Should anticoagulation be ceased after a minor head injury in patients on anticoagulation therapy, such as warfarin (International Normalized Ratio (INR) monitoring) or direct oral anticoagulants (DOACs) like apixaban (generic name: apixaban) or rivaroxaban (generic name: rivaroxaban)?

Management of Anticoagulation After Minor Head Injury

Anticoagulation should not be routinely discontinued after a minor head injury in patients with a normal initial head CT scan and who are at their neurological baseline.1

Assessment and Initial Management

Initial Evaluation

• Obtain immediate head CT for all anticoagulated patients with minor head injury
• Assess neurological status using Glasgow Coma Scale (GCS)
• Document baseline anticoagulation medication and most recent dosing
• Check coagulation parameters (INR for warfarin, appropriate tests for DOACs if available)

Risk Stratification

1. Low Risk: Normal initial head CT, GCS 15, no neurological symptoms
2. Moderate Risk: Normal initial head CT but with risk factors:
   • Loss of consciousness or amnesia
   • Age > 65 years
   • Supratherapeutic anticoagulation levels
3. High Risk: Abnormal initial head CT showing intracranial hemorrhage

Management Algorithm

For Patients with Normal Initial Head CT (No Hemorrhage)

• Continue anticoagulation therapy without interruption 1
• Do not routinely perform repeat imaging 1
• Do not routinely admit for observation if patient is at neurological baseline 1
• Provide clear discharge instructions about symptoms of delayed hemorrhage 1

For Patients with Intracranial Hemorrhage on Initial CT

• Immediately discontinue anticoagulation 2
• Reverse anticoagulant effect with appropriate agents:
  • For warfarin: Vitamin K and 4-factor PCC based on INR 1
  • For dabigatran: Idarucizumab 5g IV 1
  • For apixaban/rivaroxaban: Andexanet alfa or PCC if andexanet not available 1
• Neurosurgical consultation
• Consider restarting anticoagulation after 3-4 weeks if bleeding has stabilized 2

Evidence Analysis

The American College of Emergency Physicians provides Level B recommendations stating that patients on anticoagulants with minor head injury who have a normal initial CT and normal neurological examination do not require routine repeat imaging or admission for observation 1. This is supported by evidence showing that delayed intracranial hemorrhage is rare (approximately 1.5% in patients on NOACs) and rarely requires neurosurgical intervention 1.

Studies comparing warfarin to DOACs found that patients on warfarin had a higher rate of acute intracranial hemorrhage (RR 1.75) but not delayed hemorrhage compared to those on DOACs 3. This suggests that DOACs may have a more favorable safety profile in the context of minor head trauma.

Important Considerations

Discharge Instructions

• Provide clear instructions about symptoms requiring immediate return:
  • New or worsening headache
  • Vomiting
  • Confusion or altered mental status
  • Weakness or numbness
  • Visual disturbances

Special Populations

• Elderly patients: Higher risk of intracranial hemorrhage (50% mortality reported in anticoagulated elderly patients with traumatic brain injury) 4
• Patients on dual therapy: Combined anticoagulant and antiplatelet therapy does not significantly increase risk of acute ICH (RR 0.90) or delayed ICH (RR 2.19) compared to anticoagulant use alone 3

Follow-up Recommendations

• Consider outpatient referral for assessment of both fall risk and risk/benefit of continued anticoagulation therapy 1
• If anticoagulation was temporarily discontinued due to hemorrhage, consider DOACs over warfarin when restarting due to potentially lower risk of intracranial hemorrhage 2

Common Pitfalls to Avoid

1. Unnecessarily discontinuing anticoagulation in patients with normal CT and normal exam
2. Failing to provide adequate discharge instructions
3. Routine repeat imaging in stable patients with initial normal CT
4. Delaying reversal of anticoagulation in patients with confirmed intracranial hemorrhage

By following this evidence-based approach, clinicians can safely manage anticoagulated patients after minor head injury while minimizing both hemorrhagic and thromboembolic risks.