2.3. Study protocol
initiation of skin suturing, neuromuscular block, hypotension
EVENT
After obtaining informed consent, one of the authors (JL) randomly assigned the participants to the remimazolam or propofol group using a permuted block system. Random allocation sequences were generated for TURBT and laparoscopic cholecystectomy by one of the authors (YGJ) using R statistics 4.2.2 (R Core Team, Vienna, Austria). The size of the permuted block was 6, and the permuted block was generated independently for each surgery to maximize comparability. The allocation of the last 6 participants was adjusted to equalize the number of enrolled patients in both groups.The patients were blinded to group allocation. The hypnotic drug was prepared after the patient arrived in the operating room and the infusion device was placed outside the patient’s sight. Blinding was maintained for 24 hours after the conclusion of surgery.No premedication was administered to any participant, and they underwent standard anesthesia monitoring with a bispectral index (BIS) monitor upon arrival at the operating room. In the remimazolam group, the rate of remimazolam administration was 6 mg*kgRemifentanil infusion was administered via TCI in both groups using the Minto model. Infusion was started with an effect-site concentration 3.0 ng/mL with the hypnotic agent and titrated in range of 1.5 to 4.0 ng/mL following endotracheal intubation. Rocuronium was administered 0.8 mg per kg ideal body weight for neuromuscular block. Additional rocuronium 0.15 mg per kg ideal body weight was administered when there was a request from the surgeon for visual field improvement, surgical manipulation, or > 20% of abrupt reduction of lung compliance despite appropriate respiratory management.Ephedrine 8 mg was administered intravenously to treat the hypotension. Phenylephrine infusion was commenced where ephedrine could not resolve hypotension for 3 times at this dose in 1 event. Further treatment was determined by an attending anesthesiologist where hypotension persisted beyond this point.Ramosetron 0.3 mg was administered upon initiation of skin suturing, and the infusion of remifentanil and hypnotic drugs was ceased 5 minutes prior to the conclusion of surgery. Sugammadex was administered as a neuromuscular reversal agent. Flumazenil 0.2 mg was administered to patients in remimazolam group whose recovery of spontaneous ventilation was inadequate 10 minutes after cessation of the remimazolam infusion.