Hematology Flashcards
7 cards from real Internal Medicine Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Hematology flashcards as text
A patient has a prolonged PT but normal aPTT. Deficiency of which coagulation factor is most likely responsible?
Answer: Factor VII
Factor VII is the only coagulation factor exclusive to the extrinsic pathway; its deficiency prolongs PT without affecting aPTT.
Heparin-induced thrombocytopenia (HIT) typically develops at what time point after heparin initiation?
Answer: 5-10 days after starting heparin
Classic HIT (type II) develops 5-10 days after starting heparin due to the time required for antibody formation against platelet factor 4-heparin complexes.
Von Willebrand disease most characteristically presents with which bleeding pattern?
Answer: Mucocutaneous bleeding such as epistaxis and menorrhagia
Von Willebrand disease impairs platelet adhesion and primary hemostasis, leading to mucocutaneous bleeding; hemarthroses are more typical of hemophilia.
Which laboratory test is used to monitor patients on warfarin therapy?
Answer: Prothrombin time/INR (PT/INR)
Warfarin inhibits vitamin K-dependent factors (II, VII, IX, X), which are measured by the PT/INR; the aPTT monitors heparin therapy.
Which combination of laboratory findings is most characteristic of disseminated intravascular coagulation (DIC)?
Answer: Elevated D-dimer, prolonged PT/aPTT, low fibrinogen, and thrombocytopenia
DIC involves simultaneous widespread coagulation and fibrinolysis, consuming clotting factors and platelets, resulting in elevated D-dimer, prolonged PT/aPTT, low fibrinogen, and thrombocytopenia.
A patient with antiphospholipid syndrome (APS) is at highest risk for which complication?
Answer: Arterial and venous thrombosis and recurrent pregnancy loss
APS is a thrombophilic condition caused by antiphospholipid antibodies that promote clotting, leading to arterial/venous thrombosis and recurrent pregnancy loss.
Which anticoagulant requires NO dose adjustment in patients with severe renal failure?
Answer: Warfarin
Warfarin is hepatically metabolized and has no significant renal excretion, making it the anticoagulant that does not require dose adjustment in renal failure.