Inhalation injury
(Redirected from Inhalation exposure)
Background
- Inhalational injury a concern with history of being trapped in enclosed space for some time with toxic gases / fumes
Clinical Features
General
- Initial signs/symptoms - cough, wheezing, dyspnea, irritated mucous members (runny eyes/nose), chest pain, hypoxia
- Specific features dependent on type of exposure
Inert Gases
- Inert gases (carbon dioxide, 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-injury
Differential Diagnosis
Inhalation injury
- Unintentional
- Terrorism
- Pulmonary chemical agents
- Ammonia
- Methyl isocyanate
- methyl bromide
- Hydrochloric acid
- Chlorine
- Phosgene
- Bioterrorism
Burns
- Smoke inhalation injury (airway compromise)
- Chemical injury
- Acrolein
- Hydrochloric acid
- Tuolene diisocyanate
- Nitrogen dioxide
- Systemic chemical injury
- Specific types of burns
- Associated toxicities
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 for evidence of airway compromise or respiratory distress
- Chest x-ray, pulse oximetry, arterial blood gas
- Consider carboxyhemoglobin and/or cyanide level if any suspicion based on history
Management
General
- Separate patient from fumes/toxic agent
- Decontaminate if not done on scene
- Secure airway if necessary and ventilate, observe for respiratory distress and airway compromise
- Oxygen at 6-12 liters per minute via mask
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