Background: Redistribution hypothermia, characterized by rapid core-to-peripheral heat transfer after anesthetic induction, is a major cause of perioperative hypothermia and is linked to adverse outcomes.Propofol, widely used for induction, impairs thermoregulatory vasoconstriction.Remimazolam, a novel ultra-short-acting benzodiazepine, provides greater hemodynamic stability, but its thermoregulatory effects remain unclear.This study compared remimazolam and propofol on intraoperative hypothermia in patients undergoing urologic surgery.Methods: This retrospective observational study included adult patients ( 19 years) who underwent elective urologic surgery under general anesthesia between February 2024 and February 2025.Patients receiving remimazolam (0.2 mg/kg) or propofol (1.5-2.5 mg/kg) for induction were classified into respective groups.Propensity score matching (PSM) was performed (1:1 ratio) using demographic and perioperative covariates.The primary outcome was the incidence of redistribution hypothermia, defined as core temperature < 36.0Cwithin the first hour after induction.Secondary outcomes included severity of hypothermia, maximum temperature decrease, perioperative temperature trends, and predictors of hypothermia.Results: Among 181 patients analyzed, 71 per group were matched after PSM.Hypothermia incidence was significantly lower with remimazolam than propofol both before (16.5% vs. 50.0%,P < 0.001) and after matching (15.5% vs. 47.9%,P < 0.001).Propofol use was an independent risk factor (adjusted OR: 7.31; 95% CI: 2.81-21.58;P < 0.001).Female sex, higher BMI, and higher baseline temperature were protective factors.Conclusion: Compared with propofol, remimazolam was associated with lower incidence and severity of redistribution hypothermia in urologic surgery.These findings suggest thermoregulatory benefits of remimazolam, warranting confirmation in prospective trials.
Jung et al. (Mon,) studied this question.