LAUSR

BACKGROUND Trauma patients with hyperfibrinolysis and depletion of fibrinolytic inhibitors(DFI) measured by thrombelastography(TEG) gain clot strength with TXA, but TEG results take nearly an hour. We aimed to develop an assay, plasmin TEG(P-TEG), to more expeditiously stratify risk for massive transfusion(MT), mortality and hyperfibrinolysis. METHODS Trauma patients(n=148) were assessed using TEG assays without exogenous additives(rapid/native), with exogenous plasmin(P-TEG) or tissue plasminogen activator(tPA TEG). The plasmin dose used does not effect healthy control LY30 but causes shortened R-time relative to native TEG(P-TEG R-time4-fold higher MT rate(30% vs 7%;p=0.0015) with AUROC 0.686(p=0.028), >4-fold higher 24 hour mortality(33.3% vs 7.8%;p=0.0177), >2-fold higher 30 day mortality(35% vs. 16.4%;p=0.0483), higher rates of DFI(55 vs 18%;p<0.001), and a trend towards elevated D-dimer(19.9 vs 3.3 μg/mL;p=0.14). P-TEG was associated with hyperfibrinolysis on Rapid-TEG LY30 at the 7.6% threshold(p=0.04) but not the 3% threshold(p=0.40). P-TEG performed best in relation to DFI, with a PPV of 58% and NPV of 81%. When combined with tPA TEG TMA, P-TEG outperformed R-TEG LY30 for predicting MT(AUROC 0.811 vs 0.708). CONCLUSIONS Within 5 minutes P-TEG can stratify patients at highest risk for MT, mortality, and risk for hyperfibrinolysis. In composite with tPA TEG TMA, P-TEG outperforms Rapid-TEG LY30 for predicting MT and does so 4x faster(12.7min vs. 54.1min). The rapid results of P-TEG may be useful for those who practice selective TXA administration to maximize TXA's time-dependent efficacy. LEVEL OF EVIDENCE Level IVDiagnostic Test.