From the Guidelines
Subarachnoid hemorrhage (SAH) is a life-threatening condition that requires immediate medical attention at a hospital with neurosurgical capabilities, with the most common cause being a ruptured cerebral aneurysm, accounting for about 85% of cases, and diagnosis involves non-contrast CT scan of the brain, which is highly sensitive within the first 24 hours, as recommended by the 2023 guideline for the management of patients with aneurysmal subarachnoid hemorrhage 1.
Diagnosis and Management
The diagnosis of SAH involves the use of the Ottawa SAH Rule, which serves as a method to screen out individuals with a low likelihood of aSAH, and states that patients who present with a severe headache and meet any of the criteria outlined in the rule may need to undergo additional testing, as directed by the treating physician 1.
- The Ottawa SAH Rule criteria include:
- Age ≥40 y
- Neck pain or stiffness
- Witnessed loss of consciousness
- Onset during exertion
- Thunderclap headache (instantly peaking pain)
- Limited neck flexion on examination
- A non-contrast CT scan of the brain is highly sensitive within the first 24 hours, and if negative but clinical suspicion remains high, a lumbar puncture should be performed to evaluate for xanthochromia, especially in patients presenting > 6 hours from ictus 1.
Treatment
Initial management of SAH includes blood pressure control (targeting systolic BP 140-160 mmHg), pain management, seizure prophylaxis with levetiracetam (500-1000 mg twice daily), and nimodipine (60 mg every 4 hours for 21 days) to prevent vasospasm, as recommended by the 2023 guideline for the management of patients with aneurysmal subarachnoid hemorrhage 1.
- Definitive treatment depends on the cause but typically involves surgical clipping or endovascular coiling of aneurysms.
- Complications include rebleeding, vasospasm, hydrocephalus, and seizures, which require vigilant monitoring in an intensive care setting.
Outcome
Early intervention significantly improves outcomes, as mortality rates remain high at approximately 25-50%, and the use of high-quality CT scanners and fellowship-trained, board-certified neuroradiologists can aid in the diagnosis and management of SAH 1.
From the Research
Definition and Epidemiology
- Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke and a neurologic emergency with substantial morbidity and mortality 2.
- The incidence of SAH has remained stable over the past 30 years, but discharge mortality has decreased due to improved care in specialized neurocritical care units 2.
- Aneurysmal SAH affects six to nine people per 100,000 per year, with a 35% mortality rate and often leaves many with lasting disabilities 3.
Clinical Presentation and Diagnosis
- SAH is a medical emergency that requires early recognition and treatment to prevent secondary brain injury 2.
- The diagnosis of SAH can be challenging, and misdiagnosis can result in devastating consequences 4, 5.
- Clinical decision rules and sensitive computed tomography (CT) have made the diagnosis of SAH easier, but physicians must maintain a high index of suspicion 3.
Management and Treatment
- The management of SAH includes admission to high-volume centers, expeditious identification and treatment of the bleeding source, and management in a neurocritical care unit with enteral nimodipine, blood pressure control, and close monitoring for neurologic and medical complications 2.
- Early repair of the ruptured aneurysm by endovascular coiling or neurosurgical clipping is essential, and coiling is superior to clipping in cases amenable to both treatments 3.
- Nimodipine is the only pharmacologic treatment approved for SAH in most countries, and medical management aims to minimize early brain injury, cerebral edema, hydrocephalus, and medical complications 3.
Complications and Prognosis
- Patients with aneurysmal SAH are at risk for cerebral vasospasm and delayed cerebral ischemia, which are potentially life-threatening complications 2, 6.
- The prognosis of SAH is influenced by early brain injury from the hemorrhage, delayed cerebral ischemia, and medical complications 3.
- Observational studies suggest that outcomes are better when patients are managed in specialized neurologic intensive care units with inter- or multidisciplinary clinical groups 3.