Blood Transfusion Reactions

Key points

• • Transfusion reactions happen when the recipient's body reacts against the transfused blood or its contents, and they range from mild to life-threatening.
• • An acute haemolytic reaction, usually from giving ABO-incompatible blood by mistake, destroys the transfused red cells at once and can cause shock and kidney failure.
• • A febrile non-haemolytic reaction (fever and chills) is common, caused by cytokines that accumulate in stored blood and by recipient antibodies against donor white cells; it is usually not dangerous, but fever after transfusion still needs assessment because serious reactions can begin with fever.
• • Allergic reactions range from mild hives to, rarely, a severe whole-body (anaphylactic) reaction, which is linked with anti-IgA antibodies in some IgA-deficient people.
• • Transfusion can also transmit infection, overload the circulation with fluid, or injure the lungs (transfusion-related acute lung injury).
• • Careful blood grouping and cross-matching before transfusion, and checking the identity of the patient and the unit, prevent most serious reactions.