OXYGEN CARRIERS AND TRANSFUSION MEDICINE

The US blood supply is once again expanding (14 million units a year) and annual estimated whole blood and red blood cell (RBC) transfusion now exceeds 12 million units. The observed increase in total transfusions and units transfused per surgical procedure may result from more aggressive therapies, an aging population, and improved access to health care. While autologous blood collection has grown 20-fold in the past decade, autologous blood still accounts for <8% of transfusions and is unlikely to replace much more of the allogeneic transfusion needs. Although safer than ever, allogeneic blood still transmits infectious disease (HIV:1 in 225,000 units, hepatitis:1 in 3300 units, HTLV I/II:1 in 50,000 units) and poses additional immunologic and non-immunologic risks. Allogeneic RBCs are probably underutilized because of safety concerns.