What is the best next step for a patient with a high fever?

Management of High Fever in Patients

For patients with high fever, the best next step is to identify the underlying cause through diagnostic workup while providing supportive care, with antipyretic medications used selectively rather than routinely.

Initial Assessment and Diagnostic Approach

When encountering a patient with high fever, a systematic approach is essential:

1. Assess vital signs and clinical stability

   • Evaluate for signs of hemodynamic instability, respiratory distress, or altered mental status
   • Check temperature using reliable methods (central temperature monitoring preferred when available; otherwise oral or rectal temperatures) 1

2. Diagnostic workup (in order of priority):

   • Chest radiograph - recommended as first-line investigation for all febrile patients without obvious source 1
   • Blood cultures - collect at least two sets (ideally 60 mL total) from different anatomical sites 1
   • If patient has central venous catheter, draw simultaneous central and peripheral blood cultures 1
   • Additional testing based on clinical presentation:
     • For recent surgical patients: CT imaging of operative area if fever occurs days after surgery 1
     • For suspected urinary source: Replace urinary catheter and obtain cultures from newly placed catheter 1
     • For respiratory symptoms: Consider viral nucleic acid testing 1

Fever Management Approach

Antipyretic Therapy

Current guidelines suggest avoiding routine use of antipyretic medications solely to reduce temperature in critically ill patients (weak recommendation, moderate quality evidence) 1. This represents a shift from traditional practice of automatically treating all fevers.

Consider antipyretics in these specific scenarios:

• For patient comfort when fever causes distress 1
• In patients with limited physiologic reserves where metabolic demands of fever may be harmful 1, 2
• For patients with COVID-19 who have fever and other symptoms that would benefit from antipyretics (paracetamol/acetaminophen preferred) 1

Non-pharmacological Cooling Methods

• External cooling methods are generally less effective and less comfortable than antipyretics for fever management 3, 4
• Physical cooling methods may be considered in:
  • Hyperthermia syndromes (not typical fever)
  • Marked hyperpyrexia
  • Selected populations with neurologic impairment 5

Special Considerations for Specific Patient Populations

Stroke Patients

• Fever after stroke is associated with increased morbidity and mortality 1
• The source of fever should be identified and treated with antipyretics 1
• Consider more aggressive cooling measures for patients with severe stroke events 1

COVID-19 Patients

• Advise adequate fluid intake (no more than 2 liters per day) 1
• Use paracetamol/acetaminophen for symptomatic relief rather than NSAIDs 1
• For cough management, consider simple measures first (honey for patients >1 year old) before considering medications 1

Critically Ill Patients

• Cooling febrile critically ill patients can reduce oxygen consumption (VO₂) from 359.0 ± 65.0 to 295.1 ± 57.3 ml/min and decrease cardiac output from 8.4 ± 3.2 to 6.5 ± 1.8 L/min 2
• This cardiorespiratory unloading may benefit patients with limited oxygen delivery or respiratory failure 2

Common Pitfalls to Avoid

1. Overtreatment of fever - Remember that fever is an adaptive response to infection, and routine suppression may be harmful 5

2. Inadequate diagnostic workup - Don't treat the fever without identifying the source

3. Relying on unreliable temperature measurements - Avoid axillary, tympanic membrane, temporal artery, or chemical dot thermometers when accurate measurements are critical 1

4. Overlooking non-infectious causes of fever - Consider drug reactions, thromboembolism, tissue injury, and other non-infectious etiologies

5. Delaying antibiotics in suspected serious infection - While identifying the source is important, don't delay empiric antibiotics when serious infection is suspected

By following this approach, you can effectively manage patients with high fever while addressing the underlying cause and providing appropriate supportive care.