Factors Associated With Decision to Use and Dosing of Sugammadex in Children: A Retrospective Cross-Sectional Observational Study.

BACKGROUND: Sugammadex was initially approved for reversal of neuromuscular blockade in adults in the United States in 2015. Limited data suggest sugammadex is widely used in pediatric anesthesia practice however the factors influencing use are not known. We explore patient, surgical, and institutional factors associated with the decision to use sugammadex versus neostigmine or no reversal, and the decision to use 2 mg/kg vs 4 mg/kg dosing. METHODS: Using data from the Multicenter Perioperative Outcomes Group (MPOG) database, an EHR-derived registry, we conducted a retrospective cross-sectional study. Eligible cases were performed between January 1, 2016 and December 31, 2020, for children 0 to 17 years at US hospitals. Cases involved general anesthesia with endotracheal intubation and administration of rocuronium or vecuronium. Using generalized linear mixed models with institution and anesthesiologist-specific random intercepts, we measured the importance of a variety of patient, clinician, institution, anesthetic, and surgical risk factors in the decision to use sugammadex versus neostigmine, and the decision to use a 2 mg/kg vs 4 mg/kg dose. We then used intraclass correlation statistics to evaluate the proportion of variance contributed by institution and anesthesiologist specifically. RESULTS: There were 97,654 eligible anesthetics across 30 institutions. Of these 47.1% received sugammadex, 43.1% received neostigmine, and 9.8% received no reversal agent. Variability in the choice to use sugammadex was attributable primarily to institution (40.4%) and attending anesthesiologist (27.1%). Factors associated with sugammadex use (compared to neostigmine) include time from first institutional use of sugammadex (odds ratio [OR], 1.08, 95% confidence interval [CI], 1.08-1.09, per month, P < .001), younger patient age groups (0-27 days OR, 2.59 [2.00-3.34], P < .001; 28 days-1 year OR, 2.72 [2.16-3.43], P < .001 vs 12-17 years), increased American Society of Anesthesiologists [ASA] physical status (ASA III: OR, 1.32 [1.23-1.42], P < .001 ASA IV OR, 1.71 [1.46-2.00], P < .001 vs ASA I), neuromuscular disease (OR, 1.14 (1.04-1.26], P = .006), cardiac surgery (OR, 1.76 [1.40-2.22], P < .001), dose of neuromuscular blockade within the hour before reversal (>2 ED95s/kg OR, 4.58 (4.14-5.07], P < .001 vs none), and shorter case duration (case duration <60 minutes OR, 2.06 [1.75-2.43], P < .001 vs >300 minutes). CONCLUSIONS: Variation in sugammadex use was primarily explained by institution and attending anesthesiologist. Patient factors associated with the decision to use sugammadex included younger age, higher doses of neuromuscular blocking agents, and increased medical complexity.

Angiotensin II for the Treatment of Refractory Shock: A Matched Analysis.

OBJECTIVES: To determine if angiotensin II is associated with improved outcomes as measured by 30- and 90-day mortality as well as other secondary outcomes such as organ dysfunction and adverse events. DESIGN: Retrospective, matched analysis of patients receiving angiotensin II compared with both historical and concurrent controls receiving equivalent doses of nonangiotensin II vasopressors. SETTING: Multiple ICUs in a large, university-based hospital. PATIENTS: Eight hundred thirteen adult patients with shock admitted to an ICU and requiring vasopressor support. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Angiotensin II use had no association with the primary outcome of 30-day mortality (60% vs 56%; p = 0.292). The secondary outcome of 90-day mortality was also similar (65% vs 63%; p = 0.440) as were changes in Sequential Organ Failure Assessment scores over a 5-day monitoring period after enrollment. Angiotensin II was not associated with increased rates of kidney replacement therapy (odds ratio [OR], 1.39; 95% CI, 0.88-2.19; p = 0.158) or receipt of mechanical ventilation (OR, 1.50; 95% CI, 0.41-5.51; p = 0.539) after enrollment, and the rate of thrombotic events was similar between angiotensin II and control patients (OR, 1.02; 95% CI, 0.71-1.48; p = 0.912). CONCLUSIONS: In patients with severe shock, angiotensin II was not associated with improved mortality or organ dysfunction and was not associated with an increased rate of adverse events.

Patient-, Clinician-, and Institution-level Variation in Inotrope Use for Cardiac Surgery: A Multicenter Observational Analysis.

