Abstracts

Abstract

Introduction: Hyperfibrinolysis (HF), an integral component of trauma-induced coagulopathy, is associated with increased mortality and need for massive blood transfusion (MT). Clot lysis 30 minutes after maximum clot strength (LY30) is the standard measure of fibrinolysis by thrombelastography (TEG). The critical level to define HF and initiate anti-fibrinolytic therapy has ranged from 3-7.5%, and this variability might be due to diversity in injury type and severity. For example, less severely injured patients could tolerate higher levels of HF than more injured counterparts. We hypothesize that LY30 cutoffs that define HF are dependent on levels of injury severity and shock. Methods: Adults requiring trauma activations from 2010-2017 in two urban trauma centers were included. Cutoffs defined using the Youden Index and ROC curve analysis using MT ([ 10RBC) or death/ 24hrs as the outcome. Relative risks of MT for each cutoff were derived using Poisson regression with robust standard errors to account for intra-facility clustering. Severe traumatic brain injury (sTBI) was defined as AIS Head [ 3 and Glasgow Coma Scale (GCS) \ 9. Results: 904 patients, median age 33.5 (25-48), 81% male, ISS 10 (2-26), and 51% blunt injuries, were included. Mortality was 12%, and 11% required MT. The cutoff for HF (level with optimal prediction of MT) decreased with higher ISS and hypotension. Presence of sTBI further decreased the LY30 threshold level by 1-4%. LY30 (%) Cutoff for MT MT Total MT % + Predictive value (%) Relative Risk (95% CI) All patients 7 98 904 11 52 2.9(2-4.3) Injury Severity Score (ISS) \26 35.4 6 609 1 83 41.9(21.0-83.4) 26-50 7.0 34 196 17 50 5.3(3.2-8.7) [50 3.0 8 14 57 100 2.2(0.8-6.0) Arrival SBP (mmHg)