Statistical analysis
ESPB, NRS
The sample size was estimated with the MedSci Application (V.6.2.2, MedSci, China). We performed sample size calculations, in which a 1-point reduction in the NRS score at 12 h was considered clinically relevant. Eight patients in each group were included in our pilot study. The NRS score was 2 (1) (mean (SD)) in the ESPB group and 2.5 (1.4) in the control group at 12 h. According to a two-sided unpaired t test, 90 patients were required in each group to achieve 80% response and an α threshold of 0.05. Due to the nonparametric estimation parameter data, the sample size was increased by 15%, resulting in 104 patients per group. Considering loss to follow-up, we selected 115 patients per group. Statistical tests were conducted with IBM SPSS Statistics 26.0 (IBM, USA). The Shapiro―Wilk test was employed to test for normal distribution; the Student’s t test and the Mann―Whitney U test were used for continuous variables (normal and nonnormal distribution);and the Fisher’s exact or χ2 tests were used for categorical variables and proportions. A two-tailed, 