Authors: Rebekah Kimball; Stephanie Eyerly-Webb, PhD; Rachele Solomon, MPH; Elad Shachar; Dean Hertzler, MD; Heather Spader, MD (Longwood, FL)

Introduction:

Prognostication for outcomes following pediatric traumatic brain injury (TBI) has traditionally been based upon initial Glasgow Coma Scale (GCS) and other clinical and radiologic indicators. Although the inflammatory cascade following TBI can be both neuroprotective and destructive, inflammatory markers have not been utilized to help predict outcomes in pediatric TBI. This study is the first to utilize the neutrophil-to-lymphocyte ratio (NLR), an inflammatory marker widely utilized in other specialties, to help predict outcomes in pediatric TBI.

Methods:

A retrospective review of pediatric patients presenting to our institution with TBI from 2007 to 2017 was performed (n=188, age=0-18 years). Absolute neutrophil count and absolute lymphocyte count on admission and approximately twenty-four and forty-eight hours post-injury were used to calculate NLRs. Data points included GCS on admission, extended Glasgow Outcome Scale (GOS-E) score, and presence of post-traumatic amnesia and/or loss of consciousness. Patients were stratified based on GOS-E score: none to mild disability (GOS-E=1-2), moderate to severe disability (GOS-E=3-6), or vegetative state/death (GOS-E=7-8).

Results:

A one-way ANOVA demonstrated statistically significant differences in NLR among patients stratified by GOS-E at 24 hours [F(2,55)=6.26, p=0.004] and 48 hours [F(2,24)=7.59, p=0.003]. No significant differences in NLR or neutrophils were observed at any time point based on GCS category or post-traumatic amnesia. Patients who experienced loss of consciousness had a significantly higher NLR on admission (p=0.013) and at 24 hours (p=<0.001) compared to those who did not lose consciousness.

Conclusion:

In this study, a higher NLR twenty-four hours post-TBI predicted worse outcomes in pediatric patients. There was no difference based upon admit NLR. This suggests that NLR may be a useful outcome predictor in pediatric TBI as well as a possible future target for therapeutic intervention. Further study is warranted with larger prospective trials, different time points, and alternative inflammation markers.