American Board of Internal Medicine (ABIM) Certification Practice Exam

What should be done to reverse major bleeding associated with vitamin K antagonists?

1. Administer protamine sulfate

2. Administer fresh frozen plasma

3. Use 4-factor prothrombin complex concentrate and intravenous vitamin K

4. Apply direct pressure to the bleeding site

The correct answer is: Use 4-factor prothrombin complex concentrate and intravenous vitamin K

To effectively reverse major bleeding associated with vitamin K antagonists, the use of 4-factor prothrombin complex concentrate (PCC) combined with intravenous vitamin K is the preferred approach. Vitamin K antagonists, such as warfarin, work by inhibiting the vitamin K-dependent clotting factors II, VII, IX, and X, which are essential for normal blood coagulation. When a patient experiences major bleeding while on these medications, rapid reversal of their anticoagulant effects is critical. 4-factor prothrombin complex concentrate directly provides the clotting factors that the vitamin K antagonists inhibit, thereby rapidly restoring hemostasis. The intravenous administration of vitamin K further aids in the synthesis of new clotting factors, providing a comprehensive and effective reversal strategy. This combination addresses both the immediate need for clotting factors and the underlying cause of the anticoagulation. While fresh frozen plasma can be effective in providing clotting factors, it has a slower onset of action and may carry more risks, such as volume overload and transfusion reactions. Protamine sulfate is specifically used to reverse the effects of heparin, not vitamin K antagonists. Direct pressure may help control bleeding, but it does not address the coagulopathy caused by vitamin