Fig. 1
Study protocols. Patients were attached to monitors (ECG, sphygmomanometer, SpO2, EEG monitor, and muscle relaxation monitor) after entering the operating room. Noninvasive BP measurements were taken every minute. After adequate oxygenation, the continuous infusion group received a continuous infusion of remimazolam at 12 mg/kg/h. Patient status was assessed every 10 s. After confirming the loss of consciousness, the remimazolam infusion rate was reduced to 1 mg/kg/h. Simultaneously, remifentanil 0.3 µg/kg/min was initiated. After administering rocuronium at a dose of 0.6–0.9 mg/kg, tracheal intubation was performed. A single bolus dose administration of remimazolam (single bolus dose administration of 0.1 group: 0.1 mg/kg; single bolus dose administration of 0.2 group: 0.2 mg/kg) was administered in the single bolus dose administration group. If the patient failed to fall asleep after 2 min, an additional dose of 0.05 mg/kg of remimazolam was administered. If the patient failed to lose consciousness in the next minute, the study was discontinued, and another sedative was administered