Timing of Intraoperative Transitions of Care Among Anesthesiologists Is Not Associated With Postoperative Adverse Outcomes: Retrospective Cohort Study.

BACKGROUND: The majority of published research suggests that anesthesia handovers during major surgical procedures are associated with unintended harmful consequences. It is still unclear if the number or quality of the transition of care is the main driver of the adverse outcomes. There is even less data if the timing of the anesthesiologist handovers during the critical portion of the anesthetic continuum (induction or emergence versus surgical period) plays a role in patient outcomes. Therefore, we investigated if the anesthesiologist handovers during induction and emergence are associated with adverse patient outcomes. METHODS: This retrospective investigation included noncardiac surgical procedures occurring between January 1, 2012 and December 31, 2019 that had exactly 1 attending anesthesiologist handover. We categorized transitions of care between attending anesthesiologists as being before incision, between incision and closing, and after closing. Our primary outcome was a composite of 6 categories of surgical complications and in-hospital mortality. We created logistic generalized estimating equation models to estimate the average relative effect odds ratio between each pair of the 3 transition timing groups across the components of the composite outcome. Inverse probability of treatment weights were used to mitigate confounding on a host of baseline variables. We used Bonferroni correction to adjust for multiple comparisons between the transition groups. RESULTS: In total, we studied 36,937 procedures with exactly 1 attending anesthesiologist handover. Of these records, 4370 had the transition during induction, 24,999 between incision and closure, and 7568 during emergence. No differences were found between the transition periods and the composite outcome. The estimated average relative effect odds ratio (98.3% confidence interval [CI]) across the components of the composite outcome was as follows: (1.0002 [0.81-1.24], P = .99) between the induction and surgical period; (1.10 [0.87-1.40], P = .32) between the induction and emergence periods; and (0.91 [0.79-1.04], P = .08) between the emergence and surgical periods. CONCLUSIONS: Timing of intraoperative handover among attending anesthesiologists during noncardiac surgery is not associated with adverse patient outcomes.

Intraoperative hypotension during liver transplantation and postoperative outcomes: Retrospective cohort study.

STUDY OBJECTIVES: Evaluation of the association between intraoperative hypotension (IOH) and important postoperative outcomes after liver transplant such as incidence and severity of acute kidney injury (AKI), MACE and early allograft dysfunction (EAD). DESIGN: Retrospective, single institution study. SETTINGS: Operating room. PATIENTS: 1576 patients who underwent liver transplant in our institution between January 2005 and February 2022. MEASUREMENTS: IOH was measured as the time, area under the threshold (AUT), or time-weighted average (TWA) of mean arterial pressure (MAP) less than certain thresholds (55,60 and 65 mmHg). Associations between IOH exposures and AKI severity were assessed via proportional odds models. The odds ratio from the proportional odds model estimated the relative odds of having higher stage of AKI for higher exposure to IOH. Associations between exposures and MACE and EAD were assessed through logistic regression models. Potential confounding variables including patient baseline and surgical characteristics were adjusted for all models. MAIN RESULTS: The primary analysis included 1576 surgeries that met the inclusion and exclusion criteria. Of those, 1160 patients (74%) experienced AKI after liver transplant surgery, with 780 (49%), 248(16%), and 132 (8.4%) experiencing mild, moderate, and severe injury, respectively. No significant association between hypotension exposure and postoperative AKI (yes or no) nor severity of AKI was observed. The odds ratios (95% CI) of having more severe AKI were 1.02 (0.997, 1.04) for a 50-mmHg·min increase in AUT of MAP <55 mmHg (P = 0.092); 1.03 (0.98, 1.07) for a 15-min increase in time spent under MAP <55 mmHg (P = 0.27); and 1.24 (0.98, 1.57) for a 1 mmHg increase in TWA of MAP <55 mmHg (P = 0.068). The associations between IOH and the incidence of MACE or EAD were not significant. CONCLUSION: Our results did not show the association between IOH and investigated outcomes.

Anesthetic management in patients having catheter-based thrombectomy for acute pulmonary embolism: A narrative review.

