TYK230
Assuming a constant infusion of intravenous heparin at steady-state, administration of which of the following will SHORTEN the partial thromboplastin time (PTT):
a) FFP
b) Antithrombin III
c) Vitamin K
d) A and B
e) None of the above
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Answer
Answer e. Vitamin K administration does not generally affect the intrinsic coagulation pathway, and thus does not change the PTT. In contrast, fresh frozen plasma and antithrombin III administration provide additional substrate for heparin anticoagulation (which functions via potentiation of antithrombin), and result in a paradoxical prolongation of the PTT.
Notes
- This question originally printed in the Pediatric Anesthesiology Review Topics kindle book series, and appears courtesy of Naerthwyn Press, LLC.