Smoke inhalation

Definition

Smoke inhalation is breathing in the harmful gases, vapors, and particulate matter contained in smoke.

Description

Smoke inhalation typically occurs in victims or firefighters caught in structural fires. However, cigarette smoking also causes similar damage on a smaller scale over a longer period of time. People who are trapped in fires may suffer from smoke inhalation independent of receiving skin burns ; however, the incidence of smoke inhalation increases with the percentage of total body surface area burned. Smoke inhalation contributes to the total number of fire-related deaths each year for several reasons: the damage is serious; its diagnosis is not always easy because as of 2004 there were no sensitive diagnostic tests; and people may not show symptoms until 24 to 48 hours after the event.

Demographics

According to the National Safety Council, 3,900 people died from exposure to fire, flame, and smoke in the United States in 2001, the most recent year as of 2004 for which data were available. Smoke inhalation accounts for the majority of deaths in home fires. Children under age 11 and adults over age 70 are most vulnerable to the effects of smoke inhalation.

Causes and symptoms

The harmful materials given off by combustion injure the airways and lungs in three ways: heat damage, tissue irritation, and oxygen starvation of tissues (asphyxiation). Signs of heat damage are singed nasal hairs, burns around and inside the nose and mouth, and internal swelling of the throat. Tissue irritation of the throat and lungs may appear as noisy breathing, coughing, hoarseness, black or gray spittle, and fluid in the lungs. Asphyxiation is apparent from shortness of breath and blue-gray or cherry-red skin color. In some cases, the person may not be conscious or breathing.

When to call the doctor

A doctor should be called whenever smoke is inhaled for more than a few minutes or whenever the inhaled smoke and fumes are known to contain toxic substances.

Diagnosis

In addition to looking for the signs of heat damage, tissue irritation, and asphyxiation, the physician will assess the individual's breathing by the respiratory rate (number of breaths per minute) and motion of the chest as the lungs inflate and deflate. The person's circulation is also evaluated by the pulse rate (number of heartbeats per minute) and blood pressure. Blood tests will indicate the levels of oxygen and byproducts of poisonous gases. Chest x rays are too insensitive to show damage to delicate respiratory tissues but can show fluid in the lungs (pulmonary edema).

The physician may perform a bronchoscopy, a visual examination in which the airways and lungs are seen through a fiber optic tube inserted down the person's windpipe (trachea). Other pulmonary function tests may be performed to measure how efficiently the lungs are working.

Treatment

Treatment varies with the severity of the damage caused. The primary focus of treatment is to maintain an open airway and provide an adequate level of oxygen. If the airway is open and stable, the individual may be given high-flow humidified 100 percent oxygen by mask. If swelling of the airway tissues is closing off the airway, the person may require the insertion of an endotracheal tube to artificially maintain an open airway.

Oxygen is often the only medication necessary. However, people who have a cough with wheezing (bronchospasm), indicating that the bronchial airways are narrowed or blocked, may be given a bronchodilator to relax the muscles and increase ventilation. There are also antidotes for specific poisonous gases in the blood; dosage is dependent upon the level indicated by blood tests. Antibiotics are not given until sputum and blood cultures confirm the presence of a bacterial infection.

In institutions where it is available, hyperbaric oxygen therapy may be used to treat smoke inhalation, resulting in severe carbon monoxide or cyanide poisoning . This treatment requires a special chamber in which the person receives pure oxygen at three times the normal atmospheric pressure, thus receiving more oxygen faster to overcome loss of consciousness, altered mental state, cardiovascular dysfunction, pulmonary edema, and severe neurological damage.

Botanical medicine can help to maintain open airways and heal damaged mucous membranes. It can also help support the entire respiratory system. Acupuncture and homeopathic treatment can provide support to the whole person who has suffered a traumatic injury such as smoke inhalation.

Prognosis

Although the outcome depends of the severity of the smoke inhalation and the severity of any accompanying burns or other injuries, with prompt medical treatment, the prognosis for recovery is good. However, some people may experience chronic pulmonary problems following smoke inhalation, and those with asthma or other chronic respiratory conditions prior to smoke inhalation may find their original conditions have been aggravated by the inhalation injury.

