Immediate Neurosurgical Consultation for Subdural Hematoma Evacuation
The next best step is to immediately consult neurosurgery for urgent subdural hematoma evacuation (Option B). This patient has a rapidly expanding subdural hematoma with clear evidence of clinical deterioration (somnolence) and radiographic progression (doubling in size from 1 cm to 2 cm with midline shift), meeting established criteria for emergent surgical intervention.
Rationale for Urgent Surgical Intervention
This patient meets multiple criteria for immediate surgical evacuation:
- Hematoma thickness >5 mm with midline shift >5 mm - The current 2 cm (20 mm) thickness with associated midline shift clearly exceeds the threshold for surgical intervention 1, 2
- Documented expansion - The hematoma doubled in size over 6 hours, demonstrating active progression that will not resolve with conservative management 2
- Clinical deterioration - The patient's somnolence represents worsening neurological status, indicating increased intracranial pressure and impending herniation 1
Why Other Options Are Inappropriate
Ordering another CT scan (Option A) would cause dangerous delay when the diagnosis is already established and the patient is clinically deteriorating. The 4-hour target from injury to surgery is a commonly accepted standard, and this patient is already at 24+ hours 1. Further imaging delays definitive treatment without changing management.
Reevaluating in 4 hours (Option C) is contraindicated in a patient with documented expansion and declining mental status. This approach risks progression to irreversible herniation and death 2.
The normothermia protocol (Option D) has no role in subdural hematoma management and would represent a critical error in judgment 3.
Time-Critical Nature of This Emergency
The maximum acceptable time from injury to surgery is approximately 4 hours, though this is not rigidly evidence-based 1. This patient is already beyond that window at 24+ hours post-injury. The documented expansion over 6 hours with clinical deterioration makes this a neurosurgical emergency requiring immediate intervention, not further observation or imaging 1, 2.
Expected Surgical Approach
Neurosurgery will likely perform craniotomy with hematoma evacuation, as this is the standard approach for acute subdural hematomas of this size with mass effect 1, 2. In elderly patients with refractory intracranial hypertension, decompressive craniectomy may be considered, though age considerations (typically under 65-70 years for best outcomes) apply 1, 2.
Critical Pitfall to Avoid
The most dangerous error would be delaying surgical consultation in favor of additional imaging or observation. Symptomatic subdural hematomas with documented expansion and midline shift require immediate neurosurgical evaluation, as delays lead to neurological deterioration and significantly poorer outcomes 2.