Platelet dysfunction in trauma: a sub study of the FEISTY pilot trial analysing whole blood aggregometry data.

Abstract

To identify platelet hypofunction and its associations in severely injured trauma patients presenting with haemorrhage. Planned sub-study of data collected from the FEISTY trial; an Australian multicentre, randomised controlled pilot trial investigating early fibrinogen replacement in severely injured trauma patients. Four major trauma centres in Queensland, Australia. Adult trauma patients (age ≥18 years) presenting with clinically significant haemorrhage or potential for significant transfusion requirements. Platelet function parameters arachidonic acid (ASPI), adenosine diphosphate (ADP), and thrombin receptor-activating peptide (TRAP) assessed via Multiplate® analysis, rotational thromboelastometry (ROTEM®) parameters EXTEM, FIBTEM, and PLTEM (EXTEM - FIBTEM), transfusion requirements, and clinical outcomes. Significant platelet hypofunction was detected in this cohort of severely injured trauma patients at time of presentation, with 70 % of patients having hypofunction in at least one Multiplate® channel. The median ASPI area under the curve and 95 % confidence interval were below the lower reference range, indicating this population had reduced platelet function. In patients with deranged platelet function, significantly lower platelet count (p ≤ 0.001), EXTEM amplitude at five minutes (A5) and maximum clot firmness (MCF) (p = 0.001, p ≤ 0.001), and PLTEM A5 and MCF (p = 0.005, p = 0.003) were identified compared to patients with normal platelet function. A significant improvement in platelet function parameters was not observed following platelet transfusion. Platelet hypofunction is common in severely injured trauma patients. This was true both before and after platelet transfusion, suggesting trauma precipitates alteration of the vascular circulating milieu in a way that impairs platelet function. Characterisation of this change might lead to targeted interventions to improve haemostasis.