What is the recommended management for a 10 mm subdural hematoma?

Management of 10mm Subdural Hematoma

A 10mm subdural hematoma requires immediate neurosurgical evaluation and typically warrants surgical evacuation, particularly if accompanied by midline shift >5mm or neurological deterioration. 1

Immediate Surgical Indications

Perform immediate surgical evacuation when the subdural hematoma thickness is ≥10mm AND any of the following are present: 1

• Midline shift >5mm on CT imaging 1, 2
• Neurological deterioration or decreased level of consciousness 1
• GCS decline of ≥2 points 1
• Signs of herniation (anisocoria, bilateral mydriasis, abnormal pupils) 1

The 10mm threshold is critical—acute subdural hematomas exceeding this thickness generally require immediate surgical evacuation regardless of neurological condition. 3 This recommendation is based on the high risk of neurological deterioration and elevated intracranial pressure associated with hematomas of this size. 1

Conservative Management Criteria

Conservative management with close neuromonitoring may be considered ONLY if ALL of the following are met: 1

• No midline shift >5mm 2
• Stable neurological examination with GCS ≥13 1
• No signs of elevated intracranial pressure 2
• Patient is elderly with good baseline neurologic exam 4

A subset of older patients meeting surgical criteria but maintaining a monitorable neurologic exam can be followed closely, allowing delayed intervention (median 11 days) with smaller surgical procedures. 4 However, this approach requires continuous neurological monitoring and immediate surgical readiness. 1

Pre-Surgical Optimization

Coagulation Reversal (if applicable)

Before any surgical intervention, achieve the following targets: 1

• PT/aPTT <1.5 times normal control 1, 2
• Platelet count >50,000/mm³ 1, 2
• For anticoagulated patients: rapid reversal with prothrombin complex concentrate plus vitamin K 1

Imaging Protocol

• Obtain non-contrast head CT within 3 hours of symptom onset 1
• Consider CT angiography to identify contrast extravasation (predicts expansion risk) 1
• 28-38% of patients demonstrate hematoma expansion on subsequent imaging 1

Surgical Approach Selection

For acute subdural hematoma ≥10mm, craniotomy or decompressive craniectomy is preferred over burr holes. 3

• Decompressive craniectomy should be considered for patients with:

  • Coma (GCS <8) 5
  • Large hematomas with significant midline shift 5
  • Elevated ICP refractory to medical management 5

• Burr hole drainage is reserved for chronic subdural hematomas, not acute presentations 1

Hemodynamic Management During Intervention

Maintain strict hemodynamic targets throughout emergency care: 1, 2

• Systolic blood pressure >100 mmHg OR mean arterial pressure >80 mmHg 1, 2
• Cerebral perfusion pressure ≥60 mmHg (if ICP monitoring in place) 1
• PaO₂ between 60-100 mmHg 1, 2
• PaCO₂ between 35-40 mmHg 1, 2

Bridge Therapies (Temporizing Measures Only)

If immediate surgery is delayed due to logistics, use the following ONLY as temporary bridges: 1

• Mannitol (0.25-0.5 g/kg IV every 6 hours) for impending herniation 1, 2
• Hyperventilation targeting PaCO₂ 35-40 mmHg for acute herniation 1

Critical caveat: These interventions must NOT replace or delay definitive surgical evacuation when clear surgical indications exist. 1 Delaying surgery for "medical optimization" beyond basic resuscitation worsens prognosis. 1

Post-Operative ICP Monitoring Indications

ICP monitoring after evacuation is indicated if ANY of the following are present: 1

• Pre-operative motor GCS ≤5
• Pre-operative anisocoria or bilateral mydriasis
• Pre-operative hemodynamic instability
• Compressed basal cisterns or midline shift >5mm
• Intra-operative cerebral edema
• Post-operative emergence of new intracranial lesions

Use intraparenchymal ICP probes over intraventricular drains (lower infection rate: 2.5% vs 10%; lower hemorrhage risk: 0-1% vs 2-4%). 1

Special Considerations

Spontaneous Resolution

While spontaneous resolution of acute subdural hematomas >10mm is theoretically possible, it is exceedingly rare and should NOT influence initial management decisions. 6 The vast majority require immediate surgical evacuation. 6

Elderly Patients

Elderly patients with 10mm subdural hematomas carry significant mortality and morbidity with surgery. 4 However, with close neuromonitoring, delayed intervention (allowing conversion to chronic subdural hematoma) may be safe in select patients with good neurologic exams, enabling smaller surgical procedures. 4 This requires continuous monitoring and immediate surgical availability. 4

Anticoagulated Patients

Patients on anticoagulation require rapid reversal before any intervention and have higher risk of expansion. 1, 2 Anticoagulation can typically be restarted approximately 4 weeks after surgical removal if no ongoing fall risk exists. 1