AbstractBackground and ObjectivesCold‐stored whole blood (CSWB) is increasingly used in damage control resuscitation. Haemostatic function of CSWB seems superior to that of reconstituted whole blood, and it is sufficiently preserved for 14–21 days. To provide evidence for a yet insufficiently studied aspect of prehospital CSWB use, we compared in vitro haemostatic properties of CSWB and currently used in‐hospital and prehospital blood component therapies.Materials and MethodsBlood was obtained from 24 O RhD positive male donors. Three products were prepared: CSWB, in‐hospital component therapy (red blood cells [RBCs], OctaplasLG and platelets 1:1:1) and prehospital component therapy (RBCs and lyophilized plasma 1:1). Samples were drawn on days 1 and 14 of CSWB or RBC cold storage. On day 14, platelet concentrates at their expiry (5 days) were used for 1:1:1 mixing. Conventional clotting assays, rotational thromboelastometry, thrombin formation and platelet function were assessed.ResultsHaemoglobin, platelet count, fibrinogen and coagulation factor levels remained closest to physiological in CSWB. Factor VIII activity decreased markedly by day 14 in CSWB. The decline in platelet function was prominent in CSWB. However, CSWB on day 14 yielded physiological EXTEM MCF, suggesting haemostatically sufficient platelet function. Despite haemodilution and lower coagulation factor levels, in‐hospital component therapy was haemostatically adequate. Prehospital component therapy formed the weakest clots. Thrombin formation potential remained comparable and stable in all groups.ConclusionCurrent prehospital component therapy fails to offer the clotting potential that CSWB does. CSWB and current in‐hospital 1:1:1 component therapy show similar haemostatic potential until 14 days of storage.