What are the grading scales and management strategies for Subarachnoid Hemorrhage (SAH)?

Subarachnoid Hemorrhage Grading Scales and Management Strategies

The most widely used and recommended grading scales for subarachnoid hemorrhage (SAH) are the Hunt and Hess (HH) scale and the World Federation of Neurological Surgeons (WFNS) scale, which should be used to determine initial clinical severity and predict outcomes in all SAH patients. 1, 2

Major Grading Scales for SAH

Hunt and Hess Scale

Grade	Clinical Description
I	Asymptomatic or minimal headache and slight nuchal rigidity
II	Moderate to severe headache, nuchal rigidity, no neurological deficit except cranial nerve palsy
III	Drowsiness, confusion, or mild focal deficit
IV	Stupor, moderate to severe hemiparesis, possible early decerebrate rigidity
V	Deep coma, decerebrate rigidity, moribund appearance

World Federation of Neurological Surgeons (WFNS) Scale

Grade	Glasgow Coma Scale	Focal Motor Deficit
I	15	Absent
II	13-14	Absent
III	13-14	Present
IV	7-12	Present or Absent
V	3-6	Present or Absent

Fisher Scale (for CT findings)

Grade	CT Findings
1	No blood detected
2	Diffuse or vertical layers < 1mm thick
3	Localized clot and/or vertical layer ≥ 1mm thick
4	Intracerebral or intraventricular clot with diffuse or no SAH

Management Algorithm Based on SAH Grade

Initial Assessment and Stabilization (All Grades)

1. Secure airway if GCS ≤8 or deteriorating neurological status 2
2. Maintain appropriate oxygenation without hyperventilation 2
3. Place nasogastric/orogastric tube to prevent aspiration 2
4. Perform non-contrast head CT; if negative but high clinical suspicion, perform lumbar puncture 1
5. Obtain vascular imaging (CTA or DSA) to identify aneurysm location 2

Management Based on Grade

Low-Grade SAH (HH/WFNS I-III)

1. Early aneurysm obliteration (within 24 hours) 2

   • Multidisciplinary decision between endovascular coiling and surgical clipping
   • Early treatment significantly reduces rebleeding risk

2. Blood pressure management

   • Maintain systolic BP <160 mmHg using titratable agents 2
   • Avoid hypotension to maintain cerebral perfusion

3. Nimodipine administration

   • 60 mg orally every 4 hours for 21 days 2, 3
   • Improves neurological outcomes by reducing severity of deficits from vasospasm

4. Monitoring for complications

   • Daily neurological assessments
   • Transcranial Doppler to monitor for vasospasm
   • Regular electrolyte monitoring, particularly sodium levels

High-Grade SAH (HH/WFNS IV-V)

1. Individualized treatment approach 1

   • Consider medical comorbidities and pre-hemorrhage functional status
   • Shared decision-making with family/surrogate decision makers

2. Aggressive management of modifiable conditions 1

   • Treat seizures, hydrocephalus, electrolyte abnormalities
   • Place external ventricular drain (EVD) if symptomatic hydrocephalus

3. Aneurysm treatment

   • Despite high mortality (>50%), treatment should be considered as good outcomes are possible in 39-40% of treated patients 1
   • Patients >65 years can still achieve functional independence (42% at 6-year follow-up) 1

4. Nimodipine administration

   • 60 mg orally every 4 hours for 21 days (standard dose) 3
   • For patients with hepatic cirrhosis, dose should be reduced due to increased bioavailability 3

Management of Complications

Vasospasm and Delayed Cerebral Ischemia

1. Maintain euvolemia
2. Continue nimodipine therapy
3. Consider induced hypertension for symptomatic vasospasm
4. Consider angioplasty for refractory vasospasm 2

Hydrocephalus

1. Monitor for signs of acute hydrocephalus
2. Place external ventricular drain if symptomatic 2

Rebleeding Prevention

1. Early aneurysm treatment (within 24 hours)
2. Blood pressure control (systolic BP <160 mmHg)
3. Bedrest until aneurysm is secured 1

Venous Thromboembolism Prevention

1. Initiate prophylaxis once aneurysm is secured 2

Prognostic Considerations

• The Hunt and Hess grade is the strongest predictor of outcome 2
• Grades I-III have better outcomes than Grades IV-V
• Even in high-grade SAH, good recovery is possible in approximately 25% of patients 3
• Case fatality rate after aneurysmal hemorrhage is approximately 50% 2
• Misdiagnosis of SAH is associated with nearly 4-fold higher likelihood of death or disability 2

Common Pitfalls and Caveats

1. Misdiagnosis: Failure to obtain non-contrast head CT in patients with sudden severe headache is the most common diagnostic error 2

2. Ultraearly rebleeding: Risk is highest (15%) within the first 24 hours, with 70% occurring within 2 hours of initial SAH 1

3. Sentinel headaches: Can precede major SAH by days to weeks, occurring in 10-43% of patients 2

4. Neuropsychological deficits: Patients with no gross neurological deficits may still have subtle cognitive or neurobehavioral difficulties that impair social adjustment and occupational function 1

5. Hydrocephalus management: Recent data suggest that preoperative ventriculostomy followed by early aneurysm treatment does not increase rebleeding risk 1

6. Nimodipine timing: Administration should begin as soon as diagnosis is confirmed, as it improves outcomes despite lack of arteriographic evidence that it prevents or relieves arterial spasm 3