A survey of oral vitamin K use by anticoagulation clinics.
BACKGROUND
Despite published reports of its safety and efficacy, oral vitamin K (phytonadione) may not be widely used for patients with warfarin-associated coagulopathy. We tested the hypothesis that recommendations for phytonadione use from the American College of Chest Physicians (ACCP) Fifth Consensus Conference on Antithrombotic Therapy are not routinely incorporated into the clinical practice of many anticoagulation clinics.


METHODS
Surveys were mailed to 100 separate clinics in the southwestern region of the United States that are members of the Anticoagulation Forum, an association of anticoagulation clinic personnel and medical directors in the United States and Canada. Respondents were presented with 4 scenarios involving asymptomatic patients taking warfarin whose international normalized ratio is supratherapeutic. In each scenario, the respondents were told the patient's international normalized ratio and whether the patient was at "high" risk for bleeding.


RESULTS
Of 53 respondents, 13 (25%) indicated that their clinics never use oral phytonadione. Eighteen (34%) indicated that their clinics use subcutaneous phytonadione, despite the absence of a recommendation for this in the ACCP guidelines published in 1998. For each scenario, we made a judgment as to whether the respondent's management was consistent with guidelines found in the ACCP Fifth Consensus Conference on Antithrombotic Therapy. Overall, only 17 respondents (32%) provided all 4 answers consistent with the ACCP recommendations.


CONCLUSIONS
For patients with supratherapeutic international normalized ratio values, our survey suggests that a substantial number of anticoagulation clinics underutilize oral phytonadione.
University of New Mexico Hospital, Department of Internal Medicine 5ACC, 2211 Lomas NE, Albuquerque, NM 87131, USA. elibby@salud.unm.edu
Edward N
EN
Libby
David A
DA
Garcia
D000284:Administration, Oral; D000328:Adult; D000554:Ambulatory Care Facilities / Q000592:standards*; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D000933:Antifibrinolytic Agents / Q000008:administration & dosage*; D001777:Blood Coagulation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004363:Drug Utilization / Q000706:statistics & numerical data*; D005260:Female; D019983:Guideline Adherence; D019538:Health Care Surveys; D006300:Health Services Misuse; D006470:Hemorrhage / Q000139:chemically induced / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D015206:Southwestern United States; D014812:Vitamin K / Q000008:administration & dosage*; D014859:Warfarin / Q000009:adverse effects* / Q000627:therapeutic use
D000925:Anticoagulants; D000933:Antifibrinolytic Agents; D014812:Vitamin K; D014859:Warfarin