Smoke inhalation injury


  • Main cause of mortality in fire-related death
  • Associated with closed-space fires, especially when patient has decreased mental status (e.g. substance use, head injury)
  • Thermal injury:
    • Due to inhaling superheated gases in an enclosed space
    • Direct thermal trauma and associated edema usually limited to upper airway, but lower respiratory tract may be injured if steam inhaled
  • Chemical injury:
    • Direct toxicity to airways and lung parenchyma from noxious chemicals combusted

Clinical Features

Thermal injury

  • Soot around nares or in mouth
  • Carbonaceous sputum
  • Singed nasal or facial hair
  • Dyspnea, stridor, drooling, dysphonia, respiratory distress

Chemical injury

Varies depending on substance burned in fire

  • Acrolein: found in wood and petroleum
  • Hydrochloric acid: product of polyvinyl chloride (structural component of high-rise buildings, plastics) combustion.
    • Can persist in air up to an hour after fire extinguished
    • PVCs and other arrhythmias
    • Delayed onset (2-12 hours) pulmonary edema
    • Dyspnea, chest pain
  • Tuolene diisocyanate: seat cushions, carpet, insulation
    • Severe bronchospasm
  • Nitrogen dioxide: fires involving automobiles, agrecultural waste

Systemic chemical injury

Differential Diagnosis


Inhalation injury



  • Assess ABCs, burns resuscitation
  • ABG or VBG, carboxyhemoglobin
  • ECG, monitor on telemetry
  • Chest x-ray
  • Low threshold for direct or video laryngoscopy, fiberoptic airway eval



  • Intubate if:
    • Respiratory distress, respiratory depression, or altered mental status
    • Progressive hoarseness
    • Supraglottic or laryngeal edema/inflammation on bronchoscopy or NPL
    • Full thickness burns to face or perioral region
    • Circumferential neck burns
    • Major burns over 40-60% of body surface area

Remember, the intubation will only get more difficult as edema worsens!


  • Respiratory distress or airway compromise will need admission
  • Observe for 1-4 hours if no signs or symptoms of inhalation injury develop or if all resolved within 1 hour consider discharging patient home with instructions for return for re-evaluation next day or sooner if pulmonary and/or airway symptoms develop

See Also


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