Which type of RBC transfusion reaction occurs within 30 seconds of administration?

• A. Febrile non-hemolytic
• B. Acute hemolytic
• C. Hyperacute
• D. Delayed hemolytic

Answer: (C)

The type of red blood cell (RBC) transfusion reaction that occurs within 30 seconds of administration is hyperacute hemolytic reaction. This type of reaction is characterized by a rapid and intense immune response to the transfused blood, typically because of the recipient having pre-existing antibodies against the donor's ABO blood group antigens.

When incompatible blood is transfused, the pre-existing antibodies bind to the donor RBCs, leading to complement activation and subsequent hemolysis of the transfused red blood cells. This reaction is immediate due to the preformed antibodies, causing severe symptoms such as increased heart rate, fever, and potential shock right after the transfusion begins.

In contrast, other types of transfusion reactions, such as febrile non-hemolytic and acute hemolytic reactions, have a longer onset time and result from different mechanisms. Febrile non-hemolytic reactions usually manifest after a few hours and are associated with fever due to leukocyte antibodies. Acute hemolytic reactions can occur rapidly but often have a slightly delayed timing due to the antibody response building up after the transfusion starts, usually within the first few hours. Delayed hemolytic reactions occur days to weeks after transfusion, as