INHALATION INJURY

Smoke inhalation injury is mediated by inhaled toxic gases and carbonaceous particles (soot).

- Risk factors for inhalation injury include burns sustained in an enclosed space (structure, vehicle, or shipboard fires); extensive TBSA; flame burns of the face; and extremes of age.
- Inhalation injury is associated with a higher mortality, especially in burn wounds with >40% TBSA.
- Clinical signs include progressive voice changes, soot about the mouth and nares, dyspnea, and respiratory distress. Hypoxemia may be a late finding. (See Initial Burn Survey for airway management recommendations). If available, bronchoscopy should be used to confirm diagnosis, grade injury severity, and lavage for debris removal.
- Patients diagnosed with inhalation injury should receive aerosolized unfractionated heparin, 5000 units per ETT every 4 hours; mix heparin with albuterol, as heparin can induce bronchospasm.

Carbon monoxide (CO) toxicity include those exposed to smoke from burning hydrocarbons (e.g., vehicle or generator exhaust) or cellulose-containing materials (wood, paper, charcoal).

- Symptoms of CO toxicity include confusion, stupor, coma, seizures, and cardiac ischemia.
- Treatment: Administer 100% oxygen and measure carboxyhemoglobin levels via co-oximetry if available.

Cyanide is encountered in fires involving certain nitrogen-containing materials such as polyurethane. Initial symptoms include dizziness, headache, nausea, and anxiety.

- High-dose exposure causes rapid onset of coma, seizure, respiratory depression, hypotension, and tachycardia. Lactate levels > 8 mmol/L suggest cyanide toxicity.
- Treatment: Administer 100% oxygen via mechanical ventilation. Hydroxocobalamin (Cyanokit) is the preferred antidote; infuse 5 g IV over 7 minutes. It may be infused over 2-5 minutes in cases of cardiac arrest or severe hypotension and may be repeated if no clinical improvement. Cyanokit should be available at every Role 3 hospital, and at Role 2 hospitals as well if there is a high risk of managing burn casualties. Role 2 MTFs (including Role 2 capable combatant vessels) should be equipped with Cyanokits if evacuation to Role 3 MTFs is long or not permissive. Cyanokit typically causes dramatic red/violaceous coloration of skin, mucus membranes, and urine; it may also cause hypertension and acute kidney injury.

Hydrogen fluoride (HF) is a byproduct of standard fire-suppression systems. Exposure to HF may result in rapidly progressive or fatal respiratory failure despite minimal external evidence of injury. Symptoms include shortness of breath, cough, hypoxia, and hypocalcemia; there must be a high level of suspicion for HF inhalation.10

- Treatment of HF inhalation injury is primarily supportive.
- Telemetry monitoring and measure calcium levels. If hypocalcemia is present, administer IV calcium followed by nebulized calcium gluconate (1.5 ml of 10% calcium gluconate in 4.5 ml water) q4hr until normalization of serum calcium levels.
- Consider steroids if symptoms do not improve.

Refer to the Inhalation Injury and Toxic Industrial Chemical Exposure CPG for additional information.4