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Smoke inhalation is breathing in the harmful gases, vapors, and particulate matter contained in smoke.
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.
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 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.
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.
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.
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.
Johnson, Norma Jean. "Smoke Inhalation." eMedicine World Medical Library. http://www.emedicine.com.
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.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
smoke inhalationToxicology A cause of death in fire victims linked to toxic gases, especially, CO and hydrogen cyanide–HCN. See Cyanide.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.