Pulmonary embolism is the third leading cause of cardiovascular death. Novel percutaneous catheter-based thrombectomy techniques are rapidly becoming popular in high-risk pulmonary embolism - especially in the presence of contraindications to thrombolysis. The interventional nature of these procedures and the risk of sudden cardiorespiratory compromise requires the presence of an anesthesiologist. Facilitating catheter-based thrombectomy can be challenging since qualifying patients are often critically ill. The purpose of this narrative review is to provide guidance to anesthesiologists for the assessment and management of patients having catheter-based thrombectomy for acute pulmonary embolism. First, available techniques for catheter-based thrombectomy are reviewed. Then, we discuss definitions and application of common risk stratification tools for pulmonary embolism, and how to assess patients prior to the procedure. An adjudication of risks and benefits of anesthetic strategies for catheter-based thrombectomy follows. Specifically, we give guidance and rationale for use monitored anesthesia care and general anesthesia for these procedures. For both, we review strategies for assessing and mitigating hemodynamic perturbations and right ventricular dysfunction, ranging from basic monitoring to advanced inodilator therapy. Finally, considerations for management of right ventricular failure with mechanical circulatory support are discussed.

Combined Liver Transplant and Cardiac Surgery: Long-Term Outcomes and Predictors of Success.

OBJECTIVE: We aim to report our institutional outcomes of single-staged combined liver transplantation (LT) and cardiac surgery (CS). SUMMARY BACKGROUND DATA: Concurrent LT and CS is a potential treatment for combined cardiac dysfunction and end-stage liver disease, yet only 54 cases have been previously reported in the literature. Thus, the outcomes of this approach are relatively unknown, and this approach has been previously regarded as extremely risky. METHODS: Thirty-one patients at our institution underwent combined cardiac surgery and liver transplant. Patients with at least one-year follow-up were included. The Leave-One-Out Cross-Validation (LOOCV) machine-learning approach was used to generate a model for mortality. RESULTS: Median follow-up was 8.2 years (IQR 4.6-13.6 y). One- and five-year survival was 74.2% (N=23) and 55% (N=17), respectively. Negative predictive factors of survival included recipient age>60 years (P=0.036), NASH-cirrhosis (P=0.031), Coronary Artery Bypass-Graft (CABG)-based CS (P=0.046) and pre-operative renal dysfunction (P=0.024). The final model demonstrated that renal dysfunction had a relative weighted impact of 3.2 versus CABG (1.7), age ≥60y (1.7) or NASH (1.3). Elevated LT+CS risk score was associated with an increased five-year mortality after surgery (AUC=0.731, P=<0.001). Conversely, the widely accepted STS-PROM calculator was unable to successfully stratify patients according to 1- (P>0.99) or 5-year (P=0.695) survival rates. CONCLUSIONS: This is the largest series describing combined LT+CS, with joint surgical management appearing feasible in highly selected patients. CABG and pre-operative renal dysfunction are important negative predictors of mortality. The four-variable LT+CS score may help predict patients at high risk for post-operative mortality.

Artificial Intelligence for Perioperative Medicine: Perioperative Intelligence.

The anesthesiologist's role has expanded beyond the operating room, and anesthesiologist-led care teams can deliver coordinated care that spans the entire surgical experience, from preoperative optimization to long-term recovery of surgical patients. This expanded role can help reduce postoperative morbidity and mortality, which are regrettably common, unlike rare intraoperative mortality. Postoperative mortality, if considered a disease category, will be the third leading cause of death just after heart disease and cancer. Rapid advances in technologies like artificial intelligence provide an opportunity to build safe perioperative practices. Artificial intelligence helps by analyzing complex data across disparate systems and producing actionable information. Using artificial intelligence technologies, we can critically examine every aspect of perioperative medicine and devise innovative value-based solutions that can potentially improve patient safety and care delivery, while optimizing cost of care. In this narrative review, we discuss specific applications of artificial intelligence that may help advance all aspects of perioperative medicine, including clinical care, education, quality improvement, and research. We also discuss potential limitations of technology and provide our recommendations for successful adoption.

Outcomes of Liver Transplantation in Patients With Preexisting Coronary Artery Disease.

