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Case: A 73-year-old female presented to the emergency department (ED) after she tripped and fell, striking her head. On arrival, she appeared to be in no acute distress, was alert and oriented, and was neurologically intact with a Glasgow Coma Scale score (GCS) of 15. Vital signs: blood pressure 162/87 mmHg, heart rate 80/min and irregularly irregular, respiratory rate 16/min, and pulse oximetry 96% on room air. She did have a scalp hematoma but without overlying laceration or palpable bony abnormality. She was currently taking warfarin for atrial fibrillation and her international normalized ratio (INR) in the ED was 3.9. A head CT was obtained rapidly and was negative for acute intracranial bleed or skull fracture. Introduction
Five oral anticoagulants are available in the United States: warfarin (Coumadin®), dabigatran (Pradaxa®), rivaroxaban (Xarelto®), apixaban (Eliquis®), and edoxaban (Savaysa®). Warfarin has been in clinical use since 1954, and for more than 55 years, it was essentially the only oral anticoagulant available. In the past five years, new or novel oral anticoagulants (NOACs) have been released for use. Alternatively, these agents also are known as non-vitamin K antagonist oral anticoagulants, indicating that their mechanism of activity does not involve antagonism of the synthesis of the vitamin K-dependent coagulation factors, or direct oral anticoagulants (DOACs), reflecting that they directly inhibit one of the factors involved in the coagulation cascade. In the United States, four NOACs or DOACs currently are available: dabigatran, rivaroxaban, apixaban, and edoxaban.
Indications for Anticoagulation Reversal
The primary indication for emergency reversal of oral anticoagulation is on-going major or life-threatening bleeding. A secondary indication is when an emergent surgical or invasive procedure is required and reversal is indicated to prevent periprocedural bleeding. For both warfarin and the DOACs, a primary reversal strategy for emergent reversal is replacement of the deficient or inhibited coagulation factor(s).1 This is most intuitive in cases of warfarin-related bleeding, in which multiple coagulation factors are deficient. DOAC-treated patients have only one factor inhibited, and replacement strategies involve administration of enough factor to overcome inhibition induced by the DOAC present in the circulation. Many institutions have developed standardized anticoagulation reversal protocols to streamline patient care and minimize potential for errors.2
In many circumstances, the challenge is not the method of reversal,...