Adherence to guidelines for the management of excessive warfarin anticoagulation

Objectives The American College of Chest Physicians (ACCP) provides guidelines for the management of excessive anticoagulation in patients receiving warfarin. This multi-site prospective cohort study evaluated patient-level practice patterns and adherence to ACCP guidelines. Methods Patients presenting with an INR a parts per thousand yen 4.5 between January 3 and April 29, 2005 were observed and therapeutic management documented. Adherence was assessed retrospectively. Results Four hundred and seventeen patients from 22 centers were observed. The mean, initial INR was 7.7. At enrollment, 85% of the patients had an INR < 9 or were not bleeding; 15% were seriously bleeding. Treatment for 170 patients (41%) did not adhere to guidelines. Among those, 15% were undertreated, 48% overtreated. Lack of adherence was attributed primarily to excessive doses (mean initial dose = 6.9 mg) and inappropriate routes of administration (subcutaneous or intramuscular) of vitamin K1. Conclusion Adherence to the ACCP guidelines is low. Inappropriate use of vitamin K1 is the primary reason.