Definition of Transfusion

Transfusion: The transfer of blood or blood products from one person (the donor) into another person (the recipient's) bloodstream. In most situations, this is done as a lifesaving maneuver to replace blood cells or blood products lost through severe bleeding. Transfusion of your own blood (autologous) is the safest method but requires planning ahead and not all patients are eligible. Directed donor blood allows the patient to receive blood from known donors. Volunteer donor blood is usually most readily available and, when properly tested has a low incidence of adverse events.

Blood transfusion and blood conservation are complementary activities that constitute the clinical arena of transfusion medicine. A review of transfusion medicine in The New England Journal of Medicine further concludes that:

• The use of blood transfusion has declined, largely because of concern about the safety of the blood supply.
• The presence now of a very safe blood supply suggests that outcomes need to be monitored to identify patients in whom transfusion may be underused (as well as overused).
• No given level of hemoglobin can, it seems, be used as a universal threshold for transfusion.
• Strategies to avoid blood transfusion will no longer be driven by the known risks, since they are now so low that no alternative is currently as safe as a blood transfusion.
• Instead, blood conservation will be driven more by issues related to the costs and inventory of blood.

Source: LT Goodnough, ME Brecher, MH Kanter, and JP AuBuchon. Transfusion Medicine. New Engl J Med 1999; 340: 438-447; 525-533.