BACKGROUND: Conflicting evidence exists regarding the risks and benefits of inotropic therapies during cardiac surgery, and the extent of variation in clinical practice remains understudied. Therefore, the authors sought to quantify patient-, anesthesiologist-, and hospital-related contributions to variation in inotrope use. METHODS: In this observational study, nonemergent adult cardiac surgeries using cardiopulmonary bypass were reviewed across a multicenter cohort of academic and community hospitals from 2014 to 2019. Patients who were moribund, receiving mechanical circulatory support, or receiving preoperative or home inotropes were excluded. The primary outcome was an inotrope infusion (epinephrine, dobutamine, milrinone, dopamine) administered for greater than 60 consecutive min intraoperatively or ongoing upon transport from the operating room. Institution-, clinician-, and patient-level variance components were studied. RESULTS: Among 51,085 cases across 611 attending anesthesiologists and 29 hospitals, 27,033 (52.9%) cases received at least one intraoperative inotrope, including 21,796 (42.7%) epinephrine, 6,360 (12.4%) milrinone, 2,000 (3.9%) dobutamine, and 602 (1.2%) dopamine (non-mutually exclusive). Variation in inotrope use was 22.6% attributable to the institution, 6.8% attributable to the primary attending anesthesiologist, and 70.6% attributable to the patient. The adjusted median odds ratio for the same patient receiving inotropes was 1.73 between 2 randomly selected clinicians and 3.55 between 2 randomly selected institutions. Factors most strongly associated with increased likelihood of inotrope use were institutional medical school affiliation (adjusted odds ratio, 6.2; 95% CI, 1.39 to 27.8), heart failure (adjusted odds ratio, 2.60; 95% CI, 2.46 to 2.76), pulmonary circulation disorder (adjusted odds ratio, 1.72; 95% CI, 1.58 to 1.87), loop diuretic home medication (adjusted odds ratio, 1.55; 95% CI, 1.42 to 1.69), Black race (adjusted odds ratio, 1.49; 95% CI, 1.32 to 1.68), and digoxin home medication (adjusted odds ratio, 1.48; 95% CI, 1.18 to 1.86). CONCLUSIONS: Variation in inotrope use during cardiac surgery is attributable to the institution and to the clinician, in addition to the patient. Variation across institutions and clinicians suggests a need for future quantitative and qualitative research to understand variation in inotrope use affecting outcomes and develop evidence-based, patient-centered inotrope therapies.

Electroencephalographic Biomarkers, Cerebral Oximetry, and Postoperative Cognitive Function in Adult Noncardiac Surgical Patients: A Prospective Cohort Study.

BACKGROUND: Perioperative neurocognitive disorders are a major public health issue, although there are no validated neurophysiologic biomarkers that predict cognitive function after surgery. This study tested the hypothesis that preoperative posterior electroencephalographic alpha power, alpha frontal-parietal connectivity, and cerebral oximetry would each correlate with postoperative neurocognitive function. METHODS: This was a single-center, prospective, observational study of adult (older than 18 yr) male and female noncardiac surgery patients. Whole-scalp, 16-channel electroencephalography and cerebral oximetry were recorded in the preoperative, intraoperative, and immediate postoperative settings. The primary outcome was the mean postoperative T-score of three National Institutes of Health Toolbox Cognition tests-Flanker Inhibitory Control and Attention, List Sorting Working Memory, and Pattern Comparison Processing Speed. These tests were obtained at preoperative baseline and on the first two postoperative mornings. The lowest average score from the first two postoperative days was used for the primary analysis. Delirium was a secondary outcome (via 3-min Confusion Assessment Method) measured in the postanesthesia care unit and twice daily for the first 3 postoperative days. Last, patient-reported outcomes related to cognition and overall well-being were collected 3 months postdischarge. RESULTS: Sixty-four participants were recruited with a median (interquartile range) age of 59 (48 to 66) yr. After adjustment for baseline cognitive function scores, no significant partial correlation (ρ) was detected between postoperative cognition scores and preoperative relative posterior alpha power (%; ρ = -0.03, P = 0.854), alpha frontal-parietal connectivity (via weight phase lag index; ρ = -0.10, P = 0.570, respectively), or preoperative cerebral oximetry (%; ρ = 0.21, P = 0.246). Only intraoperative frontal-parietal theta connectivity was associated with postoperative delirium (F[1,6,291] = 4.53, P = 0.034). No electroencephalographic or oximetry biomarkers were associated with cognitive or functional outcomes 3 months postdischarge. CONCLUSIONS: Preoperative posterior alpha power, frontal-parietal connectivity, and cerebral oximetry were not associated with cognitive function after noncardiac surgery.

