Subarachnoid Hemorrhage

Background

• Subarachnoid hemorrhage (SAH) is an uncommon type of stroke in which bleeding in the subarachnoid space leads to brain injury, high rates of morbidity, and death.
• SAH is most often caused by head trauma. In the absence of head trauma, the rupture of an intracranial aneurysm is the most common cause (in about 85% of nontraumatic SAH cases). Less frequently, SAH can be idiopathic or be from a variety of other causes.
• The global reported incidence of subarachnoid hemorrhage is 9.1 cases per 100,000 persons/year, with incidence peaking in adults aged 50-60 years old.
• Modifiable risk factors include hypertension, smoking, alcohol abuse, and sympathomimetic drug use such as cocaine.

Evaluation

• Suspect subarachnoid hemorrhage (SAH) with a sudden onset of severe headache (reported in about 70% of patients) (Strong recommendation).
• Other symptoms (with or without headache) may include nausea, vomiting, photophobia, altered consciousness, focal neurologic deficits, and seizures.
• Consider using the Ottawa SAH rule to identify patients with acute nontraumatic headache requiring further investigation.
• For detecting SAH:
  • Urgently perform noncontrast computed tomography (CT) scan as the primary diagnostic tool (Strong recommendation).
  • If noncontrast CT equivocal or negative, perform cerebrospinal fluid (CSF) analysis (Strong recommendation).
  • Consider magnetic resonance imaging (MRI) if the CT scan is inconclusive or cannot be done, but a negative finding with MRI does not obviate the need for cerebrospinal fluid analysis (Weak recommendation).
• After SAH is diagnosed, perform vascular imaging to determine the cause of the hemorrhage (Strong recommendation).
  • Consider initially using noninvasive CT angiography (Weak recommendation).
  • Perform catheter cerebral angiography if CT angiography is inconclusive (Strong recommendation).

Management

• Determine severity with a validated grading scale such as Hunt and Hess or World Federation of Neurological Surgeons scales (Strong recommendation).
• Transfer patient to a comprehensive stroke center if possible (Strong recommendation).
• Conduct regular neurological assessments as part of regular vital sign evaluation using standardized tools, ideally every 1-4 hours until patient is stable according to local protocols (Strong recommendation).
• Closely monitor blood pressure and maintain as normotensive to reduce risk of rebleeding before aneurysm repair (Strong recommendation).
• For aneurysmal subarachnoid hemorrhage
  • Repair aneurysm as soon as possible with goal of complete obliteration (Strong recommendation).
  • Choose endovascular coiling over surgical clipping for aneurysm repair if patient is eligible for both, but base choice on input from multidisciplinary team and characteristics of patient and aneurysm (Strong recommendation).
  • Consider stenting of ruptured aneurysm if less risky options have been excluded (Weak recommendation).
  • Consider urgent evacuation of hematoma if decreased consciousness and large intraparenchymal extension at time aneurysm is secured (Weak recommendation).
  • If aneurysm repair is delayed and patient has increased risk of rebleeding, consider short-term (< 72 hours) therapy with tranexamic acid or aminocaproic acid if not contraindicated (Weak recommendation).
  • After aneurysm repair, perform immediate cerebrovascular imaging to identify remnant or recurrence that may require treatment (Strong recommendation).
• Maintain euvolemia (Strong recommendation).
• Start oral nimodipine 60 mg every 4 hours for 14-21 days if patient presents ≤ 96 hours after SAH onset and has adequate blood pressure (Strong recommendation). Consider regimen of 30 mg every 2 hours if concerns of hypotension.
• Other medications have limited or unclear evidence for efficacy, including magnesium sulfate, antiplatelet agents, endothelin receptor antagonists, statins, and tirilazad.
• Pain management - Recommend treating with acetaminophen (if no liver dysfunction), morphine sulphate, or codeine.
• Elevate head 30 degrees for ≥ 24-48 hours (Strong recommendation).
• Manage acute complications:
  • Cerebral vasospasm and ischemia
    • Consider transcranial Doppler ultrasound daily or every other day to monitor for vasospasm.
    • For cerebral ischemia, induce hypertension unless blood pressure elevated or precluded by cardiac status (Strong recommendation).
    • For symptomatic cerebral vasospasm, consider cerebral balloon angioplasty and/or selective intra-arterial vasodilator therapy (particularly if no response to hypertensive therapy) (Weak recommendation).
  • Hydrocephalus - perform cerebrospinal fluid diversion via external ventricular drainage or lumbar drainage (Strong recommendation).
  • Seizure
    • Consider prophylactic antiseizure medication during immediate post-hemorrhagic period, but note that some organizations recommend against this (Weak recommendation).
    • Consider long-term antiseizure medications if patient at increased risk of seizure disorder such as history of seizure, intracerebral hematoma, intractable hypertension, infarction, or aneurysm at middle cerebral artery (Weak recommendation).
  • Hyponatremia
    • Reported in up to 30% of patients; may be due to syndrome of inappropriate secretion of antidiuretic hormone (SIADH) or cerebral salt wasting.
    • If suspected, consider monitoring volume status by some combination of central venous pressure, pulmonary wedge pressure, and fluid balance (Weak recommendation).
    • Consider crystalloid or colloid fluids for managing volume contraction (Weak recommendation).
    • Consider fludrocortisone acetate and hypertonic saline solution for prevention and correction of hyponatremia (Weak recommendation).
  • Fever - consider aggressive control during acute phase of subarachnoid hemorrhage (Weak recommendation).
  • Elevated blood glucose - consider careful glucose management with strict hypoglycemia avoidance (Weak recommendation).
  • Heparin-induced thrombocytopenia - monitor for early detection and targeted treatment (Strong recommendation).
  • Deep vein thrombosis - provide venous thromboembolism prophylaxis (such as sequential compression devices) and monitor for early detection and targeted treatment (Strong recommendation).
  • Anemia - consider packed red blood cell infusion in patients at risk of cerebral ischemia (Weak recommendation).
  • Neurogenic pulmonary edema
    • Differentiate from cardiogenic pulmonary edema and other common causes of respiratory distress.
    • Perform supportive care.
  • Neurocardiogenic injury - closely monitor for cardiac abnormalities such as prolonged QTc interval, arrhythmias, and stress cardiomyopathy (Takotsubo cardiomyopathy) and manage accordingly.
  • Renal dysfunction - consider renal protection strategies such as adequate hydration, avoiding contrast enhanced imaging if possible, and using caution with nephrotoxic drugs.
• For patients with poor prognosis for neurological recovery:
  • Consider initial course of supportive nonsurgical management (Weak recommendation).
  • Establish goals early after hospital arrival with patient and/or designated decision-maker (Strong recommendation).