Neutrophil-to-lymphocyte ratio as a predictive marker for severe pediatric sepsis

Background Although neutrophil-to-lymphocyte ratio (NLR) has been extensively studied in several diseases, its role in pediatric sepsis remains unclear. Our study aimed to assess the predictive significance of NLR for severe pediatric sepsis in the pediatric intensive care unit (PICU). Methods We retrospectively recruited critically ill children in the PICU with severe pediatric sepsis from January 2019 to January 2020 in West China Hospital of Sichuan University. Univariate and multivariable logistic regression analysis was used to assess the risk factors of severe pediatric sepsis. Receiver operating characteristic (ROC) curves were plotted for the comparison of the prediction significance of NLR. Results Overall, 202 patients (severe sepsis 45; non-severe sepsis 157) were included. In the severe sepsis group, the levels of NLR (P<0.001), procalcitonin (PCT; P<0.001), and the Pediatric Risk of Mortality score (PRISM III) were higher than those in the nonsevere sepsis group (P<0.001). The PICU stay time (P<0.001), mechanical ventilation length (P=0.004), and hospital stay time (P<0.001) in the severe sepsis patients were noticeably more extended than those in the control patients. The area under the ROC curve (AUC) of NLR was 0.715 (P<0.001), which was higher than that of the PRISM III score (AUC =0.651, P<0.001) and PCT (AUC =0.647, P<0.001). Furthermore, the constructed predictive model of NLR + PCT + PRISM III showed a better prediction significance than they alone (AUC =0.888, P<0.001). Conclusions Results indicated that the initial NLR value was a significant biomarker for predicting severe pediatric sepsis. The combined NLR and PCT improved the evaluation for further early identification of severe sepsis in children.