How to manage a fever above 38 degrees?

Management of Fever Above 38°C

For patients with fever above 38°C, antipyretic treatment with ibuprofen (oral, 0.2g every 4-6 hours, maximum 4 times in 24 hours) is recommended when temperature exceeds 38.5°C, with a target of reducing temperature to below 38°C. 1

Initial Assessment of Fever

• Fever is defined as a temperature above 38°C (100.4°F) 1
• Accurate temperature measurement is essential - central temperature monitoring methods (pulmonary artery catheters, bladder catheters, esophageal thermistors) are preferred when available; otherwise, oral or rectal temperatures are recommended over less reliable methods like axillary or tympanic measurements 1
• Evaluate for potential underlying causes of fever, including infections, which may require specific treatment 1
• Consider blood cultures, urine cultures, and chest radiography to rule out infection in febrile patients 1

Pharmacological Management

First-line Treatment:

• When temperature exceeds 38.5°C, administer ibuprofen 0.2g orally every 4-6 hours (maximum 4 doses in 24 hours) 1
• Target temperature reduction to below 38°C, as extremely low body temperature may impair antiviral treatment 1

Alternative Antipyretics:

• Paracetamol (acetaminophen) is an effective alternative, though studies suggest it may be less effective than other NSAIDs at standard doses 2, 3
• Metamizol has shown good antipyretic efficacy but may cause more significant blood pressure reduction compared to paracetamol 2
• Diclofenac has demonstrated effective antipyretic action with longer duration compared to aspirin 4

Special Considerations

Critically Ill Patients:

• Fever in critically ill patients is common and associated with increased ICU length of stay 5
• Consider the balance between reducing metabolic demand (through fever reduction) and preserving host defense mechanisms when deciding to treat fever 5
• In patients with intracerebral hemorrhage, pharmacologically treating elevated temperature may be reasonable to improve functional outcomes 1

Immunotherapy-Related Fever:

• For patients receiving CAR T-cell therapy with fever ≥38°C (Grade 1 CRS):
  • Provide supportive care with antipyretics and IV hydration 1
  • Consider empiric broad-spectrum antibiotics if neutropenic 1
  • For persistent fever >3 days, consider tocilizumab 1

Pediatric Considerations:

• In pediatric patients, fever is defined as temperature ≥38°C 1
• For children with fever due to CAR T-cell therapy, initial management includes antipyretics and careful monitoring for progression to higher-grade CRS 1

Supportive Care Measures

• Ensure adequate hydration and electrolyte balance 1
• Monitor vital signs regularly, especially in critically ill patients 1
• For patients with significant symptoms or comorbidities, more aggressive fever management may be warranted 1

Common Pitfalls to Avoid

• Don't treat fever too aggressively in all cases, as fever may play a beneficial role in fighting infection 5
• Avoid missing underlying serious infections that require specific treatment beyond antipyretics 1
• Be aware that antipyretics can mask symptoms of worsening infection without addressing the underlying cause 1
• Consider the hemodynamic effects of different antipyretics - NSAIDs and metamizol may cause more significant blood pressure reduction than paracetamol 2