Effect of remimazolam on postoperative delirium in elderly patients undergoing major abdominal surgery: a randomized...

Older patients are at a high risk of postoperative delirium (POD), and the choice of general anesthesia may affect postoperative cognitive outcomes. As a new type of benzodiazepine, remimazolam has wide application prospects in clinical anesthesia owing to its rapid onset, non-organ metabolism, and low respiratory and circulatory depression. This study aimed to compare the effect of propofol-based versus remimazolam-based general anesthesia on the incidence of delirium after major abdominal surgery in older adults.

A total of 370 older adults (≥65 to <90 years old) scheduled to undergo major abdominal surgery (>2 h) were randomized to receive propofol or remimazolam-based general anesthesia. Trained investigators assessed delirium within 5 days postoperatively using the Confusion Assessment (CAM) or Confusion Assessment Intensive Care Unit scale. The incidence of delirium between the two groups was compared using protocol and intention-to-treat analyses.

There was no significant difference in the incidence of POD between the two groups (per-protocol: 29 [17.1%] vs. 34 [19.7%]; odds ratio (OR) [95%]: 1.189 [0.688-2.057], P  = 0.578). In subgroup analysis, age ≥75 years interacted with the intervention (OR [95% confidence interval {CI}]: 2.700 [1.118-6.521], interaction P < 0.001). The incidence of hypotension was lower in the remimazolam group (OR [95% CI]: 0.460 [0.262-0.807], P = 0.009). There were no significant differences in pain scores or other adverse events between the two groups ( P > 0.05).

Our study, combined with the literature, suggests that remimazolam does not increase the risk of POD in older patients compared with propofol. Larger studies are required to confirm or rule out this effect. Given the safety profile and wide availability of remimazolam, the choice of general anesthetic strategy for special populations may be more instructive.