What is the diagnostic workup and treatment for subarachnoid hemorrhage (SAH)?

From the Guidelines

The diagnostic workup and treatment for subarachnoid hemorrhage (SAH) should begin with immediate evaluation by physicians with expertise in stroke management, and patients should be treated as a medical emergency 1.

Diagnostic Workup

The diagnostic workup for SAH begins with a non-contrast head CT scan, which is highly sensitive if performed within 6 hours of symptom onset 1.

• If the CT is negative but clinical suspicion remains high, a lumbar puncture should be performed to look for xanthochromia or red blood cells in the cerebrospinal fluid 1.
• CT angiography or digital subtraction angiography is then necessary to identify the underlying cause, most commonly a ruptured cerebral aneurysm 1.

Treatment

Treatment starts with stabilization of vital functions, including airway management and blood pressure control (typically maintaining systolic BP between 140-160 mmHg) 1.

• Nimodipine 60mg every 4 hours for 21 days should be administered to prevent vasospasm, as recommended by the American Heart Association/American Stroke Association guidelines 1.
• For aneurysmal SAH, definitive treatment involves securing the aneurysm either by endovascular coiling or surgical clipping, ideally within 24-48 hours 1.
• Patients require close neurological monitoring in an ICU setting for complications such as rebleeding, hydrocephalus (which may require external ventricular drainage), and delayed cerebral ischemia 1.
• Seizure prophylaxis with levetiracetam 500-1000mg twice daily may be considered in the acute phase 1.
• Pain control, deep vein thrombosis prophylaxis, and management of medical complications are also essential components of care 1.

Management Approach

The aggressive management approach is justified by the high mortality (30-50%) and morbidity associated with SAH, with early intervention significantly improving outcomes by preventing rebleeding and managing complications promptly 1.

• The severity of SAH patients should be determined using a validated scale, such as the World Federation of Neurological Surgeons (WFNS), GCS, Hunt and Hess scale (H&H), NIHSS, and the Fisher Scale 1.
• Patients with SAH and negative noninvasive vascular imaging should be considered for further imaging with catheter angiography 1.
• Patients who present within 96 hours of a SAH and have an adequate blood pressure should immediately be started on nimodipine for 14 to 21 days 1.

From the FDA Drug Label

In animal experiments, nimodipine had a greater effect on cerebral arteries than on arteries elsewhere in the body perhaps because it is highly lipophilic, allowing it to cross the blood-brain barrier; concentrations of nimodipine as high as 12. 5 ng/mL have been detected in the cerebrospinal fluid of nimodipine-treated subarachnoid hemorrhage (SAH) patients. Nimodipine has been shown, in 4 randomized, double-blind, placebo-controlled trials, to reduce the severity of neurological deficits resulting from vasospasm in patients who have had a recent subarachnoid hemorrhage (SAH). Nimodipine is indicated for the improvement of neurological outcome by reducing the incidence and severity of ischemic deficits in patients with subarachnoid hemorrhage from ruptured intracranial berry aneurysms regardless of their post-ictus neurological condition (i.e., Hunt and Hess Grades I-V).

The diagnostic workup and treatment for subarachnoid hemorrhage include:

• Diagnosis: The diagnosis of subarachnoid hemorrhage is typically made using a combination of clinical presentation, imaging studies (such as CT or MRI), and laboratory tests.
• Treatment: The treatment of subarachnoid hemorrhage typically involves:
  • Nimodipine: Nimodipine is indicated for the improvement of neurological outcome by reducing the incidence and severity of ischemic deficits in patients with subarachnoid hemorrhage from ruptured intracranial berry aneurysms.
  • Surgical intervention: Surgical intervention, such as clipping or coiling of the aneurysm, may be necessary to prevent further bleeding.
  • Supportive care: Supportive care, such as management of blood pressure, pain, and other symptoms, is also important. The use of nimodipine in the treatment of subarachnoid hemorrhage is supported by clinical trials, which have shown that it can reduce the severity of neurological deficits resulting from vasospasm 2. The dosage and administration of nimodipine for this indication are described in the drug label 2.

From the Research

Diagnostic Workup for Subarachnoid Hemorrhage

• The diagnostic workup for subarachnoid hemorrhage (SAH) typically involves non-contrast computed tomography (CT) as the initial imaging modality 3.
• If the non-contrast CT is negative, a lumbar puncture may be performed to rule out SAH 3.
• CT angiography (CTA) is also commonly used to evaluate patients with non-traumatic SAH, with high sensitivity and specificity for detecting intracranial aneurysms 4.
• The importance of arterial attenuation for the detection of intracranial aneurysms on CTA has been emphasized, with higher attenuation values associated with true positive ruptured aneurysms 4.

Treatment for Subarachnoid Hemorrhage

• The management of patients with SAH should adhere to currently available treatment guidelines, which include admission to high-volume centers, early identification and management of the bleeding source, and evaluation and treatment decision for unsecured aneurysms by a multidisciplinary team 5.
• Patients with SAH should be managed in the neurocritical care unit with oral nimodipine, blood pressure control, euvolemia, and frequent monitoring for neurologic and systemic complications 5.
• Delayed cerebral ischemia secondary to cerebral vasospasm should be treated with induced hypertension and endovascular therapies once confirmed 5.
• Spinal subarachnoid hemorrhage can be due to a ruptured spinal aneurysm, but other underlying causes should also be considered, and management strategies should be tailored to the individual patient 6.

Diagnostic Challenges

• Digital subtraction angiography (DSA) may be necessary to identify vascular pathology in patients with CTA-negative SAH, with a yield of 13% in one study 7.
• The pattern of SAH on imaging may suggest the cause of hemorrhage, with diffuse SAH more likely to be due to aneurysm rupture and perimesencephalic SAH more likely to be due to aneurysm rupture or vasculitis/vasculopathy 7.