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Acute Haemolytic Transfusion Reaction — RACP Adult Medicine MCQ

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ModerateHaematologyAcute Haemolytic Transfusion ReactionRACP Adult Medicine

A 60-year-old man receives a blood transfusion for anaemia from GI bleeding. Six hours later, he develops fever (39.5°C), rigors, back pain, hypotension, and dark urine. His repeat Hb has not risen as expected. What is the most likely transfusion reaction?

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Correct answer: B — Acute haemolytic transfusion reaction (ABO incompatibility)

Fever, rigors, back/loin pain, hypotension, and dark urine (haemoglobinuria) occurring within hours of transfusion is an acute haemolytic transfusion reaction, most commonly due to ABO incompatibility from clerical error. Free haemoglobin causes renal vasoconstriction and DIC. Management: immediately STOP the transfusion, maintain IV access, send the unit and fresh blood sample to the blood bank for re-crossmatch and DAT, commence aggressive IV hydration to maintain renal perfusion, and monitor for DIC. This is a medical emergency with mortality up to 10%.

Reference: National Blood Authority – 2024 – Patient Blood Management Guidelines; ANZSBT – 2024 – Transfusion Reaction Guidelines