Statistical analysis
Statistical analysis was performed using IBM SPSS, version 26. We tested the correlation of NO serum to APACHE II and SAPS II scoring in predicting the patients’ outcomes. Student’s t test (continuous variable) and Fisher’s exact test (categorical variable) were used for comparisons between survivors and non-survivors. Spearman rank correlation was used to establish interrelationships between the different variables. For each predictor variable, sensitivity and specificity were calculated using Fisher’s exact test. Receiver operating characteristic curve (ROC) was plotted using 1‐specificity on X‐axis (false‐positive fraction [FPF]) and sensitivity (true‐positive fraction [TPF]) on Y‐axis for all the predictor variables.