Smoke inhalation injury is direct damage to the airways and lung tissue caused by exposure to heat, particulate matter in smoke and the gaseous by-products of fire.
Lung injury can be caused by chemical and thermal insults. A variety of noxious gases, irritants and asphyxiants (lack of oxygen) are generated depending on the material burnt. Carbon monoxide is the predominant cause of death among fire victims. Injury occurs as a result of direct heat damage to the upper airway and lining of the nose. Injury to the tissue occurs due to inhalation of carbon monoxide, inhalation of other toxins that irritate the airways and inhalation of particulate matter that adheres to the airways and small air sacs in the lungs.
The extent of damage depends on duration of exposure to smoke and burning material. Lungs may be severely damaged with little physical burning signs. Initial symptoms include constriction of lungs, airways swelling, mucus production, inflammation of trachea and bronchial areas and fluid accumulation in lungs. These symptoms are evident in first two to three days after exposure to smoke. Other common signs and symptoms are
Soot in the nasal or throat passages
Rapid breathing and increased depth of respiration
Breathing effort that suggests upper airway obstruction by swelling
Postural adaptations to respiratory distress (i.e., positioning the body to make breathing easier)
Mucous membranes may be cherry red, pale, or cyanotic (blue)