Initial Management of Subarachnoid Hemorrhage

Diagnostic Approach

The American Heart Association recommends obtaining noncontrast head CT immediately as the first-line diagnostic test, which has 98-100% sensitivity within the first 12 hours after SAH, declining to 93% at 24 hours 2, 3
If CT is nondiagnostic but clinical suspicion remains high, the American College of Radiology suggests performing lumbar puncture looking specifically for xanthochromia and elevated bilirubin in cerebrospinal fluid 2, 3

The American Stroke Association recommends grading clinical severity immediately using validated scales (Hunt and Hess or World Federation of Neurological Surgeons scale), as initial severity is the most useful predictor of outcome 4, 2
The American Heart Association suggests maintaining systolic blood pressure <160 mmHg using titratable intravenous agents to balance rebleeding risk against maintaining cerebral perfusion pressure 4, 1, 2
The Neurocritical Care Society recommends administering oral nimodipine 60 mg every 4 hours for 21 consecutive days to all patients with SAH, starting as soon as possible within 96 hours of hemorrhage onset 4

The American Association of Neurological Surgeons recommends securing the aneurysm as early as feasible (ideally within 24 hours) to reduce rebleeding risk, which carries a 70% case fatality rate 4, 1, 2
The Society of NeuroInterventional Surgery suggests that for aneurysms technically amenable to both approaches, endovascular coiling should be considered over surgical clipping based on superior outcomes in randomized trials 4, 2
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 4, 2

The Neurocritical Care Society recommends maintaining euvolemia and normal circulating blood volume to prevent delayed cerebral ischemia—avoid both hypovolemia and prophylactic hypervolemia 4, 2
The American Heart Association suggests monitoring closely for neurological deterioration from the three most life-threatening early complications: rebleeding, acute hydrocephalus, and early cerebral ischemia 7
Do not delay aneurysm treatment beyond 72 hours unless medically necessary, as rebleeding risk increases progressively (5.7% at 0-3 days, 9.4% at 4-6 days, 12.7% at 7-10 days) 3