PB1026 - Whole blood better supports platelet measures of haemostasis compared to red cells and plasma: an ex vivo spiking study

Background: ¬Current prehospital haemostatic resuscitation is largely based on platelet-poor blood components, e.g. red cells and plasma (RCP). Clinical trials have demonstrated improved outcomes compared to crystalloid resuscitation but the effect of these components and whole blood (WB) on trauma-induced coagulopathy (TIC) have not been fully characterised.

Aims: Compare the ability of WB versus RCP to correct ex vivo platelet-related haemostatic parameters in patients with TIC.

Methods: Samples were collected from trauma patients who activated the major haemorrhage protocol prehospital and were enrolled into a prospective cohort study (ISRCTN12962642) at a UK major trauma center in 2021/2022. Each sample was aliquoted and spiked ex vivo with a volume of RCP or WB equivalent to four units. ROTEM EXTEM and FIBTEM were performed on non-spiked and spiked samples. Platelet count was measured using flow cytometry, while aggregation and agglutination with multiple electrode aggregometry. The original components and healthy-donor samples were assayed as controls (REC 07/Q702/24). RCP and WB were stored at 4°C up to two weeks.

Results: Samples from 19 adult trauma patients and 5 healthy donors were analysed. Patients’ median age was 31 years, 89% were male, TIC was present in 68% (EXTEM A5 <=40mm), 74% had platelet dysfunction (EXTEM-FIBTEM A5 <=30mm) and 39% died. Samples spiked with WB compared to RCP were characterised by better preserved and higher overall clot strength (EXTEM A5 37mm [35-42] vs 35mm [30-39], p=0.001) and platelet-related clot strength (EXTEM-FIBTEM A5 30mm [26-33] vs 27mm [24-30], p=0.001) (Figure 1A-C). WB-spiking reduced overall incidence of TIC and corrected platelet dysfunction in two samples (Figure 1B-D). While both RCP and WB similarly corrected EXTEM CT (p=0.501), other measures of clotting and fibrinolysis kinetics, platelet count, aggregation and agglutination were better preserved or ameliorated by WB (Figure 2).

Conclusion(s): When compared to RCP ex vivo, WB preserves or improves most platelet-related haemostatic parameters.