Master Blood Transfusion MCQs: Coagulation & Hematology

Question 1

Which coagulation factor is deficient in Hemophilia A?

Accepted Answer

Factor VIII — Hemophilia A = Factor VIII deficiency; Hemophilia B = Factor IX deficiency (Christmas disease).

Question 2

Most common cause of prolonged PT with normal aPTT?

Accepted Answer

Factor VII deficiency — Factor VII is only in the extrinsic pathway (measured by PT); its deficiency prolongs PT while leaving aPTT normal.

Question 3

PT 45s, aPTT 65s (both prolonged) — most likely cause?

Accepted Answer

Liver disease — Liver disease impairs synthesis of multiple coagulation factors, prolonging both pathways.

Question 4

Blood product for thrombocytopenia with active bleeding?

Accepted Answer

Platelet concentrate — Thrombocytopenia = low platelets; replacing platelets directly addresses the bleeding cause.

Question 5

The crossmatch test primarily detects?

Accepted Answer

All of the above — The crossmatch detects any antibody-antigen reaction between donor RBCs and recipient serum.

Question 6

Emergency transfusion, blood type unknown — give?

Accepted Answer

O negative RBCs — O negative is the universal donor — no A, B, or Rh antigens to trigger reactions.

Question 7

Cryoprecipitate contains high concentrations of all EXCEPT?

Accepted Answer

Factor IX — Cryo contains: fibrinogen, Factor VIII, Factor XIII, vWF, and fibronectin. Factor IX is NOT in cryoprecipitate.

Question 8

Positive direct antiglobulin test (DAT) indicates?

Accepted Answer

Antibodies bound to patient's RBCs — DAT detects IgG or complement already coating the patient's own RBCs in vivo.

Question 9

Most serious immediate complication of blood transfusion?

Accepted Answer

Acute hemolytic reaction — ABO-incompatible transfusion causes massive intravascular hemolysis, DIC, renal failure — rapidly fatal.

Question 10

Most sensitive lab test for detecting DIC?

Accepted Answer

D-dimer — D-dimer is highly sensitive for DIC — elevated whenever clot formation and lysis are simultaneously occurring.

Question 11

Von Willebrand disease is characterized by?

Accepted Answer

Prolonged bleeding time and aPTT — vWF is needed for platelet adhesion (bleeding time) and carries Factor VIII (aPTT).

Question 12

Mechanism of action of warfarin?

Accepted Answer

Vitamin K antagonism — Warfarin inhibits Vitamin K epoxide reductase, blocking activation of factors II, VII, IX, and X.

Question 13

Patient on heparin — monitored using?

Accepted Answer

aPTT — Heparin potentiates antithrombin III; therapeutic target is 1.5–2.5× normal aPTT.

Question 14

Heparin-induced thrombocytopenia (HIT) typically occurs?

Accepted Answer

5–10 days after starting heparin — HIT is immune-mediated via antibodies against heparin-PF4 complexes.

Question 15

Most important blood group system after ABO and Rh?

Accepted Answer

Kell — Kell antigens are highly immunogenic and clinically the next most significant after ABO and Rh.

Question 16

Massive transfusion is defined as?

Accepted Answer

>100% volume in 24h — Replacement of the entire blood volume (~5L) within 24 hours, or 10 units of RBCs.

Question 17

FFP:Platelets:RBCs ratio in massive transfusion protocol?

Accepted Answer

1:1:1 — Evidence-based damage control resuscitation uses a balanced 1:1:1 ratio.

Question 18

Antithrombin III deficiency predisposes to?

Accepted Answer

Thrombotic disorders — ATIII is a natural anticoagulant; its deficiency causes thrombophilia.

Question 19

Most common inherited bleeding disorder?

Accepted Answer

Von Willebrand disease — vWD affects ~1% of the population — the most common inherited bleeding disorder worldwide.

Question 20

Factor V Leiden mutation causes?

Accepted Answer

Resistance to activated protein C — Factor V Leiden makes Factor Va resistant to cleavage by activated Protein C, causing thrombophilia.

Question 21

TRALI is most commonly caused by?

Accepted Answer

Donor antibodies against recipient leukocytes — Donor anti-HLA or anti-HNA antibodies activate recipient neutrophils in the lung, causing non-cardiogenic pulmonary edema within 6 hours.

Question 22

Shelf life of platelet concentrates at room temperature?

Accepted Answer

5 days — Stored at 20–24°C with agitation; limited to 5 days due to bacterial contamination risk.

Question 23

Which factor is NOT part of the intrinsic coagulation pathway?

Accepted Answer

Factor VII — Factor VII belongs exclusively to the extrinsic pathway. Intrinsic: XII, XI, IX, VIII.

Question 24

Protein S functions as a cofactor for?

Accepted Answer

Protein C — Protein S enhances activated Protein C's ability to degrade Factors Va and VIIIa.

Question 25

Most common cause of acquired coagulation disorder?

Accepted Answer

Liver disease — The liver synthesizes nearly all coagulation factors — liver disease is the most common acquired coagulopathy globally.

Question 26

Leukoreduction of blood products primarily prevents?

Accepted Answer

Febrile non-hemolytic reactions — Leukoreduction removes donor WBCs whose cytokines/antigens cause fever — the most common transfusion reaction.

Question 27

Normal platelet count range?

Accepted Answer

150,000–450,000/μL

Question 28

Which condition requires irradiated blood products?

Accepted Answer

All of the above — Irradiation destroys donor T lymphocytes to prevent transfusion-associated GvHD in at-risk patients.

Question 29

The mixing study corrects in which condition?

Accepted Answer

Hemophilia A — Mixing corrects factor deficiencies but NOT when inhibitors (antibodies against factors) are present.

Question 30

Post-transfusion purpura typically occurs?

Accepted Answer

5–10 days post-transfusion — Alloantibodies (usually anti-HPA-1a) destroy both donor and patient's own platelets 5–10 days post-transfusion.

Master Blood Transfusion MCQs: Coagulation & Hematology

Questions, Answers & Explanations