Remimazolam sedation for spinal anaesthesia surgery and its effect on perioperative cognitive function in elderly patients: a multicentre, placebo-controlled study

Abstract BACKGROUND Remimazolam, a novel ultra-short-acting benzodiazepine, is a potential sedative for non-general anaesthesia surgery in the elderly. This study aimed to investigate the appropriate sedative dosage of remimazolam and its effects on perioperative cognitive function in elderly patients undergoing non-general anaesthesia surgery. METHODS This multicentre, placebo-controlled trial enrolled 330 elderly patients undergoing non-general anaesthesia procedures at eight centres in China from July 2021 to February 2022, with 238 ultimately completing the study. The primary endpoints were the dose of successful sedation with remimazolam and the changes in perioperative cognitive function. Adverse events were recorded to assess drug safety. RESULTS The induction dose of remimazolam for sedation in spinal anaesthesia in elderly patients was 5.38 mg (95% confidence interval [CI], 5.20 to 5.56), maintained at a rate of 0.223 mg·kg− 1·h− 1 (95% CI, 0.201 to 0.237) with no serious adverse effects. Compared with the saline group, there was no statistical difference in the Mini-Mental State Examination scores in the experimental group on Day2 morning (P : 0.886), Day2 afternoon (P : 0.864), and Day7 (P : 0.613), and no statistical difference in the Montreal Cognitive Assessment scores on Day2 morning (P : 0.687), Day2 afternoon (P : 0.827), and Day7 (P : 0.483). CONCLUSIONS Remimazolam besylate is an effective sedative drug during spinal anaesthesia in elderly patients, with a successful induction dose of 5.38 mg (95% CI, 5.20 to 5.56), maintained at a rate of 0.223 mg·kg− 1·h− 1 (95% CI, 0.201 to 0.237) and a good safety profile without altering the short-term postoperative cognitive function.