How should temperature be managed in a patient with aspirin (acetylsalicylic acid) overdose?

Management of Temperature in Aspirin (Acetylsalicylic Acid) Overdose

In patients with aspirin overdose, fever should be treated promptly with acetaminophen to reduce morbidity and mortality, as hyperthermia exacerbates salicylate toxicity and can worsen outcomes. 1

Pathophysiology of Temperature Disturbances in Aspirin Overdose

Aspirin overdose commonly causes temperature abnormalities through several mechanisms:

• Uncoupling of oxidative phosphorylation leading to increased metabolic rate
• Direct stimulation of the temperature regulation center in the hypothalamus
• Increased metabolic demands and oxygen consumption
• Enhanced release of neurotransmitters and free radical production

Temperature Management Approach

Initial Assessment

• Monitor core body temperature continuously in all aspirin overdose patients
• Assess for signs of hyperthermia (temperature >38°C/100.4°F)
• Recognize that even modest temperature elevations (>37.5°C/99.5°F) can worsen outcomes

Treatment Algorithm

1. For temperature ≥37.5°C (99.5°F):

   • Initiate acetaminophen 650-1000mg every 4-6 hours (maximum 4000mg/day) 1
   • Avoid NSAIDs including ibuprofen as they may antagonize aspirin's antiplatelet effects and worsen toxicity 1
   • Monitor temperature response within 1 hour of intervention

2. For persistent hyperthermia despite acetaminophen:

   • Add external cooling measures (cooling blankets, ice packs to axilla/groin)
   • Consider more aggressive cooling if temperature remains >38.5°C (101.3°F)
   • Evaluate for other causes of fever (infection, serotonin syndrome)

3. For severe hyperthermia (>40°C/104°F):

   • Consider transfer to ICU for advanced temperature management
   • Implement surface or intravascular cooling devices if available
   • Maintain normothermia (36.5-37.5°C/97.7-99.5°F)

Special Considerations

• Avoid aspirin for fever management in aspirin overdose patients as this would worsen toxicity 1
• Temperature management should be integrated with other critical interventions:
  • Fluid resuscitation and correction of electrolyte abnormalities
  • Alkalization of urine (target urine pH >7.5) to enhance salicylate elimination
  • Consideration of hemodialysis for severe toxicity 2
• Monitor for signs of acetaminophen toxicity if multiple doses are required, especially in patients with liver dysfunction

Monitoring Response

• Continuous temperature monitoring until normothermia is established for at least 24 hours
• Serial vital signs including respiratory rate (to detect respiratory alkalosis)
• Arterial blood gases to monitor acid-base status
• Serum salicylate levels to track elimination

Common Pitfalls to Avoid

• Failing to recognize fever as a significant factor in aspirin toxicity morbidity
• Using NSAIDs for temperature control, which may worsen toxicity
• Overlooking the need for aggressive temperature management in moderate-to-severe overdose
• Focusing solely on temperature without addressing other aspects of aspirin toxicity management
• Delaying acetaminophen administration when temperature begins to rise

Temperature management is just one component of comprehensive aspirin overdose management, but addressing hyperthermia promptly can significantly improve patient outcomes by reducing metabolic demands and preventing further neurological injury 1.