Inhalation exposure

Background

  • Inhalational injury a concern with history of being trapped in enclosed space for some time with toxic gases / fumes

Clinical Features

  • Initial signs/symptoms - coughing, wheezing, dyspnea, irritated mucous members (runny eyes/nose), chest pain, hypoxia
  • Specific features dependent on type of exposure

Inert Gases

  • Inert gases (carbon dioxise, fuel gases) displace air and oxygen producing asphyxia
  • Present with severe hypoxia

Irritant Gases

  • Irritant gases (ammonia, formaldehyde, chlorine, nitrogen dioxide) when dissolved in water lining respiratory tract produce a chemical burn and inflammatory response
  • More soluble the gas produces more upper airway burns/irritation symptoms
  • Less soluble gases produce more pulmonary injury and respiratory distress

Systemic Toxins

  • Includes carbon monoxide, hydrogen cyanide, hydrogen sulfide
  • Interfere with delivery of oxygen for use in cellular energy production
  • Liver, kidney, brain, lung and other organ damage

Allergic

  • Inhaled gases, particles, aerosols
  • Produce bronchospasms and edema similar to asthma

Smoke Inhalation / Thermal

  • Most fatalities from burn injuries are attributed to smoke inhalation
  • Soot in posterior pharynx, singed nasal hair
  • Hyperacute - severe wheezing, bronchoconstriction, significant hypoxemia
  • Acute pulmonary edema - onset at 48-72 hours post injury in a previously asymptomatic patient
  • Bronchopneumonia often at 10 days post-inury

Differential Diagnosis

Inhalation exposure

Terrorism
Unintentional

Evaluation

  • Look for evidence of exposure
    • Estimated time of exposure
    • Open or enclosed space
    • Associated events such as fire, blast, etc.?
    • Is the exposure known?
    • Material on patient? Does patient smell of chemical?
Examples - smoke inhalation from burning building, leak of a solvent, chemical fumes
  • Physical examination with focus on airway and pulmonary system
  • Observe of evidence of airway compromise or respiratory distress

Management

General

  • Separate patient from fumes/toxic agent
  • Decontaminate if not done on scene
  • Secure airway if necessary and ventilate
  • Oxygen at 6-12 liters per minute via mask
  • Chest x-ray, pulse oximetry, arterial blood gases
  • Consider carboxyhemoglobin level or cyanide level if any suspicion based on history
  • Observe for respiratory distress and airway compromise

Inert Gases

  • Remove victim from the gas
  • Fresh air or oxygen
  • Observe for sequelae from hypoxia (myocardial infarction, cerebral injury)

Allergic

  • Aerosolized bronchodilators
  • Corticosteroids in patients with history of reactive airway disease

Smoke Inhalation / Thermals

  • Ensure adequate oxygenation, ventilation, pulmonary toilet and fluid resuscitation

Disposition

  • 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

External Links

Video

[[Category:WikEM]]

References