BACKGROUND: Advances in surgical and medical technology over the years has made liver transplantation possible for older and higher risk patients. Despite rigorous preoperative cardiac testing, cardiovascular events remain a major cause of death after orthotopic liver transplantation (OLT). However, there are little data on the outcomes of OLT in patients with preexisting coronary artery disease (CAD). This study aimed to compare all-cause and cardiovascular mortality of patients with and without history of CAD undergoing OLT. METHODS: Six hundred ninety-three adult patients with cirrhosis underwent liver transplantation between July 2013 and December 2018 (female n = 243, male n = 450; median age 59). RESULTS: During the study period of 5 y (median follow-up, 24.1 mo), 92 of 693 patients (13.3%) died. All-cause mortality in the CAD group was significantly higher than in the non-CAD group (26.7% versus 9.6%; P <0.01). Cardiovascular events accounted for 52.5% of deaths (n = 21) in patients with CAD compared with 36.5% (n = 19) in non-CAD patients. At 6 mo, patients with combined nonalcoholic steatohepatitis (NASH)/CAD had significantly worse survival than those with CAD or NASH alone ( P <0.01). After 6 mo, patients with CAD alone had similar survival to those with combined NASH/CAD. CONCLUSIONS: Patients with preexisting CAD before liver transplantation are at higher risk of death from any cause, specifically cardiovascular-related death. This risk increases with coexisting NASH. The presence of NASH and CAD at the time of liver transplant should prompt the initiation of aggressive risk factor modification for patients with CAD.

Sequential hypothermic and normothermic perfusion preservation and transplantation of expanded criteria donor livers.

BACKGROUND: The purpose of this study was to assess the safety and feasibility of sequential hypothermic oxygenated perfusion and normothermic machine perfusion and the potential benefits of graft viability preservation and assessment before liver transplantation. METHODS: With the Food and Drug Administration and institutional review board approval, 17 expanded criteria donor livers underwent sequential hypothermic oxygenated perfusion and normothermic machine perfusion using our institutionally developed perfusion device. RESULTS: Expanded criteria donor livers were from older donors, donors after cardiac death, with steatosis, hypertransaminasemia, or calcified arteries. Perfusion duration ranged between 1 and 2 hours for the hypothermic oxygenated perfusion phase and between 4 and 9 hours for the normothermic machine perfusion phase. Three livers were judged to be untransplantable during normothermic machine perfusion based on perfusate lactate, bile production, and macro-appearance. One liver was not transplanted because of recipient issue after anesthesia induction and failed reallocation. Thirteen livers were transplanted, including 9 donors after cardiac death livers (donor warm ischemia time 16-25 minutes) and 4 from donors after brain death. All livers had the standardized lactate clearance >60% (perfusate lactate cleared to <4.0 mmol/L) within 3 hours of normothermic machine perfusion. Bile production rate was 0.2 to 10.7 mL/h for donors after brain death livers and 0.3 to 6.1 mL/h for donors after cardiac death livers. After transplantation, 5 cases had early allograft dysfunction (3 donors after cardiac death and 2 donors after brain death livers). No graft failure or patient death has occurred during follow-up time of 6 to 13 months. Two livers developed ischemic cholangiopathy. Compared with our previous normothermic machine perfusion study, the bile duct had fewer inflammatory cells in histology, but the post-transplant outcomes had no difference. CONCLUSION: Sequential hypothermic oxygenated perfusion and normothermic machine perfusion preservation is safe and feasible and has the potential benefits of preserving and evaluating expanded criteria donor livers.

Liver Transplant Outcomes in Patients With Postcapillary Pulmonary Hypertension.

Postcapillary pulmonary hypertension (PH) can be seen in cirrhosis. Research and treatment goals exist for patients with portopulmonary hypertension but not for postcapillary PH. The aim of this study was to investigate outcomes after liver transplant (LT) for patients with postcapillary PH. Methods: This was a retrospective cohort study of 1173 patients who underwent LT at our center between 2010 and 2020. Using a propensity score matched analysis followed by multivariable Cox modeling on matched patients, we compared post-LT survival between patients with and without postcapillary PH. We also compared several post-LT outcomes between patient with different types of PH. Results: Sixty-eight patients had PH, and 50 had postcapillary PH. The median age was 59 y and the sample was 54% male. There was no significant difference in mortality between patients with postcapillary PH and patients without PH (hazard ratio, 1.72; 95% confidence interval, 0.90-3.31; P = 0.10). There was no significant difference in survival between patients with any type of PH and those without PH. There was no significance difference in post-LT survival, acute kidney injury, or pulmonary edema between patients with different types of PH. Patients with postcapillary PH who survived had a higher cardiac output than those who died (11 L/min in patients who lived, as compared with 8 L/min in patients who died; P = 0.03). Conclusions: Postcapillary PH does not appear to convey a negative impact on post-LT survival. A higher cardiac output may be protective against mortality in patients with postcapillary PH.

