A patient is admitted with prolonged epistaxis and prolonged bleeding from a recent tooth extraction. Initial screening workup reports prolonged APTT and BT, and abnormal aggregation on the PFA. Which of the following tests would not help define the disorder?
A) von Willebrand's factor activity
B) von Willebrand's factor antigen
C) Factor VIII assay
D) Prothrombin time

Question

Quizplus · Accepted Answer

The prolonged APTT and BT and abnormal aggregation on the PFA suggest a possible factor deficiencies or von Willebrand's disease, which are both related to the intrinsic pathway. Prothrombin time, on the other hand, assesses the extrinsic pathway and would not help define the disorder. Therefore, it is not a useful test in this scenario. The other three tests, (A) von Willebrand's factor activity, (B) von Willebrand's factor antigen, and (C) Factor VIII assay, all assess the intrinsic pathway and are more appropriate for further evaluation of the patient's bleeding disorder.

A Patient Is Admitted with Prolonged Epistaxis and Prolonged Bleeding