Statistical analysis
Wilson’s
IBM SPSS (ver. 25) was used for all statistical analyses. The demographic characteristics were analyzed using analysis of variance (ANOVA), chi-square, Fisher or Kruskal–Wallis tests. The primary outcome was also analyzed using Wilson’s and/or Fisher tests. Time to MOAA/S ≤ 1 and loss of the eyelash reflex were evaluated using the Kruskal–Wallis test, followed by Student's The sample size calculation was based on the data from our previous clinical experience. Assuming that the success rate of induction with propofol injection was 100% and the difference in the success rate of induction with a ciprofol equally potent dose was not > 3%, a sample size of 23 patients in each group would produce a two-sided 95% confidence interval (CI) of − 0.1 to 0.1. Considering that the dropout rate would be about 25%, the sample size was rounded to 30 patients in the dose escalation + expansion study. Therefore, we started with 10 patients in each group in the part 1 dose escalation and planned to add another 20 patients in the part 2 dose expansion.