Elevated admission INR strongly predicts mortality in victims of abusive head trauma.

BACKGROUND: Victims of abusive head trauma have poor outcomes compared to other injured children. There is often a delay in diagnosis as these young patients are unable to communicate with healthcare providers. These critically injured patients would benefit from early identification and therapy.

METHODS: We performed a retrospective review of our single hospital trauma registry from 2005-2014. All level 1 pediatric (age 0-17) trauma patients who sustained abusive head trauma were included. Exclusion criteria included: no admission coagulation studies, prehospital product transfusion, preexisting coagulation disorder or death upon arrival. Primary outcome was mortality; secondary outcomes were early blood transfusion and neurosurgical intervention.Univariate analysis included Fisher exact and Wilcoxon rank-sum testing; we then performed logistic regression modeling and calculated adjusted odds ratios (AOR) to control for known predictors of poor outcome including hypotension, hypothermia, acidosis, ISS, and Head AIS.

RESULTS: In 101 total subjects, 35% (n=35) had INR≥1.3 on admission. On univariate analysis, patients with coagulation dysregulation were more likely to have hypothermia, hypotension, acidosis, high ISS and low GCS (all p<0.05). There was no difference in age, anemia, and incidence of polytrauma. Overall mortality was 24.8% (n=25) which varied significantly based on admission INR (60% INR≥1.3 vs 6% INR>1.3, p<0.001). Patients with elevated INR were also more likely to have early PRBC transfusion (p=0.003) and neurosurgical intervention (p=0.011). In logistic regression analysis, admission INR was the strongest independent predictor of mortality with increased odds of 3.65 (p=0.045). Adjusted odds ratio after controlling specifically for hypotension, hypothermia and acidosis was 6.25 (p=0.006) and after controlling for head AIS and admission GCS the AOR=5.27 (p=0.007).

CONCLUSIONS: Admission INR≥1.3 strongly predicts mortality in abusive head trauma. These patients should be targeted for early aggressive interventions and monitoring with the goal of improving patient outcomes. Further study is warranted to investigate potential therapeutic targets in trauma-induced coagulation dysregulation.

LEVEL OF EVIDENCE: III, prognostic and epidemiological.