Smoke inhalation injury

Background

  • 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
    • Pulmonary edema, bronchorrhea, bronchospasm, VQ mismatch which can cause hypoxemia
    • Tearing, conjunctivitis
  • 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 arrythmias
    • Delayed onset (2-12 hours) pulmonary edema
    • Dypsnea, chest pain
  • Tuolene diisocyanate: seat cushions, carpet, insulation
    • Severe bronchospasm
  • Nitrogen dioxide: fires involving automobiles, agrecultural waste
    • Uncommon but brief exposure can be lethal
    • Severe bronchospasm, laryngospasm, pulmonary edema
    • Later: interstitial lung disease

Systemic chemical injury

Differential Diagnosis

Burns

Evaluation

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

Management

AIRWAY

  • 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!

Disposition

See Also

External Links

References