What is the management for a subdural hematoma (SDH)?

Management of Subdural Hematoma

For symptomatic chronic subdural hematomas presenting with altered consciousness, burr hole drainage is the preferred first-line surgical treatment, while acute subdural hematomas with thickness >10mm or midline shift >5mm require immediate craniotomy evacuation. 1, 2

Initial Assessment and Diagnostic Workup

• Obtain non-contrast CT scan immediately to characterize hematoma size, location, mass effect, and midline shift 1, 3
• Perform complete neurological assessment using Glasgow Coma Scale (GCS), pupillary examination, and focal neurological deficits 1, 3
• Verify anticoagulant or antiplatelet use as these medications significantly increase risk of hematoma expansion 3, 4
• Assess for concurrent injuries including subarachnoid hemorrhage, which predicts hematoma expansion 4

Surgical Indications and Timing

Acute Subdural Hematoma

• Evacuate surgically if thickness >10mm OR midline shift >5mm, regardless of GCS score 2
• **Evacuate if GCS <9 with hematoma <10mm thick** when: GCS decreased by ≥2 points from injury to admission, asymmetric/fixed dilated pupils present, or ICP >20mmHg 2
• Perform craniotomy with or without bone flap removal as the surgical technique for acute SDH in comatose patients (GCS <9) 2
• Operate as soon as possible when surgical indications are met, though the absolute timing (within hours) is less critical than controlling underlying brain injury and ICP 5, 2

Chronic Subdural Hematoma

• Perform burr hole drainage for symptomatic chronic SDH with altered consciousness, vomiting, or neurological deficits 1
• Reserve craniotomy for acute-on-chronic SDH with solid components 1
• Consider subdural drain placement during surgery to reduce recurrence rates 1, 3

Conservative Management Criteria

• Manage conservatively when hematoma is small (<5mm thickness), minimal mass effect (<5mm midline shift), no signs of intracranial hypertension, and no neurological deterioration 3, 2
• No patient with initial SDH ≤3mm required surgery in recent analysis, though 11% enlarged (maximum 10mm) 4
• Consider tranexamic acid 750mg daily for non-emergency chronic SDH cases not requiring immediate surgery, which can resolve hematomas without surgery 6

Intracranial Pressure Management

• Place ICP monitor in all comatose patients (GCS <9) with acute SDH 2
• Secure airway with intubation and mechanical ventilation with end-tidal CO₂ monitoring for severe traumatic brain injury 3
• Consider external ventricular drainage for persistent intracranial hypertension despite sedation and correction of secondary insults 3
• Avoid hypocapnia as it induces cerebral vasoconstriction and increases ischemia risk 3

Post-Operative Management

• Maintain euvolemia and avoid hypovolemia to optimize cerebral perfusion 1, 3
• Avoid hypervolemia as it does not improve outcomes and may cause complications 1
• Monitor for complications including seizures, infection, and hematoma reaccumulation 3

Risk Stratification for Hematoma Expansion

Key predictors of expansion include: 4

• Larger initial SDH size (8.5mm threshold best predicts need for surgery)
• Concurrent subarachnoid hemorrhage
• Hypertension
• Convexity location
• Initial midline shift present

Critical Pitfalls to Avoid

• Do not delay surgical intervention in symptomatic patients with altered consciousness, as this leads to neurological deterioration and worse outcomes 1, 3
• Elderly patients require intensive monitoring as small hematomas can expand rapidly, especially on anticoagulants 3
• The primary brain injury severity and ICP control are more critical to outcome than the absolute timing of clot removal in acute SDH 5
• Postoperative ICP >45mmHg strongly correlates with poor outcome, making aggressive ICP management essential 5

Special Considerations

• For recurrent or persistent chronic SDH with thick membranes in patients >60 years, peritoneal drainage via low-pressure shunt provides rapid improvement, no recurrence, and membrane disappearance 7
• In spontaneous intracranial hypotension with SDH, small or asymptomatic hematomas should be managed conservatively while treating the CSF leak; symptomatic hematomas with mass effect may need burr hole drainage in conjunction with leak treatment 8