Purpose: Contemporary trauma resuscitation prioritizes control of bleeding and uses major haemorrhage protocols (MHPs) to prevent and treat coagulopathy. We aimed to determine whether augmenting MHPs with Viscoelastic Haemostatic Assays (VHA) would improve outcomes compared to Conventional Coagulation Tests (CCTs). Methods: This was a multi-centre, randomized controlled trial comparing outcomes in trauma patients who received empiric MHPs, augmented by either VHA or CCT-guided interventions. Primary outcome was the proportion of subjects who, at 24 h after injury, were alive and free of massive transfusion (10 or more red cell transfusions). Secondary outcomes included 28-day mortality. Pre-specified subgroups included patients with severe traumatic brain injury (TBI). Results: Of 396 patients in the intention to treat analysis, 201 were allocated to VHA and 195 to CCT-guided therapy. At 24 h, there was no difference in the proportion of patients who were alive and free of massive transfusion (VHA: 67%, CCT: 64%, OR 1.15, 95% CI 0.76-1.73). 28-day mortality was not different overall (VHA: 25%, CCT: 28%, OR 0.84, 95% CI 0.54-1.31), nor were there differences in other secondary outcomes or serious adverse events. In pre-specified subgroups, there were no differences in primary outcomes. In the pre-specified subgroup of 74 patients with TBI, 64% were alive and free of massive transfusion at 24 h compared to 46% in the CCT arm (OR 2.12, 95% CI 0.84-5.34). Conclusion: There was no difference in overall outcomes between VHA-and CCT-augmented-major haemorrhage protocols.

Trauma hemorrhage is a leading cause of death and disability worldwide. Platelets are fundamental to primary hemostasis, but become profoundly dysfunctional in critically injured patients by an unknown mechanism, contributing to an acute coagulopathy which exacerbates bleeding and increases mortality. The objective of this study was to elucidate the mechanism of platelet dysfunction in critically injured patients. We found that circulating platelets are transformed into procoagulant balloons within minutes of injury, accompanied by the release of large numbers of activated microparticles which coat leukocytes. Ballooning platelets were decorated with histone H4, a damage-associated molecular pattern released in massive quantities after severe injury, and exposure of healthy platelets to histone H4 recapitulated the changes in platelet structure and function observed in trauma patients. This is a report of platelet ballooning in human disease and of a previously unrecognized mechanism by which platelets contribute to the innate response to tissue damage.

Patients presenting with low ML and low DD levels have low injury severity and normal outcomes. Conversely, patients with low ML but high DD levels are severely injured, functionally coagulopathic and have poor clinical outcomes. These patients have low tissue plasminogen activator levels and are not detectable by ROTEM. S100A10 is a cell surface plasminogen receptor which may drive the hyperfibrinolysis in these patients and which when shed artificially lowers %ML ex-vivo.

Therapeutic, level III.