Assessment of Vitamin K Use in the Inpatient Treatment of Excessive Anticoagulation

Abstract

Background: Guidelines from the Seventh American College of Chest Physicians (ACCP) Conference on Antithrombotic and Thrombolytic Therapy provide specific recommendations for the management of patients with supratherapeutic international normalized ratios (INRs). Objective: To assess the appropriateness of vitamin K administration in inpatients with excessive anticoagulation, according to existing guidelines. Methods: A retrospective chart review was performed for randomly selected patients on warfarin therapy who received vitamin K during hospitalization. Data were collected on patient demographics, vitamin K dose and route of administration, warfarin dose, alternative therapies, and INR values before and after vitamin K administration. The appropriateness of vitamin K use was evaluated based on indication, route, and dose. Results: A total of 136 patient charts were reviewed. The majority (71%, n = 97) of patients had a baseline INR of less than 5, with a mean INR of 4.4 ± 2.9 SD. Seventy-five patients had documented bleeding events on admission, 49% of which were considered major. Average time to repeat INR was 9.7 ± 6.8 SD hours. Seventy-one percent of patients had a documented appropriate indication for vitamin K, 42% received an appropriate dose, and 27% received vitamin K via the appropriate route of administration. Only 21% of patients received vitamin K for an appropriate indication, at an appropriate dose, via an appropriate route. Conclusions: At our institution, the current use of vitamin K for excessive anticoagulation is inconsistent and suboptimal with regard to route, dose, and monitoring parameters. Education of both medical and pharmacy staff is essential to improving compliance with ACCP recommendations.