Massive blood transfusions: the impact of Vietnam military data on modern civilian transfusion medicine.

To determine the coagulation defects associated with massive blood transfusions, coagulation studies were performed on 21 battle casualties admitted to the US Naval Support Activity Hospital, Da Nang, Vietnam. All but one patient who received less than 20 units of Acid-Citrate-Dextrose blood (7 patients) did not develop a coagulopathy. All patients who received more than 20 units (14 patients) developed a clinically significant coagulation defect. Although the partial thromboplastin and prothrombin times were markedly prolonged (i.e., low Factor V and XIII levels), restoring these times to normal levels by fresh frozen plasma administration did not terminate the clinical coagulopathy.In all 12 patients who had platelet counts less than 60,000/mm(3), a clinical bleeding problem (coagulopathy) developed. The coagulopathy eventually spontaneously resolved (n = 4), was successfully treated with fresh blood (n = 4), or the patients died (n = 4). A mathematical analysis confirmed that the thrombocytopenia is dilutional in origin and is the primary cause of a coagulopathy from massive blood transfusions. The authors conclude that clinically important coagulopathies predictably occur after administration of 20-25 units of stored Acid-Citrate-Dextrose blood in acutely wounded, previously healthy soldiers. Fresh frozen plasma should not be a major therapeutic choice for coagulopathies in massive blood transfusions. Treatment of dilutional thrombocytopenia (50,000/mm(3)) is a primary component of treating coagulopathies associated with massive blood transfusions.