Background To determine the prevalence of platelet dysfunction, using an end-point of assembly into a stable thrombus, following severe injury. Background: Although the current debate on acute traumatic coagulopathy (ATC) has focused on the consumption or inhibition of coagulation factors, the question of early platelet dysfunction in this setting remains unclear. Study Design Prospective platelet function in assembly and stability of the thrombus was determined within 30 minutes of injury using whole blood samples from trauma patients at the point of care employing thrombelastography (TEG)-based platelet functional analysis. Results There were 51 patients in the study. There were significant differences in the platelet response between trauma patients and healthy volunteers such that there was impaired aggregation to these agonists. In trauma patients, the median ADP inhibition of platelet function was 86.1% (IQR: 38.6–97.7%), compared to 4.2 % (IQR 0–18.2%) in healthy volunteers. Following trauma, the impairment of platelet function in response to AA was 44.9% (IQR 26.6–59.3%), compared to 0.5% (IQR 0–3.02%) in volunteers (Wilcoxon non parametric test p<0.0001 for both tests). Conclusions In this study, we show that platelet dysfunction is manifest following major trauma, before significant fluid or blood administration. These data suggest a potential role for early platelet transfusion in severely injured patients at risk for postinjury coagulopathy.

BACKGROUND The acute coagulopathy of trauma is present in up to one third of patients by the time of admission, and the recent CRASH-2 and MATTERs trials have focused worldwide attention on hyperfibrinolysis as a component of acute coagulopathy of trauma. Thromboelastography (TEG) is a powerful tool for analyzing fibrinolyis, but a clinically relevant threshold for defining hyperfibrinolysis has yet to be determined. Recent data suggest that the accepted normal upper bound of 7.5% for 30-minute fibrinolysis (LY30) by TEG is inappropriate in severe trauma, as the risk of death rises at much lower levels of clot lysis. We wished to determine the validity of this hypothesis and establish a threshold value to treat fibrinolysis, based on prediction of massive transfusion requirement and risk of mortality. METHODS Patients with uncontrolled hemorrhage, meeting the massive transfusion protocol (MTP) criteria at admission (n = 73), represent the most severely injured trauma population at our center (median Injury Severity Score [ISS], 30; interquartile range, 20–38). Citrated kaolin TEG was performed at admission blood samples from this population, stratified by LY30, and evaluated for transfusion requirement and 28-day mortality. The same analysis was conducted on available field blood samples from all non-MTP trauma patients (n = 216) in the same period. These represent the general trauma population. RESULTS Within the MTP-activating population, the cohort of patients with LY30 of 3% or greater was shown to be at much higher risk for requiring a massive transfusion (90.9% vs. 30.5%, p = 0.0008) and dying of hemorrhage (45.5% vs. 4.8%, p = 0.0014) than those with LY30 less than 3%. Similar trends were seen in the general trauma population. CONCLUSION LY30 of 3% or greater defines clinically relevant hyperfibrinolysis and strongly predicts the requirement for massive transfusion and an increased risk of mortality in trauma patients presenting with uncontrolled hemorrhage. This threshold value for LY30 represents a critical indication for the treatment of fibrinolysis.