Ex vivo haemostatic capacity of plasma upon thawing and beyond: a comparison between fresh frozen plasma ( FFP ) and frozen plasma prepared from whole blood stored at room temperature up to 24 hours postcollection ( RTFP 24)

Background/objectives We compared the ex vivo haemostatic capacity of RTFP 24 with FFP upon thawing and >24 h post‐thaw. We included thrombin generation ( TG ) as few studies had compared global haemostatic function, and most did not directly compare RTFP 24 with FFP >24 h post‐thaw. Materials/methods Twenty units each of RTFP 24 and FFP were measured for coagulation factors and thrombin generation upon thawing (D0) and 4 days post‐thaw (D4). Labile factors were also measured from D1 to D3. 10 single cryoprecipitate units were each prepared from FFP and RTFP 24, and measured for FXIII , FVIII and fibrinogen at D0. Results At D0, RTFP 24 was comparable to FFP except for lower FV , protein S, endogenous thrombin potential ( ETP ) and higher FXIII . These differences were likely clinically insignificant since 95% and 80% of RTFP 24 met our laboratory's reference ranges for FV /protein S and ETP , respectively. There were no differences between RTFP 24‐ and FFP ‐derived cryoprecipitate. At D4, RTFP 24 was comparable to FFP except for lower FV , ETP , and higher FXI and FXIII . More RTFP 24 than FFP had ETP lower than our laboratory's reference range (45% vs 15%). Multiple coagulation factors and all TG parameters declined from their respective baselines. The percentage declines were comparable or less in RTFP 24, except for protein C, fibrinogen and time to peak. Conclusion RTFP 24 and FFP , and their derived cryoprecipitate have comparable haemostatic capacity upon thawing. RTFP 24 has poorer TG potential than FFP >24 h post‐thaw, not supporting universal extension of RTFP 24's shelf life except to facilitate urgent transfusions for massive haemorrhage.