Transfusion Reactions Flashcards
What are the two main classifications of transfusion reactions based on timing?
Acute: Occur within 24 hours of transfusion.
Delayed: Occur >24 hours post-transfusion.
What are the clinical signs of an acute hemolytic transfusion reaction (AHTR)?
Fever, chills, pain (flank/back), hypotension, hemoglobinuria, DIC, renal failure.
Caused by ABO incompatibility or clerical errors.
How does a delayed hemolytic transfusion reaction (DHTR) present?
Fever, jaundice (day 5+), unexplained drop in hemoglobin.
Due to anamnestic response (e.g., anti-Jka, anti-Kidd antibodies).
What is the mechanism of febrile non-hemolytic transfusion reactions (FNHTR)?
Cytokines from donor WBCs or recipient anti-HLA antibodies.
Symptoms: Fever ≥1°C, chills, rigors (no hemolysis).
What distinguishes a mild allergic reaction from a severe/anaphylactic reaction?
Mild: Hives, itching (IgE-mediated).
Severe: Wheezing, hypotension, shock (anti-IgA in IgA-deficient patients).
What are the diagnostic criteria for TRALI?
Acute hypoxia + bilateral pulmonary edema within 6 hours of transfusion.
Mechanism: Donor anti-HLA/HNA antibodies activate neutrophils.
How is TA-GVHD prevented?
Irradiation of blood products (25 Gy) to kill donor lymphocytes.
Mortality: 90%.
What causes transfusion-associated circulatory overload (TACO)?
Rapid volume overload → pulmonary edema, hypertension.
Prevention: Slow infusion, diuretics.
What lab tests confirm bacterial contamination of a blood unit?
Gram stain, culture of unit/patient.
Symptoms: High fever, rigors, shock.
What is the first step when a transfusion reaction is suspected?
STOP the transfusion.
Maintain IV with saline.
Notify blood bank + send samples (post-tx DAT, CBC, urine).
What does a positive DAT post-transfusion indicate?
Antibody-coated donor RBCs (immune hemolysis).
Requires antibody identification and antigen-negative units.
Which reaction is prevented by using male-only plasma?
TRALI (reduces anti-HLA antibodies from multiparous donors).
What is post-transfusion purpura (PTP)?
Thrombocytopenia 2 weeks post-tx due to anti-HPA-1a.
Treat with IVIG or plasmapheresis.
What are the reporting requirements for severe transfusion reactions in Canada?
TTISS-ON (moderate-severe reactions).
CBS/Health Canada (fatal/unexpected reactions within 24h).
What causes citrate toxicity?
Massive transfusion → binds ionized calcium (hypocalcemia).
Symptoms: Tetany, arrhythmias.
