From the Guidelines
Neurogenic fevers following cardiac arrest are primarily caused by damage to the hypothalamus, which regulates body temperature, during the global ischemia of cardiac arrest, disrupting normal thermoregulatory mechanisms and leading to hyperthermia. The management of neurogenic fever should prioritize a stepwise approach, starting with ruling out infectious causes through appropriate cultures and imaging before attributing fever to neurologic injury 1.
Causes of Neurogenic Fever
- Damage to the hypothalamus during cardiac arrest
- Disruption of normal thermoregulatory mechanisms
- Global ischemia affecting the brain's temperature regulation centers
Management Approach
- Rule out infectious causes
- Use acetaminophen (650-1000mg every 6 hours) as the first-line agent for temperature control
- Consider adding a cooling blanket or other external cooling devices if acetaminophen is ineffective
- For refractory cases, consider advanced pharmacologic options such as scheduled NSAIDs like ibuprofen (400-600mg every 6 hours) or targeted temperature management (33-36°C) for 24-48 hours in the ICU setting 1
Important Considerations
- Avoid aggressive cooling below 33°C as this may worsen outcomes
- Regular neurological assessments should continue throughout fever management
- The approach should be adjusted based on the patient's clinical response and overall condition
- Active prevention of fever for at least 72 hours in post–cardiac arrest patients who remain comatose is suggested 1
From the Research
Causes of Neurogenic Fever Following Cardiac Arrest
The exact causes of neurogenic fever following cardiac arrest are not explicitly stated in the provided studies. However, the studies suggest that:
- Fever or hyperthermia during the first few days after cardiac arrest is associated with worse outcomes 2, 3, 4, 5
- Higher temperatures can lead to secondary brain injury by increasing seizures, brain edema, and metabolic demand 5
- Hypoxic-ischemic brain injury (HIBI) is a major cause of death after cardiac arrest, and temperature control may mitigate HIBI 4
Temperature Management After Cardiac Arrest
The studies recommend:
- Actively preventing fever by targeting a temperature of 37.5 °C or less for comatose patients after cardiac arrest 3
- Controlling temperature to prevent hyperthermia, as higher temperatures can lead to secondary brain injury 5
- Monitoring core temperature and actively preventing fever (37.7 °C) for at least 72 hours in patients who are comatose after resuscitation from cardiac arrest 4
Key Findings
- The Targeted Temperature Management 2 (TTM-2) trial documented no difference in 6-month mortality among comatose postcardiac arrest patients managed at 33 °C vs. targeted normothermia 3
- A systematic review and meta-analysis concluded that temperature control with a target of 32-34 °C did not improve survival or favorable functional outcome after cardiac arrest 3
- The International Liaison Committee on Resuscitation currently recommends monitoring core temperature and actively preventing fever for at least 72 hours in patients who are comatose after resuscitation from cardiac arrest 4