Indications for Emergent Surgery in Subdural Hematoma
A midline shift of > 5 mm is an indication for emergent surgical evacuation in a patient with a subdural hematoma, regardless of the patient's Glasgow Coma Scale (GCS) score. 1
Surgical Indications for Subdural Hematoma
Surgical management of subdural hematomas depends on several factors:
Definite Indications for Emergent Surgery:
- Midline shift > 5 mm on CT scan 1
- Hematoma thickness > 10 mm 1
- Neurological deterioration (decrease in GCS by 2 or more points) 1
- Asymmetric or fixed and dilated pupils 1
Other Important Considerations:
- Intracranial pressure (ICP) > 20 mm Hg in comatose patients 1
- Presence of significant mass effect with brain compression 2
- Clinical deterioration in patients initially managed conservatively 3
Specific Management Approach
For Supratentorial Subdural Hematomas:
- Surgical evacuation should be performed as soon as possible when indicated 1
- Craniotomy with or without bone flap removal and duraplasty is recommended for comatose patients (GCS < 9) 1
- All comatose patients (GCS < 9) with acute subdural hematoma should undergo ICP monitoring 1
For Posterior Fossa Subdural Hematomas:
- Surgical decompression is generally recommended when associated with brainstem compression or hydrocephalus 3
- External ventricular drain (EVD) alone is insufficient and potentially harmful, especially if basal cisterns are compressed 3
Clinical Pearls and Pitfalls
Important Considerations:
- While timing of surgery has been debated, patients with indications for surgery should undergo evacuation as soon as possible 1
- The extent of primary underlying brain injury may be more important than the subdural clot itself in determining outcome 4
- Ability to control ICP is critical to outcome 4
Potential Pitfalls:
- Relying solely on ICP measurements without considering clinical status and imaging findings
- Delaying surgery in patients with clear surgical indications
- Misinterpreting laboratory abnormalities like pseudothrombocytopenia, which may falsely suggest contraindication to surgery 2
Conclusion
In the case of the 72-year-old woman with a subdural hematoma after a fall, the presence of a midline shift > 5 mm is a clear indication for emergent surgical evacuation. While an ICP of 23 mm Hg is elevated and concerning, the midline shift alone is sufficient to warrant immediate surgical intervention regardless of other factors.