Neutrophil-lymphocyte ratio: A novel outcome prognosticator following traumatic brain injury: A retrospective analysis

Objective: To assess the prognostic significance of Neutrophil-to-Lymphocyte Ratio (NLR) upon presentation in predicting mortality rates and outcomes among patients who sustained moderate to severe traumatic brain injury (TBI) including polytrauma. Methods: Single-centre, retrospective study on 478 TBI patients treated between January 2019 to January 2022. Patients with moderate to severe traumatic brain injury admitted within 24 h of injury were included. Patient demographics, clinico-radiological findings, GCS, NLR on admission, Marshall grade on admission, polytrauma, and modified Rankin Score (mRS) at 6 months were analyzed. The outcome measure was dichotomized based on mRS 0-3 as a good outcome and 4-6 as a poor outcome. A statistical analysis was done using a regression model with IBM SPSS V24.0 software. Results: The study group included 434 patients with a mean age of 41.41 +/- 17.36 years, ranging from 6 months to 90 years. Besides TBI, 200 (46.08 %) patients had polytrauma. Receiver operating curve (ROC) analysis of NLR for prediction of outcome after 6 months in patients without polytrauma, revealed an NLR cut-off value of >6.24 with an area under the curve (AUC) +/- standard error (SE) of 0.717 +/- 0.0340 with a corresponding p-value of <0.0001, which correlated with poor outcome. Age, GCS, NLR on admission, and Marshall grade were found to have a significant association with mortality and 6-month mRS in patients with TBI without polytrauma. Conclusion: In cases of moderate to severe Traumatic Brain Injury (TBI) without polytrauma, NLR emerges as a dependable predictor, capable of forecasting both mortality and 6-month modified Rankin Scale (mRS) outcomes. In patients with polytrauma, NLR's reliability for prognostication following TBI is compromised.