CT Scan Criteria for Elderly Patients on Anticoagulants After Closed Head Injury

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 that would otherwise guide selective imaging in non-anticoagulated patients, according to the Journal of the American College of Radiology and Annals of Emergency Medicine 3, 4, 1

Age ≥65 years is independently a high-risk criterion for neurosurgical intervention according to the Canadian CT Head Rule, and this patient's age ≥70 further increases the risk 4, 1
The combination of anticoagulation and age ≥70 creates a particularly high-risk scenario that absolutely warrants immediate CT imaging 1

A Glasgow Coma Scale <15 at 2 hours post-injury would reinforce the decision for CT imaging 1
Suspected open or depressed skull fracture would also support the need for CT imaging 1
Signs of basilar skull fracture, such as hemotympanum, raccoon eyes, Battle's sign, CSF otorrhea/rhinorrhea, would indicate a need for CT imaging 4, 1
Vomiting ≥2 episodes would be a high-risk feature that reinforces the decision for CT imaging 4, 1
Loss of consciousness or post-traumatic amnesia would also be a factor that supports CT imaging 4, 2
Focal neurological deficits would indicate a need for CT imaging 4

Do not rely on clinical decision rules designed for non-anticoagulated patients, as anticoagulation fundamentally changes risk stratification and mandates imaging independent of these tools, according to the Journal of the American College of Radiology and Annals of Emergency Medicine 3, 4, 1, 2

If CT is negative, provide detailed discharge instructions about warning signs requiring immediate return, such as worsening headache, vomiting, confusion, increased sleepiness, focal deficits, or abnormal behavior 2
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