Treatment of Subdural Hemorrhage
Immediate surgical evacuation is indicated for symptomatic subdural hematomas with significant mass effect, neurological deterioration, or decreased level of consciousness, while small asymptomatic hematomas can be managed conservatively with close monitoring. 1
Initial Assessment and Surgical Triage
The first priority is determining surgical urgency based on three key factors 1:
- Glasgow Coma Scale (GCS) score - Assess eye opening, verbal response, and motor response 2. Patients with GCS ≤8 typically require urgent intervention 1
- Pupillary examination - Abnormal pupils indicate herniation risk and demand immediate action 1
- CT imaging characteristics - Measure maximal hematoma thickness and degree of midline shift 1
Critical imaging thresholds: No patient with initial subdural hematoma ≤3 mm required surgery in recent studies, though 11% enlarged to maximum 10 mm 3. An initial size of 8.5 mm best predicts need for surgical intervention 3.
Surgical Indications (Immediate Intervention Required)
Proceed directly to surgery when 1:
- Symptomatic subdural hematoma with mass effect
- Progressive neurological deterioration
- Decreased level of consciousness
- Significant midline shift on imaging
For chronic subdural hematomas specifically: Burr hole drainage is the preferred first-line approach, with subdural drain placement to reduce recurrence 1.
Critical pitfall: Do not delay surgical intervention when neurological deterioration occurs - delays lead to significantly poorer outcomes 1. The traditional teaching that surgery within 4 hours improves mortality may be less critical than previously thought; the extent of underlying brain injury and ability to control intracranial pressure are more important determinants of outcome than absolute timing of clot removal 4.
Conservative Management Strategy
Conservative management is appropriate for 1:
- Stable patients without significant neurological deficits
- Small hematomas (particularly ≤3 mm)
- Asymptomatic presentations
Required monitoring includes 1:
- Regular neurological assessments (serial GCS, pupillary exams, focal deficits)
- Maintaining euvolemia (avoid both hypovolemia and hypervolemia)
- Serial CT imaging to monitor for progression
Predictors of hematoma expansion requiring closer surveillance 3:
- Larger initial subdural hematoma size
- Concurrent subarachnoid hemorrhage
- Hypertension
- Convexity location
- Initial midline shift present
Medical Management of Elevated Intracranial Pressure
When elevated ICP is present, mannitol is the primary osmotic agent 5:
- Dosing: 0.25 gram/kg IV over 30 minutes, repeated every 6-8 hours as needed 5
- Maximum effect: Achieves peak ICP reduction within 30 minutes 5
- Administration: Preferably through large central vein; use in-line filter due to crystal formation risk 5
Critical monitoring during mannitol therapy 5:
- Serum osmolarity and electrolytes (sodium, potassium, calcium, phosphate)
- Renal function and urine output
- Cardiac and pulmonary status
- Intracranial pressure
Discontinue mannitol if 5:
- Renal function worsens
- CNS toxicity develops (confusion, lethargy, coma)
- Cardiac or pulmonary status deteriorates
- Serum osmolarity becomes dangerously elevated
Important caveat: Rebound increase in intracranial pressure may occur several hours after mannitol infusion, particularly in patients with compromised blood-brain barrier 5.
Anticoagulation Reversal
For patients on anticoagulation who develop subdural hematoma 1, 6:
- Immediate reversal: Use prothrombin complex concentrate plus vitamin K for warfarin-associated hemorrhages 1
- Anticoagulation interruption: Typically 7-15 days, with low risk of ischemic events during this period 1
- Restart timing: Approximately 4 weeks after surgical removal if no ongoing fall risk or alcohol abuse 1
High-risk populations: Patients on clopidogrel have particularly high mortality rates (OR = 14.7) after traumatic intracranial hemorrhage 6. Elderly patients on any anticoagulant with head trauma should be transported to facilities capable of rapid reversal 6.
Special Considerations
Elderly patients (≥65 years) 6:
- Ground-level falls account for 34.6% of all deaths in this age group 6
- Mortality risk increases further after age 74 6
- Brain atrophy creates more space for brain movement during impact, increasing strain on bridging veins 6
- Lower triage thresholds needed (systolic BP <110 mmHg is significant) 6
Non-traumatic subdural hematoma: Consider ruptured intracranial aneurysm as a cause, particularly when subarachnoid hemorrhage is absent 7. Perform cerebral angiography if clinical suspicion exists 7.
Subdural hematoma with spontaneous intracranial hypotension: Perform MRI of brain with contrast and whole spine to investigate for spinal CSF leak 1, 8. Treat the underlying CSF leak as primary management, with epidural blood patch as initial treatment 8.
Delayed presentations: Subdural hematomas can develop despite normal initial CT scan, with diagnosis delayed an average of 47 days in some cases 9. Repeat CT is indicated for patients with persistent post-traumatic symptoms despite normal initial imaging 9.
Post-Operative Management
Antiepileptic drugs are NOT recommended for primary prevention of post-traumatic seizures - they show no benefit and may worsen neurological outcomes 1. Consider antiepileptics only if specific risk factors present (chronic subdural hematoma, prior epilepsy) 1.
Avoid hypervolemia - it does not improve outcomes and may cause complications 1.