Should enoxaparin be discontinued in a patient with a history of acute on chronic subdural hematoma (SDH) and cerebral infarction, currently on mechanical deep vein thrombosis (DVT) prophylaxis?

Discontinue Enoxaparin Immediately

Yes, you should discontinue enoxaparin immediately in this patient with acute-on-chronic subdural hematoma (SDH), and continue mechanical DVT prophylaxis only. 1

Primary Rationale

The neurology team's directive for mechanical prophylaxis only directly addresses the critical safety concern in this clinical scenario. The presence of acute hemorrhage within a chronic subdural collection creates an ongoing bleeding risk that contraindicates pharmacological anticoagulation.

Key Safety Considerations

Timing of Pharmacological Prophylaxis:

• Enoxaparin should be withheld for at least 2-3 days after major trauma, and only reconsidered after careful review of current patient condition and risk-benefit ratio 1
• For intracranial hemorrhage specifically, pharmacological VTE prophylaxis should be avoided for at least 48 hours after onset, with careful risk assessment and repeat brain imaging demonstrating hematoma stability before any initiation 1
• This patient received enoxaparin on the same day as diagnosis, which violates these safety parameters

Hemorrhage Expansion Risk:

• The Neurocritical Care Society guidelines recommend discontinuing LMWH when intracranial hemorrhage is present or suspected 2
• Case reports document delayed extensive subdural hematomas developing in patients receiving enoxaparin after head trauma 3
• Even with weight-based dosing, intracranial hemorrhage expansion occurs in 1.6% of cases when enoxaparin is started after traumatic brain injury 4

High-Risk Patient Factors

This patient has multiple features that amplify bleeding risk:

Age-Related Risk:

• At 76+ years, this patient falls into the high-risk category for bleeding complications with enoxaparin 1
• Elderly patients (>75 years) require reduced dosing (0.75 mg/kg subcutaneously every 12 hours) if enoxaparin is eventually used 1

Cerebrovascular History:

• Two prior cerebral artery occlusions with infarction increase the complexity of anticoagulation decisions 5
• History of cerebral infarction does not justify overriding the acute hemorrhage contraindication

Cardiac History:

• While CABG x3 and cardiac catheterization history suggest atherosclerotic disease, this does not change the immediate management of active intracranial hemorrhage 2

Recommended Management Strategy

Immediate Actions

Discontinue Enoxaparin:

• Stop all doses immediately 2, 1
• Document the discontinuation and rationale clearly in the medical record

Implement Mechanical Prophylaxis:

• Apply thigh-high intermittent pneumatic compression (IPC) devices immediately, ideally within 24 hours of admission 1
• Continue IPC devices until the patient becomes independently mobile, at discharge, or by 30 days (whichever comes first) 1

Monitoring Requirements:

• Daily neurological assessments to detect any deterioration 1
• Daily skin integrity checks under IPC devices 1
• Vital signs monitoring per protocol 1

Criteria for Reconsidering Pharmacological Prophylaxis

Enoxaparin may only be reconsidered if ALL of the following criteria are met:

1. Minimum time elapsed: At least 48-72 hours post-injury 1
2. Imaging stability: Repeat CT demonstrates hematoma stability with no expansion 1, 5
3. Neurological stability: Examination remains stable or improving 1
4. Formal assessment: Risk-benefit evaluation documented by neurosurgery 1

Alternative Anticoagulation if Needed

If pharmacological prophylaxis becomes absolutely necessary:

• Consider unfractionated heparin (UFH) instead of enoxaparin 1
• UFH allows more precise titration via aPTT monitoring 1
• UFH has a shorter half-life, enabling rapid reversal if bleeding occurs 1
• This provides a safer option in the setting of recent intracranial hemorrhage

Common Pitfalls to Avoid

Do not restart enoxaparin based solely on:

• Cardiac or stroke history requiring "anticoagulation" 5
• Immobility concerns without documented hematoma stability 1
• Arbitrary time intervals without repeat imaging 1

Do not use prophylactic-dose enoxaparin 30 mg BID in this patient even if eventually cleared:

• This dose is inadequate for VTE prophylaxis in most patients 4
• If enoxaparin is eventually appropriate, use weight-based dosing with anti-Xa monitoring 4
• However, given age >75 years, reduced dosing would be required 1

Documentation Recommendation

Document clearly that enoxaparin was discontinued due to:

1. Acute-on-chronic subdural hematoma with active hemorrhage
2. Neurology recommendation for mechanical prophylaxis only
3. Guideline-based contraindication to pharmacological anticoagulation in acute intracranial hemorrhage
4. Plan for repeat imaging and reassessment before any consideration of pharmacological prophylaxis

This approach prioritizes the immediate mortality risk from intracranial hemorrhage expansion over the delayed risk of VTE, which can be adequately mitigated with mechanical prophylaxis in the acute phase 1, 2.