Association between choice of reversal agent for neuromuscular block and postoperative pulmonary complications in patients at increased risk undergoing non-emergency surgery: STIL-STRONGER, a multicentre matched cohort study.

BACKGROUND: Postoperative pulmonary complications are a source of morbidity after major surgery. In patients at increased risk of postoperative pulmonary complications we sought to assess the association between neuromuscular blocking agent reversal agent and development of postoperative pulmonary complications. METHODS: We conducted a retrospective matched cohort study, a secondary analysis of data collected in the prior STRONGER study. Data were obtained from the Multicenter Perioperative Outcomes Group. Included patients were aged 18 yr and older undergoing non-emergency surgery under general anaesthesia with tracheal intubation with neuromuscular block and reversal, who were predicted to be at elevated risk of postoperative pulmonary complications. This risk was defined as American Society of Anesthesiologists Physical Status 3 or 4 in patients undergoing either intrathoracic or intra-abdominal surgery who were either aged >80 yr or underwent a procedure lasting >2 h. Cohorts were defined by reversal with neostigmine or sugammadex. The primary composite outcome was the occurrence of pneumonia or respiratory failure. RESULTS: After matching by institution, sex, age (within 5 yr), body mass index, anatomic region of surgery, comorbidities, and neuromuscular blocking agent, 3817 matched pairs remained. The primary postoperative pulmonary complications outcome occurred in 224 neostigmine cases vs 100 sugammadex cases (5.9% vs 2.6%, odds ratio 0.41, P<0.01). After adjustment for unbalanced covariates, the adjusted odds ratio for the association between sugammadex use and the primary outcome was 0.39 (P<0.0001). CONCLUSIONS: In a cohort of patients at increased risk for pulmonary complications compared with neostigmine, use of sugammadex was independently associated with reduced risk of subsequent development of pneumonia or respiratory failure.

Anesthetic Practice Trends and Perceptions Toward Postoperative Delirium: A Mixed-Methods Analysis.

BACKGROUND: Delirium is the most common postoperative complication in older adults, though anesthesiologist awareness of delirium prevention guidelines-and associated practice trends-remains unknown. METHODS: This was a convergent mixed-methods study, which simultaneously analyzed quantitative and qualitative data to determine delirium guideline awareness among anesthesiologists and practice patterns based on guideline recommendations. Quantitative data were abstracted from the Multicenter Perioperative Outcomes Group database for noncardiac surgery patients (2009-2020) aged 65 years and older. Linear trends were reported for select guideline-based delirium prevention recommendations via regression modeling. Anesthesiologists (n = 40) from a major academic center without a structured delirium reduction program on hospital wards were then surveyed regarding knowledge and practices with respect to postoperative delirium. For qualitative data, 3 focus groups were held to further discuss guideline awareness and identify challenges with delirium prevention. RESULTS: Quantitative results demonstrated a significant decline in the proportion of cases with midazolam between 2009 and 2020, with the largest decrease observed with urologic surgeries (-3.9%/y; 95% confidence interval [CI], -4.2 to -3.6; P < .001). Use of regional anesthesia increased over this period, particularly with gynecologic surgeries (+2.3%/y; 95% CI, 1.2-3.4; P = .001). Anesthesiologist survey results revealed variable guideline awareness, as 21 of 39 (54%) respondents reported being aware of guidelines for anesthetic management of older adults. Importantly, unawareness of delirium management guidelines was the most frequently cited challenge (17 of 37, 46%) when caring for older adults. Finally, focus group participants were largely unaware of postoperative delirium guidelines. However, participants conveyed key barriers to delirium identification and prevention, including the unclear pathophysiology, nonmodifiable risk factors, and system-based hospital challenges. Participants also expressed a desire for decision-support systems, integrated within the perioperative workflow, that provide evidence-based recommendations for reducing delirium risk. CONCLUSIONS: Perioperative practice trends are indicative of an improving environment for postoperative delirium. However, delirium guideline awareness remains variable among anesthesiologists, and key barriers continue to exist for identifying and preventing postoperative delirium.

Does Anesthesia Quality Improvement Participation Lead to Incremental Savings in a Surgical Quality Collaborative Population? A Retrospective Observational Study.

