What is the recommended emergent management of subarachnoid hemorrhage?

Emergent Management of Subarachnoid Hemorrhage

Secure the ruptured aneurysm as early as possible—ideally within 24 hours—because early rebleeding carries a 70–80% mortality and early treatment is the only proven intervention to prevent this catastrophic complication. 1

Immediate Diagnostic Workup

• Obtain a non-contrast head CT immediately for any patient with sudden severe headache; CT sensitivity is 98–100% within 12 hours but declines to 93% at 24 hours and 57–85% by day 6. 1, 2

• If CT is negative but clinical suspicion remains high, proceed directly to lumbar puncture looking for xanthochromia and elevated bilirubin; spectrophotometric analysis performed >6 hours after onset has 100% sensitivity and 95.2% specificity. 1

• After confirming SAH, perform digital subtraction angiography with 3D rotational imaging to identify the aneurysm and guide treatment planning. 1, 2

• Rapidly assess clinical severity using Hunt-Hess or World Federation of Neurological Surgeons (WFNS) scales, as the initial grade is the strongest predictor of outcome. 1, 2

Blood Pressure Management (Prior to Aneurysm Securing)

• Target systolic blood pressure <160 mmHg using short-acting titratable IV agents (nicardipine or labetalol) while maintaining mean arterial pressure ≥65 mmHg. 1, 2

• Never permit MAP <65 mmHg, as hypotension precipitates cerebral ischemia and worsens outcomes. 1

• Avoid sudden profound drops in blood pressure, which may trigger cerebral ischemia even before the aneurysm is secured. 1

Nimodipine Therapy

• Start oral nimodipine 60 mg every 4 hours immediately (ideally within 96 hours of SAH onset) and continue for 21 consecutive days to reduce delayed cerebral ischemia and improve neurological outcomes. 1, 2, 3

• If the patient cannot swallow, extract capsule contents with an 18-gauge needle into a syringe labeled "Not for IV Use" and administer via nasogastric tube, flushing with 30 mL normal saline. 3

• Nimodipine improves outcomes but does NOT prevent angiographic vasospasm—its benefit is neuroprotective, not vasodilatory. 1, 2

Aneurysm Securing: Timing and Modality

Timing

• Secure the aneurysm within 24 hours whenever feasible; rebleeding risk is highest in the first 2–12 hours (4–13.6% within 24 hours, >33% within 3 hours), and mortality from rebleeding is 70–80%. 1, 2

Choice of Treatment

• For anterior circulation aneurysms amenable to both techniques, endovascular coiling is preferred over surgical clipping because it yields superior 1-year functional outcomes. 1, 2

• For posterior circulation aneurysms, endovascular coiling is strongly favored; it reduces the risk of death or dependency (relative risk 0.41 versus clipping). 1, 2

• For patients with large intraparenchymal hematoma (>50 cm³) who retain spontaneous respiration and pain response, perform emergency surgical clot evacuation combined with aneurysm clipping; this reduces mortality from ~80% to ~27%. 1

• For wide-neck aneurysms not amenable to primary coiling or clipping, stent-assisted coiling or flow-diverter devices are reasonable alternatives. 1

• Do NOT use stents or flow-diverters for ruptured saccular aneurysms that can be treated with primary coiling or clipping, as they require dual antiplatelet therapy and increase hemorrhagic complications (e.g., ventriculostomy-related bleeding). 1

• Aim for complete aneurysm obliteration whenever technically possible; incomplete obliteration markedly raises rebleeding risk and need for retreatment. 1, 2

Management of Acute Hydrocephalus

• Treat acute symptomatic hydrocephalus urgently with cerebrospinal fluid diversion via external ventricular drain or lumbar drain, depending on the clinical scenario. 1, 2

Transfer to Specialized Centers

• Transfer immediately to a high-volume center (>35 SAH cases/year) with dedicated cerebrovascular neurosurgeons, endovascular specialists, and neurocritical care teams. 1, 2

• Treatment decisions should involve a multidisciplinary team comprising both endovascular and microsurgical specialists. 1

Fluid and Hemodynamic Management

• Maintain euvolemia and normal circulating blood volume; prophylactic hypervolemia ("triple-H" therapy) does not improve outcomes and may cause harm. 1, 2

Management of Delayed Cerebral Ischemia (If It Develops)

• If symptomatic delayed cerebral ischemia develops, induce hypertension while maintaining euvolemia, unless baseline blood pressure is already elevated or cardiac status precludes it. 1, 2

• Consider cerebral angioplasty and/or selective intra-arterial vasodilator therapy as adjuncts or alternatives to induced hypertension for refractory vasospasm. 1

Antifibrinolytic Therapy (Limited Role)

• Short-course antifibrinolytics (<72 hours) such as tranexamic acid may be considered ONLY when aneurysm securing is unavoidably delayed, the patient has high rebleeding risk, and no contraindications exist. 1

• The 2023 ULTRA trial showed tranexamic acid does NOT significantly reduce rebleeding rates or improve functional outcomes when aneurysms are secured early, so routine use is not recommended. 1

Supportive Care

• Initiate venous thromboembolism prophylaxis once the aneurysm has been secured. 1

• Use rapid-sequence intubation with adequate pre-oxygenation and meticulous avoidance of blood-pressure swings if airway protection is required. 1

• If the patient is anticoagulated, perform emergent reversal based on clinical judgment. 1

Vascular Imaging Follow-Up

• Obtain immediate post-treatment vascular imaging to detect residual aneurysm or recurrence. 1

• Schedule follow-up vascular imaging at 6 and 18 months; retreatment should be strongly considered for clinically significant growing remnants. 1

Critical Pitfalls to Avoid

• Do NOT delay aneurysm treatment beyond 24 hours when feasible; early rebleeding risk increases progressively and mortality remains 70–80%. 1, 2

• Do NOT employ prophylactic hypervolemia ("triple-H" therapy), which lacks supporting evidence and may be detrimental. 1, 2

• Do NOT use stents or flow-diverters for ruptured saccular aneurysms amenable to primary coiling or clipping due to higher complication risk from required antiplatelet therapy. 1

• Do NOT allow hypotension (MAP <65 mmHg) during blood-pressure management, as it compromises cerebral perfusion. 1

Evidence Base

Nimodipine therapy and endovascular aneurysm repair are the only two interventions with strong supporting evidence for improving outcomes after subarachnoid hemorrhage, based on high-quality randomized controlled trials. 1 All other intensive care strategies lack robust randomized trial data, highlighting the need for vigilant clinical judgment and adherence to these proven interventions. 1