What is the management of suspected subarachnoid hemorrhage?

Management of Suspected Subarachnoid Hemorrhage

Immediately obtain a noncontrast head CT scan, and if negative with high clinical suspicion, proceed directly to lumbar puncture looking for xanthochromia and elevated bilirubin. 1

Initial Diagnostic Approach

Imaging Strategy

• CT sensitivity is time-critical: 98-100% within 12 hours, declining to 93% at 24 hours and 57-85% by day 6, making early imaging essential 1, 2
• If CT is nondiagnostic and clinical suspicion remains high, lumbar puncture must follow immediately 2
• Proper LP technique requires specific evaluation for xanthochromia and bilirubin in cerebrospinal fluid 2

Clinical Assessment

• Rapidly grade severity using Hunt and Hess or World Federation of Neurological Surgeons scales, as initial grade is the strongest predictor of outcome 1, 2
• Maintain high suspicion in patients with acute onset severe headache, as SAH is misdiagnosed in up to 12% of cases 2, 3

Immediate Management (Pre-Aneurysm Obliteration)

Blood Pressure Control

• Control blood pressure with titratable agents between symptom onset and aneurysm obliteration, balancing rebleeding risk against maintaining cerebral perfusion pressure 1, 2
• Avoid systolic blood pressure >160 mmHg 3
• In prehospital settings, ensure adequate airway with preoxygenation and pharmacological blunting of reflex dysrhythmia during intubation 3

Nimodipine Administration

Administer oral nimodipine 60 mg every 4 hours for 21 consecutive days starting within 96 hours of hemorrhage onset. 1, 2

• This is a Class I, Level of Evidence A recommendation that reduces cerebral infarction by 34% and poor outcomes by 40% 1
• Nimodipine does NOT prevent angiographic vasospasm but improves neurological outcomes 1, 4
• If patient cannot swallow, extract capsule contents with 18-gauge needle into oral syringe (labeled "Not for IV Use"), administer via nasogastric tube, and flush with 30 mL normal saline 4
• Never administer intravenously—this can cause life-threatening hypotension 4
• Reduce dose to 30 mg every 4 hours in patients with hepatic cirrhosis due to increased bioavailability 4

Definitive Aneurysm Treatment

Timing and Approach

• Perform surgical clipping or endovascular coiling as early as feasible to reduce rebleeding risk 1, 2
• Rebleeding risk is highest in first 24 hours (15% "ultraearly rebleeding"), with 70% occurring within 2 hours of initial hemorrhage 1, 2
• For aneurysms amenable to both techniques, endovascular coiling is preferred and associated with lower long-term seizure rates 1, 2
• Complete aneurysm obliteration should be achieved whenever technically possible 1, 2

Management of Acute Complications

Hydrocephalus

• Treat acute symptomatic hydrocephalus (occurs in 15-87% of patients) with external ventricular drainage or lumbar drainage depending on clinical scenario 1, 2
• Do NOT wean external ventricular drainage over >24 hours, as this does not reduce need for permanent shunting 1

Delayed Cerebral Ischemia Prevention

• Maintain euvolemia and normal circulating blood volume 1, 2
• Do NOT perform prophylactic triple-H therapy (hypervolemia, hypertension, hemodilution) to minimize iatrogenic risks 1
• For symptomatic delayed cerebral ischemia, elevate blood pressure (induced hypertension) and maintain euvolemia 1, 2

Invasive Monitoring

• Use invasive monitoring (intracranial pressure monitoring, arterial lines) in high-grade SAH patients with limited neurological examination 1

Follow-Up Imaging and Surveillance

• Obtain immediate post-treatment cerebrovascular imaging to identify aneurysm remnants 1, 2
• Perform delayed follow-up imaging at 6 months and 18 months for coiled aneurysms 1, 2
• Consider retreatment if clinically significant remnant identified 2

Long-Term Management

Blood Pressure Control

• Target systolic blood pressure <160 mm Hg in chronic phase to prevent aneurysm recurrence 1

Rehabilitation and Screening

• Refer all survivors for comprehensive multidisciplinary evaluation including cognitive, behavioral, and psychosocial assessments using validated screening tools 1
• Screen for mood disorders, as early identification allows interventions that improve long-term outcomes 1

Medications to AVOID

Do NOT use the following for vasospasm prophylaxis: 1

• Routine statin therapy
• Intravenous magnesium
• Aspirin
• Enoxaparin
• Tirilazad

Transfer Considerations

• Hospitals with low SAH volume (<10 per year) should consider early transfer to high-volume centers (>35 cases per year) with experienced cerebrovascular surgeons and multidisciplinary neurointensive care services 3, 5