Incidence of postoperative delirium and quality of recovery in older patients undergoing gastrectomy under general anaesthesia with remimazolam vs. propofol: a randomised non-inferiority study

Introduction: Due to its haemodynamic stability and rapid recovery from anaesthesia, remimazolam is an attractive hypnotic drug for general anaesthesia in older patients. However, remimazolam must show non-inferiority in terms of the incidence of delirium and quality of postoperative recovery to be used as an alternative to propofol for maintenance of general anaesthesia. Methods: Patients aged ≥ 65 y scheduled to undergo gastrectomy were randomly allocated to maintenance of general anaesthesia with a remimazolam infusion (remimazolam group) or propofol target-controlled infusion (propofol group) in a 1:1 ratio. The primary outcome measure was the incidence of delirium within 72 h of surgery (assessed using the confusion assessment method). Secondary outcomes included the quality of recovery at 24 h postoperatively (assessed using the translated Korean version of the 15-item Quality of Recovery questionnaire) and the incidence of postoperative nausea, retching and vomiting. Results: Of 461 patients randomly allocated in the study, 432 were included in the analysis (216 in each group). The incidence of delirium was 17/216 (7.9%) in patients allocated to the remimazolam group and 17/216 (7.9%) in those allocated to the propofol group (unadjusted odds ratio 1.00, 95%CI 0.50–2.02, p = 1.000). Quality of recovery scores were also similar between groups at 24 h postoperatively (median (IQR [range]) 109 (102–115 [54–140]) vs. 109 (104–115 [70–137]) for the remimazolam and propofol groups, respectively (p = 0.627); unadjusted odds ratio -0.03, 95%CI -0.19–0.13). Discussion: Remimazolam can be used as an alternative to propofol in older patients undergoing gastrectomy from the perspective of the incidence of postoperative delirium and quality of recovery.