What pre-operative medication should a graduate nurse administer before a liver biopsy?

Administering vitamin K before a liver biopsy is essential due to its role in promoting blood clotting. Liver biopsies carry the risk of bleeding complications, particularly since the liver is involved in synthesizing clotting factors. Patients who are at risk of bleeding, either due to liver dysfunction or the use of anticoagulants, may benefit from vitamin K, as it aids in the production of clotting factors II, VII, IX, and X.

In the context of the other options, aminocaproic acid is an antifibrinolytic agent used in situations where there’s a need to prevent excessive bleeding, but it is not typically administered pre-operatively for a biopsy. Heparin is an anticoagulant that would increase the risk of bleeding during the procedure and is usually not indicated pre-operatively. Warfarin is another anticoagulant that also heightens bleeding risks and would generally need to be held or reversed prior to the procedure. Using vitamin K optimizes clotting ability and minimizes the chance of post-procedure hemorrhage, making it the favorable choice in this case.