How is central fever managed?

Management of Central Fever

Central fever should be managed by first excluding all infectious and non-infectious causes through systematic diagnostic workup, then treating with antipyretic medications for symptomatic relief while avoiding routine temperature reduction in the absence of neurological injury. 1, 2

Diagnostic Approach: Rule Out Other Causes First

Central fever is a diagnosis of exclusion that requires thorough investigation before attribution to neurological dysregulation. 1, 3

Initial diagnostic workup must include:

• Chest radiograph for all ICU patients with new fever, as pneumonia is the most common infection causing fever in ICU patients 4, 1
• Blood cultures (at least two sets, 60 mL total) to identify bacteremia 1, 2
• Simultaneous central and peripheral blood cultures if a central venous catheter is present 1
• CT imaging for patients with recent thoracic, abdominal, or pelvic surgery if initial workup is unrevealing 4, 1, 2
• Lumbar puncture if altered consciousness or focal neurologic signs are unexplained and not contraindicated 4, 1, 2

Key diagnostic features suggesting central fever:

• Onset within 72 hours of ICU admission (odds ratio 2.20 for central fever) 5
• Persistent temperature elevation without cyclic pattern 1, 6
• Diagnosis of subarachnoid hemorrhage, intraventricular hemorrhage, or tumor (odds ratio 6.33) 5
• Absence of infiltrate on chest radiograph (odds ratio 3.02) 5
• Recent blood transfusion (odds ratio 3.06) 5
• Negative cultures combined with the above features predicts central fever with 90% probability 5

Temperature Monitoring

Use central temperature monitoring methods when available including pulmonary artery catheter thermistors, bladder catheters, or esophageal balloon thermistors, as these are most accurate for diagnosis and management. 4, 1, 2

When central monitoring is unavailable, use oral or rectal temperatures rather than axillary, tympanic membrane, temporal artery, or chemical dot thermometers, which are unreliable in critically ill patients. 4, 1, 2

Pharmacologic Management

Standard Antipyretic Therapy

For patients who desire symptomatic relief or comfort, use antipyretic medications (acetaminophen or NSAIDs) rather than non-pharmacologic cooling methods. 4, 1, 2

Avoid routine use of antipyretics solely for temperature reduction in critically ill patients without neurological injury, as fever management does not improve 28-day mortality, hospital mortality, or shock reversal. 4, 1

Special Considerations for Neurological Injury

For patients with acute neurological injury (stroke, traumatic brain injury, subarachnoid hemorrhage), aggressively treat fever to normal levels (target 36.0-37.5°C) with antipyretics, as uncontrolled neurogenic fever precipitates secondary brain injury through increased intracranial pressure and metabolic demands. 1, 2, 6

Do not delay antipyretic treatment while searching for fever source in neurologically injured patients, as fever duration correlates with worse outcomes. 2

Refractory Central Fever

When standard antipyretics fail, consider pharmacologic agents with anecdotal evidence:

• Propranolol 20-30 mg every 6 hours, which reduced temperatures by at least 1.5°C within 48 hours in traumatic brain injury patients with autonomic dysfunction 7, 8
• Bromocriptine (dosing varies in case reports) 7
• Baclofen (dosing varies in case reports) 7

These agents lack definitive dosing strategies or randomized trial evidence but have demonstrated ability to restore normothermia in case reports. 7

For severe refractory cases, utilize automated feedback-controlled temperature management devices to maintain temperature with minimal variation (≤±0.5°C per hour, ≤1°C per 24 hours). 2

Critical Pitfalls to Avoid

Never diagnose central fever without excluding infection first, as approximately 50% of fevers in ICU patients are infectious, and delayed antibiotic treatment increases mortality. 4, 3, 9

Do not assume absence of fever excludes infection in elderly patients or those on immunosuppressive medications, as these populations may have blunted fever responses. 1

Recognize that temperatures >38.9°C (102°F) are more likely infectious rather than central in origin. 9

All management of central fever in neurologically injured patients should occur in ICU settings given the acuity, frequent intracranial pressure elevations, and need for intensive monitoring. 2