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

Diagnostic Approach

Initial Imaging

• 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
• Noncontrast head CT is the first-line diagnostic test and should be obtained immediately in all suspected cases 2
• If CT is nondiagnostic and clinical suspicion remains high, proceed directly to lumbar puncture without delay 2

Lumbar Puncture Technique

• Look specifically for xanthochromia and elevated bilirubin in cerebrospinal fluid, as these are the critical diagnostic markers 1, 2
• Proper technique and interpretation are essential to distinguish traumatic LP from true SAH 2
• SAH is frequently misdiagnosed (up to 12% of cases), so maintain high suspicion in patients with acute onset severe headache 2

Clinical Severity Assessment

• Rapidly assess using Hunt and Hess or World Federation of Neurological Surgeons scales immediately upon diagnosis, as initial grade is the strongest predictor of outcome 1, 2
• Document the severity score as it guides prognosis and triage decisions 3

Immediate Management (Pre-Aneurysm Treatment)

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
• Target systolic blood pressure <160 mmHg to prevent rebleeding 3
• Avoid excessive blood pressure fluctuations, particularly during intubation if required 3

Airway Management (If Needed)

• Ensure adequate airway, breathing, and circulation with attention to preoxygenation and pharmacological blunting of reflex dysrhythmia 3
• After intubation, place nasogastric or orogastric tube to reduce aspiration risk 3
• Avoid hyperventilation as it may worsen cerebral ischemia 3

Nimodipine Administration

• Administer oral nimodipine 60 mg every 4 hours for 21 consecutive days, starting within 96 hours of hemorrhage onset (Class I, Level of Evidence A) 1, 2
• Nimodipine reduces cerebral infarction by 34% and poor outcomes by 40%, though it does not prevent angiographic vasospasm 1
• 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 nimodipine intravenously as 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 as it is associated with lower long-term seizure rates 1, 2
• Complete aneurysm obliteration should be achieved whenever technically possible 1, 2

Transfer Considerations

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

Management of Acute Complications

Hydrocephalus

• Treat acute symptomatic hydrocephalus with external ventricular drainage or lumbar drainage depending on clinical scenario (Class I, Level of Evidence B) 1, 2
• Acute hydrocephalus occurs in 15-87% of patients and requires cerebrospinal fluid diversion 1
• 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; avoid prophylactic hypervolemia and hemodynamic augmentation 1, 2
• Prophylactic triple-H therapy (hypervolemia, hypertension, hemodilution) should not be performed to minimize iatrogenic risks 1
• For symptomatic delayed cerebral ischemia, elevate blood pressure (induced hypertension) and maintain euvolemia 1, 2
• This approach reduces progression and severity of delayed cerebral ischemia 1

Invasive Monitoring

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

Medications to Avoid

• Do not use routine statin therapy or intravenous magnesium for vasospasm prophylaxis 1
• Aspirin, enoxaparin, and tirilazad have been shown ineffective 1

Follow-Up Imaging

• 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 is identified 2

Long-Term Management

• Refer all survivors for comprehensive multidisciplinary evaluation including cognitive, behavioral, and psychosocial assessments using validated screening tools 1
• Target systolic blood pressure <160 mmHg in chronic phase to prevent aneurysm recurrence 1
• Physical, cognitive, behavioral, and quality of life deficits are common and can persist long-term 1