BACKGROUND: The Anesthesiology Performance Improvement and Reporting Exchange (ASPIRE) Collaborative Quality Initiative (CQI) was launched as a partnership among hospitals to measure quality, review evidence-based practices, and improve anesthesia-related outcomes. Cost savings and improved patient outcomes have been associated with surgical CQI participation, but the impact of an anesthesia CQI on health care cost has not been thoroughly assessed. In this study, we evaluated whether participation in an anesthesia CQI led to health care savings. We hypothesized that ASPIRE participation is associated with reduced total episode payments for payers and major, high-volume procedures included in the Michigan Value Collaborative (MVC) registry. METHODS: In this retrospective observational study, we compared MVC episode payment data from Group 1 ASPIRE hospitals, the first cluster of 8 Michigan hospitals to join ASPIRE in January 2015, to non-ASPIRE matched control hospitals. MVC computes price-standardized, risk-adjusted payments for patients insured by Blue Cross Blue Shield of Michigan Preferred Provider Organization, Blue Care Network Health Maintenance Organization, and Medicare Fee-for-Service plans. Episodes from 2014 comprised the pre-ASPIRE time period, and episodes from June 2016 to July 2017 constituted the post-ASPIRE time period. We performed a difference-in-differences analysis to evaluate whether ASPIRE implementation was associated with greater reduction in total episode payments compared to the change in the control hospitals during the same time periods. RESULTS: We found a statistically significant reduction in total episode (-$719; 95% CI [-$1340 to -$97]; P = .023) payments at the 8 ASPIRE hospitals (N = 17,852 cases) compared to the change observed in 8 matched non-ASPIRE hospitals (N = 12,987 cases) for major, high-volume surgeries, including colectomy, colorectal cancer resection, gastrectomy, esophagectomy, pancreatectomy, hysterectomy, joint replacement (knee and hip), and hip fracture repair. In secondary analyses, 30-day postdischarge (-$354; 95% CI [-$582 to -$126]; P = .002) payments were also significantly reduced in ASPIRE hospitals compared to non-ASPIRE controls. Subgroup analyses revealed a significant reduction in total episode payments for joint replacements (-$860; 95% CI [-$1222 to -$499]; P < .001) at ASPIRE-participating hospitals. Sensitivity analyses including patient-level covariates also showed consistent results. CONCLUSIONS: Participation in an anesthesiology CQI, ASPIRE, is associated with lower total episode payments for selected major, high-volume procedures. This analysis supports that participation in an anesthesia CQI can lead to reduced health care payments.

Use of neuromuscular blockade for neck dissection and association with iatrogenic nerve injury.

BACKGROUND: Cranial nerve injury is an uncommon but significant complication of neck dissection. We examined the association between the use of intraoperative neuromuscular blockade and iatrogenic cranial nerve injury during neck dissection. METHODS: This was a single-center, retrospective, electronic health record review. Study inclusion criteria stipulated patients > 18 years who had ≥ 2 neck lymphatic levels dissected for malignancy under general anesthesia with a surgery date between 2008 - 2018. Use of neuromuscular blockade during neck dissection was the primary independent variable. This was defined as any use of rocuronium, cisatracurium, or vecuronium upon anesthesia induction without reversal with sugammadex prior to surgical incision. Univariate tests were used to compare variables between those patients with, and those without, iatrogenic cranial nerve injury. Multivariable logistic regression determined predictors of cranial nerve injury and was performed incorporating Firth's estimation given low prevalence of the primary outcome. RESULTS: Our cohort consisted of 925 distinct neck dissections performed in 897 patients. Neuromuscular blockade was used during 285 (30.8%) neck dissections. Fourteen instances (1.5% of surgical cases) of nerve injury were identified. On univariate logistic regression, use of neuromuscular blockade was not associated with iatrogenic cranial nerve injury (OR: 1.73, 95% CI: 0.62 - 4.86, p = 0.30). There remained no significant association on multivariable logistic regression controlling for patient age, sex, weight, ASA class, paralytic dose, history of diabetes, stroke, coronary artery disease, carotid atherosclerosis, myocardial infarction, and cardiac arrythmia (OR: 1.87, 95% CI: 0.63 - 5.51, p = 0.26). CONCLUSIONS: In this study, use of neuromuscular blockade intraoperatively during neck dissection was not associated with increased rates of iatrogenic cranial nerve injury. While this investigation provides early support for safe use of neuromuscular blockade during neck dissection, future investigation with greater power remains necessary.

