Association between a remimazolam-propofol combination for maintenance of anesthesia and extubation time: a propensity score analysis.

BACKGROUND: This study aimed to evaluate the effect of combined administration of remimazolam and propofol on extubation time during anesthesia maintenance. METHODS: This retrospective study was conducted at Hamamatsu University Hospital, enrolling adult patients who underwent non-cardiac surgery between September 2020 and October 2024. Eligible patients underwent invasive arterial pressure monitoring and anesthesia maintenance with remimazolam alone (RB group), propofol alone (PROP group), or a combination of both (RB + PROP group). Extubation time was defined as the interval between the cessation of sedative administration and tracheal extubation. Propensity score matching was performed after adjusting for age, sex, body mass index, American Society of Anesthesiologists Physical Status, preoperative comorbidities, type of surgery, combined with epidural anesthesia, scheduled or emergency surgery, operation time, and blood loss. The primary endpoint was the extubation time, while the secondary endpoints included the severity of hypotension, assessed by the time-weighted average area under the threshold, and the incidence of postoperative nausea and vomiting. RESULTS: The study included 165, 403, and 178 patients in the RB, PROP, and RB + PROP groups, respectively. After propensity score matching, 75 matched cohorts were analyzed. Among the three groups, significant differences were found in terms of extubation time and hypotension (p < 0.001 and p = 0.04, respectively), whereas the incidence of postoperative nausea and vomiting did not significantly differ (p = 0.23). In multiple comparisons, the RB group (9.0 min) and the RB + PROP group (9.0 min) had significantly shorter extubation times than the PROP group (13.0 min) (each p < 0.001). Time-weighted average area under the threshold was significantly lower in the RB group (0.74 mmHg) than in the PROP group (2.03 mmHg) (p = 0.03). CONCLUSION: Extubation time with combined remimazolam and propofol was comparable to that with remimazolam alone, and both were shorter than that with propofol alone.