posttransfusion

Posttransfusion refers to events and outcomes that occur after the administration of blood or blood products. It covers adverse reactions, laboratory changes, and clinical sequelae that arise in the period shortly after transfusion and, for some conditions, over the ensuing days to weeks. The term helps distinguish posttransfusion phenomena from those that occur before or during transfusion.

Posttransfusion reactions are commonly categorized by timing. Immediate reactions can include febrile nonhemolytic reactions, mild to moderate allergic reactions, and, less frequently, anaphylaxis. Transfusion-associated circulatory overload and transfusion-related acute lung injury may present within several hours of infusion. Acute hemolytic reactions typically become evident during or soon after the transfusion. Delayed posttransfusion events include delayed hemolytic transfusion reactions (days to weeks), transfusion-associated purpura (rare thrombocytopenia occurring days after), and other immune or infectious complications that may manifest later.

Evaluation of a suspected posttransfusion reaction begins with stopping the transfusion, maintaining IV access, and monitoring vital signs. Laboratory assessment may include repeat blood typing and crossmatching, direct antiglobulin test, bilirubin, hemoglobin, lactate dehydrogenase, and haptoglobin. Management is syndrome-specific and supportive, addressing overload with diuretics or fluids judiciously, providing respiratory support for TRALI, administering antihistamines or epinephrine for allergic reactions, and treating anemia or iron depletion as needed. Infection suspicion prompts cultures and appropriate antimicrobial therapy.

Prevention focuses on proper donor-recipient matching, leukoreduction, irradiation when indicated, and careful observation during and after transfusion. Standardized posttransfusion monitoring and reporting improve early detection and management of adverse events. Overall risk has decreased with improved screening and processing, though rare events remain possible.