Prevention

Smoke inhalation is best avoided by preventing structural fires. Doing so involves inspection of wiring; safe use and storage of flammable liquids; and maintenance of clean, well-ventilated chimneys, wood stoves, and space heaters. Properly placed and working smoke detectors in combination with rapid evacuation plans minimize a person's exposure to smoke in the event of a fire. When escaping a burning building, a person should move close to the floor where there the air is cooler and clearer to breathe because hot air rises, carrying gases and particulate matter upward. Finally, firefighters should always wear proper protective gear.

Parental concerns

Parents should monitor their homes to make sure they provide a safe environment for everyone, including their children. They should also monitor play and recreational activities to limit exposure to smoke or toxic fumes. Parents should regularly check smoke detectors and change batteries every six months. In addition, families should have a fire escape plan, including a designated meeting area away from the house. This plan should be practiced periodically.

Resources

BOOKS

Beamis, John F., et al. Interventional Pulmonary Medicine. New York: Marcel Dekker, 2003.

Hanley, Michael E., and Carolyn H. Welsh. Current Diagnosis & Treatment in Pulmonary Medicine. New York: McGraw-Hill, 2003.

Piantadosi, Claude A. "Physical, Chemical, and Aspiration Injuries of the Lung." In Cecil Textbook of Medicine, 22nd ed. Edited by Lee Goldman et al. Philadelphia: Saunders, 2003, pp. 538–467.

Rodgers, George C., and Nancy J. Matyunas. "Toxic gases." In Nelson Textbook of Pediatrics, 17th ed. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2003, pp. 2374.

Speizer, Frank E. "Environmental Lung Diseases." In Harrison's Principles of Internal Medicine, 15th ed. Edited by Eugene Braunwald et al. New York: McGraw-Hill, 2001, pp. 1467–74.

PERIODICALS

Stefanidou, M., and S. Athanaselis. "Toxicological aspects of fire." Veterinary and Human Toxicology 46, no. 4 (2004): 196–9.

ORGANIZATIONS

American Academy of Emergency Medicine. 611 East Wells St., Milwaukee, WI 53202. Web site: <www.aaem.org/>.

American College of Emergency Physicians. PO Box 619911, Dallas, TX 75261–9911. Web site: <www.acep.org/>.

American College of Occupational and Environmental Medicine. 55 West Seegers Rd., Arlington Heights, IL 60005. Web site: <www.acoem.org/>.

American College of Osteopathic Emergency Physicians. 142 E. Ontario St., Suite 550, Chicago, IL 60611. Web site: <www.acoep.org/>.

American College of Physicians. 190 N Independence Mall West, Philadelphia, PA 19106–1572. Web site: <http://www.acponline.org/>.

American Lung Association. 1740 Broadway, New York, NY 10019. Web site: <www.lungusa.org/diseases/lungtb.html>.

American Thoracic Society. 1740 Broadway, New York, NY 10019. Web site: <www.thoracic.org/>.

WEB SITES

"Burns." Merck Manual. Available online at <www.merck.com/mmhe/sec24/ch289/ch289a.html> (accessed December 23, 2004).

Lafferty, Keith. "Smoke Inhalation." eMedicine, November 2,2004. Available online at <www.emedicine.com/EMERG/topic538.htm> (accessed December 23, 2004).

L. Fleming Fallon Jr., MD, DrPH

KEY TERMS

Asphyxiation —Oxygen starvation of tissues. Chemicals such as carbon monoxide prevent the blood from carrying sufficient oxygen to the brain and other organs. As a result, the person may lose consciousness, stop breathing, and die without artificial respiration (assisted breathing) and other means of elevating the blood oxygen level.

Hyperbaric oxygen therapy —Medical treatment in which oxygen is administered in specially designed chambers, under pressures greater than that of the atmosphere, in order to treat specific medical conditions, such as carbon monoxide poisoning, smoke inhalation, and certain bacterial infections.

Pulmonary —Referring to the lungs and respiratory system.

Pulmonary edema —An accumulation of fluid in the tissue of the lungs.

