Internal Medicine Exam Hematology 2

Question 1

A patient has a prolonged PT but normal aPTT. Deficiency of which coagulation factor is most likely responsible?

Accepted Answer

Factor VII

Answer

Factor VII is the only coagulation factor exclusive to the extrinsic pathway; its deficiency prolongs PT without affecting aPTT.

Question 2

Heparin-induced thrombocytopenia (HIT) typically develops at what time point after heparin initiation?

Accepted Answer

5-10 days after starting heparin

Answer

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.

Question 3

Von Willebrand disease most characteristically presents with which bleeding pattern?

Accepted Answer

Mucocutaneous bleeding such as epistaxis and menorrhagia

Answer

Von Willebrand disease impairs platelet adhesion and primary hemostasis, leading to mucocutaneous bleeding; hemarthroses are more typical of hemophilia.

Question 4

Which laboratory test is used to monitor patients on warfarin therapy?

Accepted Answer

Prothrombin time/INR (PT/INR)

Answer

Warfarin inhibits vitamin K-dependent factors (II, VII, IX, X), which are measured by the PT/INR; the aPTT monitors heparin therapy.

Question 5

Which combination of laboratory findings is most characteristic of disseminated intravascular coagulation (DIC)?

Accepted Answer

Elevated D-dimer, prolonged PT/aPTT, low fibrinogen, and thrombocytopenia

Answer

DIC involves simultaneous widespread coagulation and fibrinolysis, consuming clotting factors and platelets, resulting in elevated D-dimer, prolonged PT/aPTT, low fibrinogen, and thrombocytopenia.

Internal Medicine Exam Practice Test

Internal Medicine Exam Practice Test

Internal Medicine Exam Hematology 2