Statistical analysis
SPSS 25.0 data analysis software was used to analyze and process the data. The measurement data conforming to the normal distribution are expressed as the mean ± standard deviation (SD), and an independent sample t test was used for intergroup comparisons. Nonnormally distributed measurement data are represented by the median (M) and interquartile range (IQR), and Wilcoxon rank sum tests were used for between-group comparisons. For counting data, we used the number of patients, and the chi-square test or Fisher’s exact test was used for comparisons between groups. For comparison between groups of hemodynamic indicators (MAP, HR) and serological indicators (β-endorphin, SOD, MDA, NSE, S100β) at different time points, repeated measure ANOVA was used, followed by multiple adjustment with Bonferroni correction. A 