What is the initial management for a patient diagnosed with a Subdural Hematoma (SDH) on a Computed Tomography (CT) scan?

Initial Management of Subdural Hematoma on CT

All patients with subdural hematoma diagnosed on CT require immediate hospital admission to a monitored setting with serial neurological assessments and urgent neurosurgery consultation, regardless of Glasgow Coma Scale (GCS) score, due to the risk of delayed deterioration. 1

Immediate Actions Upon Diagnosis

Neurosurgical Consultation

• Obtain immediate neurosurgical consultation at presentation, not just if deterioration occurs 1
• Patients should be managed in centers with neurosurgical expertise 2

Admission Decision Algorithm

• All patients with SDH require hospital admission regardless of size or GCS score 1
• ICU admission is appropriate for patients with GCS ≤13, focal neurological deficits, or elderly status 1
• Patients with isolated small SDH (<10 cm³ volume) without additional intracranial hemorrhages may be managed on a monitored floor rather than ICU, as they demonstrate neurologic and medical stability and rarely require neurosurgical intervention 3
• Patients with SDH >10 cm³ demonstrate poor clinical courses and require ICU monitoring 3

Hemodynamic Management

• Maintain mean arterial pressure ≥80 mmHg to ensure adequate cerebral perfusion 1, 4
• Maintain systolic blood pressure >100 mmHg 4
• Maintain oxygen saturation >95% to prevent hypoxemic secondary injury 1
• Avoid hypovolemia to optimize cerebral perfusion 4

Monitoring Protocol

Neurological Assessment Schedule

• Perform GCS monitoring every 15 minutes for the first 2 hours, then hourly for 12 hours 1
• Document individual GCS components (Eye, Motor, Verbal) rather than sum scores, as component profiles predict outcomes 1
• Assess pupillary size and reactivity at each evaluation 1
• Monitor for focal neurological deficits and level of confusion/orientation hourly 1
• Continue regular neurological evaluations at least every 4 hours initially 4

Repeat Imaging Considerations

• A decrease of 2 or more points in GCS score warrants immediate repeat CT scanning 1
• For anticoagulated patients, perform 24-hour repeat CT imaging even with initially negative scans, as delayed hemorrhage occurs in 1.4-4.5% of cases 1
• Serial CT scanning is recommended for patients managed conservatively 5, 6

Conservative vs. Surgical Management Decision Tree

Criteria for Conservative Management

Conservative management may be considered for highly selected patients meeting ALL of the following criteria 5, 6:

• GCS score of 15 with midline shift <10 mm on CT 6
• GCS score 13-14 with midline shift <5 mm on CT 6
• No mass effect on CT 5
• SDH thickness ≤10 mm 5
• No additional intracranial abnormalities (cerebral contusions) 5
• Close observation capability with serial neurological assessments 6

Important caveat: Patients with midline shift >5 mm and GCS <15 typically exhaust cerebral compensatory mechanisms within 3 days and require surgical evacuation 6

Indications for Surgical Evacuation

Proceed to immediate surgical evacuation if ANY of the following are present 1:

• Clinical deterioration with GCS decline ≥2 points
• Development of additional focal neurological deficits indicating mass effect
• Signs of herniation (pupillary changes, posturing)
• Failure to show neurological improvement within 72 hours
• Initial SDH size ≥8.5 mm (best threshold predicting need for surgery) 7

Special Populations

Anticoagulated/Antiplatelet Patients

• 70% of elderly patients on anticoagulation or antiplatelet therapy who deteriorate do so within the first 24 hours 1
• Delayed ICH after negative initial CT is very rare (0.6% for warfarin patients), with none requiring neurosurgical intervention in one study, though 2 deaths occurred 2
• Mandatory 24-hour observation with repeat CT scan at 20-24 hours post-initial scan 2
• Do not routinely reverse anticoagulation for negative initial CT scans 2

Elderly Patients (Age >60)

• Increased risk of abnormal CT findings and deterioration 1
• Cerebral atrophy present in over half of elderly SDH patients, which may allow larger hematomas before symptoms develop 5
• Higher threshold for ICU admission given increased risk profile 1

Critical Pitfalls to Avoid

• Never administer long-acting sedatives or paralytics before neurosurgical evaluation, as this masks clinical deterioration 1
• Do not discharge based solely on "mild" GCS of 13-14 when SDH is confirmed on CT 1
• Do not delay correction of secondary insults (hypotension, hypoxia) while waiting to prognosticate 1
• Do not make irreversible decisions before 72 hours unless brain death criteria are met or clear clinical deterioration occurs 1
• No patient with initial SDH ≤3 mm required surgery in recent studies, though 11.1% enlarged to maximum 10 mm 7

ICP Monitoring Considerations

Indications for ICP Monitoring

Consider ICP monitoring after SDH evacuation if ANY of the following are present 2:

• Preoperative GCS motor response ≤5
• Preoperative anisocoria or bilateral mydriasis
• Preoperative hemodynamic instability
• Preoperative severity signs on imaging (compressed basal cisterns, midline shift >5 mm, other intracranial lesions)

When ICP Monitoring May Not Be Necessary

• Initial CT scan is strictly normal with no evidence of clinical severity 2
• Risk of ICP monitoring complications (catheter placement failure 10%, infection 2.5-10%, intracerebral hemorrhage 0-4%) must be weighed against benefits 2

Observation Duration and Follow-up

• Patients managed conservatively require observation for at least 24-72 hours 1
• Total hospital stay of 6-7 days may suffice for those who become fully conscious 6
• Repeat CT studies before discharge are mandatory 6
• Close follow-up during the first 3-4 weeks is advisable 6

Predictors of SDH Expansion

The following factors significantly predict hematoma expansion and should heighten vigilance 7:

• Larger initial SDH size
• Concurrent subarachnoid hemorrhage
• Hypertension
• Convexity location
• Initial midline shift

Serial GCS assessments provide substantially more valuable information than single determinations, as declining scores indicate poorer prognosis 1