Neutrophil Lymphocyte Ratio and Platelet Lymphocyte Ratio as Predictors of Disease Severity and Mortality in Critically Ill Children: A Retrospective Cohort Study

Objectives: The aim of this study was to determine the ability of Neutrophil lymphocyte ratio and Platelet lymphocyte ratio to predict severity of illness as assessed by 2 scoring systems, namely, Pediatric Logistic Organ Dysfunction-2(PELOD-2) and Pediatric Risk of Mortality-III(PRISM-III) and outcome. Methods: This was a retrospective cohort study wherein all critically ill children aged 1month to 18years admitted in pediatric intensive care unit from January 2021 to October 2022 were included. Children with chronic systemic diseases and with hematological illness were excluded from the study. Demographic details, diagnosis, PRISM-III-24 and PELOD-2 scores at admission and outcome were retrieved from the hospital case records. NLR and PLR values were compared among among high and normal PRISM-III and PELOD-2 groups as well as among survivors and non survivors. Results: A total of 325 patients with critical illness were included with a mean (SD) age of 7(5) years and a male: female ratio of 3:2. The values of NLR were significantly higher among the patients with high PRISM-III (2.2 vs 1.3, p value 0.006) and PELOD-2 ( 2 vs 1.4, p value 0.015) groups compared to normal. The NLR and PLR were significantly higher among the non survivors compared to the survivors. (2.3 vs. 1.4, p value 0.013, and 59.4 vs. 27.3, p value 0.016 for NLR and PLR respectively). The area under the Receiver operating characteristics curve for NLR and PLR was 0.617and 0.609 respectively. A high PLR, PRISM-III and PELOD- 2 were the factors found to be independently associated with mortality on multiple logistic regression analysis. Conclusions: Patients with high NLR are associated with more severe illness at admission. NLR and PLR are useful parameters to predict mortality.