EDAIC Coagulation and Transfusion Medicine 5 — Questions and Answers
Question 1: A patient develops fever, rigors, and hypotension during a red cell transfusion. The direct antiglobulin test (DAT) is positive. What is the most likely diagnosis?
- Febrile non-hemolytic transfusion reaction
- Acute hemolytic transfusion reaction (Correct answer)
- Transfusion-related acute lung injury (TRALI)
- Transfusion-associated circulatory overload (TACO)
Correct answer: Acute hemolytic transfusion reaction
A positive DAT with hemolysis signs indicates acute hemolytic transfusion reaction from ABO incompatibility.
Question 2: What distinguishes TRALI from TACO in a patient who develops acute respiratory distress after transfusion?
- TRALI presents with elevated BNP and hypertension; TACO presents with fever
- TRALI presents with bilateral infiltrates and low/normal filling pressures; TACO presents with elevated filling pressures and responds to diuresis (Correct answer)
- TRALI is caused by volume overload; TACO is immune-mediated
- Both have identical hemodynamic profiles
Correct answer: TRALI presents with bilateral infiltrates and low/normal filling pressures; TACO presents with elevated filling pressures and responds to diuresis
TRALI is immune-mediated lung injury with non-cardiogenic pulmonary edema; TACO is hydrostatic pulmonary edema with elevated filling pressures.
Question 3: A patient with thrombocytopenia and a rising creatinine after heparin exposure has a 4Ts score of 6. What is the next step?
- Continue heparin and recheck platelets in 24 hours
- Stop all heparin and start a non-heparin anticoagulant (Correct answer)
- Transfuse platelets immediately
- Perform bone marrow biopsy
Correct answer: Stop all heparin and start a non-heparin anticoagulant
A 4Ts score ≥4 indicates intermediate-to-high probability of HIT; all heparin must be stopped and alternative anticoagulation started.
Question 4: Which factor deficiency is associated with a prolonged aPTT but no clinical bleeding tendency?
- Factor VIII deficiency
- Factor XII deficiency (Correct answer)
- Factor IX deficiency
- Factor XI deficiency
Correct answer: Factor XII deficiency
Factor XII (Hageman factor) deficiency prolongs aPTT but does not cause bleeding because it is not essential for in vivo hemostasis.
Question 5: In obstetric hemorrhage with suspected placental abruption, which specific coagulopathy should be anticipated?
- Hemophilia A
- Hyperfibrinogenemia
- Acute DIC with hypofibrinogenemia (Correct answer)
- Isolated thrombocytopenia
Correct answer: Acute DIC with hypofibrinogenemia
Placental abruption releases large amounts of thromboplastin, triggering DIC with consumption of fibrinogen and other factors.
Question 6: What is the half-life of transfused platelets in a non-immune thrombocytopenic patient?
- Approximately 6–12 hours
- Approximately 3–5 days (Correct answer)
- Approximately 7–10 days
- Approximately 14 days
Correct answer: Approximately 3–5 days
Transfused platelets survive approximately 3–5 days in the absence of immune destruction or consumption.
Question 7: Which reversal agent is indicated for life-threatening bleeding in a patient on rivaroxaban?
- Idarucizumab
- Andexanet alfa (Correct answer)
- Protamine sulfate
- Vitamin K
Correct answer: Andexanet alfa
Andexanet alfa is the specific reversal agent for Factor Xa inhibitors including rivaroxaban and apixaban.
EDAIC Coagulation and Transfusion Medicine 5
A patient develops fever, rigors, and hypotension during a red cell transfusion.
The direct antiglobulin test (DAT) is positive.
What is the most likely diagnosis?