As noted in Chapter 9, concentrated immune gamma globulin (IV-GG) may contain red cell antibodies and also antibodies against various infectious agents such as hepatitis viruses, cytomegalovirus, and Epstein-Barr virus. Enough IV-GG may be transfused so that the transfused antibodies are detectable in recipient serum. This may cause problems in differential diagnosis of infection and significance of red cell antibodies unless the IV-GG therapy is known to the blood bank and all consultants.

Storage of red blood cells. After approximately two thirds of RBC shelf life, some of the RBCs lose vitality and become spherocytes. Since spherocytosis is a feature of certain isoimmune and autoimmune hemolytic anemias, transfusion of such blood before diagnostic investigation may cause confusion. Potassium concentration slowly rises during storage as it escapes from devitalized RBCs. After about two thirds of RBC shelf life, plasma potassium levels reach about 18 mEq/L, roughly four times normal. Although the hyperkalemia of stored RBCs seems to have little effect on most persons, even when many units are transfused, it may be undesirable if the patient already has an elevated serum potassium level, as seen in uremia or acute renal failure. Ammonium levels of stored blood also increase and may reach values of 10-15 times normal toward the expiration date of the RBCs. Transfusion of large volumes of such blood may be dangerous in patients with severe liver disease. Medications in donor blood theoretically could be a problem to the recipient. This is rarely mentioned in the medical literature, possibly due to current use of packed RBCs rather than whole blood.