Delayed Discharge From the Intensive Care Unit Is Associated With Longer Hospital Lengths of Stay.

OBJECTIVE: The study authors sought to determine if delayed discharge from the intensive care unit (ICU) secondary to a lack of floor beds led to longer postoperative hospital length of stay (LOS) or more hospital readmissions. DESIGN: A retrospective study comparing patients with delayed discharge from the ICU to patients without delayed discharge. SETTING: At a cardiovascular ICU in a tertiary care university hospital. PARTICIPANTS: A total of 5,777 patients that were ready for discharge from the ICU after recovering from cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The authors used linear regression to measure postoperative hospital LOS and logistic regression to measure hospital readmission in patients whose transfer out of the ICU was delayed at least overnight to patients who were transferred out the same day. There were 3,903 patients transferred to the stepdown unit on the same day as the transfer order and 1,874 patients were transferred on a subsequent day. The postoperative LOS was shorter in the no delay group (9 ± 9 v 11 ± 10 days, standardized difference = 0.162), whereas the stepdown unit stay was similar (6 ± 6 v 5 ± 6 days, standardized difference = 0.076). The readmission rates were 15% in the no delay group versus 14% in the delayed discharge group (standardized difference = 0.032). After adjustment, the authors found by linear regression that delayed discharge was associated with an increase (0.72 [95% CI 0.43-1.01] days, p < 0.001) in postoperative LOS but was not associated with readmission. CONCLUSIONS: The study authors found that patients who had their discharge from the ICU delayed had an increased hospital LOS but a similar rate of hospital readmission.

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.

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.

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.

Use of the Change in Weaning Parameters as a Predictor of Successful Re-Extubation.

OBJECTIVE: Weaning parameters are well studied in patients undergoing first time extubation. Fewer data exists to guide re-extubation of patients who failed their first extubation attempt. It is reasonable to postulate that improved weaning parameters between the first and second extubation attempt would lead to improved rates of re-extubation success. To investigate, we studied a cohort of patients who failed their first extubation attempt and underwent a second attempt at extubation. We hypothesized that improvement in weaning parameters between the first and the second extubation attempt is associated with successful reextubation. INTERVENTIONS: Rapid shallow breathing index (RSBI), maximum inspiratory pressure (MIP), vital capacity (VC), and the blood partial pressure of CO2 (PaCO2) were measured and recorded in the medical record prior to extubation along with demographic information. We examined the relationship between the change in extubation and re-extubation weaning parameters and re-extubation success. MEASUREMENTS AND MAIN RESULTS: A total of 1283 adult patients were included. All weaning parameters obtained prior to re-extubation differed between those who were successful and those who required a second reintubation. Those with reextubation success had slightly lower PaCO2 values (39.5 ± 7.4 mmHg vs. 41.6 ± 9.1 mmHg, p = 0.0045) and about 13% higher vital capacity volumes (1021 ± 410 mL vs. 907 ± 396 mL, p = 0.0093). Lower values for RSBI (53 ± 32 breaths/min/L vs. 69 ± 42 breaths/min/L, p < 0.001) and MIP (-41 ± 12 cmH2O vs. -38 ± 13 cm H2O), p = 0.0225) were seen in those with re-extubation success. Multivariable logistical regression demonstrates lack of independent associated between the change in parameters between the 2 attempts and re-extubation success. CONCLUSIONS: The relationship between the changes in extubation parameters through successive attempts is driven primarily by the value obtained immediately prior to re-extubation. These findings do not support waiting for an improvement in extubation parameters to extubate patients who failed a first attempt at extubation if extubation parameters are compatible with success.

Identification of intraoperative management strategies that have a differential effect on patients with reduced left ventricular ejection fraction: a retrospective cohort study.

