What is the Hunt and Hess classification used for in a patient with a history of hypertension presenting with subarachnoid hemorrhage?

Hunt and Hess Classification for Subarachnoid Hemorrhage

Primary Purpose and Clinical Application

The Hunt and Hess classification is a clinical grading scale used to determine initial clinical severity and predict outcome in patients with aneurysmal subarachnoid hemorrhage. 1

The American Heart Association/American Stroke Association strongly recommends using clinical scales like Hunt and Hess (or World Federation of Neurological Societies grade) immediately upon presentation to standardize severity assessment and guide prognostication. 1, 2

The Hunt and Hess Grading System

The scale consists of 6 grades based on clinical presentation: 1

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

Prognostic Value in Hypertensive Patients

In patients with preexisting hypertension presenting with SAH, the Hunt and Hess grade serves multiple critical functions:

Risk Stratification for Rebleeding

• Higher Hunt and Hess grades independently predict acute hydrocephalus, intraventricular blood, and need for ventricular drainage. 1
• Hypertension combined with worse neurological status (higher Hunt and Hess grade) increases rebleeding risk in the first 2 weeks after SAH. 1
• The combination of hypertension and aneurysm rupture creates elevated transmural pressure across the aneurysm wall, making grade assessment crucial for blood pressure management decisions. 4

Treatment Decision-Making

• High-grade patients (Hunt and Hess 4-5) require individualized assessment but should not be automatically excluded from treatment—studies show 30-40% can achieve favorable outcomes with aggressive management. 1
• The American Heart Association recommends securing the aneurysm as early as feasible (ideally within 24 hours) regardless of grade, though higher grades require more intensive monitoring. 2, 3
• For Hunt and Hess Grade III patients specifically, urgent aneurysm securing with surgical clipping or endovascular coiling is recommended, combined with intensive monitoring for deterioration. 3

Blood Pressure Management Guidance

• The American Heart Association suggests maintaining systolic blood pressure <160 mmHg using titratable intravenous agents to balance rebleeding risk against cerebral perfusion. 2, 3
• This target is particularly important in hypertensive patients with higher Hunt and Hess grades, where the risk of rebleeding must be weighed against maintaining adequate cerebral perfusion pressure. 1

Clinical Pitfalls and Important Considerations

Timing of Grade Assessment

• Critical finding: Clinical grades assessed on hospital day 3 have significantly higher prognostic accuracy than admission grades. 5
• Early neurological improvement or deterioration (changes in Hunt and Hess grade from day 1 to days 2-5) substantially alters outcome predictions—each point increase in grade worsens odds ratio for poor outcome by 2.57. 5
• The American Stroke Association emphasizes that initial severity remains the most useful single predictor, but serial assessments are essential. 2

Limitations of the Scale

• The Hunt and Hess scale was derived retrospectively, and intra-observer/inter-observer variability has not been thoroughly validated. 6
• Some evidence suggests GCS-based grading systems may have superior predictive accuracy and inter-rater reliability compared to Hunt and Hess. 7, 8
• Despite these limitations, Hunt and Hess remains widely used and recommended by major guidelines for standardized communication. 1

Factors Beyond the Grade

• Age, preexisting hypertension, amount of blood on CT, aneurysm location/size, and presence of intraventricular hemorrhage all influence prognosis independent of Hunt and Hess grade. 6
• Composite scores incorporating radiographic findings (like VASOGRADE or HAIR scores) may provide additional prognostic information but add complexity. 1

Monitoring Requirements by Grade

For Hunt and Hess Grade III patients (lethargy, confusion, mild focal deficit): 3

• Mandatory intensive monitoring with serial neurological assessments
• Watch specifically for deterioration from rebleeding, hydrocephalus, or vasospasm
• Maintain blood pressure control with continuous titratable agents
• Plan for early aneurysm securing within 24 hours when feasible

For high-grade patients (4-5): 1

• 92% develop vasospasm requiring close monitoring. 9
• Despite poor initial presentation, 30% can achieve good clinical outcomes with aggressive treatment. 1
• Treatment decisions should incorporate discussion with family/surrogates but should not automatically exclude these patients from intervention. 1