What is the management of subarachnoid hemorrhage?

Management of Subarachnoid Hemorrhage

Immediate Diagnosis and Stabilization

Obtain a non-contrast head CT immediately as the first diagnostic step, which has 98-100% sensitivity within the first 12 hours but declines rapidly to 93% at 24 hours and only 57-85% by day 6. 1, 2, 3

• If CT is negative but clinical suspicion remains high, proceed immediately to lumbar puncture with careful examination for xanthochromia and bilirubin in the cerebrospinal fluid 1, 4
• Rapidly assess neurological status using validated grading scales (Hunt-Hess or World Federation of Neurological Surgeons scale), as initial clinical severity is the strongest predictor of outcome 2, 4, 3
• Transfer the patient immediately to a high-volume center (>35 SAH admissions per year) with experienced cerebrovascular surgeons, endovascular specialists, and dedicated neurocritical care units—this reduces mortality from 39% to 27% 2, 3, 5

Blood Pressure Management

Control blood pressure with titratable agents to balance rebleeding risk against maintaining cerebral perfusion pressure, as ultraearly rebleeding occurs in 15% of patients within the first 24 hours (with 70% of these occurring within 2 hours) 4, 3

Definitive Aneurysm Treatment

Perform early aneurysm obliteration urgently to reduce rebleeding risk, with rebleeding rates increasing over time: 5.7% at 0-3 days, 9.4% at 4-6 days, 12.7% at 7-10 days, and 21.5% at 15-32 days if untreated. 4, 3

• For aneurysms amenable to both surgical clipping and endovascular coiling, endovascular coiling is the preferred approach based on superior functional outcomes in randomized trials 2, 4, 3
• Complete obliteration of the aneurysm should be achieved whenever technically possible 4

Nimodipine Administration

Administer oral nimodipine 60 mg every 4 hours for 21 consecutive days, starting within 96 hours of hemorrhage onset, to improve neurological outcomes. 2, 4, 6

• If the patient cannot swallow, extract capsule contents with an 18-gauge needle into a syringe labeled "Not for IV Use" and administer via nasogastric tube, followed by 30 mL normal saline flush 6
• Never administer nimodipine intravenously—this can cause life-threatening hypotension 6
• Reduce dose to 30 mg every 4 hours in patients with severe hepatic cirrhosis due to increased bioavailability 6
• Avoid grapefruit juice, which interferes with nimodipine metabolism 6

Management of Acute Hydrocephalus

Place external ventricular drainage urgently for acute symptomatic hydrocephalus, which is a common and life-threatening complication 2, 4, 3

Prevention and Treatment of Delayed Cerebral Ischemia

• Maintain euvolemia and normal circulating blood volume through goal-directed fluid management 2, 4, 3
• Avoid prophylactic hypervolemia—it does not improve outcomes and may be harmful 2, 3
• For symptomatic delayed cerebral ischemia, induce hypertension as first-line therapy unless baseline blood pressure is already elevated or cardiac status precludes it 2, 4, 3

Antifibrinolytic Therapy

Short-term tranexamic acid or aminocaproic acid is reasonable to reduce early rebleeding risk in patients with significant delay to aneurysm obliteration and no medical contraindications 2, 3

Neurocritical Care Unit Management

• Provide continuous monitoring for neurological deterioration, intracranial pressure changes, and systemic complications in a dedicated neurocritical care unit 2, 5
• Initiate venous thromboembolism prophylaxis once the aneurysm is secured 3
• Avoid phenytoin for seizure prophylaxis, as it is associated with excess morbidity and mortality 3

Follow-up Imaging

Perform immediate post-treatment cerebrovascular imaging to identify aneurysm remnants or recurrence, with delayed follow-up vascular imaging recommended to detect any clinically significant remnants requiring retreatment 2, 4, 3

Critical Pitfalls to Avoid

• Misdiagnosis occurs in up to 12% of cases, most commonly from failure to obtain a non-contrast CT scan 1, 4
• Recognize that 20% of patients report a sentinel headache (warning leak) 2-8 weeks before major rupture—diagnosing this can be lifesaving 1
• CT sensitivity declines rapidly after 12 hours, so maintain high suspicion and proceed to lumbar puncture if CT is negative beyond this window 1, 2