BACKGROUND: There are few data to guide the intraoperative management of patients with reduced left ventricular ejection fraction (LVEF). This study aimed to describe how patients with reduced LVEF are managed differently and to identify and treatments had a different risk profile in this population. METHODS: We performed a retrospective cohort study of adult patients who underwent general anesthesia for non-cardiac surgery. The effect of anesthesia medications and fluid balance was compared between those with and without a reduced preoperative LVEF. The primary outcome was a composite of acute kidney injury, myocardial injury, pulmonary complications, and 30-day mortality. Multivariable logistic regression was used to adjust for confounders. Treatments that affected patients with reduced LVEF differently were defined as those associated with the primary outcome that also had a significant interaction with LVEF. RESULTS: A total of 9420 patients were included. Patients with reduced LVEF tended to have a less positive fluid balance. Etomidate, calcium, and phenylephrine were use more frequently, while propofol and remifentanil were used less frequently. Remifentanil affected patients with reduced LVEF differently than those without (interaction term OR 2.71, 95% CI 1.30-5.68, p = 0.008). While the use of remifentanil was associated with fewer complications in patients with normal systolic function (OR 0.54, 95% CI 0.42-0.68, p < 0.001), it was associated with an increase in complications in patients with reduced LVEF (OR = 3.13, 95% CI 3.06-5.98, p = 0.026). CONCLUSIONS: Patients with a reduced preoperative LVEF are treated differently than those with a normal LVEF when undergoing non-cardiac surgery. An association was found between the use of remifentanil and an increase in postoperative adverse events that was unique to this population. Future research is needed to determine if this relationship is secondary to the medication itself or reflects a difference in how remifentanil is used in patients with reduced LVEF.

Correlation between brain tissue oxygen tension and regional cerebral oximetry in uninjured human brain under conditions of changing ventilation strategy.

Controversy surrounds regional cerebral oximetry (rSO2) because extracranial contamination and unmeasured changes in cerebral arterial:venous ratio confound readings. Correlation of rSO2 with brain tissue oxygen (PbrO2), a "gold standard" for cerebral oxygenation, could help resolve this controversy but PbrO2 measurement is highly invasive. This was a prospective cohort study. The primary aim was to evaluate correlation between PbrO2 and rSO2 and the secondary aim was to investigate the relationship between changing ventilation regimens and measurement of PbrO2 and rSO2. Patients scheduled for elective removal of cerebral metastases were anesthetized with propofol and remifentanil, targeted to a BIS range 40-60. rSO2 was measured using the INVOS 5100B monitor and PbrO2 using the Licox brain monitoring system. The Licox probe was placed into an area of normal brain within the tumor excision corridor. FiO2 and minute ventilation were sequentially adjusted to achieve two set points: (1) FiO2 0.3 and paCO2 30 mmHg, (2) FiO2 1.0 and paCO2 40 mmHg. PbrO2 and rSO2 were recorded at each. Nine participants were included in the final analysis, which showed a positive Spearman's correlation (r = 0.50, p = 0.036) between PbrO2 and rSO2. From set point 1 to set point 2, PbrO2 increased from median 6.0, IQR 4.0-11.3 to median 22.5, IQR 9.8-43.6, p = 0.015; rSO2 increased from median 68.0, IQR 62.5-80.5 to median 83.0, IQR 74.0-90.0, p = 0.047. Correlation between PbrO2 and rSO2 is evident. Increasing FiO2 and PaCO2 results in significant increases in cerebral oxygenation measured by both monitors.

Clinically applicable approach for predicting mechanical ventilation in patients with COVID-19.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) requiring mechanical ventilation have high mortality and resource utilisation. The ability to predict which patients may require mechanical ventilation allows increased acuity of care and targeted interventions to potentially mitigate deterioration. METHODS: We included hospitalised patients with COVID-19 in this single-centre retrospective observational study. Our primary outcome was mechanical ventilation or death within 24 h. As clinical decompensation is more recognisable, but less modifiable, as the prediction window shrinks, we also assessed 4, 8, and 48 h prediction windows. Model features included demographic information, laboratory results, comorbidities, medication administration, and vital signs. We created a Random Forest model, and assessed performance using 10-fold cross-validation. The model was compared with models derived from generalised estimating equations using discrimination. RESULTS: Ninety-three (23%) of 398 patients required mechanical ventilation or died within 14 days of admission. The Random Forest model predicted pending mechanical ventilation with good discrimination (C-statistic=0.858; 95% confidence interval, 0.841-0.874), which is comparable with the discrimination of the generalised estimating equation regression. Vitals sign data including SpO2/FiO2 ratio (Random Forest Feature Importance Z-score=8.56), ventilatory frequency (5.97), and heart rate (5.87) had the highest predictive utility. In our highest-risk cohort, the number of patients needed to identify a single new case was 3.2, and for our second quintile it was 5.0. CONCLUSION: Machine learning techniques can be leveraged to improve the ability to predict which patients with COVID-19 are likely to require mechanical ventilation, identifying unrecognised bellwethers and providing insight into the constellation of accompanying signs of respiratory failure in COVID-19.

