Inflammatory cytokines and neurotrauma biomarkers are acutely elevated in military combat casualties and predict resource use

Introduction Triage of and evacuation decisions for military service members deployed into combat zones experiencing traumatic injuries are serious challenges for military medical providers. We explored the utility of inflammatory biomarkers in determining injury severity and predicting hospital resource utilization to improve the effectiveness of casualty care. Methods Serum levels of inflammatory cytokines (eNAMPT, IL-6, PSGL-1, ANG-2, IL-1β, IL-1RA, TNF-α, and S100A8) and neurotrauma biomarkers (GFAP, NfL, and tau) were analyzed in trauma-exposed warfighters ( n = 39) evacuated to a medical treatment facility. Prior to analysis, outliers were removed via robust regression and outlier removal, with the results analyzed using the Mann–Whitney test, Kruskal–Wallis test w/ Dunn, or Spearman correlation. Results All the tested biomarkers were significantly elevated ( p < 0.0001) in combat casualties vs. healthy controls ( n = 46) and exhibited injury type-specific elevations. Serum eNAMPT ( p = 0.033) and TNF-α ( p = 0.047) were significantly higher in penetrating wounds vs. blunt trauma; IL-1β ( p = 0.005) and S100A8 ( p = 0.005) were significantly elevated in thermal injures vs. blunt trauma; and GFAP ( p < 0.001) and NfL ( p = 0.017) were significantly elevated in blunt trauma vs. thermal injury. Statistical correlations between biomarkers and clinical outcomes indicated the following: (i) duration of mechanical ventilatory support correlated with IL-1RA level ( p = 0.021); (ii) duration of hospital stay correlated with IL-6 ( p = 0.016) and eNAMPT levels ( p = 0.046); and (iii) duration of ICU stay correlated with eNAMPT ( p = 0.016) and S100A8 ( p = 0.017) levels. Conclusions Our results extend prior reports of innate immune activation following traumatic injury and suggest a diverse panel of inflammatory biomarkers may predict hospital resource utilization to inform prioritization of local resources and evacuation to higher levels of care.