New-Onset Atrial Fibrillation in Patients Undergoing Liver Transplantation: Retrospective Analysis of Risk Factors and Outcomes.

OBJECTIVE: The authors aimed to identify predictors of new-onset postoperative atrial fibrillation (POAF) during the initial 90 days following liver transplantation, and to assess the association between POAF in-hospital and 1-year mortality. DESIGN: A retrospective cohort study. SETTING: At a university hospital between 2005 and 2017. PATIENTS: Adults without a history of preoperative atrial fibrillation who underwent orthotopicliver transplantation. MEASUREMENT AND MAIN RESULTS: The authors assessed the univariate association between new-onset of POAF in the postoperative period and each potential factor through a logistic regression model. Moreover, they explored predictors for POAF through stepwise selection. Finally, the authors assessed the relationship between POAF and in-hospital and 1-year mortality using logistic regression models, and whether the duration of atrial fibrillation was associated with in-hospital and 1-year mortality. Among 857 patients, 89 (10.4%) developed POAF. Using only preoperative variables, pulmonary hypertension, age, Model for End-Stage Liver Disease (MELD) score, and White race were identified as the most important predictors. Model discrimination was 0.75 (95% CI: 0.69-0.80), and incorporating intraoperative variables was 0.77 (95% CI: 0.72-0.82). In-hospital mortality was observed in 7.2% (6/83) of patients with new-onset of POAF, and in 2.8% (22/768) without, with confounder-adjusted odds ratio (OR) 1.00 (97.5% CI: 0.29,3.45; p = 0.996). One-year mortality was 22.4% (20/89) in patients who developed POAF and 8.3% (64/768) in patients who did not, confounder-adjusted OR 2.64 (97.5% CI: 1.35-5.16; p = 0.001). The duration of POAF did not affect long-term postoperative mortality. CONCLUSION: Preoperative, mostly unmodifiable comorbidities are important risk factors for new-onset POAF after liver transplantation. The POAF was not associated with in-hospital mortality, but with increased 1-year mortality. Once developed, the duration of POAF did not affect long-term mortality after a liver transplant.

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.

Effect of intraoperative subhypnotic infusion of propofol on postoperative nausea and vomiting: A retrospective analysis.

STUDY OBJECTIVE: To measure the possible association between subhypnotic propofol infusion during general balanced anesthesia and the incidence of PONV. DESIGN: Retrospective Cohort Analysis Using Propensity Score Matching. SETTING: Postanesthesia care unit and inpatient unit. PATIENTS: Patients with American Society of Anesthesiologists (ASA) physical status I-IV, undergoing non-cardiac surgery lasting >2 h were included. Patients were excluded if transferred to the intensive care unit after surgery or received ketamine. Initially 70,976 patients were screened, and a cohort of 51,707 eligible adult patients undergoing non-cardiac surgery under general balanced anesthesia between 2015 and 2019 were included. Using a propensity score matching, 3185 patients who received subhypnotic propofol during general balanced anesthesia were matched with 5826 patients who did not receive subhypnotic propofol in a 1:2 ratio. INTERVENTIONS: None. MEASUREMENTS: The primary outcome was the incidence of PONV during PACU stay. The secondary outcome was the incidence of PONV within the first 24 h after surgery. Exploratory outcomes were time-to-extubation and length of hospital stay. MAIN RESULTS: A total of 9011 patients were included (3185 patients who received propofol infusion, and 5826 patients who did not receive propofol infusion) after propensity score matching. The adjusted odds ratio for PONV incidence was 1.03 (95% CI: 0.90, 1.18; p = 0.635) in PACU, and 1.05 (95% CI: 0.90, 1.23; P = 0.50) within 24 h after surgery. The length of hospital stay was 6 h shorter (ratio of means (95% CI) of 0.92, 0.89, 0.94), p < 0.001) and time-to-extubation was 2 min longer (ratio of means 1.24 (1.20, 1.28), p < 0.001) in patients receiving subhypnotic propofol infusion. CONCLUSIONS: Our study suggests that subhypnotic propofol infusion during general balanced anesthesia is not associated with a reduction in the incidence of PONV during PACU stay and within the first 24 h after surgery. However, it is associated with decreased LOS and increased time-to-extubation, but differences in neither outcome were clinically important.

