Management and Treatment of Suspected Subarachnoid Hemorrhage

Diagnosis

Subarachnoid hemorrhage (SAH) is a medical emergency that is frequently misdiagnosed (up to 12% of cases), and a high index of suspicion must exist in patients with acute onset of severe headache, according to the American Heart Association 1, 2
Acute diagnostic workup should include noncontrast head CT, which if nondiagnostic, should be followed by lumbar puncture, as recommended by the American College of Radiology 2, 3
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, based on evidence from the American Journal of Neuroradiology 1, 4
Proper lumbar puncture technique and interpretation of cerebrospinal fluid (CSF) results are critical, looking specifically for xanthochromia and bilirubin, as stated by the American Academy of Neurology 1

The initial clinical severity of SAH should be rapidly determined using validated scales (e.g., Hunt and Hess, World Federation of Neurological Surgeons) as it is the most useful indicator of outcome, according to the American Association of Neurological Surgeons 2, 3
Between symptom onset and aneurysm obliteration, blood pressure should be controlled with a titratable agent to balance the risk of stroke, hypertension-related rebleeding, and maintenance of cerebral perfusion pressure, as recommended by the American Heart Association 2, 5
Oral nimodipine (60 mg every 4 hours for 21 consecutive days) should be administered to all patients with SAH to improve neurological outcomes, though it has not been shown to prevent cerebral vasospasm, based on evidence from the American College of Cardiology 2, 5

Surgical clipping or endovascular coiling of the ruptured aneurysm should be performed as early as feasible to reduce the rate of rebleeding, as recommended by the American Stroke Association 2, 5
For patients with ruptured aneurysms technically amenable to both endovascular coiling and neurosurgical clipping, endovascular coiling should be considered, according to the Society of NeuroInterventional Surgery 2, 6
Complete obliteration of the aneurysm is recommended whenever possible, based on evidence from the American Association of Neurological Surgeons 2, 5

SAH-associated acute symptomatic hydrocephalus should be managed by cerebrospinal fluid diversion (external ventricular drainage or lumbar drainage, depending on the clinical scenario), as recommended by the Neurocritical Care Society 2, 5
Maintenance of euvolemia and normal circulating blood volume is recommended to prevent delayed cerebral ischemia (DCI), according to the American Heart Association 2, 5
Induction of hypertension is recommended for patients with DCI unless blood pressure is elevated at baseline or cardiac status precludes it, based on evidence from the American College of Cardiology 2, 6

After any aneurysm repair, immediate cerebrovascular imaging is generally recommended to identify remnants or recurrence of the aneurysm that may require treatment, as stated by the American Society of Neuroradiology 2, 3
In the absence of contraindications, patients who undergo coiling or clipping should have delayed follow-up vascular imaging, with consideration for retreatment if there is a clinically significant remnant, according to the Society of NeuroInterventional Surgery 2, 5

The timing of surgery after SAH is significantly related to the likelihood of preoperative rebleeding, with rates increasing as time passes (0-3 days: 5.7%; 4-6 days: 9.4%; 7-10 days: 12.7%; 11-14 days: 13.9%; 15-32 days: 21.5%) 7

Small or asymptomatic subdural hematomas should be managed conservatively while treating the CSF leak 8
Symptomatic hematomas with significant mass effect may need burr hole drainage 8

The risk of "ultraearly rebleeding" (within 24 hours of initial SAH) may be 15%, which is considerably higher than previously recognized, with high mortality rates 9
70% of ultraearly rebleeds occur within 2 hours of initial SAH 9
In patients with ventriculostomy, early treatment of the ruptured aneurysm should follow to minimize rebleeding risk 9

For patients with cerebral venous thrombosis in the context of SAH, epidural blood patch should be prioritized as initial treatment, with consideration of anticoagulation on an individual basis 8
For patients with superficial siderosis, MRI of the brain and spine with blood-sensitive sequences should be performed 8
Patients with SAH who develop ataxia, hearing loss, or myelopathic features should be evaluated for superficial siderosis 8