Causes of Fever

Key Features

• Morbidity and mortality increase with age and comborbidities
• Most common sources in elderly: respiratory, genitourinary, skin/soft-tissue
• Atypical presentations: functional decline, altered mental status

Immediate Evaluation and Management

• Critical Findings
  • Altered mental status
  • Respiratory distress
  • Hemodynamic instability
• Critical Interventions
  • Airway management, supplemental O2
  • Cardiac monitoring
  • Fluid resuscitation
  • Empiric antibiotics
  • Cooling measures (T>41.0°C)

Pathophysiology of Fever

Production of endogenous or exogenous pyrogens

Increase temperature set point in hypothalamus

Patient experiences chills when core temperature < set point

Vasoconstriction, shivering causes fever

Patient experiences euthermia, though may feel malaise, fatigue

Resolution

Patient experiences sweats until core temperature returns to normal set point

References

1. Blum, F., & Biros, M. (2013). Fever in the Adult Patient. In Rosen’s Emergency Medicine – Concepts and Clinical Practice (8th ed., Vol. 1, pp. 119-123). Elsevier Health Sciences.