What is the management approach for a patient presenting with symptoms suggestive of subarachnoid hemorrhage, using the Hunt and Hess classification?

Hunt and Hess Classification in Subarachnoid Hemorrhage Management

What is the Hunt and Hess Classification?

The Hunt and Hess classification is a clinical grading scale (Grades 0-5) that determines initial neurological severity and predicts outcome in patients with aneurysmal subarachnoid hemorrhage, and should be assessed immediately upon presentation to guide treatment urgency and prognosis. 1, 2

The grading system consists of:

• Grade 0: Unruptured aneurysm 2
• Grade 1: Asymptomatic or mild headache 2
• Grade 1a: Fixed neurological deficit without meningeal or brain reaction 2
• Grade 2: Moderate to severe headache, cranial nerve palsy, nuchal rigidity 2
• Grade 3: Lethargy, confusion, mild focal deficit 2
• Grade 4: Stupor, hemiparesis, early decerebrate posturing 2
• Grade 5: Coma, decerebrate posturing, moribund appearance 2

Clinical Application and Prognostic Value

Initial Hunt and Hess grade is the strongest predictor of outcome after aneurysmal SAH and must be documented rapidly to guide treatment decisions. 1, 3 The severity assessment should be performed by emergency care providers using this validated scale and recorded in the emergency department. 1

Higher Hunt and Hess grades independently predict:

• Acute hydrocephalus requiring ventricular drainage 2
• Increased rebleeding risk, particularly in hypertensive patients during the first 2 weeks 2
• Need for more intensive monitoring and earlier aneurysm securing 3

Early neurological changes from hospital day 1 to day 3 significantly alter prognosis—each point improvement in Hunt and Hess grade reduces odds of poor outcome by 72% (OR 0.28), while each point deterioration increases odds of poor outcome by 157% (OR 2.57). 4 Clinical grades assessed on day 3 have significantly higher prognostic accuracy than admission grades. 4

Management Algorithm Based on Hunt and Hess Grade

All Grades: Immediate Actions

Secure the aneurysm as early as feasible, ideally within 24 hours of presentation, regardless of Hunt and Hess grade. 2, 5 This recommendation applies to all grades because rebleeding carries a 70% case fatality rate. 5

Maintain systolic blood pressure <160 mmHg using titratable intravenous agents (such as nicardipine or labetalol) to balance rebleeding risk against cerebral perfusion. 2, 5 This is particularly critical in hypertensive patients with higher grades. 2

Administer oral nimodipine 60 mg every 4 hours for 21 consecutive days starting as soon as possible within 96 hours of hemorrhage onset. 5, 6 This applies to all Hunt and Hess grades I-V. 6

Grade-Specific Management

Grades I-II (Compensated):

• Proceed directly to aneurysm securing with surgical clipping or endovascular coiling 7
• Consider endovascular coiling over surgical clipping when technically feasible based on superior outcomes in randomized trials 5
• These patients have 96% excellent to fair outcomes with acute surgical repair and nimodipine 8

Grade III (Subcompensated):

• Urgent aneurysm securing combined with intensive monitoring for deterioration from rebleeding, hydrocephalus, or vasospasm 2
• Mandatory serial neurological assessments with continuous blood pressure control 2
• Maintain euvolemia—avoid both hypovolemia and prophylactic hypervolemia 5
• Approximately 86% achieve excellent to fair outcomes with aggressive early treatment 8

Grades IV-V (Decompensated):

• Do not automatically exclude from treatment—30-40% can achieve good clinical outcomes with aggressive management 2, 3
• Implement aggressive supportive treatment before aneurysm securing 7
• Perform ventriculostomy in all decompensated patients 7
• Immediately evacuate any intracranial hematomas with mass effect 7
• Treat vasospasm with balloon angioplasty as soon as diagnosed 7
• Proceed to aneurysm securing when condition stabilizes to compensated state 7
• Treatment decisions should incorporate discussion with family/surrogates 2
• Coil embolization can be performed successfully despite poor medical condition, with 30% achieving good outcomes at mean 23-month follow-up 9

Critical Monitoring Requirements

Monitor closely for the three most life-threatening early complications: rebleeding, acute hydrocephalus, and early cerebral ischemia. 5 Rebleeding risk increases progressively: 5.7% at 0-3 days, 9.4% at 4-6 days, and 12.7% at 7-10 days. 5

Maintain euvolemia and normal circulating blood volume—prophylactic hypervolemia does not prevent delayed cerebral ischemia and should be avoided. 1, 5 Studies show no difference in cerebral blood flow, symptomatic spasm, or functional outcomes between hypervolemic and normovolemic therapy. 1

Common Pitfalls to Avoid

Do not delay aneurysm treatment beyond 72 hours unless medically necessary, as rebleeding risk increases progressively. 5 Early management reduces in-hospital rebleeding and allows more aggressive management of cerebral vasospasm. 1

Avoid systemic and metabolic insults including hyperglycemia, acidosis, electrolyte fluctuations, hypoxia, and hyperthermia—all worsen outcomes. 1 Hypomagnesemia is common after SAH and associated with poor outcome; consider magnesium supplementation. 1

Do not rely solely on admission Hunt and Hess grade for prognosis—reassess on day 3 for significantly improved prognostic accuracy. 4 Early neurological changes dramatically alter outcome trajectory. 4

Transfer Considerations

Low-volume hospitals (<10 SAH cases per year) should consider early transfer to high-volume centers (>35 SAH cases per year) with experienced cerebrovascular surgeons, endovascular specialists, and multidisciplinary neurocritical care services. 5 Treatment in high-volume centers is associated with better outcomes. 1