Neutrophil-To-Lymphocyte Ratio as a Prognostic Marker in Pediatric Intensive Care: A North Indian Cohort Study

Abstract

Background and Aims: Acute infectious diseases continue to account for substantial morbidity and mortality among children admitted to pediatric intensive care units (PICUs). Early recognition of children at risk of deterioration is important for timely monitoring and escalation of care. The neutrophil-to-lymphocyte ratio (NLR), derived from a routine complete blood count, offers a simple measure of the inflammatory and immune response. The present observational cohort study assessed the prognostic value of admission NLR for mortality and organ dysfunction in children with acute infectious diseases admitted to a tertiary care PICU in North India.
Materials and methods: This 18-month observational cohort study was conducted in a tertiary care teaching hospital in North India. Consecutive eligible children aged 1 month to 18 years admitted with acute infectious diseases were enrolled and followed until PICU discharge, hospital discharge, or mortality. Admission NLR was calculated from the initial complete blood count. Organ dysfunction was evaluated with the PEdiatric Logistic Organ Dysfunction-2 (PELOD-2) score within 24 hours of admission. The primary outcome was PICU mortality. Secondary outcomes included the relationship of NLR with organ dysfunction scores and the duration of PICU and hospital stay.
Results: All 100 enrolled children were included in the analysis. Median NLR was higher among non-survivors [4.13 (1.89-5.46)] than survivors [1.31 (0.79-3.21); p = 0.030]. Receiver operating characteristic analysis showed an area under the curve of 0.759 (95% confidence interval 0.627-0.890; p = 0.034) for mortality prediction. Sensitivity, specificity, positive predictive value, and negative predictive value were 66.67%, 70.21%, 12.50%, and 97.06%, respectively. Admission NLR showed mild but statistically significant positive correlations with neurologic dysfunction (r = 0.213, p = 0.033) and cardiovascular dysfunction (r = 0.307, p = 0.002). No significant correlation was observed with PICU or total hospital stay.
Conclusion: Admission NLR is a low-cost, readily available marker associated with mortality and selected organ dysfunction in critically ill children with acute infectious diseases. It may support early risk stratification in resource-limited settings, provided it is interpreted alongside clinical assessment and validated severity scores.