Statistical analysis
PONV
The sample size was calculated based on the results of our preliminary experiments and an expected QoR-40 score difference of 10 with 95% power (α = 0.05 and β = 0.1), which indicated that 40 patients were required per group. The QoR-40 scores, patient characteristics (age, height, weight, and body mass index), surgery duration, time to extubation, and time to recovery are expressed as the mean ± standard deviation, and analyzed using student’s t test. The incidence of PONV was expressed as ratio using the chi-square or Fisher exact test; 