A febrile transfusion reaction is defined as a rise in temperature of 2°F within what time frame after transfusion?

• A. 2°F rise within 1 hour
• B. 1°C rise within 2 hours
• C. 3°F rise within 2 hours
• D. No fever

Answer: (A)

A febrile transfusion reaction is identified by a fever that develops soon after a transfusion starts, typically due to inflammatory mediators or antibodies reacting to donor leukocytes. The standard criterion used here is a rise of 2°F within one hour of beginning the transfusion. This rapid, modest fever is characteristic of febrile transfusion reactions and distinguishes it from no fever or from larger fevers that might suggest other issues. The other options don’t fit this typical timing and magnitude: a 1°C rise within two hours is a smaller change and not the threshold described for this reaction, a 3°F rise within two hours is a higher fever and not the defined criterion in this context, and no fever would not define a febrile reaction.