Sedation efficacy of different dose of remimazolam with sufentanil for nerve block in young and elderly patients: a randomized, controlled study

PURPOSE: Anxiety and pain commonly occur during nerve block, we aimed to investigate the sedation efficacy of different doses of remimazolam with sufentanil in young and elderly patients. METHODS: In this randomized trial, patients aged 18–85 years who underwent nerve block was enrolled. All patients received sufentanil 0.08 μg/kg for analgesia. Young patients (age < 65 years) were randomized into the control group (Group C, 0.9% saline), medium-dose remimazolam (Group M, 0.06 mg/kg) and high-dose remimazolam group (Group H, 0.08 mg/kg). Elderly patients (age ≥ 65 years) were randomized into the Group C, low-dose remimazolam group (Group L, 0.04 mg/kg) and Group M. Primary outcome was the success rate of procedure sedation. Respiratory depression and hypoxia were the interested safety outcomes. RESULTS: Ninety young and 114 elderly patients were enrolled, respectively. In comparison with Groups C and M, young patients in Group H had the highest success rate of procedure sedation (80.0 vs. 73.3 vs. 43.3%, P = 0.006). Elderly patients in Groups M and L had similar success rates of procedure sedation, which were significantly higher than that in Group C (78.9 vs. 78.9 vs. 50.0%, P = 0.007). In elderly patients, the incidence of respiratory depression and hypoxia tended to be higher in Group M than those in Groups L and C (both P < 0.001). CONCLUSION: Remimazolam 0.08 mg/kg provided the best sedation efficacy in young patients while remimazolam 0.04 mg/kg with the trend of less respiratory adverse events was more optimal for elderly patients. TRIAL REGISTRATION: http://www.chictr.org.cn/showproj.aspx?proj=122016. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00540-022-03142-8.