Value of neutrophil-to-lymphocyte ratio, procalcitonin, and C-reactive protein in help to predict weaning outcome: a prospective, observational cohort study

Purpose: We evaluated and compared the value of neutrophil-to-lymphocyte ratio (NLR), procalcitonin (PCT), and C-reactive protein (CRP) prior to weaning in predicting weaning outcome in invasively ventilated patients. Materials and Methods: We conducted an observational cohort study over a 3.5-year period in a 12-bed ICU. Patients underwent an spontaneous breathing trial (SBT) when they were ready to wean, and were extubated when they passed the trial. Immediately before the SBT, we measured the evaluated diagnosis tools. Results: Among the 269 patients in the study, 94 (34.9%) failed the weaning process. NLR values were positively correlated with PCT levels and CRP levels in both weaning success and weaning failure group. The adjusted logistic regression model demonstrated that NLR value >11 (odds ratio [OR], 4.66; 95% confidence interval [CI], 2.63–8.26; p = 0.000), PCT level >4 ng/mL (OR, 5.96; 95% CI, 3.11–11.41; p = 0.000) and CRP level >58 mg/L (OR, 3.16; 95% CI, 1.84–5.41; p = 0.000) were the independent predictors for weaning failure. The area under the ROC curves for NLR value, PCT level, and CRP level were 0.77, 0.70, 0.58, respectively. A NLR value of >11, PCT level of >4ng/mL, and CRP level of >58 mg/L prior to weaning had the best combination of sensitivity, specificity, positive predictive value, and negative predictive value, and diagnostic accuracy for predicting weaning failure. Conclusions: Measuring NLR valve, PCT level, and CRP level prior to weaning may help to predict weaning outcome.