From the Guidelines
Yes, fevers can potentially worsen intracranial vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). Fever management is an important component of care in these patients. When fever occurs, prompt treatment with antipyretics such as acetaminophen (650-1000 mg every 4-6 hours, not exceeding 4000 mg daily) is recommended 1. For persistent fevers, physical cooling methods like cooling blankets may be necessary. The relationship between fever and vasospasm stems from several mechanisms: elevated body temperature increases cerebral metabolic demands, potentially worsening ischemia in areas already compromised by vasospasm; fever can trigger inflammatory cascades that may exacerbate vessel narrowing; and hyperthermia can directly affect vascular tone. Additionally, fever often indicates underlying infection, which itself can worsen vasospasm through systemic inflammatory responses. Maintaining normothermia (temperature below 37.5°C) is therefore considered an important goal in aSAH management, alongside other measures like maintaining euvolemia and appropriate blood pressure control to minimize vasospasm risk and its neurological consequences.
Key Considerations
- Fever management is crucial in aSAH patients to prevent worsening of intracranial vasospasm.
- Antipyretics like acetaminophen are recommended for fever treatment.
- Physical cooling methods may be necessary for persistent fevers.
- Maintaining normothermia is essential in aSAH management.
Evidence Summary
The most recent and highest quality study, a guideline from a French expert panel published in 2018 1, suggests considering targeted temperature management (TTM) to lower intracranial pressure (ICP) and/or improve neurological outcome in comatose patients with aneurysmal subarachnoid hemorrhage. This guideline supports the importance of fever management in aSAH patients. Previous studies, including guidelines from the American Heart Association/American Stroke Association 1, also emphasize the need for fever management and maintaining normothermia in aSAH patients.
Clinical Implications
In clinical practice, it is essential to monitor aSAH patients closely for fever and initiate prompt treatment to maintain normothermia. This, combined with other measures like euvolemia and appropriate blood pressure control, can help minimize the risk of intracranial vasospasm and its neurological consequences.
From the Research
Fever and Intracranial Vasospasm in Aneurysmal Subarachnoid Hemorrhage (SAH)
- Fever is a common complication after aneurysmal subarachnoid hemorrhage (SAH) and can worsen neurologic injury 2
- Predictive factors for fever after SAH include anterior communicating artery aneurysm, Hunt and Hess grade, SAH sum score, intraventricular hemorrhage sum score, and body mass index 2
- Fever is an independent risk factor for delayed cerebral ischemia (DCI) and unfavorable outcomes after aneurysmal SAH 2, 3
- The duration and severity of fever are associated with poor functional outcome in patients with aSAH, with early onset of fever and number of hours with fever being significant predictors 3
- Prolonged fever should be avoided, but subfebrile temperatures may not justify intervention 3
Management of Fever and Vasospasm in SAH
- Enteral nimodipine remains the only approved measure to potentially prevent DCI 4
- Other interventions, such as calcium channel blockers, cisternal irrigation, and lumbar cerebrospinal fluid drainage, have shown limited and variable success in preventing vasospasm and DCI 4
- Hypothermia has been used as a last-resort option for SAH patients with intracranial hypertension or cerebral vasospasm resistant to conventional treatment, but it is associated with significant complications 5