Transfusion Practice and Adverse Transfusion Reactions
Acute reactions (within 24 hours)
Acute hemolytic transfusion reaction is usually ABO-incompatible from a clerical error; fever, chills, flank or chest pain, hemoglobinuria, DIC, and shock appear early. Stop the transfusion, keep the line open with saline, support the patient, and begin the workup. Febrile nonhemolytic reactions (a rise of 1 C or more) come from cytokines or leukocyte antibodies and are prevented by leukoreduction. Allergic and urticarial reactions are mild and may be treated with antihistamine before restarting; anaphylaxis suggests IgA deficiency with anti-IgA and requires washed or IgA-deficient products. Septic reactions stem from bacterial contamination, especially in platelets. Pulmonary reactions must be separated: TRALI is antibody-mediated (HLA or HNA), associated with donor plasma, and reduced by male-predominant plasma; TACO is volume overload and responds to diuretics.
Delayed reactions
Delayed hemolytic reactions reflect an evanescent antibody, with falling hemoglobin and a positive DAT days later. Transfusion-associated GVHD is fatal, occurring 1-6 weeks later with pancytopenia and rash, and is prevented only by irradiation. Post-transfusion purpura presents with thrombocytopenia 5-12 days after transfusion, typically anti-HPA-1a, and is treated with IVIG. Chronic iron overload, hyperkalemia, hypocalcemia from citrate, and hypothermia complete the list.
Workup
Stop the transfusion, perform a clerical check and visual inspection, repeat ABO/Rh and DAT on a post-transfusion sample, compare pre- and post-transfusion plasma for hemolysis, and culture the unit when sepsis is suspected. Report to the blood bank and, for fatalities, to the FDA.
Traps
Isolated urticaria without other findings may be treated and the same unit restarted; any fever with hemolytic signs means stop permanently. TRALI is not fluid overload. Leukoreduction does not prevent TA-GVHD; only irradiation does.
Rule of thumb: stop, keep the vein open with saline, and return the bag and tubing to the blood bank whenever hemolysis or sepsis is suspected.