Daily Anesthesiology Research Analysis

IMPORTANCE: Delirium is common after cardiac surgery and associated with adverse outcomes. Intraoperative benzodiazepines may increase postoperative delirium but restricting intraoperative benzodiazepines has not yet been evaluated in a randomized trial. OBJECTIVE: To determine whether an institutional policy of restricted intraoperative benzodiazepine administration reduced the incidence of postoperative delirium. DESIGN, SETTING, AND PARTICIPANTS: This pragmatic, multiperiod, patient- and assessor-blinded, cluster randomized crossover trial took place at 20 North American cardiac surgical centers. All adults undergoing open cardiac surgery at participating centers during the trial period were included through a waiver of individual patient consent between November 2019 and December 2022. INTERVENTION: Institutional policies of restrictive vs liberal intraoperative benzodiazepine administration were compared. Hospitals (clusters) were randomized to cross between the restricted and liberal benzodiazepine policies 12 to 18 times over 4-week periods. MAIN OUTCOMES AND MEASURES: The primary outcome was the incidence of delirium within 72 hours of surgery as detected in routine clinical care, using either the Confusion Assessment Method-Intensive Care Unit or the Intensive Care Delirium Screening Checklist. Intraoperative awareness by patient report was assessed as an adverse event. RESULTS: During the trial, 19 768 patients (mean [SD] age, 65 [12] years; 14 528 [73.5%] male) underwent cardiac surgery, 9827 during restricted benzodiazepine periods and 9941 during liberal benzodiazepine periods. During restricted periods, clinicians adhered to assigned policy in 8928 patients (90.9%), compared to 9268 patients (93.2%) during liberal periods. Delirium occurred in 1373 patients (14.0%) during restricted periods and 1485 (14.9%) during liberal periods (adjusted odds ratio [aOR], 0.92; 95% CI, 0.84-1.01; P = .07). No patient spontaneously reported intraoperative awareness. CONCLUSIONS AND RELEVANCE: In intention-to-treat analyses, restricting benzodiazepines during cardiac surgery did not reduce delirium incidence but was also not associated with an increase in the incidence of patient-reported intraoperative awareness. Given that smaller effect sizes cannot be ruled out, restriction of benzodiazepines during cardiac surgery may be considered. Research is required to determine whether restricting intraoperative benzodiazepines at the patient level can reduce the incidence of postoperative delirium. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03928236.

IMPORTANCE: Normothermic machine perfusion (NMP) has been shown to reduce peritransplant complications. Despite increasing NMP use in liver transplant (LT), there is a scarcity of real-world clinical experience data. OBJECTIVE: To compare LT outcomes between donation after brain death (DBD) and donation after circulatory death (DCD) allografts preserved with NMP or static cold storage (SCS). DESIGN, SETTING, AND PARTICIPANTS: This single-center, retrospective observational cohort study included all consecutive adult LTs performed between January 2019 and December 2023 at the Mayo Clinic in Arizona. Data analysis was performed between February 2024 and June 2024. Outcomes of DBD-SCS, DBD-NMP, DCD-SCS, and DCD-NMP transplants were compared. EXPOSURE: DBD and DCD livers preserved on NMP or SCS. MAIN OUTCOMES AND MEASURES: The primary outcomes were early allograft dysfunction (EAD), intraoperative transfusion, and post-LT hospital resource use, including length of stay (LOS) and readmissions. Secondary outcomes included acute kidney injury (AKI) and 1-year graft and patient survival. RESULTS: A total of 1086 LTs were included in the following 4 groups: DBD-SCS (n = 480), DBD-NMP (n = 63), DCD-SCS (n = 264), and DCD-NMP (n = 279). Among LT recipients, median (IQR) age was 60.0 years (52.0-66.0); 399 LT recipients (36.7%) were female. DCD-NMP had the lowest EAD rate (17.5%), followed by DCD-SCS (50.0%), DBD-NMP (36.8%), and DBD-SCS (27.3%) (P < .001). DCD-NMP had the lowest intraoperative transfusion requirement compared to all other groups. Hospital and intensive care unit (ICU) LOS were shortest in DCD-NMP (median [IQR] hospital LOS, 5.0 days [4.0-7.0]; P = .01; median [IQR] ICU LOS, 1.5 days [1.2-3.1]; P = .01). One-year cumulative readmission probability was 86% lower for DCD-NMP vs DCD-SCS (95% CI, 0.09-0.22; P < .001) and 53% lower for DBD-NMP vs DBD-SCS (95% CI, 0.26-0.87; P < .001). AKI events were lower in DCD-NMP (31.1%) vs DCD-SCS (47.4%) (P = .001). Compared to SCS, the NMP group had a 78% overall reduction in graft failure (hazard ratio [HR], 0.22; 95% CI, 0.10-0.49; P < .001). For those receiving DCD allografts, the risk reduction was even more pronounced, with an 87% decrease in graft failure (HR, 0.13; 95% CI, 0.05-0.33; P < .001). NMP was significantly protective from patient mortality vs SCS (HR, 0.31; 95% CI, 0.12-0.80; P = .02). CONCLUSIONS AND RELEVANCE: In this observational high-volume cohort study, NMP significantly improved LT clinical outcomes and reduced hospital resource use, especially in DCD allografts. NMP may enhance access to LT by addressing the challenges historically linked with DCD liver use.

BACKGROUND: Tranexamic acid is an antifibrinolytic agent routinely used during hip and knee joint replacement surgery to minimize bleeding. Chronic kidney disease is a common chronic health problem seen among adults requiring major arthroplasty surgery. Tranexamic acid is renally cleared and may accumulate in chronic kidney disease. Optimal tranexamic acid dosing and dose adjustment for chronic kidney disease patients needing major arthroplasty is unknown. The objective of this study was to serially measure plasma tranexamic acid concentrations in patients with varied kidney function undergoing hip or knee replacement surgery for population pharmacokinetic modeling and to guide new dosing recommendations. METHODS: A prospective cohort study enrolled 21 adults undergoing hip or knee replacement surgery between June 2020 and September 2022. Based on estimated glomerular filtration rate, the patients were stratified into good (greater than or equal to 60 ml · min -1 · 1.73 m -2 ) and poor (less than 60 ml · min -1 · 1.73 m -2 ) renal function. Serial blood samples were taken to measure plasma tranexamic acid concentration levels (primary outcome) after an intravenous tranexamic acid 20-mg/kg bolus dose after anesthesia induction. Secondary clinical outcomes included adverse events (thromboembolic events, seizures), red cell transfusion, mortality, and length of hospital stay. Analyses used curve stripping and population pharmacokinetic modeling and simulation. RESULTS: Plasma tranexamic acid concentration levels were higher in patients with poor renal function and clearance compared to those with good renal function. Population pharmacokinetic modeling tested various tranexamic acid bolus and maintenance infusion regimens. Simulations revealed that single-bolus tranexamic acid administration leads to rapid rise and decline in plasma concentrations. This study identified that plasma tranexamic acid levels of 50 to 75 mg/l were maintained for approximately 4 h using a tranexamic acid bolus infusion of 15 mg/kg over a 15-min duration together with a maintenance infusion of 7.5 or 5 mg · kg -1 · h -1 for 2 h for the good and poor renal function groups, respectively. There was no difference in secondary outcomes. CONCLUSIONS: Population pharmacokinetic modeling and simulation resulted in recommendations for a new dosing regimen to optimize the antifibrinolytic effect of tranexamic acid and avoid excessive dosing.