Discussion
pain
Propofol has been reported to have a narrow therapeutic index and the guidelines recommend usage only by experienced anesthesiologists, with close monitoring and individual dose adjustments [The main finding of the present study was that the success rates of induction with ciprofol-0.5 mg/kg as an i.v. bolus was comparable to that of propofol-2.0 mg/kg. When lower doses of ciprofol (0.3 or 0.4 mg/kg) were given, a top-up dose was occasionally needed after the initial bolus injection to achieve a 100% success rate of induction. The results also showed that patients in ciprofol-0.5 mg/kg group had the shortest time of loss of the eyelash reflex and that the 0.4 mg/kg group had the longest duration for successful induction and the shortest emergence times. In terms of safety, there were no significant differences among the ciprofol and propofol groups in the incidence of AEs. Vital signs were relatively stable during induction of general anesthesia and even during intubation, and no significant differences were found in term of the accumulated dose of the rescue drugs used to treat AEs. Considering the efficacy and safety endpoints, ciprofol 0.5 mg/kg for induction of general anesthesia was as effective and safe as propofol at a dose of 2.0 mg/kg. No difference in hemodynamic stability during the induction period among the 5 groups was due to prompt treatment with rescue drugs.There is another potential advantage of ciprofol, namely less injection pain on administration compared to propofol. This conjecture is based on the fact that the injection pain produced by propofol is attributable to the absolute drug concentration in the aquatic phase [There were a number of limitations to the study. First, patients were not randomly assigned to groups and a future randomized study will be conducted. In addition, selection bias might have existed as the differences in ASA statuses between the 5 groups were significant (Supplementary Table 1). Second, the administration of the premedication midazolam and sufentanil, but the study design was intended to reflect real clinical practice as much as possible. It should however be noted that the use of a combination of midazolam and sufentanil as premedication has been standard practice in clinical anesthesia for a number of years [