What is the management of suspected subarachnoid hemorrhage?

Management of Suspected Subarachnoid Hemorrhage

The management of suspected subarachnoid hemorrhage (SAH) requires rapid diagnosis with non-contrast head CT followed by lumbar puncture if CT is negative, and immediate transfer to a high-volume neurosurgical center for definitive treatment of the underlying aneurysm through surgical clipping or endovascular coiling. 1

Initial Diagnosis

• SAH is a medical emergency that is frequently misdiagnosed (up to 12% of cases), requiring a high index of suspicion in patients presenting with acute onset of severe headache 1
• The diagnostic algorithm should include:
  • Non-contrast head CT as the initial imaging modality 1
  • CT sensitivity is highest (98-100%) within the first 12 hours after SAH, declining to 93% at 24 hours and 57-85% by day 6 1
  • If CT is negative but clinical suspicion remains high, lumbar puncture must be performed to look for xanthochromia and bilirubin in the cerebrospinal fluid 2, 1
• Selective cerebral angiography is the gold standard for diagnosing cerebral aneurysms as the cause of SAH 2
• CTA and MRA may be considered when conventional angiography cannot be performed in a timely fashion 2

Initial Management

• Rapidly assess clinical severity using validated scales (Hunt and Hess Scale, Fisher Scale, Glasgow Coma Scale, or World Federation of Neurological Surgeons Scale) as it is the most useful indicator of outcome 2, 1
• Airway management is paramount due to the potential for neurological deterioration; if endotracheal intubation is necessary, use rapid sequence intubation protocols with attention to preoxygenation and avoidance of unnecessary blood pressure fluctuations 2
• Blood pressure control should be achieved with a titratable agent to balance the risk of stroke, hypertension-related rebleeding, and maintenance of cerebral perfusion pressure 1, 3
• If definitive expertise is not directly available, expedient transfer to an appropriate high-volume referral center should be arranged immediately 2, 1

Definitive Treatment

• Surgical clipping or endovascular coiling of the ruptured aneurysm should be performed as early as feasible to reduce the rate of rebleeding 1, 3
• For patients with ruptured aneurysms technically amenable to both endovascular coiling and neurosurgical clipping, endovascular coiling should be considered as the first option 1, 3
• The risk of "ultraearly rebleeding" (within 24 hours of initial SAH) may be 15%, with 70% occurring within 2 hours of initial SAH 1
• Complete obliteration of the aneurysm is recommended whenever possible 1

Medical Management

• Oral nimodipine should be administered to all patients at a dose of 60 mg every 4 hours for 21 consecutive days, starting within 96 hours of hemorrhage onset 1, 4
• Nimodipine improves neurological outcomes though it has not been shown to prevent cerebral vasospasm itself 4
• If the patient cannot swallow, nimodipine capsules can be administered by making a hole in both ends of the capsule with an 18-gauge needle and extracting the contents into a syringe designed for oral administration 4
• Maintenance of euvolemia and normal circulating blood volume is recommended to prevent delayed cerebral ischemia (DCI) 1, 3
• Prophylactic hypervolemia and triple-H therapy are not recommended as they can increase complications 3

Management of Complications

Hydrocephalus

• Acute symptomatic hydrocephalus should be managed by cerebrospinal fluid diversion (external ventricular drainage or lumbar drainage) 1, 3
• Chronic symptomatic hydrocephalus should be treated with permanent cerebrospinal fluid diversion 3

Delayed Cerebral Ischemia (DCI)

• Induction of hypertension is recommended for patients with DCI unless blood pressure is elevated at baseline or cardiac status precludes it 1
• Transcranial Doppler ultrasonography can be used to monitor for vasospasm development 3

Seizure Management

• Routine prophylactic anticonvulsants are not recommended for all patients with SAH 3

Follow-up Care

• After aneurysm repair, immediate cerebrovascular imaging is recommended to identify remnants or recurrence of the aneurysm that may require treatment 1, 3
• In the absence of contraindications, patients who undergo coiling or clipping should have delayed follow-up vascular imaging 1

Common Pitfalls and Considerations

• Misdiagnosis is common in SAH; maintain high suspicion with acute severe headache 3
• Hypervolemia is potentially harmful and associated with excess morbidity; euvolemia should be the target 3
• Severely disturbed liver function may result in increased bioavailability of nimodipine requiring dose reduction to one 30 mg capsule every 4 hours with close monitoring 4
• Grapefruit juice should be avoided during nimodipine therapy 4