Respiratory complications are a major source of morbidity and mortality from fires. Overall, nearly one-third of all victims of major burns suffer from various degrees of smoke inhalation injury. Smoke inhalation is responsible for approximately 75% of deaths from structural fires in the United States. The mortality rate is greater among patients who have both cutaneous burns and inhalation injury. Severe injury to the respiratory tract can occur in the absence of surface burns. Several factors are associated with greater risk of incurring respiratory injury: trapping of victims in confined spaces, unconsciousness of victims, fires involving plastics or steam, and victims who are small children or elderly individuals. The likelihood of suffering asphyxia or respiratory inhalation injury is increased in the presence of cutaneous burns. Unconscious victims are at higher risk of incurring injury caused by loss of the protective mechanisms of holding one’s breath and laryngospasm. Injuries of the respiratory tract are distributed as follows: 60% upper airway, 30% major lower airway, and 10% parenchymal. Injuries may occur at several levels simultaneously.

The time course of clinical symptoms depends on the type and severity of injury. Carbon monoxide (CO) intoxication, upper airway tract injury, and tracheobronchial obstruction develop in the first 24 hours. Late pulmonary injury likely is attributable to metabolic, infectious, or circulatory derangements complicating the surface burns. During the next 2 to 5 days, noncardiogenic pulmonary edema may develop, particularly in the presence of superimposed sepsis. Nosocomial pneumonia and pulmonary embolism usually occur late, more than 5 days after the event.