What is the management of subarachnoid hemorrhage?

Management of Subarachnoid Hemorrhage

Immediate Stabilization and Transfer

Patients with subarachnoid hemorrhage must be transferred immediately to high-volume centers (>35 SAH admissions annually) with experienced cerebrovascular surgeons, endovascular specialists, and dedicated neurocritical care units, as this reduces mortality from 39% to 27%. 1, 2

• Rapidly assess neurological status using validated grading scales (Hunt-Hess or World Federation of Neurological Surgeons scale), as clinical severity at presentation is the strongest predictor of outcome 1, 3
• Control blood pressure with titratable agents to balance rebleeding risk against maintaining cerebral perfusion pressure, recognizing that ultraearly rebleeding risk is 15% within the first 24 hours (70% occur within 2 hours) 3, 4

Diagnostic Workup

• Obtain non-contrast head CT immediately, which has 98-100% sensitivity within 12 hours but declines to 93% at 24 hours and 57-85% by day 6 1, 3, 4
• If CT is nondiagnostic, proceed to lumbar puncture looking specifically for xanthochromia and bilirubin 3
• Perform digital subtraction angiography (DSA) once SAH is confirmed to identify the bleeding source and evaluate aneurysm geometry, as small aneurysms may not be detected on CTA due to spatial resolution limitations 4

Aneurysm Securing

Early aneurysm treatment should be performed urgently to reduce rebleeding risk, which increases with time: 5.7% at 0-3 days, 9.4% at 4-6 days, 12.7% at 7-10 days, 13.9% at 11-14 days, and 21.5% at 15-32 days if untreated. 5, 1, 3, 4

• For aneurysms amenable to both surgical clipping and endovascular coiling, endovascular coiling is the preferred approach based on superior functional outcomes in randomized trials 1, 3, 4
• Complete obliteration of the aneurysm is recommended whenever possible 3
• Mean time to treatment is shorter with endovascular coiling (1.1 days) versus surgery (1.8 days), resulting in fewer preoperative hemorrhages 5

Medical Management

Administer oral nimodipine 60 mg every 4 hours for 21 consecutive days starting within 96 hours of hemorrhage onset to improve neurological outcomes. 1, 3, 4, 6

• Nimodipine improves neurological outcomes though it does not prevent cerebral vasospasm itself 3, 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 with 30 mL normal saline flush 6
• DO NOT administer nimodipine intravenously—this can cause life-threatening hypotension 6
• Reduce dose to 30 mg every 4 hours in patients with hepatic cirrhosis due to increased bioavailability 6
• Avoid grapefruit juice as it interferes with CYP3A4 metabolism 6

Prevention and Management of Delayed Cerebral Ischemia

• Maintain euvolemia and normal circulating blood volume through goal-directed fluid management 1, 3, 4, 7
• Avoid prophylactic hypervolemia—it does not improve outcomes and may be harmful 1, 3, 4
• For symptomatic delayed cerebral ischemia, induce hypertension as first-line therapy unless baseline blood pressure is already elevated or cardiac status precludes it 1, 3, 4
• Consider endovascular therapies for refractory cases 2

Management of Acute Hydrocephalus

Place external ventricular drainage urgently for acute symptomatic hydrocephalus, which is a common and life-threatening complication. 1, 3, 4

• When preoperative ventriculostomy is followed by early aneurysm treatment, rebleeding risk is not increased 3, 4
• Lumbar drainage may be considered depending on the clinical scenario 3

Additional Medical Management

• 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 1, 4
• Initiate venous thromboembolism prophylaxis once the aneurysm is secured 4
• Avoid phenytoin for seizure prophylaxis—it is associated with excess morbidity and mortality 4

Monitoring and Follow-up

• Provide care in a dedicated neurocritical care unit with continuous monitoring for neurological deterioration, intracranial pressure changes, and systemic complications 1, 2
• Perform immediate post-treatment cerebrovascular imaging to identify aneurysm remnants or recurrence 1, 3, 4
• Conduct delayed follow-up vascular imaging with strong consideration for retreatment if clinically significant remnants are identified 1, 3, 4

Common Pitfalls

• Misdiagnosis occurs in up to 12% of cases—maintain high index of suspicion for acute onset severe headache 3
• Inadvertent intravenous administration of nimodipine can cause cardiovascular collapse requiring pressor support 6
• Postoperative rebleeding rate is low (1.6% overall) but incomplete aneurysm obliteration carries 1.5% annual recurrent hemorrhage rate for all incompletely clipped aneurysms 5
• For incompletely clipped aneurysms with broad residual neck, annual recurrence rate is 19% with 3.8% recurrent hemorrhage rate 5