Transplantation of declined livers after normothermic perfusion.

BACKGROUND: The persistent shortage of liver allografts contributes to significant waitlist mortality despite efforts to increase organ donation. Normothermic machine perfusion holds the potential to enhance graft preservation, extend viability, and allow liver function evaluation in organs previously discarded because considered too high-risk for transplant. METHODS: Discarded livers from other transplant centers were transplanted after assessment and reconditioning with our institutionally developed normothermic machine perfusion device. We report here our preliminary data. RESULTS: Twenty-one human livers declined for transplantation were enrolled for assessment with normothermic machine perfusion. Six livers (28.5%) were ultimately discarded after normothermic machine perfusion because of insufficient lactate clearance (>4.1 mmol/L after 4 hours), limited bile production (<0.5 mI/h), or moderate macrosteatosis, whereas 15 (71.5%) were considered suitable for transplantation. Normothermic machine perfusion duration was from 3 hours, 49 minutes to 10 hours, 29 minutes without technical problems or adverse events. No intraoperative or major early postoperative complications occurred in all transplanted recipients. No primary nonfunction occurred after transplantation. Seven livers had early allograft dysfunction with fast recovery, and 1 patient developed ischemic cholangiopathy after 4 months treated with biliary stents. All other patients had good liver function with a follow-up time of 8 weeks to 14 months. CONCLUSION: In total, 71.5% of discarded livers subjected to ex vivo normothermic machine perfusion were successfully transplanted after organ perfusion and assessment using an institutionally built device. This study challenges the current viability criteria reported in the literature and calls for a standardization of viability markers collection, an essential condition for the advancement of the field.

Cardiac considerations in liver transplantation.

Cardiovascular events have a major impact on overall outcomes after liver transplantation. Today's transplant patients are older than those in the past and therefore are more likely to have coexisting cardiac comorbidities. In addition, pathophysiologic effects of advanced liver disease on the circulatory system pose challenges in perioperative management. This review discusses important preoperative, intraoperative, and postoperative cardiac considerations in patients undergoing liver transplant.

Comparison of Coronary Artery Calcium Scoring with Dobutamine Stress Echo for Detection of Coronary Artery Disease Before Liver Transplantation.

BACKGROUND Dobutamine stress echocardiography (DSE) is commonly used for cardiovascular assessment before orthotopic liver transplantation (OLT). The coronary artery calcium score (CACS) is a useful screening tool for coronary artery disease (CAD). We aimed to compare the sensitivity and specificity of DSE and CACS for CAD in OLT candidates. MATERIAL AND METHODS A total of 265 of the 1589 patients who underwent OLT at our center between 2008 and 2019 had preoperative coronary angiography (CAG). Of these, 173 had DSE and 133 had a CT scan suitable for CACS calculation within 1 year of OLT. Patients with a nondiagnostic DSE were excluded (n=100). Two reviewers evaluated CACS on CT scans. The sensitivity/specificity of DSE and CACS for detection of angiographically significant CAD were calculated for patients with both tests (n=36). A separate analysis compared the sensitivity/specificity of a diagnostic DSE (n=73) and CACS (n=133) against CAG for all patients with either test. RESULTS Sensitivity and specificity were 57.1% and 89.7%, respectively, for DSE, compared with 71.4% and 62.1% for CACS at ≥100 Agatston score. For the analysis of all patients with either test, the sensitivity/specificity of DSE for detection of CAD and CACS were 30.8% and 85.0% and 80.0% and 62.8%, respectively. On ROC analysis, CACS was a satisfactory predictor of obstructive CAD (AUC, 0.76±0.06, 95% CI, 0.66-0.87; P<0.001). CONCLUSIONS CACS may be an important tool for cardiovascular assessment in patients undergoing OLT. DSE was nondiagnostic in a large percentage of OLT candidates, limiting its use in this population.

