INTRODUCTION AND EPIDEMIOLOGY
Smoke inhalation is a serious medical problem and continues to have a significant impact on the morbidity and mortality of patients with flame burns. According to the American Burn Association repository, inhalation injury is one of the most lethal characteristics of burn patients, and its presence is associated with an overall mortality rate of 20% between 2009 and 2018; mortality is only 2.9% in those patients without smoke inhalation.1 Inhalation injury is present in 17% of patients with flame burns,2 and its presence prolongs the length of hospital stay 2.5-fold compared to those without smoke inhalation injury (24 days vs. 10 days).2
Similar percentages of fire victims who have sustained smoke inhalation appear in several other countries.3–6 In patients with combined injury, the lung is the critical organ, and the progressive respiratory failure associated with pulmonary edema is a pivotal determinant of mortality.7–9 Although not as lethal, smoke inhalation alone is a serious problem. It is estimated by the World Health Organization that there are more than one billion people who develop airway and pulmonary inflammation as a result of inhaling smoke from indoor cooking fires, forest fires, and burning of crops.10,11
The inhalation of smoke has been of interest for a number of years, especially as the result of the use of gas warfare. In the 1940s there were two very large fires that focused interest on the inhalation of smoke in fire victims. The first was a fire at a nightclub in Boston called the Cocoanut Grove, where a large number of people were trapped in a burning building and consequently sustained severe inhalation injury.12,13 It is interesting that in recent times a similar fire occurred in a nightclub near Boston in Rhode Island. The second occurred in Texas City across the bay from Galveston, Texas.14 Here a ship exploded in a harbor and set off a chain of explosions and fires among some 50 refineries and chemical plants, resulting in more than 2000 hospital admissions of patients with smoke inhalation alone, as well as those with burn injuries, many of whom who had simultaneously inhaled smoke as well. These two disasters led to the establishment of centers for the care of burn victims and to research into the pathophysiology of burn injury. In many ways, the burn victims of the 9/11 disaster were similar to these individuals since the burns and inhalation involved combustion of petroleum products.15,16 Approximately half (49%) of 790 victims who survived the World Trade Center attack had an inhalation injury.16,17
THE FIRE ENVIRONMENT: TOXIC SMOKE COMPOUNDS
Inhalation injury is caused by steam or toxic inhalants such as fumes, gases, and mists. Fumes consist of small particles dispersed in air with various irritants or cytotoxic chemicals adherent to the particles. Mists ...