Treatment of Central Fever
For central fever—a diagnosis of exclusion after ruling out infectious and inflammatory causes—symptomatic treatment with antipyretic medications (acetaminophen or ibuprofen) is recommended over non-pharmacologic cooling methods, though routine antipyretic use solely for temperature reduction does not improve mortality in critically ill patients. 1, 2
Diagnostic Confirmation Required First
Before treating presumed central fever, you must systematically exclude other causes:
- Obtain chest radiograph for all ICU patients with new fever 1, 2
- Collect at least two sets of blood cultures (60 mL total); if central venous catheter present, obtain simultaneous central and peripheral cultures 1
- Consider CT imaging for patients with recent thoracic, abdominal, or pelvic surgery 1, 2
- Evaluate for lumbar puncture if neurological symptoms present and not contraindicated 1
Central fever is defined as core temperature >37.5°C driven by neurological dysregulation without evidence of sepsis or clinically significant inflammatory processes, and should only be diagnosed after this workup is negative. 1
Pharmacologic Treatment Approach
First-Line Antipyretic Therapy
When patients desire symptomatic relief, use antipyretic medications rather than non-pharmacologic cooling:
- Acetaminophen is a pain reliever/fever reducer that can be used for symptomatic management 3
- Ibuprofen is an alternative option, though it has important precautions regarding its anti-inflammatory effects potentially masking diagnostic signs 4
- Dosing for ibuprofen: When used for fever in general contexts, 0.2 g orally per dose, can be repeated every 4-6 hours but no more than 4 times in 24 hours 5
Critical Considerations for Treatment Decisions
Do NOT routinely use antipyretics solely to reduce temperature numbers in critically ill patients, as this approach has not been shown to improve 28-day mortality, hospital mortality, or shock reversal in non-neurocritically ill patients. 1, 2
However, in patients with neurological conditions, uncontrolled neurogenic fever can precipitate secondary brain injury, making prompt fever treatment more important. 1 For patients with acute ischemic stroke specifically, prompt fever treatment is recommended to prevent worse outcomes. 5, 1
Temperature Monitoring Strategy
Use the most accurate monitoring method available:
- Preferred: Central temperature monitoring (pulmonary artery catheters, bladder catheters, or esophageal thermistors) 1, 2, 6
- When central monitoring unavailable: Oral or rectal temperatures are preferred over less reliable axillary or tympanic measurements 1, 2, 6
Important Clinical Pitfalls to Avoid
Do not treat the thermometer reading instead of the patient's symptoms and comfort. 2 The decision to use antipyretics should be based on patient distress and underlying neurological risk, not arbitrary temperature thresholds.
Be aware that certain populations have blunted fever responses: elderly patients and those on immunosuppressive medications may not mount typical fever responses, yet still have serious infections. 1, 6 Monitor for other signs of infection including unexplained hypotension, tachycardia, tachypnea, confusion, leukocytosis, or elevated inflammatory markers. 6
Ibuprofen's anti-inflammatory activity may diminish the utility of fever as a diagnostic sign in detecting complications of presumed noninfectious conditions. 4 This is particularly relevant when central fever diagnosis remains uncertain.
Special Consideration for Neurological Patients
In the neurocritical care population, the balance shifts toward more aggressive fever management because uncontrolled fever can cause secondary brain injury. 1 For these patients, symptomatic treatment with antipyretics is appropriate even though it doesn't improve mortality in general ICU populations, because the mechanism of harm (secondary brain injury) differs from septic patients.