Acute hemolytic transfusion reactions typically occur within how many minutes of starting a blood transfusion?

• A. 15 minutes
• B. 2 hours
• C. 6 hours
• D. 24 hours

Answer: (A)

Acute hemolytic transfusion reactions happen when donor red blood cells are incompatible with the recipient, usually due to ABO mismatch, and trigger rapid intravascular destruction of those cells. Because this reaction is immediate and immune-driven, signs commonly appear within minutes after the transfusion begins, most often within the first 15 minutes. That tiny window reflects how quickly the body responds to incompatible cells. Reactions occurring much later—hours or a day after starting the transfusion—are not the acute type and are instead associated with other transfusion reactions or delayed hemolysis. If a reaction is suspected, stop the transfusion right away and follow protocol toSupport patient safety and investigation.