Efficacy and safety of continuous infusion of remimazolam for sedation in elderly patients undergoing colonoscopic polypectomy: A non-inferiority prospective controlled clinical trial.

Background: To study the efficacy and safety of a bolus dose of remimazolam followed by its continuous infusion, and to identify its optimal maintenance dose in elderly patients undergoing colonoscopic polypectomy, with the aim of determining a reasonable and safe sedative and analgesic regimen for this patient population. Methods: A prospective randomized clinical trial was performed in elderly patients scheduled for colonoscopic polypectomy between January and November 2023. Eligible patients were randomly assigned into 3 groups: two experimental groups (R1 and R2), with patients given alfentanil 10 μg/kg and a bolus dose of remimazolam 6 mg/kg/h, followed by a maintenance infusion of remimazolam 0.5 mg/kg/h and 0.75 mg/kg/h, respectively, and a control group, with patients given 10 μg/kg alfentanil and 1.5 mg/kg propofol, and then 2-3 mg/kg/h propofol maintenance. The primary outcome was the sedation success rate. The secondary outcomes included vital sign changes, the bispectral index, anesthesia duration, operation duration, awakening time, and post anesthesia care unit length of stay, as well as the incidence of adverse effects. Results: A total of 126 patients were enrolled in the study, with 40, 38, and 41 patients placed in the control (P), R1, and R2 groups, respectively. The baseline characteristics of the patients were comparable among the three groups. The sedation success rate was 100 % in all three groups (95 % CI 0.17-0.19). Compared with group P, groups R1 and R2 had significantly lower incidences of hypotension (both Conclusions: In elderly patients undergoing colonoscopic polypectomy, intravenous remimazolam bolus injection followed by continuous infusion could be applied with alfentanil to provide adequate sedation, with little disruption to hemodynamics. A continuous infusion of remimazolam at a dose of 0.5 mg/kg/h may be adopted due to its low impact on the post-procedure awakening time.