When is External Ventricular Drainage (EVD) indicated in intracerebral hemorrhage (ICH)?

When is External Ventricular Drainage (EVD) Indicated in Intracerebral Hemorrhage?

EVD should be performed in patients with spontaneous ICH or intraventricular hemorrhage (IVH) who have hydrocephalus contributing to decreased level of consciousness, as this is a lifesaving procedure that reduces mortality. 1

Primary Indication: Hydrocephalus with Decreased Consciousness

• EVD is a Class 1 (strongest) recommendation for patients with ICH/IVH and hydrocephalus causing decreased level of consciousness 1
• Hydrocephalus is an independent predictor of mortality after ICH, and EVD rapidly decreases intracranial pressure (ICP) secondary to hydrocephalus 1
• EVD placement is an independent predictor of reduced mortality at hospital discharge in patients with Glasgow Coma Scale (GCS) score >3 who present with hydrocephalus 1
• In patients with moderate to large IVH and higher clinical severity (GCS <13, ICH volume >11 mL, Graeb score ≥7), EVD placement alone is associated with improved survival compared with conservative treatment 1

Secondary Indications: Severe ICH with Reduced Consciousness

For patients with moderate to severe ICH/IVH with reduced level of consciousness, ICP monitoring and treatment via EVD might be considered to reduce mortality and improve outcomes. 1

Specific Clinical Parameters:

• GCS score ≤8: ICP monitoring and treatment might be considered 1
• GCS scores 9-12: Retrospective data suggests ICP monitoring may be beneficial in this moderate severity group 1
• Clinical evidence of transtentorial herniation: EVD may be considered 1
• Significant IVH: Patients with IVH requiring drainage 1

Quantitative Thresholds from Research Evidence

While not formal guideline recommendations, research data provides useful thresholds:

• Graeb score >5 (indicating moderate to severe IVH) is an independent predictor of EVD placement 2
• LeRoux score ≥9 has 80.8% sensitivity and 76.5% specificity for identifying patients likely to need EVD 3
• Evans index ≥0.245 correlates with EVD requirement 3

EVD Plus Intraventricular Fibrinolysis

For patients with GCS >3 and primary IVH or IVH extension from supratentorial ICH <30 mL requiring EVD, minimally invasive IVH evacuation with EVD plus thrombolytic is safe and reasonable compared with EVD alone to reduce mortality. 1

• The addition of intraventricular fibrinolysis (alteplase or urokinase) hastens clot removal and results in further mortality reduction (22.4% with fibrinolysis vs. 40.9% without, P<0.00001) 1
• Fibrinolysis reduces catheter occlusion rates from 37.3% to 10.6% 1
• However, the effectiveness for improving functional outcomes (not just mortality) remains uncertain 1

Important Clinical Caveats

Timing Considerations:

• EVD should be placed early - in most cases (69.7%), ventriculostomy is performed in the operating room just before surgical intervention 4
• Multi-institutional data suggests EVD use is associated with lower 30-day mortality in patients with greater ICH volumes, higher ICH scores, and lower admission GCS scores 1

Coagulation Management:

• Before EVD insertion, evaluate and correct coagulation status 1
• Prior antiplatelet use may justify platelet transfusion before the procedure 1
• Warfarin use requires reversal of coagulopathy before placement 1

Risk-Benefit in Specific Populations:

• Do NOT place EVD in patients with GCS score of 3 - these patients have extremely poor prognosis regardless of intervention 1
• In patients with small hematomas and limited IVH, EVD is usually not required as ICP elevations are uncommon 1
• For thalamic ICH specifically, retrospective data shows EVD placement had no significant correlation with clinical outcomes, suggesting more selective use 1

What EVD Does NOT Improve (Based on Current Evidence)

• Functional outcomes remain uncertain - while EVD reduces mortality, the benefit for improving functional outcomes (modified Rankin Scale 0-3) is not well established 1
• Routine ICP monitoring in all ICH patients is not supported - secondary analyses from ERICH and MISTIE III trials do not support routine ICP monitoring 1

Common Pitfall to Avoid:

The most critical error is delaying EVD placement in patients with hydrocephalus and decreased consciousness. This is the one scenario with Class 1 evidence where EVD is definitively lifesaving. Waiting for further neurological deterioration in this population increases mortality. 1