Autotransfusion from experimental hemothorax: levels of coagulation factors

The coagulation system was investigated in five dogs undergoing autotransfusion from experimental hemothorax. One fourth of the blood volume was bled into the pleural space, drained, and autotransfused. The hemothorax blood showed: very prolonged PT and PTT; very low platelets and fibrinogen; midly elevated FDP; very low coagulation factors VIII, and V; reduced XII, prothrombin, X, XI, and VII. Partial clotting, mild fibrinolysis, and fibrin deposition over the pulmonary pleura seemed to cause incoagulability of hemothorax blood. Post autotransfusion arterial blood showed: normal PT and PTT; 25% decrease in platelets, and 31% decrease in fibrinogen from baseline values. There was also an overall 20% reduction of fibrinogen from baseline values. There was also an overall 20% reduction of all clotting factors, but their levels remained above 50% activity. It was concluded that autotransfusion from a hemothorax of 25% the blood volume in dogs causes a mild loss of hemostatic components, but does not significantly compromise the clotting mechanism.