Head Injury and Oral Anticoagulants

See Traumatic Brain Injury guideline: Early Management
Any patient who is taking an anticoagulant such as warfarin or other oral anticoagulants (dabigatran, rivaroxaban, apixaban) is at high risk of developing a significant intracranial haemorrhage from minor head injury mechanisms. CT imaging of the brain should be performed on all patients with a history of head injury.
In addition, platelet inhibitor therapy (aspirin (e.g. Astrix, Cartia), dipyridamole (Asasantin, Persantin), clopidogrel (Iscover, Plavix), prasugrel (Effient), ticagrelor (Brilinta)) also increases the risk for haemorrhagic injuries but to a lesser degree.
These patients often have significant comorbidities also, all of which will have a direct impact on surgical and intensive care decision making and treatment. The effects of anticoagulation and antiplatelet drugs may require their reversal, with consideration of the risks of exacerbation of the underlying condition.
Where intracranial haemorrhage is present, patients on anticoagulation medication may deteriorate because of extension of their bleed leading to mass effect, brain compression and herniation. In these patients, reversal of medications should be commenced with appropriate reversal agents. Consultation with ARV should take place prior to administration.
For immediate reversal of anticoagulation in patients with bleeding due to warfarin, prothrombin complex concentrates (Prothrombinex-VF in Australia) are preferred over fresh frozen plasma (FFP). The dose for prothrombin complex concentrates is 35–50 units/kg IV. This aims to achieve complete reversal of an excessive INR within 15 minutes. The dose for life-threatening bleeding should be the maximum 50 units/kg.1
In the setting of isolated traumatic brain injury, FFP is not routinely needed in combination with prothrombin complex concentrates unless there is life-threatening bleeding. If life-threatening bleeding is present the dose of FFP is 150–300 mL by IV infusion. Where Prothrombinex-VF is unavailable the dose for FFP is 15 mL/kg IV infusion. Time is required for determining the patient’s blood type (or use group AB plasma), thawing of the product and subsequent infusion.
Vitamin K is essential for sustaining the reversal achieved by PCC or FFP. IV administration produces a more rapid response than oral administration in the short term. The dose is 5–10 mg IV.
Anticoagulation should only be restarted after discussion with Neurosurgeons.