An evaluation of intravenous vitamin k for warfarin reversal: are guideline recommendations being followed?

Hosp Pharm. 2015 Jan;50(1):18-24. doi: 10.1310/hpj5001-18.

Abstract

Background: Vitamin K antagonists (eg, warfarin) remain the mainstay of anticoagulation therapy in the United States, with over 22 million prescriptions being filled annually. Unfortunately, warfarin therapy is difficult to manage and increases bleeding risk. The 2012 American College of Chest Physicians guidelines created a warfarin reversal algorithm that suggested the stringent use of intravenous vitamin K.

Objective: The purpose of this evaluation was to determine the rates of adherence with guideline recommendations in clinical practice.

Method: A convenience sample of 3 months of intravenous vitamin K medication administration data (September to November 2013) was obtained to conduct a retrospective review. Patients with underlying hepatic dysfunction or lack of warfarin therapy were excluded. Vitamin K use was evaluated for consistency with the 2012 guidelines.

Results: A total of 364 patients were reviewed and 119 were included. Vitamin K utilization was consistent with guideline recommendations for a total of 30 (25.2%) patients. The most common site of active bleeding requiring reversal was head bleeds, consisting of 56.6% of bleeds. A single dose of 10 mg of vitamin K was the most frequently used dosing strategy. Fresh frozen plasma (73.3%) and four-factor prothrombin complex concentrate (36.7%) were the most commonly used factor products.

Conclusion: This evaluation demonstrates that there is a difference between clinical judgment and guideline adherence. True adherence with the guidelines may not be necessary; however, there is room for improvement in both the appropriateness and safety of intravenous vitamin K use.

Keywords: anticoagulation; anticoagulation reversal; guideline; phytonadione; vitamin K; warfarin.