Up-down determination of the 90% effective dose (ED90) of remimazolam besylate for anesthesia induction.

BACKGROUND

Remimazolam besylate for injection is a novel benzodiazepine. Reasonable selection and proper application of anesthetics is critical for patients. This study aims to determine the 90% effective dose (ED90) of remimazolam besylate for anesthesia induction in patients undergoing painless colonoscopy.

METHODS

A dose-response study was carried out in 112 patients undergoing painless colonoscopy between December 2020 and January 2021. The initial dose of remimazolam was 7.5 mg. The anesthesiologist assessed whether the depth of sedation was satisfactory according to the Modified Observer's Assessment of Alertness and Sedation (MOAA/S) scale. If the MOAA/S score of one patient was >1 point, the loading dose for the next patient was increased by 2.5 mg. If the MOAA/S score was ≤1 point, the current dose was maintained or reduced by 2.5 mg for the next patient according to a 9:1 biased coin design. The ED90 of remimazolam besylate for anesthesia induction for painless colonoscopy was calculated. The adverse events and complications of remimazolam besylate were recorded.

RESULTS

When the drug concentration was 1 mg/mL and the infusion rate was 1,000 mL/h, the ED90 of remimazolam besylate for painless colonoscopy was 11.43 mg [95% confidence interval (CI): 9.85-13.02 mg].

CONCLUSIONS

A loading dose of 12 mg remimazolam besylate for healthy adult patients undergoing painless colonoscopy can safely, effectively, and quickly induce patients to fall asleep and shorten the anesthesia induction time.