Anesthesia Induction With Intravenous Bolus or Continuous Infusion of Remimazolam

Bolus injection and continuous infusion are two widely used methods for intravenous administration of drugs. Bolus injection possibly leads to a rather high drug plasma concentration temporarily, however, it can induce a rapid onset of drug effects and attain a desired clinical state fast. On the contrary, continuous infusion is able to avoid excessive drug levels in plasma, but it takes longer to achieve the proper effect. In this study, the investigators hypothesize that the bolus injection of remimazolam can reduce anesthesia induction time when compared to the continuous infusion of remimazolam, and also maintain hemodynamic stability. (The researchers will investigate the effect of the bolus injection of remimazolam during anesthesia induction in terms of its safety and efficacy when compared with the continuous infusion.)