Background: Remimazolam, a novel ultra-short-acting benzodiazepine, is a potential sedative for non-general anesthesia 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 anesthesia surgery.Methods: This multicenter, placebo-controlled trial enrolled 330 elderly patients undergoing non-general anesthesia procedures at eight centers 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 anesthesia in elderly patients was 5.38 mg (95% confidence interval [CI], 5.20–5.56), maintained at a rate of 0.223 mg·kg⁻¹·h⁻¹ (95% CI, 0.201–0.237) with no serious adverse effects. Compared with the standard saline group, there was no statistical difference in the MMSE scores on Day 2 morning (P = 0.886), Day 2 afternoon (P = 0.864), and Day 7 (P = 0.613), and no statistical difference in the MoCA scores on Day 2 morning (P = 0.687), Day 2 afternoon (P = 0.827), and Day 7 (P = 0.483) in remimazolam group.Conclusion: Remimazolam besylate is an effective sedative for elderly patients undergoing neuraxial anesthesia. It was successfully induced at a dose of 5.38 mg and maintained at 0.223 mg·kg⁻¹·h⁻¹, demonstrating a good safety profile without affecting short-term postoperative cognitive function.Clinical Trial Registration: http://www.chictr.org.cn (ChiCTR2100048744).

Background: During procedures that are not performed under general anesthesia, elderly patients often have adverse emotions such as nervousness and anxiety due to their consciousness. Sedation is frequently used to relieve these symptoms. However, the adverse effects from currently prescribed sedative drugs such as midazolam, dexmedetomidine, and propofol are common and unavoidable. There has been limited research on the use of remimazolam besylate, a new sedative drug, to determine the effectiveness of the medication in reducing perioperative cognitive dysfunction in elderly patients undergoing non-general anesthesia procedures and to assess the efficacy of the medication in reducing sedation. Methods: This prospective, multicenter, randomized, single-blind, placebo-controlled trial was conducted from July 2021 to February 2022. The study included 330 elderly patients aged > 65 years who underwent non-general anesthesia procedures. Patients were randomly assigned (2:1) to two groups: the remimazolam besylate group and control group. Outcomes: The primary outcomes included sedation levels achieved at target doses and changes in perioperative cognitive function. Additionally, time to awakening, the incidence of postoperative delirium, change in anxiety level, change in sleep rhythm, and the incidence of adverse events during sedation were measured as secondary outcomes.