SMOKE INHALATION

DEFINITION

Smoke inhalation is breathing in smoke. Smoke contains many substances that can cause damage to the human body.

DESCRIPTION

The most common cause of smoke inhalation is fire in a structure, such as a home, office, or factory. People trapped in a burning structure as well as firefighters may inhale smoke produced by the fire.

Cigarette smoking also produces the effects of smoke inhalation. People who smoke do not get as much smoke into their lungs at once as someone trapped in a structural fire. Over a long period of time, however, the effects of cigarette smoking can add up. And eventually the effects on a person's lungs from smoking can be as bad or worse than those caused by other forms of smoke inhalation.

Smoke inhalation is responsible for a large number of the deaths caused by structural fires each year. In many cases, patients do not show symptoms of smoke inhalation until twenty-four to forty-eight hours after the fire. Because of this, they may not be diagnosed correctly and their medical problem may not be treated soon enough or by the correct methods.

CAUSES

The smoke a person inhales can cause damage to the body in three different ways. First, the smoke may actually cause burns. The smoke is carried in by hot air that can damage or destroy tissues in the mouth, nose, and upper respiratory (breathing) system.

Smoke can also cause damage by irritating tissues. The materials found in smoke can be toxic (poisonous) to cells or they can cause physical damage by rubbing across tissues.

Finally, smoke can harm the body because it cuts off the supply of oxygen. Cells need oxygen in order to remain alive and function normally. If too much smoke is present in the body, it can prevent oxygen from reaching cells. Cells and tissues then begin to die from oxygen starvation.

Smoke Inhalation: Words to Know

Bronchodilator:

A substance that causes muscles in the respiratory system to relax.

Bronchoscope:

A device consisting of a long thin tube with a light and camera on the end for looking into a patient's airways and lungs

Pulmonary:

Pertaining to the lungs.

Respiratory system:

The nose, tonsils, larynx, pharynx, lungs, and other structures used in the process of breathing.

Toxic:

Poisonous.

SYMPTOMS

Some symptoms of smoke inhalation are visible to the naked eye. For example, nose hairs may be burned and there may be burns on the throat and inside the nose. The throat may also begin to swell up.

Smoke inhalation causes other obvious symptoms including noisy breathing, coughing, hoarseness, black or gray saliva (spit), and fluids in the lungs. A person who is not receiving enough oxygen may become short of breath and may develop a bluish-gray or cherry-red skin color. As the condition becomes worse, the patient may lose consciousness or stop breathing.

DIAGNOSIS

Diagnosis of smoke inhalation is based on personal history and physical examination. In most cases, the patient will visit a doctor because he or she has been present at a structural fire. The possibility of smoke inhalation will be clear. In the case of a smoker, this connection may not be so obvious.

A physical examination may reveal some or all of the symptoms listed above. In addition, the doctor can listen to the patient's chest and take his or her pulse rate. Smoke inhalation may cause abnormal chest sounds and a decreased pulse rate.

Blood tests may also be taken. A blood test can show the amount of oxygen in the blood. It can also show if toxic gases from the smoke are present in the blood. A chest X ray will not show damage to the respiratory system but it may show the presence of fluids in the lungs.

FIRE SPRINKLER SYSTEMS

The first fire sprinkler system was built in 1874 by the American inventor Henry S. Parmalee. He developed the system to protect the factory in which he built pianos.

Sprinkler systems soon became popular in large factories and warehouses. But they did not seem to have any use in the large majority of office buildings and other structures. They were much too expensive to build.

Attitudes about sprinkler systems began to change in the 1940s. A number of horrible fires were responsible for this change. Perhaps the most important was a fire that struck the Coconut Grove Night Club in Boston in 1942. In that fire, 492 people were killed, many by smoke inhalation.

Before long, city governments began to insist on sprinkler systems in all new office and apartment buildings. For example, New York City requires such systems in all high-rise buildings. The city of Chicago requires sprinkler systems in all nursing homes. Some communities even require sprinkler systems in private homes. San Clemente, California, is one such community.

