Question

question 84
anna is noted to have prolonged bleeding after an intravenous needle is removed. a
subsequent laboratory test reveals a prolonged activated partial thromboplastin (aptt) time
with a normal prothrombin time (pt). based on this result, the provider may suspect alteration
in function of which factor?
factor v
factor vii
factor viii
factor x

Explanation:

• Prothrombin time (PT) tests the extrinsic pathway (factors VII, X, V, prothrombin, and fibrinogen).
• Activated partial thromboplastin time (aPTT) tests the intrinsic pathway (factors VIII, IX, XI, XII, X, V, prothrombin, and fibrinogen).
• Since PT is normal (extrinsic pathway factors like VII are likely okay) and aPTT is prolonged, a factor in the intrinsic pathway is likely affected. Factor VIII is part of the intrinsic pathway.

Answer:

Factor VIII