Grouping and intervention
All patients in both Group RR and Group RA were started with an induction dose of remimazolam besylate (Yichang Humanwell Pharmaceutical Co., Ltd., China) 0.2 mg/kg, followed by a maintenance dosage of 1.0 mg/kg/h by continuous IV infusion until the loss of consciousness (absence of eyelash reflex) [In Group RR, after induction with remimazolam besylate and confirmation of the absence of the eyelash reflex, infusion with remifentanil (Yichang Humanwell Pharmaceutical Co., Ltd.) was started with a TCI pump (Guangxi VERYARK Technology Co., Ltd., China), and the effective effect-site concentration (Ce) (Minto pharmacokinetic model) was 1.5 ng/ml [In Group RA, after induction with remimazolam besylate and confirmation of the absence of the eyelash reflex, infusion with alfentanil (Yichang Humanwell Pharmaceutical Co., Ltd.) was started with an initial bolus dose of 20 µg/kg over 30 s and then maintained at an initial rate of 0.16 µg/kg/min [