Effective dose of remimazolam combined with different doses butorphanol inhibiting response to cervical dilation during artificial abortion: A randomized dose-finding clinical study

The purpose was to determine the effective dose of remimazolam (RMZ) combined with different doses butorphanol inhibiting response to cervical dilation during artificial abortion. This is a prospective, randomized, and double-blind study. Sixty-one female patients were randomly assigned to Group B10 (31 patients) and Group B15 (30 patients). All patients were given RMZ 5 min after an intravenous (IV) administration of butorphanol 10 μg/kg (Group B10) and 15 μg/kg (Group B15). According to the pre-experiment, the first dose of RMZ in the first patient was 0.35 mg/kg, and the adjacent geometric dose ratio was 0.9. The centered isotonic regression was performed to determine the ED50 and ED90 of RMZ and their corresponding 90% confidence interval (CI). The total RMZ dose administered, recovery time, and anesthesia-related adverse events were all recorded. The recovery time in Group B10 was significantly shorter than in Group B15. The incidence of post-operative nausea and vomiting (PONV) in the B10 and B15 groups was 3.2% and 16.7%, respectively. Therefore, to enhance the sedative effect of RMZ, the recommended dose of butorphanol is 10 μg/kg, and the ED50 and ED90 of the RMZ during painless artificial abortion were 0.263 and 0.331 mg/kg, respectively.