The use of long-term oral anticoagulant (OAC) therapy for the treatment and prevention of thrombosis and thromboembolism is widespread. Emergency providers are likely to encounter patients on OACs on a regular basis. Warfarin remains the most commonly prescribed oral anticoagulant in Australia, prescribed for the management of chronic atrial fibrillation (AF) in order to prevent stroke, to prevent thrombus formation in patients with mechanical heart valves (MHV’s) and for treatment of venous thromboembolisation (VTE).2
Vitamin K antagonists (Warfarin) are one of the oldest anticoagulants on the market having been in clinical use for over 60 years. With the development of newer medications, there is a now a range of anticoagulant therapy options available including Direct Xa inhibitors (Rivaroxiban and Apixaban) and direct Thrombin inhibitors (Dabigatran). Each have advantages and disadvantages as well as elimination times and reversal requirements.
The assessment and management of the trauma patient who is anticoagulated pre-injury adds additional complexity to an already difficult presentation. Bleeding has been found to be one of the main causal factors of mortality after physical injury (30-40%) and should be regarded as potentially reversible.3 Other factors which may contribute to the risk of bleeding include age >65 years, steroid use, malnutrition, hepatic insufficiency, renal failure, underlying malignancy, excessive alcohol use, platelet dysfunction as well as the use of therapies that affect platelet function such as aspirin, clopidogrel and NSAIDs.4
Clinicians must act quickly to ascertain the level of bleeding and to identify patient’s regular medications, coagulation status and the most appropriate method of reversal if indicated. If the patient is under the effects of anticoagulant medications, the risk of bleeding is increased, especially if it cannot be reversed quickly. Further complication to the patients care is from the concurrent medical comorbidities for which the patient is anticoagulated. Questioning the patient or family members regarding the patient’s coagulation status should become a part of routine questioning, particularly among older patients.
While most patients presenting to the ED who are taking OACs are likely to be taking Warfarin, it is important for all emergency care providers to gain familiarity with the newer or direct OACs (DOACs), previously termed novel oral anticoagulants (NOAC) and to understand how standard coagulation testing is affected.