1. During the third winter campaign in Korea, the hematologic reaction to wounding was studied in thirty-seven casualties at the time of initial resuscitation.
2. Of particular interest was the effect of massive transfusions of stored blood. The results of storage of blood—high plasma hemoglobin and potassium, low labile factor activity, nonviable platelets and leukocytes—had little deleterious effect on patients who received as much as 20 to 30 pints in less than six hours. The loss of transfused red cells because of nonviability was no more than expected.
3. At the time of resuscitation and shortly thereafter, there was a remarkable loss of circulating red cell mass in patients with wounds that involved much tissue destruction. It is believed that the loss was due to hemolysis but the mechanism is unknown. The loss of red cells may be so rapid that a patient with bilateral traumatic amputation of the legs and an adequate hemostasis would become severely anemic if one hesitated to use large, rapid transfusions. Patients with severe shock whose wounds involved less tissue damage (lacerated colon, for example) did not destroy red cells in this fashion. After moderate transfusions such patients often became polycythemic. Transfusions had to be carried out rather gingerly because of a tendency to develop signs of congestion.
4. During the early days of recuperation from severe wounds the patients often tended to become anemic. The anemia appeared to be the result of hemolytic processes plus a relative inhibition of red cell formation.
5. Universal donor blood, group O, was used in all transfusions. In patients who are not group O the massive transfusions resulted in the virtual replacement by red cells of another group. The patient’s plasma sometimes contained antibodies against red cells of his hereditary blood group. Gradual hemolysis of native red cells by transfused antibodies was observed. This was not a clinical hemolytic reaction and did not appear to be detrimental to the patient. The presence of the foreign antibodies made it impossible in some cases to crossmatch the patient with blood of his hereditary group and suggested a source of danger in attempting such transfusions. After transfusion with the universal donor blood has begun, it is recommended that no change be made to blood of another group until at least two weeks have elapsed.
6. No incompatible transfusion reactions were encountered. Several hemoclastic reactions may have been caused by gross contamination of the blood stream from the site of wounds or from the peritoneal cavity.