Part IV: Transfusion Medicine
You are running a large military blood bank in Afghanistan. During a current surge in combat operations, you anticipate a much higher number of severe military and civilian casualties. You need to issue blood to battalion field stations scattered around the country for emergency administration in settings where no typing or cross-matching is possible. The number of potential blood donors among military personnel far exceeds the number of units you can draw, refrigerate, and transport to the field stations. Therefore you give highest priority to donors with which of the following blood types?
People with O-negative blood are sometimes called universal donors. O-negative blood was used extensively in battalion aid stations throughout the Vietnam War. In recipients with type A or type B blood, presence of anti-B or anti-A antibodies in their plasma will not bind to and lyse type O red cells. Rh-negative blood is used to avoid inducing sensitization to this common and highly antigenic protein. (The answer is A.)
A 32-year-old woman with acute myeloid leukemia had induction chemotherapy with a combination of strongly myelosuppressive agents. Ten days after initiation of therapy, she has shaking chills, dysphagia, and dyspnea. Physical examination revealed a temperature of 103°F, oral and pharyngeal mucositis, rales in her right lower lungs, and small petechiae on her lower legs. Laboratory values are as follows:
Hemoglobin 5.9 g/dL, hematocrit 17.8%, mean cell volume 90 fL, reticulocyte count 0.3%
White blood cell count 980 per microliter with 12% neutrophils, 2% monocytes, 3% myeloblasts, and 83% lymphocytes
Platelet count 22,000 per microliter
A chest radiograph shows a small, faint, right lower lobe infiltrate. The blood bank should administer which of the following products?
A. Neutrophils, platelets, and packed red cells
B. Platelets and packed red cells
D. Neutrophils and packed red cells
This is a commonly encountered clinical scenario. The patient should receive packed red cells. Leukocyte transfusions have not been shown to be effective. With few exceptions, platelets are not transfused unless the patient’s platelet count is 10,000 or less. Whole blood is not transfused except in a battlefield setting. (The answer is C.)