Heat Injury

Heat injury is a pathological rise of core body temperature to unsafe levels, and is graded by severity into:

This covers environmental heat injury. Hyperthermia is covered under Fever and Hyperthermia.

Epidemiology and Risk Factors

Pathophysiology

Aetiology

Causes include:

  • Environmental hyperthermia
    Usually combination of:
    • High ambient temperatures
    • Physical workload
    • Unacclimatised
  • Endocrine
    • Thyrotoxicosis
    • Phaeochromocytoma
  • Drug induced
    • Malignant hyperthermia
    • Neuroleptic malignant syndrome
    • Serotonin syndrome
    • Sympthomimetic toxicity
    • MAO-I toxicity
    • Anticholinergic toxicity
    • Salicylate toxicity
  • Drug withdrawal
    • Alcohol
    • Benzodiazepines
    • Baclofen

Clinical Features

Diagnostic Approach and DDx

Investigations

Bedside:

Laboratory:

Imaging:

Other:

Management

  • Rapid temperature ↓ to <38°C

Resuscitation:

A detailed comparison of cooling methods is provided under Fever and Hyperthermia.

  • C
    • Fluid resuscitation
    • Use cool saline
  • E
    • Cooling
      • Shaded area
      • ↓ Activity
      • Active external cooling
        • Ice-water immersion
        • Fans

Specific therapy:

Supportive care:

Disposition:

Preventative:

Marginal and Ineffective Therapies

Anaesthetic Considerations

Complications

  • C
    • Shock
      Distributive and hypovolaemic.

Prognosis

Key Studies

References

  1. Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.