Associations between intraoperative and post-anesthesia care unit hypotension and surgical ward hypotension.

STUDY OBJECTIVE: To test whether patients who experience hypotension in the post-anesthesia care unit or during surgery are most likely to experience hypotension on surgical wards. DESIGN: A prediction study using data from two randomized controlled trials. SETTING: Operating room, post-anesthesia care unit, and surgical ward. PATIENTS: 550 adult patients having abdominal surgery with ASA physical status I-IV. INTERVENTIONS: Blood pressure measurement per routine intraoperatively, and with continuous non-invasive monitoring postoperatively. MEASUREMENTS: The primary predictors were minimum mean arterial pressure (<60, <65, <70 and < 80 mmHg) and minimum systolic blood pressure (<70, <75, <80, <85 mmHg) in the post-anesthesia care unit. The secondary predictors were intraoperative minimum blood pressures with the same thresholds as the primary ones. Our outcome was ward hypotension defined as mean pressure < 70 mmHg or systolic pressure < 85 mmHg. A threshold was considered clinically useful if both sensitivity and specificity exceeded 0.75. MAIN RESULTS: Minimum mean and systolic pressures in the post-anesthesia care unit similarly predicted ward mean or systolic hypotension, with the areas under the curves near 0.74. The best performing threshold was mean pressure < 80 mmHg in the post-anesthesia care unit which had a sensitivity of 0.41 (95% confidence interval [CI], 0.35, 0.47) and specificity of 0.91 (95% CI, 0.87, 0.94) for ward mean pressure < 70 mmHg and a sensitivity of 0.44 (95% CI, 0.37, 0.51) and specificity of 0.88 (95% CI, 0.84, 0.91) for ward systolic pressure < 85 mmHg. The areas under the curves using intraoperative hypotension to predict ward hypotension were roughly similar at about 0.60, with correspondingly low sensitivity and specificity. CONCLUSIONS: Intraoperative hypotension poorly predicted ward hypotension. Pressures in the post-anesthesia care unit were more predictive, but the combination of sensitivity and specificity remained poor. Unless far better predictors are identified, all surgical inpatients should be considered at risk for postoperative hypotension.

Machine Learning Models to Predict Major Adverse Cardiovascular Events After Orthotopic Liver Transplantation: A Cohort Study.

OBJECTIVE: To develop machine learning models that can predict post-transplantation major adverse cardiovascular events (MACE), all-cause mortality, and cardiovascular mortality in patients undergoing liver transplantation (LT). DESIGN: Retrospective cohort study. SETTING: High-volume tertiary care center. PARTICIPANTS: The study comprised 1,459 consecutive patients undergoing LT between January 2008 and December 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: MACE, all-cause mortality, and cardiovascular mortality were modeled using logistic regression, least absolute shrinkage and selection surgery regression, random forests, support vector machine, and gradient-boosted modeling (GBM). All models were built by splitting data into training and testing cohorts, and performance was assessed using five-fold cross-validation based on the area under the receiver operating characteristic curve and Harrell's C statistic. A total of 1,459 patients were included in the final cohort; 1,425 (97.7%) underwent index transplantation, 963 (66.0%) were female, the median age at transplantation was 57 (11-70) years, and the median Model for End-Stage Liver Disease score was 20 (6-40). Across all outcomes, the GBM model XGBoost achieved the highest performance, with an area under the receiver operating curve of 0.71 (95% confidence interval [CI] 0.63-0.79) for MACE, a Harrell's C statistic of 0.64 (95% CI 0.57-0.73) for overall survival, and 0.72 (95% CI 0.59-0.85) for cardiovascular mortality over a mean follow-up of 4.4 years. Examination of Shapley values for the GBM model revealed that on the cohort-wide level, the top influential factors for postoperative MACE were age at transplantation, diabetes, serum creatinine, cirrhosis caused by nonalcoholic steatohepatitis, right ventricular systolic pressure, and left ventricular ejection fraction. CONCLUSION: Machine learning models developed using data from a tertiary care transplantation center achieved good discriminant function in predicting post-LT MACE, all-cause mortality, and cardiovascular mortality. These models can support clinicians in recipient selection and help screen individuals who may be at elevated risk for post-transplantation MACE.

