How should a subarachnoid hemorrhage be treated?

Treatment of Subarachnoid Hemorrhage

Secure the ruptured aneurysm within 24 hours using endovascular coiling (preferred for most cases), start nimodipine 60 mg every 4 hours immediately, control blood pressure to systolic <160 mmHg before securing (then target MAP >90 mmHg after), and admit to a specialized neurocritical care unit. 1

Immediate Emergency Management

Diagnosis and Initial Stabilization

• Obtain non-contrast head CT immediately; sensitivity is 98-100% within 12 hours but drops to 93% at 24 hours and 57-85% by day 6 1
• If CT is negative beyond 6 hours or neurological deficit is present, perform lumbar puncture for xanthochromia (100% sensitivity, 95.2% specificity when done >6 hours after onset) 1
• Perform digital subtraction angiography with 3D rotational imaging immediately after SAH confirmation to identify the aneurysm 1
• Grade clinical severity using Hunt-Hess or WFNS scales on presentation—this is the strongest predictor of outcome 1
• Transfer immediately to a high-volume center (>35 SAH cases/year) with neurosurgery, endovascular, and neurocritical care expertise 1

Blood Pressure Control (Pre-Aneurysm Securing)

• Target systolic BP <160 mmHg using short-acting titratable IV agents (nicardipine or clevidipine preferred) 1, 2
• Maintain MAP ≥65 mmHg at all times—never allow hypotension as it causes cerebral ischemia 1, 2
• Avoid BP drops >70 mmHg within 1 hour, as rapid reductions compromise cerebral perfusion 2
• Place arterial line for continuous beat-to-beat monitoring to minimize BP variability, which independently worsens outcomes 2
• Perform neurological checks every 1-2 hours during BP titration to detect early ischemia 2

Nimodipine Administration

• Start oral nimodipine 60 mg every 4 hours within 96 hours of onset and continue for 21 days 1
• If patient cannot swallow, administer via enteral tube (≈80 mg daily) or rectal suppository (≈325 mg daily) 1
• Nimodipine improves neurological outcomes but does not prevent angiographic vasospasm 1

Aneurysm Securing (The Definitive Treatment)

Timing

• Secure the aneurysm within 24 hours whenever feasible—early rebleeding carries 70-80% mortality 1
• Rebleeding risk is highest in the first 2-12 hours (4-13.6% within 24 hours, >33% within 3 hours) 1

Treatment Modality Selection

Anterior circulation aneurysms amenable to both techniques:

• Primary endovascular coiling is preferred over surgical clipping (superior 1-year functional outcomes) 1
• Consider clipping in patients <40 years for long-term durability 1

Posterior circulation aneurysms:

• Endovascular coiling is strongly favored (relative risk 0.41 for death/dependency vs. clipping) 1

Large intraparenchymal hematoma (>50 cm³) with depressed consciousness:

• Emergency surgical evacuation + aneurysm clipping reduces mortality from ≈80% to ≈27% 1

Wide-neck aneurysms not amenable to primary coiling/clipping:

• Stent-assisted coiling or flow-diverter devices are reasonable 1

Critical pitfall to avoid:

• Do NOT use stents or flow-diverters for ruptured saccular aneurysms suitable for primary coiling/clipping—they increase complications (hemorrhage from required dual antiplatelet therapy) 1

Treatment Goals

• Aim for complete aneurysm obliteration whenever technically possible 1
• If complete obliteration is not achievable, partial treatment securing the rupture site is acceptable with planned retreatment in 1-3 months 1

Neurocritical Care Unit Management

Acute Hydrocephalus

• Perform urgent CSF diversion via external ventricular drain or lumbar drain if acute symptomatic hydrocephalus develops 1
• Use standardized EVD bundle protocol 1

Fluid Management

• Maintain euvolemia—do NOT use prophylactic hypervolemia ("triple-H" therapy), which lacks evidence and may cause harm 1

Blood Pressure Management (Post-Aneurysm Securing)

• Target MAP >90 mmHg (or SBP 160-200 mmHg) to prevent delayed cerebral ischemia 1, 2
• Management goals shift dramatically after securing—the priority becomes preventing delayed cerebral ischemia (typically occurs days 4-12) 2

Delayed Cerebral Ischemia Treatment

• If symptomatic DCI develops, induce hypertension (MAP >90 mmHg) while maintaining euvolemia unless baseline BP is already elevated or cardiac contraindications exist 1
• Use norepinephrine as first-line vasopressor with continuous arterial line monitoring 2
• If induced hypertension fails within 1-2 hours, consider cerebral angioplasty and/or selective intra-arterial vasodilator therapy 1
• Use transcranial Doppler to monitor for vasospasm (mean flow velocities >100 cm/sec indicate vasospasm) 2

Additional Supportive Care

• Initiate pharmacologic VTE prophylaxis once aneurysm is secured 1
• Reverse anticoagulation emergently if patient is anticoagulated 1
• Withhold aspirin and antiplatelet agents until after aneurysm is secured 1

Monitoring and Follow-Up

• Obtain immediate post-treatment vascular imaging to detect residual aneurysm 1
• Schedule follow-up imaging at 6 and 18 months; strongly consider retreatment for growing remnants 1
• Implement multidisciplinary rehabilitation with validated screening tools for physical, cognitive, and behavioral deficits 1

Critical Pitfalls to Avoid

1. Do NOT delay aneurysm treatment beyond 24 hours when feasible 1
2. Do NOT use prophylactic hypervolemia—it does not improve outcomes 1
3. Do NOT allow hypotension (MAP <65 mmHg) at any point 1
4. Do NOT use stents/flow-diverters for saccular aneurysms amenable to primary coiling/clipping 1
5. Do NOT drop BP >70 mmHg within 1 hour 2

Evidence Quality Note

The strongest evidence supports only two interventions: nimodipine and endovascular aneurysm repair 3. Most other SAH treatments are empirically based, though the guidelines above represent the best available consensus from the 2023 AHA/ASA recommendations 1. The field requires more randomized controlled trials, particularly for intensive care interventions 3.