Head Strike on Apixaban in an Older Adult Who Lives Alone

Yes, image with a non-contrast head CT now. Anticoagulation plus a head strike with a palpable hematoma is a high-risk combination regardless of a normal neurologic exam.

Why the rules do not help. The Canadian CT Head Rule and NEXUS chest/head criteria were derived and validated in patients not on anticoagulants; most versions explicitly exclude them. Applying them here would suggest she does not need imaging because she has no vomiting, no amnesia beyond 30 minutes, no dangerous mechanism by their definition, and a GCS of 15. That reasoning is invalid for this patient. She has an ongoing pharmacologic coagulopathy, a direct occipital impact, and a visible hematoma, and anticoagulated patients can harbor intracranial hemorrhage with a completely normal exam.

Why her renal function matters. A creatinine clearance near 26 mL/min means apixaban accumulates; her effective anticoagulant exposure is higher and longer than the standard dosing interval implies. This further lowers the threshold to image and to observe.

Practical points

• Do not delay CT for labs or for a coagulation panel; PT/INR and anti-Xa levels do not reliably reflect apixaban effect and are not needed to decide on imaging.
• Image the cervical spine as well if there is any question of neck injury; low-energy falls in older adults can still fracture the spine.
• Reassessneurologically after the scan, and document the pre-injury baseline cognition so that later changes are interpretable.

Trap. A normal exam is not reassurance in this patient. The decision hinges on the anticoagulant and the mechanism, not on the absence of symptoms.

Disposition: do not discharge her home alone. The risk of delayed intracranial hemorrhage after a negative initial scan in an anticoagulated patient is low but real, generally cited in the range of roughly 0.5-2%, and higher in patients with renal impairment, larger hematomas, or more severe mechanisms. Her social situation also matters: baseline cognitive impairment, living alone, and a daughter who works nights mean that a deterioration at home would go unwitnessed.

Options

• Admit to the observation unit for serial neurologic checks (typically every 2-4 hours) with a repeat non-contrast head CT at 6-12 hours. Practice varies by institution, but if you observe, observe with a plan rather than a vague 'we will watch her'.
• Alternatively, admit for a longer period if there is no reliable observation at home, or if she lives far from the hospital.

Shared decision-making

• Explain the risk in plain terms, note that most delayed bleeds occur within 24 hours, and explain that a headache, vomiting, drowsiness, or new weakness must prompt immediate return.
• Address her wish to go home directly: she is not being detained arbitrarily, but the risk of a bleed she cannot recognize is the reason for observation. Involve the daughter by phone and document who will be present.

Also do not miss

• A medication review: is she on apixaban 5 mg twice daily appropriately? Dose reduction criteria (age 80 or older, weight 58 kg, creatinine 1.5) mean she may qualify for 2.5 mg twice daily. Flag this to her prescriber, but do not change it acutely without discussion.
• Fall risk assessment, orthostatic vitals, vision and gait evaluation, PT/OT, and home safety review. A head strike is the presentation; the fall is the disease.
• Screen for alcohol use, arrhythmia, and hypoglycemia, and check for other injuries.

Immediate priorities

• Move to a resuscitation area, secure the airway if her mental status is declining, and obtain urgent neurosurgical consultation.
• Stop apixaban and hold all anticoagulants and antiplatelets.
• Repeat the CT or obtain a CT angiogram if there is any question of an underlying vascular lesion or expansion, and check a full blood count, renal function, and type and screen.

Reversal

• Andexanet alfa is the specific reversal agent for apixaban and factor Xa inhibitors; dose depends on the agent, the dose taken, and the time since the last dose. Alternatively, 4-factor procalcitonin complex concentrate 50 units/kg is a reasonable choice and is often more available, particularly with renal impairment.
• Vitamin K does not reverse apixaban, and platelet transfusion is not indicated for a direct oral anticoagulant.
• Involve hematology, and counsel the team that reversal agents carry a real thrombotic risk, so the decision is driven by the severity of the bleed and the neurosurgeon's plan.

Blood pressure

• Lower systolic pressure to roughly 130-150 mmHg, avoiding drops below about 130 mmHg; smooth, sustained control with a titratable agent such as nicardipine is preferable to intermittent boluses. Avoid wide swings.

Disposition and support

• ICU with neurosurgery following, serial neuro checks and repeat imaging, glucose and temperature control, seizure precautions if cortical involvement, and early goals-of-care discussion with her daughter, given her baseline cognitive impairment and the poor prognosis of anticoagulant-associated intracerebral hemorrhage.

The teaching point is that delayed hemorrhage after a negative initial scan is uncommon but not rare enough to ignore in an anticoagulated older adult, and that the repeat scan is what converts a discharge decision into a resuscitation.