Lin and Callum recommend 10 mg of vitamin K to reverse warfarin anticoagulation in emergencies.1 However, a dose this high may not be required for all “emergent” situations. It is important to differentiate between emergencies on the basis of severity of bleeding and urgency of reversal of warfarin anticoagulation. Anticoagulation can be reversed with 2.5 to 5 mg of vitamin K administered intravenously in a patient taking warfarin who requires urgent surgery.2 This lower dose of vitamin K is especially important when anticoagulation needs to be resumed once hemostatis has been achieved after surgery.
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