The universal donor blood type for patients with unknown blood type is type O positive blood for males and O negative for females. Because O negative blood is rare the study will initiate the change in practice in adult male patients and later extend it to female patients if feasible. The study will determine the effects of WB transfusion in adult male patients compared to transfusion of PRBCS, plasma, and platelets in a 1:1:1 ratio in non adult male patients on markers of coagulation, fibrinolysis, and inflammation, as well as the development of complications and hospital mortality following severe injury.