The Effects of Intraoperative Caffeine on Postoperative Opioid Consumption and Related Outcomes After Laparoscopic Surgery: A Randomized Controlled Trial.

BACKGROUND: Surgical patients are vulnerable to opioid dependency and related risks. Clinical-translational data suggest that caffeine may enhance postoperative analgesia. This trial tested the hypothesis that intraoperative caffeine would reduce postoperative opioid consumption. The secondary objective was to assess whether caffeine improves neuropsychological recovery postoperatively. METHODS: This was a single-center, randomized, placebo-controlled trial. Participants, clinicians, research teams, and data analysts were all blinded to the intervention. Adult (≥18 years old) surgical patients (n = 65) presenting for laparoscopic colorectal and gastrointestinal surgery were randomized to an intravenous caffeine citrate infusion (200 mg) or dextrose 5% in water (40 mL) during surgical closure. The primary outcome was cumulative opioid consumption through postoperative day 3. Secondary outcomes included subjective pain reporting, observer-reported pain, delirium, Trail Making Test performance, depression and anxiety screens, and affect scores. Adverse events were reported, and hemodynamic profiles were also compared between the groups. RESULTS: Sixty patients were included in the final analysis, with 30 randomized to each group. The median (interquartile range) cumulative opioid consumption (oral morphine equivalents, milligrams) was 77 mg (33-182 mg) for caffeine and 51 mg (15-117 mg) for placebo (estimated difference, 55 mg; 95% confidence interval [CI], -9 to 118; P = .092). After post hoc adjustment for baseline imbalances, caffeine was associated with increased opioid consumption (87 mg; 95% CI, 26-148; P = .005). There were otherwise no differences in prespecified pain or neuropsychological outcomes between the groups. No major adverse events were reported in relation to caffeine, and no major hemodynamic perturbations were observed with caffeine administration. CONCLUSIONS: Caffeine appears unlikely to reduce early postoperative opioid consumption. Caffeine otherwise appears well tolerated during anesthetic emergence.

Anesthesiologist-related factors associated with risk-adjusted pediatric anesthesia-related cardiopulmonary arrest: a retrospective two level analysis.

BACKGROUND: Pediatric anesthesia-related cardiac arrest is an uncommon but catastrophic adverse event which has been, in a previous study, associated with anesthesiologist-related factors such as number of days per year providing pediatric anesthesia. We aimed to replicate this and assess other anesthesiologist-related risk factors for anesthesia-related cardiac arrest after adjusting for known underlying risk factors present in the case mix. METHODS: We analyzed a large retrospectively collected patient cohort of anesthetics administered from 2006 to 2016 to children at a tertiary pediatric hospital. Three reviewers independently reviewed cardiac arrests and categorized whether they appeared to be related to anesthesia care. Anesthesiologist-related factors including academic rank, experience, recent case mix, and days per year delivering pediatric anesthesia were assessed for association with anesthesia-related cardiac arrest after adjustment for underlying case mix. RESULTS: Cardiac arrest occurred in 240 of 109 775 anesthetics (incidence 22/10 000 anesthetics); 82 (7/10 000 anesthetics) were classified as anesthesia-related. In univariable analyses, anesthesia-related cardiac arrest was associated with age, (infants ≤180 days, p < .001) American Society of Anesthesiologists Physical Status, (>2, p < .001) American Society of Anesthesiologists Physical Status Emergency, (p = .0035) cardiac surgery, (p < .001) operating room location, (p = .0066) and resident/fellow supervision, (p = .009) but none of the anesthesiologist factors. Even after adjusting for age and American Society of Anesthesiologist Status, none of the anesthesiologist factors were associated with anesthesia-related cardiac arrest. CONCLUSIONS: Case mix explained all associations between higher risk of pediatric anesthesia-related cardiac arrest and anesthesiologist-related variables at our institution.

Utilization Patterns of Perioperative Neuromuscular Blockade Reversal in the United States: A Retrospective Observational Study From the Multicenter Perioperative Outcomes Group.

