Statistical analysis
Statistical analysis was performed using SPSS version 26.0 (IBM SPSS Inc., Chicago, IL). Continuous variables are presented as mean ± standard deviation or median [interquartile range] for normal and non-normally distributed data, respectively. Categorical variables are presented as absolute values and percentages. Means were compared using the independent group t -test or the Mann‒Whitney U test (depending on data normality) for continuous variables and the χ2 test (two-sided Fisher’s exact test) for categorical variables. Logistic regression analysis was used to screen the factors related to the outcome and meaningful indicators for the next step of Cox multivariate regression analysis. Cox proportional hazards models were used to analyze the independent effect of PASP on ventilator treatment. Spearman’s correlation analysis was used to investigate the correlation of PASP with oxygen pressure/ fraction of inspiration oxygen (PaO2:FiO2). The cumulative survival curve of ventilator weaning was estimated using the Kaplan‒Meier product-limit estimation method. A receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of PASP for weaning outcome. P < 0.05 was considered to indicate statistical significance.