Management and Treatment of Suspected Subarachnoid Hemorrhage
Subarachnoid hemorrhage (SAH) requires urgent evaluation and treatment as the risk of early aneurysm rebleeding is high and associated with very poor outcomes. 1
Diagnosis
SAH is a medical emergency that is frequently misdiagnosed (up to 12% of cases). A high index of suspicion must exist in patients with acute onset of severe headache. 1
Acute diagnostic workup should include noncontrast head CT, which if nondiagnostic, should be followed by lumbar puncture. 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
Proper lumbar puncture technique and interpretation of cerebrospinal fluid (CSF) results are critical, looking specifically for xanthochromia and bilirubin. 1
Digital subtraction angiography (DSA) with 3-dimensional rotational angiography is indicated for detection of aneurysms in patients with SAH and for planning treatment. 1
Initial Management
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. 1
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. 1
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. 1, 2
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
For patients with ruptured aneurysms technically amenable to both endovascular coiling and neurosurgical clipping, endovascular coiling should be considered. 1
Complete obliteration of the aneurysm is recommended whenever possible. 1
Low-volume hospitals (<10 SAH cases per year) should consider early transfer of patients to high-volume centers (>35 SAH cases per year) with experienced cerebrovascular surgeons, endovascular specialists, and multidisciplinary neuro-intensive care services. 1
Management of Complications
SAH-associated acute symptomatic hydrocephalus should be managed by cerebrospinal fluid diversion (external ventricular drainage or lumbar drainage, depending on the clinical scenario). 1
Maintenance of euvolemia and normal circulating blood volume is recommended to prevent delayed cerebral ischemia (DCI). 1
Induction of hypertension is recommended for patients with DCI unless blood pressure is elevated at baseline or cardiac status precludes it. 1
Early identification and targeted treatment of heparin-induced thrombocytopenia and deep venous thrombosis are recommended. 1
Follow-up Care
After any aneurysm repair, immediate cerebrovascular imaging is generally recommended to identify remnants or recurrence of the aneurysm that may require treatment. 1
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. 1
Common Pitfalls and Caveats
Warning leaks or sentinel hemorrhages may occur 2-8 weeks before major rupture, presenting as milder headaches lasting a few days. Recognition of these warning signs is critical as they occur in approximately 20% of patients with aneurysm rupture. 1
The most common diagnostic error is failure to obtain a noncontrast cranial CT. 1
In patients with negative CT but suspected SAH, lumbar puncture must be performed to rule out the diagnosis. 1
Not all SAH is aneurysmal - approximately 15-20% of patients with spontaneous SAH have no aneurysm found on initial angiogram. Management differs based on the pattern of hemorrhage on CT. 3