Question

A 50-year-old woman has end-stage liver disease due to primary biliary cirrhosis with a Model for End-Stage Liver Disease (MELD) score of 25. While a transjugular intrahepatic portosystemic shunt (TIPS) procedure, she becomes hypotensive. You hemorrhage in the liver capsule. Resuscitation includes 12 units FFP, 15 PRBC, 2 packs of platelets, and 20 units of cryoprecipitate. The patient continues to bleed. You decide to administer recombinant factor VII. The mechanism of action of factor VII includes all EXCEPT

A. Co-factor to tissue factor
B. Inhibited by antithrombin III-heparin complex
C. Factor X activation
D. Extrinsic pathway activation
E. Factor IX activation

Answer 1

Recombinant factor VII acts as a co-factor to tissue factor activates factor X, and initiates the extrinsic pathway, while it does not activate factor IX as that's part of the intrinsic pathway and also is not inhibited by antithrombin III-heparin complex.

Step-by-step explanation:

The mechanism of action of recombinant factor VII in the context of coagulation includes acting as a co-factor to tissue factor, activating factor X, and initiating the extrinsic pathway. However, factor VII does not activate factor IX; this is part of the intrinsic pathway of coagulation, which is not directly activated by factor VII. Factor VII is also not inhibited by the antithrombin III-heparin complex; this is more relevant to other clotting factors such as thrombin (factor IIa).