Statistical analysis
hypotension
The sample size was estimated using PASS 11 software (NCSS, LLC, Kaysville, UT, USA). In our pilot study, the incidence of hypotension elicited by 1.5 mg/kg of propofol was 40% (8/20), which was reduced to 10% (2/20) after pretreatment with 0.2 mg/kg of remimazolam. To achieve 80% (β = 0.20) statistical power with α = 0.05, each group would require no less than 23 patients. To account for drop-outs, we recruited 30 patients per group.Data processing was performed using SPSS 15.0 (SPSS Inc., Chicago, IL, USA). The normality test in SPSS was used to determine whether the data conformed to a normal distribution. Measurement data are expressed as mean ± standard deviation. Repeated-measures analysis of variance was performed for intragroup comparisons, and one-way analysis of variance was performed for intergroup comparisons. A P value of < 0.05 was considered statistically significant.