Chapter 94: Thermal Lung Injury and Acute Smoke Inhalation

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 (2012), inhalation injury is present in 17% of patients with flame burns and increases the overall mortality rate of these patients up to 24%, while the mortality of burn patients without inhalation injury is 3%.¹ The presence of smoke inhalation injury prolongs the length of hospital stay 2.5-fold compared to those without smoke inhalation injury (24 days vs. 10 days).¹

Similar percentages of fire victims who have sustained smoke inhalation appear in several other countries.^2–5 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.^6–8 Although not as lethal, smoke inhalation alone is a serious problem. It is estimated by the World Health Organization that there are over 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.^9,10

The inhalation of smoke has been of interest for a number of years, especially as a 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.^11,12 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.¹³ 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 over 2,000 hospital admissions of patients with smoke inhalation alone, those with burn injuries, many of whom who had simultaneously inhaled smoke as well. At any rate these two disasters led to the establishments 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.^14,15 Approximately half (49%) of 790 victims who survived the World Trade Center attack had an inhalation injury.^15,16

Toxic Smoke Compounds

The fire environment contains a number of toxic compounds, each of which is discussed in this section.

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 ...