BACKGROUND: Following the introduction of sugammadex to the US clinical practice, scarce data are available to understand its utilization patterns. This study aimed to characterize patient, procedure, and provider factors associated with sugammadex administration in US patients. METHODS: This retrospective observational study was conducted across 24 Multicenter Perioperative Outcomes Group institutions in the United States with sugammadex on formulary at the time of the study. All American Society of Anesthesiologists (ASA) physical status I-IV adults undergoing noncardiac surgery from 2014 to 2018 receiving neuromuscular blockade (NMB) were eligible. The study established 3 periods based on the date of first documented sugammadex use at each institution: the presugammadex period, 0- to 6-month transitional period, and 6+ months postsugammadex period. The primary outcome was reversal using sugammadex during the postsugammadex period-defined as 6 months after sugammadex was first utilized at each institution. A multivariable mixed-effects logistic regression model controlling for institution was developed to assess patient, procedure, and provider factors associated with sugammadex administration. RESULTS: A total of 934,798 cases met inclusion criteria. Following the 6-month transitional period, sugammadex was used on average in 40.0% (95% confidence interval [CI], 39.8-40.2) of cases receiving NMB. Multivariable analysis demonstrated sugammadex use to be associated with train-of-four count of 0-1 (adjusted odds ratio = 4.06; 95% CI, 33.83-4.31) or 2 (2.45; 2.29-2.62) vs 3-4 twitches before reversal; the amount of NMB administered (3.01; 2.88-3.16) for the highest effective dose 95 quartile compared to the lowest quartile; advanced age (1.83; 1.71-1.95) compared to age <41; male sex (1.36; 1.32-1.39) compared to female sex; major thoracic surgery (1.26; 1.13-1.39); congestive heart failure (1.17, 1.07-1.28); and ASA III or IV (1.13; 1.10-1.16) versus ASA I or II. CONCLUSIONS: Our data demonstrate broad early clinical adoption of sugammadex following Food and Drug Administration approval. Sugammadex is used preferentially in cases with higher degrees of NMB before reversal and in patients with greater burden of comorbidities and known risk factors for residual blockade or pulmonary complications.

Use of a Novel Electronic Maternal Surveillance System and the Maternal Early Warning Criteria to Detect Severe Postpartum Hemorrhage.

BACKGROUND: A leading cause of preventable maternal death is related to delayed response to clinical warning signs. Electronic surveillance systems may improve detection of maternal morbidity with automated notifications. This retrospective observational study evaluates the ability of an automated surveillance system and the Maternal Early Warning Criteria (MEWC) to detect severely morbid postpartum hemorrhage (sPPH) after delivery. METHODS: The electronic health records of adult obstetric patients of any gestational age delivering between April 1, 2017 and December 1, 2018 were queried to identify scheduled or unscheduled vaginal or cesarean deliveries. Deliveries complicated by sPPH were identified and defined by operative management of postpartum hemorrhage, transfusion of ≥4 units of packed red blood cells (pRBCs), ≥2 units of pRBCs and ≥2 units of fresh-frozen plasma, transfusion with >1 dose of furosemide, or transfer to the intensive care unit. The test characteristics of automated pages and the MEWC for identification of sPPH 24 hours after delivery were determined and compared using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) and their 95% confidence intervals (CIs). McNemar test was used to compare these estimates for both early warning systems. RESULTS: The average age at admission was 30.7 years (standard deviation [SD] = 5.1 years), mean gestational age 38 weeks 4 days, and cesarean delivery accounted for 30.0% of deliveries. Of 7853 deliveries, 120 (1.5%) were complicated by sPPH. The sensitivity of automated pages for sPPH within 24 hours of delivery was 60.8% (95% CI, 52.1-69.6), specificity 82.5% (95% CI, 81.7-83.4), PPV 5.1% (95% CI, 4.0-6.3), and NPV 99.3% (95% CI, 99.1-99.5). The test characteristics of the MEWC for sPPH were sensitivity 75.0% (95% CI, 67.3-82.7), specificity 66.3% (95% CI, 65.2-67.3), PPV 3.3% (95% CI, 2.7-4.0), and NPV 99.4% (95% CI, 99.2-99.6). There were 10 sPPH cases identified by automated pages, but not by the MEWC. Six of these cases were identified by a page for anemia, and 4 cases were the result of vital signs detected by the bedside monitor, but not recorded in the patient's medical record by the bedside nurse. Therefore, the combined sensitivity of the 2 systems was 83.3% (95% CI, 75.4-89.5). CONCLUSIONS: The automated system identified 10 of 120 deliveries complicated by sPPH not identified by the MEWC. Using an automated alerting system in combination with a labor and delivery unit's existing nursing-driven early warning system may improve detection of sPPH.