Damage to the patient's airways and lungs can be viewed directly with a bronchoscope. A bronchoscope is a device that consists of a long thin tube that can be inserted into the patient's respiratory system. The doctor can look through the tube directly into the windpipe and lungs to see if damage has occurred to tissues.

TREATMENT

The primary goal in treating smoke inhalation is to make sure that the patient is getting enough oxygen. Two steps may be necessary to achieve this objective. First, the patient's airway has to be kept open. In some cases, the patient may be breathing easily and normally. This condition suggests that the airway is open and functioning normally. In that case, all that may be necessary is to give the patient oxygen through a mask that delivers pure oxygen or air enriched with oxygen to his or her body.

If the patient is wheezing, his or her airway may be constricted (narrowed) or blocked. In that case, the first step is to open up the airways. One way to do this is to give the patient a bronchodilator (pronounced brahng-KO-DI-lay-tor). A bronchodilator is a substance that causes muscles in the respiratory system to relax. As they relax, the tubes through which air gets

into the lungs become larger. The patient is able to breathe more easily. At this point, oxygen may also be given.

In some cases it may be necessary to insert a tube into the patient's respiratory system through the nose. Oxygen can then be provided through the tube.

Other forms of treatment may be necessary also. For example, the smoke inhaled may have contained certain toxic substances. Blood tests will often show the presence of these toxic substances in the blood. They can then be treated with other substances that will react with the toxic materials and make them harmless.

PROGNOSIS

The key to complete recovery from smoke inhalation is often prompt treatment. People with relatively moderate symptoms who receive early treatment tend to recover completely from the experience. In some cases, however, patients may develop chronic respiratory or pulmonary (lung) disorders. Patients most at risk for such disorders are those who had respiratory problems such as asthma (see asthma entry) before exposure to smoke. Those patients are likely to experience more severe symptoms of their disorder than they did before the smoke inhalation.

PREVENTION

Avoiding smoke inhalation may be difficult because, of course, people usually do not choose to be present in a burning building. The best way to avoid smoke inhalation, then, is to prevent the structural fires that create the problem. Structural fires are best prevented by the use of safe electrical wiring, proper storage of flammable materials, maintenance of clean, well-ventilated chimneys and wood stoves, and other basic fire safety practices.

The damage caused by structural fires can often be reduced dramatically by the installation of smoke detectors and sprinkler systems. Studies have shown that more than 98 percent of all potentially disastrous fires can be prevented by properly installed sprinkler systems.

Finally, fire fighters should be provided with and trained in the use of proper protective gear to avoid the problems of smoke inhalation.

FOR MORE INFORMATION

Web sites

"Fire Sprinkler Facts." [Online] http://www.waycool.com/southwest/intro.html (accessed on November 5, 1999).

"Homeowners Guide to Fire Sprinkler Systems." National Fire Sprinkler Association Home Page. [Online] http://www.nfsa.org/homeown.html (accessed on November 5, 1999).

Johnson, Norma Jean. "Smoke Inhalation." [Online] http://www.emedicine.com/EMERG/topic538.htm (accessed on November 5, 1999).

Smoke Inhalation

Definition

Smoke inhalation is breathing in the harmful gases, vapors, and particulate matter contained in smoke.

Description

Smoke inhalation typically occurs in victims or firefighters caught in structural fires. However, cigarette smoking also causes similar damage on a smaller scale over a longer period of time. People who are trapped in fires may suffer from smoke inhalation independent of receiving skin burns ; however, the incidence of smoke inhalation increases with the percentage of total body surface area burned. Smoke inhalation contributes to the total number of fire-related deaths each year for several reasons: the damage is serious; its diagnosis is not always easy and there are no sensitive diagnostic tests; and patients may not show symptoms until 24-48 hours after the event. Children under age 11 and adults over age 70 are most vulnerable to the effects of smoke inhalation.

Causes and symptoms

The harmful materials given off by combustion injure the airways and lungs in three ways: heat damage, tissue irritation, and oxygen starvation of tissues (asphyxiation). Signs of heat damage are singed nasal hairs, burns around and inside the nose and mouth, and internal swelling of the throat. Tissue irritation of the throat and lungs may appear as noisy breathing, coughing, hoarseness, black or gray spittle, and fluid in the lungs. Asphyxiation is apparent from shortness of breath and blue-gray or cherry-red skin color. In some cases, the patient may not be conscious or breathing.

