Anaesthesia and interventions
death
ADVERSE EVENTS, BLIND, EMERGENCY
No premedication was given prior to surgery. All patients received standard monitoring including heart rate and rhythm, non-invasive blood pressure, arterial pulse saturation (SpOAfter confirmation of absolute anaesthesia level above T10, trial drugs were administrated by attending anaesthesiologists. In remimazolam group, a loading dose of remimazolam 0.025–0.1 mg/kg was initially given until the loss of consciousness, and then sedation depth was maintained at BIS 70–80 by continuous infusion at a rate of 0.1–1.0 mg/kg/h till end of surgery. Attending anaesthesiologist could adjust the infusion rate to maintain targeted sedation depth. Additional dosage of remimazolam 0.025–0.1 mg/kg could be given in necessary if the target BIS was not obtained at maximum infusion rate. In routine group, sedation was given at the discrete of patient’s demand with dexmedetomidine (i.e., 0.2–0.7 ug/kg/h) based on routine care. Since the BIS value was not routinely used for monitoring sedation in clinical setting, the readings of BIS value were blinded to attending anaesthesiologists in these patients.To decrease potential bias, the anaesthesiologists did not take part in enrolment, randomization, postoperative follow-up and data collection. Any exchange of information above was not allowed during the study period. Blind method was also conducted to researchers, patients, and other related healthcare providers. Emergency unmasking of randomization could be taken in terms of severe adverse events which might result in prolonged in-hospital stay, increased medical expense, disability, and death.