What are the guidelines for managing Subarachnoid Hemorrhage (SAH)?

Management of Aneurysmal Subarachnoid Hemorrhage

Initial Recognition and Transfer

Aneurysmal subarachnoid hemorrhage is a medical emergency requiring immediate recognition and transfer to a high-volume neurovascular center with multidisciplinary capabilities. 1, 2

• Maintain high clinical suspicion in any patient presenting with acute onset of severe headache, as misdiagnosis occurs in up to 12% of cases 1, 2
• Rapidly assess clinical severity using validated scales (Hunt and Hess or World Federation of Neurological Surgeons), as this is the most useful predictor of outcome 1, 2
• Transfer urgently to centers with experienced cerebrovascular surgeons, endovascular specialists, and neurocritical care services 1

Diagnostic Workup

• Obtain noncontrast head CT immediately, which has 98-100% sensitivity within the first 12 hours (declining to 93% at 24 hours and 57-85% by day 6) 2
• If CT is nondiagnostic but clinical suspicion remains high, perform lumbar puncture looking specifically for xanthochromia and bilirubin 2

Blood Pressure Management

• Control blood pressure with a titratable agent between symptom onset and aneurysm obliteration to balance the competing risks of rebleeding versus maintaining cerebral perfusion pressure 1, 2
• Avoid administration of large volumes of hypotonic fluids and intravascular volume contraction 3

Aneurysm Securement

Perform surgical clipping or endovascular coiling as early as feasible to reduce rebleeding risk, with endovascular coiling preferred for aneurysms amenable to both techniques. 1, 2

• For posterior circulation aneurysms specifically, coiling is preferred over clipping to improve outcomes 4
• Complete obliteration of the aneurysm is the goal whenever possible 1, 2, 4
• For incomplete obliteration, partial treatment securing the rupture site during the acute phase is reasonable, with retreatment planned in 1-3 months 4
• Note that the risk of ultraearly rebleeding (within 24 hours) may be as high as 15%, with 70% occurring within 2 hours of initial hemorrhage 2

Prevention of Delayed Cerebral Ischemia

Administer oral nimodipine 60 mg every 4 hours for 21 consecutive days to all patients with aSAH, starting within 96 hours of hemorrhage onset. 1, 2, 5

• Nimodipine improves neurological outcomes though it does not prevent angiographic vasospasm 5
• If the patient cannot swallow, extract capsule contents using an 18-gauge needle into a syringe labeled "Not for IV Use" and administer via nasogastric tube, followed by 30 mL normal saline flush 5
• Never administer nimodipine intravenously or by other parenteral routes, as this can cause life-threatening hypotension 5
• Maintain euvolemia and normal circulating blood volume to prevent delayed cerebral ischemia; hypervolemia is potentially harmful and associated with excess morbidity 3, 1, 2
• Monitor volume status in high-risk patients using central venous pressure, pulmonary wedge pressure, and fluid balance, treating volume contraction with crystalloid or colloid fluids 3

Management of Symptomatic Vasospasm

• Induce hypertension for patients with delayed cerebral ischemia unless blood pressure is already elevated at baseline or cardiac status precludes it 1, 2
• Consider transluminal angioplasty for vasospasm refractory to medical management 6

Hydrocephalus Management

• Manage acute symptomatic hydrocephalus with cerebrospinal fluid diversion via external ventricular drainage or lumbar drainage depending on the clinical scenario 1, 2, 4
• Chronic symptomatic hydrocephalus requires permanent cerebrospinal fluid diversion 4

Seizure Management

• Prophylactic anticonvulsants may be considered in the immediate posthemorrhagic period (incidence of seizures ranges from 6-18%) 3, 4
• Do not use routine long-term prophylactic anticonvulsants, as they are associated with worse cognitive outcomes 3
• Consider prophylaxis for patients with specific risk factors: prior seizure, intracerebral hematoma, intractable hypertension, infarction, or middle cerebral artery aneurysm 3, 4
• Note that endovascular coiling is associated with lower seizure incidence compared to surgical clipping 3, 4

Medical Complications Management

• Aggressively control fever to normothermia using standard or advanced temperature modulating systems 3, 1
• Manage glucose carefully with strict avoidance of hypoglycemia 3, 1
• Use fludrocortisone acetate and hypertonic saline to prevent and correct hyponatremia 3
• Consider packed red blood cell transfusion for anemia in patients at risk of cerebral ischemia, though the optimal hemoglobin goal remains undetermined and transfusions have been associated with worse outcomes in some series 3, 1
• Implement early identification and targeted treatment of heparin-induced thrombocytopenia and deep venous thrombosis 3, 1
• For patients requiring mechanical ventilation >24 hours, implement a standardized ICU care bundle to reduce duration of mechanical ventilation and hospital-acquired pneumonia 1

Follow-up Imaging

• Obtain immediate cerebrovascular imaging after aneurysm repair to identify remnants or recurrence requiring treatment 2
• Perform delayed follow-up vascular imaging in patients who undergo coiling or clipping, with consideration for retreatment if clinically significant remnant is present 2

Critical Pitfalls to Avoid

• Delayed diagnosis significantly increases mortality and morbidity 1
• Avoid rapid lowering of intracranial pressure, which increases rebleeding risk 7
• Do not routinely perform fenestration of the lamina terminalis, as it does not reduce shunt-dependent hydrocephalus 3
• Avoid grapefruit juice in patients taking nimodipine due to drug interactions 5
• Reduce nimodipine dose to 30 mg every 4 hours in patients with severely disturbed liver function or cirrhosis due to increased bioavailability 5