Thrombotic Disorders

Answer: D

Explanation: For a symptomatic patient with INR >10, bleeding needs to be controlled and warfarin reversed. Oral vitamin K will reduce INR by half in about 24 hours. Intravenous (IV) formulations are faster (12 hours), but not fast enough for this child with life-threatening bleeding. Vitamin K should be given but in IV form and in addition to an agent that will replace the vitamin K–dependent factors. FFP and PCCs are both good choices to give to an actively bleeding patient with warfarin overdose because they replace all vitamin K–dependent factors inhibited by warfarin. However, 10 cc/kg of FFP will not likely be enough to reverse this degree of anticoagulation. PCCs are plasma-derived factor concentrates that contain factors II, VII, IX and X (the vitamin K–dependent factors) and are effective in small volumes. Unfortunately, they are not readily available at all small centers. A recent new PCC was approved for use with the indication of warfarin reversal. rFVIIa has been shown to be effective but is associated with thrombotic risk and is only replacing the FVII being inhibited by the warfarin. For the INR to be markedly elevated, the warfarin will have had to have been in the child’s system for more than 24 hours. Gastric lavage will have little utility in reversing her coagulopathy.
Question 10