Successful orthotopic liver transplantation in a patient with a positive SARS-CoV2 test and acute liver failure secondary to acetaminophen overdose.

SARS-CoV2, first described in December 2019, was declared a pandemic by the World Health Organization in March 2020. Various surgical and medical societies promptly published guidelines, based on expert opinion, on managing patients with COVID-19, with a consensus to postpone elective surgeries and procedures. We describe the case of an orthotopic liver transplantation (OLT) in a young female who presented with acute liver failure secondary to acetaminophen toxicity to manage abdominal pain and in the setting of a positive SARS-CoV2 test. Despite a positive test, she had no respiratory symptoms at time of presentation. The positive test was thought to be residual viral load. The patient had a very favorable outcome, likely related to multiple factors including her young age, lack of respiratory COVID-19 manifestations and plasma exchange peri-operatively. We recommend a full work-up for OLT in COVID-19 patients with uncomplicated disease according to standard of care, with careful interpretation of COVID-19 testing in patients presenting with conditions requiring urgent or emergent surgery as well as repeat testing even a few days after initial testing, as this could alter management.

Hypotension Prediction Index for Prevention of Hypotension during Moderate- to High-risk Noncardiac Surgery.

BACKGROUND: The Hypotension Prediction Index is a commercially available algorithm, based on arterial waveform features, that predicts hypotension defined as mean arterial pressure less than 65 mmHg for at least 1 min. We therefore tested the primary hypothesis that index guidance reduces the duration and severity of hypotension during noncardiac surgery. METHODS: We enrolled adults having moderate- or high-risk noncardiac surgery with invasive arterial pressure monitoring. Participating patients were randomized to hemodynamic management with or without index guidance. Clinicians caring for patients assigned to guidance were alerted when the index exceeded 85 (range, 0 to 100) and a treatment algorithm based on advanced hemodynamic parameters suggested vasopressor administration, fluid administration, inotrope administration, or observation. Primary outcome was the amount of hypotension, defined as time-weighted average mean arterial pressure less than 65 mmHg. Secondary outcomes were time-weighted mean pressures less than 60 and 55 mmHg. RESULTS: Among 214 enrolled patients, guidance was provided for 105 (49%) patients randomly assigned to the index guidance group. The median (first quartile, third quartile) time-weighted average mean arterial pressure less than 65 mmHg was 0.14 (0.03, 0.37) in guided patients versus 0.14 (0.03, 0.39) mmHg in unguided patients: median difference (95% CI) of 0 (-0.03 to 0.04), P = 0.757. Index guidance therefore did not reduce amount of hypotension less than 65 mmHg, nor did it reduce hypotension less than 60 or 55 mmHg. Post hoc, guidance was associated with less hypotension when analysis was restricted to episodes during which clinicians intervened. CONCLUSIONS: In this pilot trial, index guidance did not reduce the amount of intraoperative hypotension. Half of the alerts were not followed by treatment, presumably due to short warning time, complex treatment algorithm, or clinicians ignoring the alert. In the future we plan to use a lower index alert threshold and a simpler treatment algorithm that emphasizes prompt treatment.

Quality improvement during the COVID-19 pandemic.

In response to the COVID-19 pandemic, quality improvement teams at Cleveland Clinic initiated a number of measures to guide the care of patients with suspected or confirmed COVID-19 infection and protect care givers. This included increasing the frequency of team meetings from monthly to daily or weekly and creating task forces to create protocols for patient transport, airway management, and management of personal protective equipment and medications in short supply. Enterprise wide, we postponed non-essential surgeries, set up an overflow intensive care unit onsite, created a web-based COVID-19 toolkit for all care givers, and sent daily emails about the most recent developments, decisions, and recommendations from national and international societies.

Perioperative anesthesia care for patients with confirmed or suspected COVID-19.

The operating room environment is very dynamic with many unique challenges for anesthesia teams caring for patients with confirmed or suspected COVID-19. Specific recommendations by national organizations and institution specific step-by-step guidelines and education materials are required to maintain safety for both patients and caregivers perioperatively, with transport, and medication management.