Efficacy and safety of remimazolam versus propofol for intraoperative sedation during regional anesthesia: A phase II, multicenter, randomized, active-controlled, single-blind clinical trial.

This study aimed to evaluate the efficacy and safety of remimazolam for intraoperative sedation during regional anesthesia. It was a phase II-multicenter, randomized, single-blind, parallel-group, active-controlled clinical trial (No. ChiCTR2100054956). From May 6, 2021 to July 4, 2021, patients were randomly enrolled from 17 hospitals in China. A total of 105 patients aged 18-65 years who underwent selective surgery under regional anesthesia were included. Patients received different sedatives with different dosages: 0.1 mg/kg remimazolam (HR), 0.05 mg/kg remimazolam (LR), or 1.0 mg/kg propofol (P) group, followed by a maintenance infusion. Main outcome measures included the efficacy of sedation measured by Modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) levels (1-4, 1-3, 2-3, 3, and 2-4) during the sedation procedure (the duration percentage) and incidence of adverse reactions. It showed that the duration percentage of MOAA/S levels 1-4 was 100.0 [8.1]% (median [interquartile range]), 89.9 [20.2]%, 100.0 [7.7]% in the HR, LR, and P groups, respectively. The percentage of patients in the HR, LR, and P groups who achieved MOAA/S levels 1-4 within 3 min after administration was 85.7%, 58.8%, and 82.9%, respectively. However, the time to recovery from anesthesia after withdrawal of sedatives (7.9 ± 5.7 min), incidence of anterograde amnesia (75%), and adverse effects were not statistically significant among the three groups. These findings suggest that a loading dose of remimazolam 0.1 mg/kg followed by a maintenance infusion of 0-3 mg/kg/h provides adequate sedation for patients under regional anesthesia without increasing adverse reactions.