Purpose of review: Trauma-induced coagulopathy results from a complex interplay between shock resuscitation and impaired clotting protease function. A pathophysiological role of platelets in this condition remains as yet undefined. This review examines our current knowledge of platelet function in haemostasis, possible mechanisms for aberrant activity in trauma and the role of platelet transfusions in exsanguinating haemorrhage.
Recent findings: Platelet adhesion and aggregation enable a haemostatic plug to form at the site of vessel injury. As described within cell-based models of thrombin generation, platelet membranes provide a platform to amplify clot formation. There is evidence to suggest platelet activity may be of greater importance than platelet number for clot integrity. Analysis of platelet function is limited by currently available devices. Therefore, the precise role and triggers for platelet transfusion in trauma have yet to be fully characterized. Retrospective studies show that early high-volume platelet transfusion in trauma may be associated with similar outcome benefits observed in high ratio plasma: red blood cell replacement.
Summary: Platelets undoubtedly play a pivotal role in haemostasis and trauma-induced coagulopathy. However, their specific dysfunction in trauma remains to be elucidated. Further research to characterize the dysfunctional pathways of the platelet response is required, together with clinical trials of the optimal timing and dose of platelet transfusions.