Background Fibrinolysis is a physiologic process to maintain microvascular patency by breaking down excessive fibrin clot. Hyperfibrinolysis (HF) is associated with a doubling of mortality. Fibrinolysis shutdown (SD), an acute impairment of fibrinolysis, has been recognized as a risk factor for increased mortality. The purpose of this study was to assess the incidence and outcomes of fibrinolysis phenotypes in two urban trauma centers. Study Design Injured patients admitted 2010-2013, who were ≥18 years of age, had an injury severity score (ISS) >15 were included in the analysis. Admission fibrinolysis phenotypes were determined by the clot lysis at 30 minutes (LY30): SD ≤0.8%, physiologic 0.9-2.9%, HF ≥3%. Logistic regression was used to adjust for age, arrival blood pressure, ISS, mechanism, and facility. Results 2540 patients met inclusion. Median age was 39(IQR 26-55) and median ISS was 25(IQR 20-33) with a mortality rate of 21%. Fibrinolysis shutdown was the most common phenotype (46%) followed by physiologic (36%) and hyperfibrinolysis(18%). HF was associated with the highest death rate (34%), followed by SD(22%), and physiologic (14%, p<0.001). The risk of mortality remained increased for HF(OR=3.3, 95%C: 2.4-4.6, p<0.0001) and SD(OR 1.6 95%CI 1.3-2.1, p=0.0003) compared to physiologic when adjusting for age, ISS, mechanism, head injury, and blood pressure (AUROC=0.82, 95% CI 0.80-0.84). Conclusions Fibrinolysis SD is the most common phenotype upon admission and is associated with increased mortality. Moreover, these data provide additional evidence of distinct phenotypes of coagulation impairment and that individualized hemostatic therapy may be required.

Although uncommon immediately after injury, HF is associated with prehospital crystalloid administration and shock at admission and is highly lethal. Our in vitro model confirms that tissue injury and significant crystalloid hemodilution result in severe and immediate HF.

Although there was consensus, supported by grade A-C evidence, on patient selection, the safety of short-term nonoperative management, and mesh reinforcement, among experts; there was limited evidence and broad variability in practice patterns in all other areas of practice. The lack of strong evidence and expert consensus on these topics has identified gaps in knowledge where there is need of further evidence.