Diagnosis

In addition to looking for the signs of heat damage, tissue irritation, and asphyxiation, the physician will assess the patient's breathing by the respiratory rate (number of breaths per minute) and motion of the chest as the lungs inflate and deflate. The patient's circulation is also evaluated by the pulse rate (number of heartbeats per minute) and blood pressure. Blood tests will indicate the levels of oxygen and byproducts of poisonous gases. Chest x rays are too insensitive to show damage to delicate respiratory tissues, but can show fluid in the lungs (pulmonary edema ).

The physician may perform a bronchoscopy, a visual examination in which the airways and lungs are seen through a fiber optic tube inserted down the patient's windpipe (trachea). Other pulmonary function tests may be performed to measure how efficiently the lungs are working.

Treatment

Treatment will vary with the severity of the damage caused by smoke inhalation. The primary focus of treatment is to maintain an open airway and provide an adequate level of oxygen. If the airway is open and stable, the patient may be given high-flow humidified 100% oxygen by mask. If swelling of the airway tissues is closing off the airway, the patient may require the insertion of an endotracheal tube to artificially maintain an open airway.

Oxygen is often the only medication necessary. However, patients who have a cough with wheezing (bronchospasm), indicating that the bronchial airways are narrowed or blocked, may be given a bronchodilator to relax the muscles and increase ventilation. There are also antidotes for specific poisonous gases in the blood; dosage is dependent upon the level indicated by blood tests. Antibiotics are not given until sputum and blood cultures confirm the presence of a bacterial infection.

In institutions where it is available, hyperbaric oxygen therapy may be used to treat smoke inhalation resulting in severe carbon monoxide or cyanide poisoning. This treatment requires a special chamber in which the patient receives pure oxygen at three times the normal atmospheric pressure, thus receiving more oxygen faster to overcome loss of consciousness, altered mental state, cardiovascular dysfunction, pulmonary edema, and severe neurological damage.

Alternative treatment

Botanical medicine can help to maintain open airways and heal damaged mucous membranes. It can also help support the entire respiratory system. Acupuncture and homeopathic treatment can provide support to the whole person who has suffered a traumatic injury such as smoke inhalation.

Prognosis

Although the outcome depends of the severity of the smoke inhalation and the severity of any accompanying burns or other injuries, with prompt medical treatment, the prognosis for recovery is good. However, some patients may experience chronic pulmonary problems following smoke inhalation, and those with asthma or other chronic respiratory conditions prior to smoke inhalation may find their original conditions have been aggravated by the inhalation injury.

Prevention

Smoke inhalation is best avoided by preventing structural fires. This includes inspection of wiring, safe use and storage of flammable liquids, and maintenance of clean, well-ventilated chimneys, wood stoves, and space heaters. Properly placed and working smoke detectors in combination with rapid evacuation plans will minimize a person's exposure to smoke in the event of a fire. When escaping a burning building, a person should move close to the floor where there is more cool, clear air to breathe because hot air rises, carrying gases and particulate matter upward. Finally, firefighters should wear proper protective gear.

Resources

OTHER

Johnson, Norma Jean. "Smoke Inhalation." eMedicine World Medical Library. 〈http://www.emedicine.com〉.

KEY TERMS

Asphyxiation— Oxygen starvation of tissues. Chemicals such as carbon monoxide prevent the blood from carrying sufficient oxygen to the brain and other organs. As a result, the person may lose consciousness, stop breathing, and die without artificial respiration (assisted breathing) and other means of elevating the blood oxygen level.

Hyperbaric oxygen therapy— Pure oxygen is administered to the patient in a special chamber at three times the normal atmospheric pressure. The patient gets more oxygen faster to overcome severe asphyxiation.

Pulmonary— Pertaining to the lungs.

Pulmonary edema— The filling of the lungs with fluid as the body's response to injury or infection.