Anticoagulation Service For Health Professionals

Synopsis of Guidelines for Managing Prolonged INR's - Part II

Notes:
1. If the INR is between 9 and 20; oral Vitamin K1 should be administered in a dose of 2.5 mg.
2. If the INR is >20 more aggressive measures should be used. Vitamin K should be administered by slow intravenous infusion over 10 minutes in a dose of at least 5 mg, an infusion of fresh frozen plasma and hospitalization should be considered, and the hematocrit checked for hidden bleeding.
3. If the INR is excessively out of range and dose not make sense with the recent trend in INR results in individual patients, the clinician is advised to consider the possibility of laboratory error before a dose adjustment is made. In this case, it is optimal to repeat the INR before a dose change is made to verify the results.
4. If there is serious bleeding, the patient should be hospitalized. Vitamin K should be administered by slow intravenous infusion over 10 minutes in a dose of 5–10 mg, an infusion of fresh frozen plasma should be given. Prothrombin concentrate should be considered if bleeding is life-threatening.

Managing High INR Values
Management of Patients with Markedly Prolonged
INRs and/or Active Bleeding

Clinical Situation

Guidelines

INR > 9.0, no clinically significant bleeding Hold warfarin. Vitamin K1 (3-5 mg orally); closely monitor the INR; if the INR is not substantially reduced by 24-48 h, the vitamin K1 dose can be repeated.

Serious bleeding, or major warfarin overdose (e.g., INR >20.0) requiring very rapid reversal of anticoagulant effect: Vitamin K1 (10 mg by slow IV infusion), with fresh plasma transfusion or prothrombin complex concentrate, depending upon urgency; vitamin K1 injections may be needed q12h. Recombinant Factor VIIa may be considered alternatively to prothrombin complex concentrate.
Life-threatening bleeding or serious warfarin overdose Hold warfarin. Prothrombin complex concentrate, with vitamin K1 (10 mg by slow IV infusion). Recombinant Factor VIIa may be considered alternatively to prothrombin complex concentrate.
Continuing warfarin therapy indicated after high doses of vitamin K1 Hold warfarin. Heparin, until the effects of vitamin K1 have been reversed, and patient is responsive to warfarin

7 th ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines, 2004