Moore HB, et al. - Researchers tested their hypothesis that in injured patients with low fibrinolytic activity, tranexamic acid (TXA) will not increase clot strength measured by thrombelastography (TEG) despite biomarkers of fibrinolysis activation. They performed three TEG assays [rapid (r), tissue plasminogen activator (t-PA), functional fibrinogen (FF)] on 630 patients with a median new injury severity score of 20. They evaluated response to TXA with FF-TEG by calculating percent change in clot strength with the addition of exogenous TXA in the TEG cup. Outcomes revealed multiple abnormalities of the coagulation system in patients with depletion of fibrinolysis inhibitors (DFI). DFI patients displayed significantly increased D-Dimer and lower fibrinogen and increased rates of massive transfusion and mortality. In addition, TXA in DFI patients led to significantly improved fibrin clot strength with hyperfibrinolysis (+20% clot strength p<0.001) but not with shutdown (+2%) or physiologic (-3%).