CT Scan Criteria for a 70-Year-Old on Eliquis After Fall with Closed Head Injury
A 70-year-old patient on Eliquis (apixaban) who sustains a closed head injury from a fall requires a CT scan regardless of other clinical findings, as anticoagulation therapy mandates imaging independent of clinical decision rules. 1, 2
Anticoagulation as an Absolute Indication
Patients on anticoagulants, including direct oral anticoagulants like apixaban, have a significantly elevated risk of intracranial hemorrhage (3.9%) compared to non-anticoagulated patients (1.5%) and therefore require CT imaging regardless of Glasgow Coma Scale score or presence of other risk factors. 1
The American College of Emergency Physicians recommends CT for all patients with coagulopathy, including those on anticoagulant medications, bypassing the need to assess other clinical decision rule criteria. 1
This recommendation supersedes standard clinical decision rules (Canadian CT Head Rule, New Orleans Criteria, NEXUS Head CT) that would otherwise guide selective imaging in non-anticoagulated patients. 3, 1
Additional High-Risk Factors in This Patient
Beyond anticoagulation alone, this patient has age ≥65 years, which is independently a high-risk criterion for neurosurgical intervention according to the Canadian CT Head Rule. 3, 1
The combination of these two factors (anticoagulation + age ≥70) creates a particularly high-risk scenario that absolutely warrants immediate CT imaging. 1
Clinical Assessment That Would Further Support CT
While CT is already indicated based on anticoagulation alone, assess for these additional high-risk features that would reinforce the decision:
- Glasgow Coma Scale <15 at 2 hours post-injury 1
- Suspected open or depressed skull fracture 1
- Signs of basilar skull fracture (hemotympanum, raccoon eyes, Battle's sign, CSF otorrhea/rhinorrhea) 3, 1
- Vomiting ≥2 episodes 3, 1
- Loss of consciousness or post-traumatic amnesia 3, 2
- Focal neurological deficits 3, 4
Timing Considerations
Obtain CT imaging promptly upon presentation, as early CT within 2 hours of injury has the highest yield for detecting progressive hemorrhagic injury. 5
Research suggests a 5-hour time interval between head trauma and CT allows optimal detection of lesions, though this should not delay imaging in anticoagulated patients. 4
Consider repeat CT at 6-12 hours even if initial CT is negative in anticoagulated patients, as delayed intracranial hemorrhage occurs in approximately 4.1% of anticoagulated head trauma patients. 6
Critical Pitfall to Avoid
Do not rely on clinical decision rules designed for non-anticoagulated patients. The Canadian CT Head Rule, New Orleans Criteria, and NEXUS Head CT were validated primarily in populations without significant coagulopathy. 3 Anticoagulation fundamentally changes risk stratification and mandates imaging independent of these tools. 1, 2
Evidence Regarding DOACs vs Warfarin
Patients on warfarin have higher rates of acute intracranial hemorrhage (RR 1.75) compared to those on DOACs like apixaban, but both groups require CT imaging. 6
While DOACs may have a slightly lower risk profile than warfarin, this does not eliminate the need for CT scanning in the acute setting. 6
Post-CT Management
If CT is negative:
Provide detailed discharge instructions about warning signs requiring immediate return: worsening headache, vomiting, confusion, increased sleepiness, focal deficits, or abnormal behavior. 2
Consider observation period or repeat CT at 6-12 hours given the 4.1% risk of delayed hemorrhage in anticoagulated patients, even with negative initial imaging. 6
The evidence supporting safe discharge after negative CT in mild traumatic brain injury specifically excludes patients on anticoagulation therapy, requiring individualized assessment for this population. 2
If CT shows hemorrhage:
- Consider reversal agents (andexanet alfa for apixaban) in consultation with neurosurgery, particularly if hemorrhage is expanding or patient requires surgical intervention. 7