Which blood type is the universal donor for red blood cell transfusions?

Group O is considered the universal donor for red blood cell transfusions because it lacks A and B antigens on the surface of its red blood cells. This absence of antigens means that when Group O blood is transfused into a recipient of any ABO blood type, it will not trigger an immune response due to antigen-antibody reactions, which can occur if a recipient receives blood with incompatible antigens.

In transfusions, the primary concern is the compatibility of the donor's red blood cells with the recipient's immune system. Recipients of Group A, B, or AB blood can receive Group O red blood cells without experiencing hemolysis caused by the binding of antibodies present in their plasma to the A or B antigens on the donor's red cells.

Understanding this property of Group O is critical for emergency situations where blood type may not be immediately known, allowing healthcare providers to administer red blood cells quickly and safely. Therefore, Group O is invaluable in emergency medicine and components like mass transfusions where rapid availability is essential.