaction is impacted by multiple factors. There was very little information in patient satisfaction scores to discriminate the providers, after adjusting for confounding. While patient satisfaction scores may facilitate identification of extreme outliers among anesthesiologists, there is no evidence that this metric is useful for the routine evaluation of individual provider performance.

CYP2D6 Genotype-guided Metoprolol Therapy in Cardiac Surgery Patients: Rationale and Design of the Pharmacogenetic-guided Metoprolol Management for Postoperative Atrial Fibrillation in Cardiac Surgery (PREEMPTIVE) Pilot Study

OBJECTIVES

The Preemptive Pharmacogenetic-guided Metoprolol Management for Atrial Fibrillation in Cardiac Surgery (PREEMPTIVE) pilot trial aims to use existing institutional resources to develop a process for integrating CYP2D6 pharmacogenetic test results into the patient electronic health record, to develop an evidence-based clinical decision support tool to facilitate CYP2D6 genotype-guided metoprolol administration in the cardiac surgery setting, and to determine the impact of implementing this CYP2D6 genotype-guided integrated approach on the incidence of postoperative atrial fibrillation (AF), provider, and cost outcomes.

DESIGN

One-arm Bayesian adaptive design clinical trial.

SETTING

Single center, university hospital.

PARTICIPANTS

The authors will screen (including CYP2D6 genotype) up to 600 (264 ± 144 expected under the adaptive design) cardiac surgery patients, and enroll up to 200 (88 ± 48 expected) poor, intermediate, and ultrarapid CYP2D6 metabolizers over a period of 2 years at a tertiary academic center.

INTERVENTIONS

All consented and enrolled patients will receive the intervention of CYP2D6 genotype-guided metoprolol management based on CYP2D6 phenotype classified as a poor, intermediate, extensive (normal), or ultrarapid metabolizer.

MEASUREMENTS AND MAIN RESULTS

The primary outcome will be the incidence of postoperative AF. Secondary outcomes relating to rates of CYP2D6 genotype-guided prescription changes, costs, lengths of stay, and implementation metrics also will be investigated.

CONCLUSIONS

The PREEMPTIVE pilot study is the first perioperative pilot trial to provide essential information for the design of a future, large-scale trial comparing CYP2D6 genotype-guided metoprolol management with a nontailored strategy in terms of managing AF. In addition, secondary outcomes regarding implementation, clinical benefit, safety, and cost-effectiveness in patients undergoing cardiac surgery will be examined.

Complications Associated With Mortality in the National Surgical Quality Improvement Program Database

BACKGROUND

Attributing causes of postoperative mortality is challenging, as death may be multifactorial. A better understanding of complications that occur in patients who die is important, as it allows clinicians to focus on the most impactful complications. We sought to determine the postoperative complications with the strongest independent association with 30-day mortality.

METHODS

Data were obtained from the 2012-2013 National Surgical Quality Improvement Program Participant Use Data Files. All inpatient or admit day of surgery cases were eligible for inclusion in this study. A multivariable least absolute shrinkage and selection operator regression analysis was used to adjust for patient pre- and intraoperative risk factors for mortality. Attributable mortality was calculated using the population attributable fraction method: the ratio between the odds ratio for mortality and a given complication in the population. Patients were separated into 10 age groups to facilitate analysis of age-related differences in mortality.

RESULTS

A total of 1,195,825 patients were analyzed, and 9255 deceased within 30 days (0.77%). A complication independently associated with attributable mortality was found in 1887 cases (20%). The most common causes of attributable mortality (attributable deaths per million patients) were bleeding (n = 368), respiratory failure (n = 358), septic shock (n = 170), and renal failure (n = 88). Some complications, such as urinary tract infection and pneumonia, were associated with attributable mortality only in older patients.

DISCUSSION

Additional resources should be focused on complications associated with the largest attributable mortality, such as respiratory failure and infections. This is particularly important for complications disproportionately impacting younger patients, given their longer life expectancy.