Smoke inhalation is more commonly associated with fire deaths than burns. In many cases where a dead burn victim is found, more frequently than not, the person died from smoke inhalation prior to burning. The latest estimate puts the number of smoke inhalation deaths between 5,000 and 10,000 each year. Another 23,000 injuries occur annually from smoke inhalation, including some 5,000 firefighters.
Because of lightweight construction and the increased use of synthetics in buildings and furnishings, today’s fireground environment is likely to reach flashover in a shorter period than before. As a fireground environment reaches flashover much sooner, the levels of toxic gases in the smoke also increase dramatically.
The reduced flashover time also means there is a reduced time for firefighters to intervene before flashover occurs. Conversely, it also means that potential smoke inhalation victims have much less time to escape. All that adds up to increased potential for incapacitation from smoke, thus more severe injuries.
One byproduct of fire is smoke. Smoke contains particulate matter and heated gases, such as hydrochloric acid, sulfur dioxide, ammonia and carbon dioxide, and toxins, including hydrogen sulfide and hydrogen cyanide.
Throughout history, cyanide has been used as a murder weapon, an agent of mass suicide, a war weapon and a terrorist weapon. When cyanide was used as a murder weapon, it was inserted into everyday products ingested by consumers such as Tylenol in 1982 (seven deaths), Sudafed in 1991 (two deaths) and a Coca-Cola product in 2003 (one death). Cyanide was used as an agent of mass suicide in 1978, when 913 followers of the Reverend Jim Jones committed suicide with cyanide-spiked Kool-Aid. Cyanide also was used in genocide when the Nazis in World War II used Zyklon B in concentration camp gas chambers. During World War I, the French used approximately 4,000 tons of cyanide against the Germans, and the Japanese allegedly used cyanide against the Chinese in World War II.
Terrorists also like cyanide. It has been speculated that terrorists placed cyanide in the truck used in the bombing of the World Trade Center in 1993, but it incinerated with the explosion. Cyanide was also used in the 1995 Tokyo subway attack, the 2002 London underground plot, the 2002 Rome water-supply plot and a 2003 incident in Texas.
New research from independent studies about smoke inhalation victims may very well change the treatment modality. More and more evidence suggests that victims of smoke inhalation are also suffering from cyanide poisoning.
Cyanide kills quickly by disabling the blood’s mechanism for carrying oxygen. Cyanide in a fire comes from natural substances such as wool, silk, cotton or paper. Synthetic substances, such as plastics and other polymers, also produce cyanide.
Two studies, one done in Dallas County, TX, and the other in Paris, France, were designed to assess the role of cyanide in fire-related morbidity and mortality. In both studies, blood samples were drawn as close as possible to the times of exposure to smoke.
In the Paris study, conducted in 1988 and 1989, blood was collected by the first-arriving medical squads to residential fires. A total of 109 fire victims were studied – 66 who survived and 43 who died. The data was compared against 114 control individuals – 40 with drug intoxication, 29 with carbon monoxide poisoning and 45 with major trauma.
The study showed that in some victims who died, blood levels of cyanide were in the potentially lethal range while blood levels of carbon monoxide were in the non-toxic range. The results of this study were directly opposite the thinking that smoke inhalation victims die only from carbon monoxide. Instead, the study showed that cyanide and carbon monoxide were both important when determining morbidity and mortality associated with smoke inhalation. Other results of the study showed that cyanide concentrations were directly related to the probability of death, cyanide poisoning may have been the leading cause of death in some fire victims, and cyanide and carbon monoxide may have possibly helped the toxic effects of one another.
Another study done in Dallas County collected blood within eight hours from victims exposed to smoke. The study compared 144 smoke inhalation victims who arrived alive over a two-year period at the University of Texas Health Science Center emergency room against 43 smoke inhalation victims who were dead on arrival at the Dallas County Medical Examiner’s Office during the same period.
The study found that mean blood cyanide concentrations in victims arriving alive at the emergency room were lower than concentrations in victims who were dead on arrival. The Dallas County study concluded that elevated cyanide concentrations were more present among smoke inhalation victims. It also concluded that cyanide concentrations were directly related to the probability of death, and cyanide poisoning may have been the leading cause of death over carbon monoxide poisoning.
In a study using monkeys, researchers looked at sub-lethal concentrations of cyanide in a fire to see whether cyanide may indirectly cause death by causing incapacitation, thus preventing escape from the fire and permitting more prolonged exposure to fatal concentrations of other toxins and asphyxiants.
In the study, monkeys were exposed to cyanide fumes produced by heating various substances that produce cyanide gas. The researchers found that monkeys exposed to the cyanide fumes were rapidly incapacitated at ambient concentrations that were sub-lethal.
As a result of these studies, it is easy to conclude that cyanide plays an important role in causing death and incapacitation in fires. Further, as a medical provider or firefighter, you should suspect cyanide poisoning in any person exposed to smoke from a fire in a closed space and any other smoke inhalation victims with soot in the mouth, an altered mental status and low blood pressure.
Obviously, the difference between life and death of a smoke inhalation victim is dependent upon the concentration of exposure and the time between exposure and treatment.
The current treatment of smoke inhalation victims is to remove the victim from source of exposure, do your ABCs, administer 100% oxygen and stabilize vital signs.
Based upon the results of these studies, new thinking for treatment of smoke inhalation victims is now beginning to focus toward cyanide poisoning. There are effective cyanide antidotes in the United States, but nothing geared toward treating smoke inhalation victims. Some of the more popular cyanide antidotes kits in the United States are also known as the Lilly Kit, Taylor Kit and Pasadena Kit.
The Paris, France, Fire Department does carry cyanide antidotes kits specifically for smoke inhalation victims called Cyanokit. By protocol in Paris, if a victim has soot in the nose or mouth and suffers an altered level of consciousness, the Cyanokit is used.
As we move down the road toward treating smoke inhalation victims also as cyanide poisoning victims, be prepared for new medical protocols, and cyanide antidote kits on your apparatus in the future.
Gary Ludwig will present “Does Your EMS Chief Know About This?” and “Preparing for Suicide Belt Bombers” at Firehouse Expo 2004 in Baltimore, July 13-18.
Gary Ludwig, MS, EMT-P, a Firehouse® contributing editor, is the chief of Special Operations for Jefferson County, MO. He retired in 2001 as the chief paramedic for the St. Louis Fire Department after serving the City of St. Louis for 25 years. He is also vice chairman of the EMS Section of the International Association of Fire Chiefs (IAFC). He is a frequent speaker at EMS and fire conferences nationally and internationally, and is on the faculty of three colleges. Ludwig has a master’s degree in management and business and a bachelor’s degree in business administration, and is a licensed paramedic. He also operates The Ludwig Group, a professional consulting firm. He can be reached at 636 789-5660 or via www.garyludwig.com.
