What is the initial approach for treating Subdural Hematoma (SDH) in the Intensive Care Unit (ICU)?

Initial ICU Management of Subdural Hematoma

Immediately secure the airway with tracheal intubation and mechanical ventilation while maintaining PaCO₂ within normal range (35-45 mmHg), as hypocapnia causes cerebral vasoconstriction and worsens brain ischemia. 1

Immediate Stabilization (First 30 Minutes)

Airway and Ventilation Management

• Perform rapid sequence intubation with end-tidal CO₂ monitoring to confirm correct tube placement and guide ventilation targets 1
• Maintain PaCO₂ between 35-45 mmHg; avoid hypocapnia which induces cerebral vasoconstriction and increases risk of brain ischemia 2, 1
• Target PaO₂ >60 mmHg to prevent secondary brain injury 3

Hemodynamic Resuscitation

• Maintain systolic blood pressure >110 mmHg using vasopressors (phenylephrine or norepinephrine) without delay 1
• Even a single episode of hypotension (SBP <90 mmHg) significantly worsens neurological outcomes and must be avoided 1
• Target mean arterial pressure (MAP) 80-110 mmHg to maintain adequate cerebral perfusion 3
• Use continuous infusions of sedatives rather than boluses to prevent hemodynamic instability 1

Initial Neurological Assessment

• Document Glasgow Coma Scale (GCS) score, pupillary examination (size, reactivity, symmetry), and focal neurological deficits 2, 1
• Obtain immediate non-contrast CT scan to characterize hematoma size, location, maximal thickness, degree of midline shift, and mass effect 2, 1

Surgical Decision-Making

Indications for Immediate Surgical Evacuation

Proceed urgently to surgical evacuation if the subdural hematoma demonstrates thickness >5 mm AND midline shift >5 mm. 2, 1

Additional surgical indications include: 2, 1

• Significant mass effect with neurological deterioration
• Decreased level of consciousness attributable to the hematoma
• GCS motor response ≤5

Surgical Approach

• Standard craniotomy with hematoma evacuation remains the first-line surgical approach 1
• Consider subdural drain placement during surgery to reduce recurrence rates 2
• Decompressive craniectomy should be considered for refractory intracranial hypertension in multidisciplinary discussion, particularly in patients <65-70 years 2, 1

Post-Operative ICU Management

Intracranial Pressure Monitoring

Monitor ICP after subdural hematoma evacuation if ANY of the following are present: 1

• Preoperative GCS motor response ≤5
• Preoperative anisocoria or bilateral mydriasis
• Preoperative hemodynamic instability
• Preoperative severity signs on imaging
• Intraoperative cerebral edema
• Postoperative appearance of new intracranial lesions

Cerebral Perfusion Management

• Maintain cerebral perfusion pressure (CPP) between 60-70 mmHg, as CPP <60 mmHg is associated with poor outcomes 1
• Target intracranial pressure <22 mmHg 3
• Maintain euvolemia and avoid hypovolemia to optimize cerebral perfusion 2
• Consider external ventricular drainage for persisting intracranial hypertension despite sedation and correction of secondary brain insults 2

Medical Management

• Administer anti-seizure medications for seizure prevention 3
• Reverse antiplatelet medications or anticoagulation if neurosurgical interventions are anticipated or until hemorrhage is stabilized on imaging 3
• Maintain normothermia, eucarbia, euglycemia, and euvolemia 3
• Initiate early enteral feeding, mobilization, and physical therapy 3

Monitoring for Complications

• Serial neurological assessments of GCS, pupils, and focal deficits 2
• Monitor for seizures, infection, and hematoma expansion 2
• Obtain follow-up imaging to assess for hematoma reaccumulation or new lesions 2

Conservative Management (Non-Surgical Cases)

Conservative management is appropriate only for small hematomas (<5 mm thickness, <5 mm midline shift) without mass effect or neurological deterioration. 2, 1

Conservative management protocol includes: 2, 1

• Close neurological observation with serial assessments of GCS, pupils, and focal deficits
• Serial imaging to monitor for hematoma expansion
• Maintenance of euvolemia
• All hemodynamic and ventilation targets as outlined above

Special Populations

Elderly Patients

• Require particularly careful monitoring as small hematomas can expand rapidly, especially in those on anticoagulants 2, 1
• Lower threshold for surgical intervention given higher risk of delayed deterioration 2

Patients with Small Initial Hematomas

• Hematoma volume and degree of midline shift on initial CT are independent predictors of delayed hematoma enlargement requiring surgery 4
• Patients with isolated traumatic SDH <10 cm³ blood volume demonstrate neurologic and medical stability and may not require ICU monitoring 5
• However, patients with small SDH and additional intracranial hemorrhages still benefit from ICU observation 5

Critical Pitfalls to Avoid

• Never delay surgical intervention in symptomatic patients, as this leads to neurological deterioration and poorer outcomes 2, 1
• Never allow even single episodes of hypotension (SBP <90 mmHg), which markedly worsens prognosis 1
• Never induce hypocapnia, which causes cerebral vasoconstriction and brain ischemia 2, 1
• Never use sedation boluses instead of continuous infusions, as this causes hemodynamic instability 1
• Never discharge patients with significant hematoma volume or midline shift without extended observation, as these are independent risk factors for delayed expansion requiring surgery 4