AHA/ASA Releases 2023 Guidelines on Managing Aneurysmal Subarachnoid Hemorrhage

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The American Heart Association/American Stroke Association developed the most up-to-date treatment guidelines on aneurysmal subarachnoid hemorrhage.

The American Heart Association (AHA)/American Stroke Association (ASA) released their most up-to-date treatment guidelines on aneurysmal subarachnoid hemorrhage (aSAH). The full report has been published in the journal Stroke.

Overall, the guidelines include recommendations on how clinicians can adequately manage aSAH in real-world practice.

The multidisciplinary guideline writing group represented the fields of neurocritical care, vascular medicine and surgery, neurological interventional treatment, anesthesiology, rehabilitation, nursing, and the patient community. These experts also represented numerous associations for neurology and neurointervention.

Through June 2022, the group searched literature published since the release of the last AHA/ASA guideline in 2012, and indexed in databases including MEDLINE, PubMed, and the Cochrane Library. They consulted relevant AHA documents as well, and conducted follow-up review of literature through January 2023 that could influence recommendations. They then used a modified Delphi process to reach consensus for each recommendation, and the corresponding ratings for strength of recommendation and level of evidence.

Implementing best practices in response to aSAH requires multidisciplinary care.

The group assigned authorship of each section both to maximize subject-matter expertise and to minimize conflicts of interest posed by industry affiliations. When voting on recommendations, they recused authors as needed to maintain conflict of interest boundaries.

Care Paradigm for aSAH

Implementing best practices in response to aSAH requires multidisciplinary care. Patients should receive timely access to specialized centers that include neurologic critical care units. The guideline emphasized that expert physician and nurse staffing in such centers improves mortality and functional outcomes.

Acute Care

The first 24 hours after presentation with symptoms — typically including a sudden, severe headache — are a clinically important window. Within that time, the care team should carry out initial evaluation, localize any confirmed aSAH, and initiate decisive treatment of the ruptured aneurysm.

When possible, surgical or endovascular intervention to secure the lesion completely is desirable. Rebleeding in the short term carries high risk for mortality or another poor clinical outcome. Experienced interventionists provide key inputs regarding these therapeutic options.

Balancing these decisions on interventional treatment, clinical teams must incorporate patient- and aneurysm-specific variables into the choice of therapy.

In addition, grading scales, among them the Hunt and Hess (HH) and World Federation of Neurosurgical Societies (WFNS) instruments, can inform prognosis and facilitate shared decision making.

Management of aSAH Complications

The guideline describes ICU care bundles to minimize duration of mechanical ventilation, and protect against hospital-acquired pneumonia.

Multiple organ system dysfunction after onset of aSAH portends poor outcomes. In this regard, further care bundles and other protocols are discussed for protection specific to lung injury, fever, electrolyte imbalance, hyperglycemia, venous thromboembolism, and intravascular volume depletion.

Routine antifibrinolytic therapy does not reduce risk of rebleeding or improve functional outcomes, and is not recommended.


Seizures following the onset of aSAH should be treated with antiseizure medication for 7 days. Antiseizure prophylaxis is not recommended, except in selected high-risk patients. Phenytoin is not recommended either for new-onset seizures or for prophylaxis.

Continuous electroencephalography (CEEG) can detect nonconvulsive seizures when neurological examination is inconclusive.

Delayed Cerebral Ischemia

Delayed cerebral ischemia is a common and highly deleterious complication of aSAH.

Clinical nursing expertise is crucial to monitor neurologic status in the context of delayed cerebral ischemia. Imaging studies, including Doppler and computed tomography, similarly require expert interpretation. CEEG and invasive diagnostic procedures for this purpose are recommended chiefly for high-grade aSAH.

Enteral nimodipine administration is encouraged, beginning early in treatment, to prevent vasospasm and delayed cerebral ischemia.

Maintaining adequate blood pressure and blood volume helps limit the effects of delayed cerebral ischemia. However, induced hypervolemia has been found to increase complications, without improving outcomes, and is not recommended. Routine statin and intravenous magnesium also are not recommended in this context.

Follow-Up Care After aSAH Treatment

Perioperative and follow-up cerebrovascular imaging should be performed, to monitor for possible aneurysm rerupture. Current evidence did not support any specific recommendation for timing or duration of follow-up imaging.

Multidisciplinary management should extend to late-stage care, as functional and quality-of-life sequelae are common. Screening should identify post-discharge needs, relevant to physical, emotional, and cognitive deficits. This also should inform post-discharge rehabilitation planning.

The authors acknowledge that much of the evidence base for this guideline derives from populations in well-resourced countries. This may limit generalizability of the guideline along socioeconomic, racial, and ethnic dimensions.

Disclosure: Several study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the authors’ disclosures.


Hoh BL, Ko NU, Amin-Hanjani S, et al. Guideline for the management of patients with aneurysmal subarachnoid hemorrhage: a guideline from the American Heart Association/American Stroke Association. Stroke. Published online May 22, 2023. doi:10.1161/STR.0000000000000436