After rupture: subarachnoid hemorrhage (SAH), grading, and outcomes

Aneurysmal SAH is a neurological emergency. Early severity grading helps predict outcomes and guide urgency, ICU intensity, and counseling.

Early mortality can be substantial, including pre-hospital deaths
Grades correlate with outcomes (Hunt‑Hess, WFNS)
Prevent secondary injury (rebleed, vasospasm, hydrocephalus)

What is Hunt‑Hess grading?

The Hunt‑Hess scale grades clinical severity on presentation (from mild headache/meningism to deep coma). It is one of several commonly used grading systems.

Grade Typical clinical picture (simplified)
IAsymptomatic or mild headache; mild meningism
IIModerate–severe headache; stiff neck; no major neurological deficit (may have cranial nerve palsy)
IIIDrowsiness/confusion; mild focal deficit
IVStupor; moderate–severe hemiparesis; early decerebrate rigidity
VDeep coma; decerebrate posturing; moribund appearance

Clinicians also use WFNS grade (based on GCS and deficits) and CT blood burden scales (Fisher / modified Fisher) to estimate vasospasm risk.

Outcomes: mortality and disability

Even in modern cohorts, outcomes depend strongly on initial grade, age, and complications.

  • A significant minority die before hospital arrival in population-based data.
  • Among hospitalized patients, in-hospital mortality can be around the high teens in some contemporary series, but varies widely by cohort and severity mix.
  • Many survivors have persistent issues: fatigue, headaches, cognitive slowing, mood changes, and focal deficits.
High-grade SAH is often survivable with aggressive critical care and early aneurysm securing, but prognosis worsens substantially as grade increases.

Example: in-hospital mortality by Hunt‑Hess grade (illustrative cohort)

One large prospective cohort reported in-hospital mortality approximately:

Hunt‑Hess grade In‑hospital mortality (approx.)
I–II~3%
III~9%
IV~24%
V~71%

Numbers vary by era, referral patterns, and inclusion of pre-hospital deaths. See References for the underlying study.

Major early complications (why ICU matters)

Complication What it is Why it matters
Rebleeding Re-rupture before aneurysm is secured Often catastrophic; drives urgency of definitive treatment
Vasospasm / delayed cerebral ischemia Constricted arteries days later; reduced perfusion Major cause of delayed stroke; monitored closely; treated with protocols
Hydrocephalus CSF flow obstruction → raised intracranial pressure May require external ventricular drain (EVD)
Seizures Acute or delayed seizures Can worsen brain injury; prophylaxis varies
Hyponatremia Low sodium due to neuroendocrine effects Can worsen confusion; managed carefully

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