What is the treatment for a subdural hematoma?

Treatment of Subdural Hematoma

The treatment of subdural hematoma depends critically on whether the patient is symptomatic with mass effect: symptomatic subdural hematomas with significant mass effect require burr hole drainage, while small or asymptomatic hematomas should be managed conservatively with close neurological monitoring. 1

Initial Assessment and Triage

Determine surgical urgency based on three key factors:

• Neurological status: Assess Glasgow Coma Scale (GCS), pupillary examination, and focal neurological deficits 1
• Hematoma characteristics: Measure maximal thickness and degree of midline shift on CT imaging 1, 2
• Clinical stability: Evaluate for headache, altered consciousness, vomiting, and progressive symptoms 1

Surgical Indications

Immediate surgical evacuation is indicated for:

• Symptomatic subdural hematoma with significant mass effect 3, 1
• Neurological deterioration or decreased level of consciousness 1
• Hematoma thickness >10 mm or midline shift ≥5 mm (traditional criteria, though timing can be individualized in select cases) 4, 2

Burr hole drainage is the preferred first-line surgical approach for chronic subdural hematomas, with subdural drain placement to reduce recurrence rates 1, 5. Craniotomy should be reserved for acute-on-chronic subdural hematomas with solid components that cannot be adequately drained through burr holes 1.

Conservative Management Strategy

For stable patients without significant neurological deficits, conservative management with close monitoring is appropriate 1, 4. This approach is particularly relevant for:

• Small or asymptomatic hematomas 3
• Elderly patients with stable neurological exams who initially meet surgical criteria 4
• Subdural hematomas associated with spontaneous intracranial hypotension (SIH), where treating the underlying CSF leak is the priority 3

Conservative management requires:

• Regular neurological assessments (at least every 4 hours initially) 1
• Maintain euvolemia to optimize cerebral perfusion 1
• Serial imaging to monitor for progression 1

Special Consideration: Subdural Hematoma in Spontaneous Intracranial Hypotension

When subdural hematoma occurs in the context of SIH (suggested by orthostatic headache or absence of trauma/coagulopathy/alcohol misuse), perform MRI of brain with contrast and whole spine to investigate for spinal CSF leak 3. Small or asymptomatic hematomas should be managed conservatively while treating the underlying CSF leak, whereas symptomatic hematomas with significant mass effect may need burr hole drainage in conjunction with treating the leak 3.

Delayed Surgical Intervention

In select elderly patients with initially stable neurological exams despite meeting traditional surgical criteria, delayed intervention (median 11 days) can be safely performed 4. This approach allows the acute subdural hematoma to become chronic, permitting a smaller surgery with reduced operative time and anesthetic risk 4. However, this requires close neuromonitoring and should only be considered when the neurological exam remains stable 4.

Anticoagulation Management

For patients on anticoagulation who develop subdural hematoma:

• Rapidly reverse anticoagulation using prothrombin complex concentrate (preferred over fresh frozen plasma) plus vitamin K 3
• The duration of anticoagulation interruption is typically 7-15 days, with low risk (2-3%) of ischemic events during this period 3
• Consider restarting anticoagulation after successful treatment, weighing recurrent hemorrhage risk against thromboembolic risk 3

Risk Factors for Delayed Surgical Intervention

Monitor more carefully for progression requiring delayed surgery in patients with: 2

• Increased maximal hematoma thickness on initial CT (odds ratio 1.28)
• Low hemoglobin level (odds ratio 0.67)
• High leukocyte count (odds ratio 1.14)
• Previous cerebral infarction history
• Accompanying subarachnoid hemorrhage

Medical Adjuncts

Mannitol may be used for reduction of intracranial pressure and brain mass when elevated intracranial pressure is present 6. Dexamethasone should be used with caution given side effects, and tranexamic acid may be considered as adjunct therapy though more evidence is needed 7.

Critical Pitfalls to Avoid

• Do not delay surgical intervention when neurological deterioration occurs, as this leads to poorer outcomes 1, 8
• Recognize that the extent of underlying brain injury is more important than subdural clot size in dictating outcome, particularly in acute subdural hematoma 8
• Avoid hypervolemia, as it does not improve outcomes and may cause complications 1
• Be aware that recurrence rates after surgical evacuation range from 2-37%, with risk factors including poor brain reexpansion, significant subdural air, and lack of postoperative drainage 5