BRONCHITIS

DEFINITION

Bronchitis (pronounced brong-KIE-tis) is an inflammation of the air passages between the nose and the lungs. It affects the trachea (pronounced TRAY-kee-uh), or windpipe, and the bronchi. The bronchi (pronounced BRON-kee) are air tubes through which air flows into and out of the lungs.

Bronchitis can be either acute (of brief duration) or chronic (longlasting). Acute bronchitis is usually caused by a viral or bacterial infection. It usually heals fairly quickly without complications. Chronic bronchitis is a sign of more serious lung disease. It can often be slowed, but it cannot be cured.

DESCRIPTION

Acute and chronic bronchitis are both inflammations of the air passages. However, their causes and treatments are different. Acute bronchitis occurs most frequently during the winter. It often follows a viral infection, such as a cold (see common cold entry) or the flu (see influenza entry), and may accompany a bacterial infection.

A person who has acute bronchitis is usually better within two weeks. The cough that accompanies the disease may last longer, however. As with similar infections of the airways, pneumonia (see pneumonia entry) may also develop.

Anyone can get acute bronchitis. However, people with weak immune systems, such as infants and the elderly, are more prone to the disease. Smokers and people with heart or lung disease are also at higher risk for acute bronchitis, as are people who are exposed to chemical fumes or high levels of air pollution.

Chronic bronchitis is a major cause of disability and death. The American Lung Association estimates that about fourteen million Americans suffer from the disease. Like acute bronchitis, chronic bronchitis is accompanied by severe coughing and spitting up of phlegm (pronounced FLEM). Chronic bronchitis is characterized by the presence of these symptoms for a period of at least three months in each of two consecutive years. Chronic bronchitis develops slowly. As a result, the disease is seen more often among older people than among the young and middle-aged.

CAUSES

Chronic bronchitis is caused by inhaling substances that irritate the trachea and bronchi. The most common substance is cigarette smoke. The American Lung Association estimates that 80 to 90 percent of all cases of chronic bronchitis are caused by smoking. Until recently, chronic bronchitis occurred more frequently among men than women because traditionally more men smoked than women. That trend is changing and the number of women suffering from chronic bronchitis is also increasing. Other substances

X ray of lungs with chronic bronchitis. (Reproduced by permission of

Custom Medical Stock Photo

)

that can irritate the trachea and bronchi include chemical fumes, air pollution, and other materials in the air, such as mold and dust.

Chronic bronchitis develops slowly over time. It is caused by changes in the cilia (pronounced SIL-ee-uh) that line the trachea and bronchi. Cilia are fine, hair-like projections that wave back and forth, carrying mucus through the airways. Smoke and other irritants can damage cilia, causing them to lose their ability to move mucus normally. The airways become narrow and clogged with mucus. The patient has difficulty breathing because he or she cannot get enough air into the lungs. Eventually chronic bronchitis leads to an even more serious and life-threatening disease, emphysema (pronounced em-fi-SEE-muh; see emphysema entry).

SYMPTOMS

Acute bronchitis usually begins with cold-like symptoms, such as a runny nose, sneezing, and dry cough. However, the cough soon becomes deep and painful. Coughing produces a greenish-yellow phlegm or sputum (pronounced SPYOO-tum). Phlegm and sputum are substances coughed up from the inflamed airways. They include blood, mucus, dead cells, and other materials. A fever with temperatures of up to 102°F (39°C) are common. The coughing may also be accompanied by wheezing.

In simple cases of acute bronchitis, most symptoms disappear in three to five days. The cough remains and may continue for several weeks. Acute bronchitis is often accompanied by a bacterial infection that causes its own symptoms, including fever and a general feeling of illness. The bacterial infection can be treated with antibiotics. Drugs are usually not effective against the original viral infection, however.

The first sign of chronic bronchitis is often a mild cough, sometimes called smokers' cough. This coughing may bring up small or greater amounts of phlegm. Wheezing and shortness of breath may accompany the cough. As the disease develops, breathing becomes more difficult. The patient finds it necessary to become less active. The body no longer gets enough oxygen, leading to changes in the composition of the blood.

DIAGNOSIS

To diagnose bronchitis, the doctor first takes the patient's health history and observes his or her symptoms. The doctor then listens to the patient's chest with a stethoscope. Certain sounds indicate narrowing of the airways. These sounds include moist rales, crackling, and wheezing. Moist rales is a bubbling sound caused when fluids are present in the bronchial tubes.

A sputum culture may be performed, especially if the sputum is green or has blood in it. The culture allows the doctor to determine what kinds of bacteria are present in the sputum. He or she can then decide what kind of drugs to use in killing the bacteria.

The first step in taking a sputum culture is to have the patient cough up a small amount of sputum (material from the lungs). The sample is then placed in a warm environment for two to three days. Under these conditions, bacteria grow rapidly and are easy to identify. Sputum can also be collected by means of a bronchoscopy. In this procedure, the patient is first given a local anesthetic. A tube is then passed down the airway to collect a sputum sample.

Another step in diagnosing bronchitis is a lung function test. This step requires the use of a spirometer, which is a device that measures the amount of air entering and leaving the lungs. The test is performed by having the patient breathe into the spirometer, first normally and then with force. The test is quick, easy, and painless. It is usually done in the doctor's office. A lung

The American Lung Association estimates that 80 to 90 percent of all cases of chronic bronchitis are caused by smoking. (Reproduced by permission of

AP/Wide World Photos

)

function of less than 80 percent can be the sign of bronchitis or a related lung disease.

Many lung diseases have similar symptoms. To tell them apart, a doctor may order other tests, such as a chest X ray, electrocardiogram (ECG; pronounced ih-LEK-tro-KAR-dee-o-gram), or blood tests. An ECG measures electrical activity in the heart. Other tests may be used to measure how effectively oxygen and carbon dioxide are being exchanged in the lungs.

TREATMENT

Simple cases of acute bronchitis are treated like a common cold. The patient is told to drink plenty of fluids, to rest, and to avoid smoking. An air humidifier should be used to increase moisture in the air. Acetaminophen (pronounced uh-see-tuh-MIN-uh-fuhn, trade names Datril, Tylenol, Panadol) should be taken for fever and pain. Aspirin should not be given to children because it may cause the serious illness Reye's syndrome (see Reye's syndrome entry).

Coughing that brings up phlegm should not be treated because it helps remove mucus and other harmful materials from the lungs. If not removed, they collect in the lungs and block airways. Cough suppressants can be used with dry coughs, however.

People with bronchitis may get some relief from expectorant cough medicines. While these medicines do not reduce coughing, they do thin mucus in the lungs, which makes the mucus easier to cough up.

Bacterial infections may accompany acute bronchitis. These infections can be treated with antibiotics. The most important rule about antibiotics is to take the full amount prescribed. Failure to do so can cause the infection to return. A variety of antibiotics is available for use with adults, including trimethoprim/sulfamethoxazole (pronounced tri-METH-o-prim/SULL-fuhmeth-OCK-suh-zole, trade names Bactrim or Septra), azithromycin (pronounced uh-zith-ro-MISE-uhn, trade name Zithromax), and clarithromycin (pronounced kluh-rith-ruh-MISE-uhn, trade name Biaxin). Children under the age of eight are usually given amoxicillin (pronounced uh-MOK-sih-SIL-in, trade names Amoxil, Pentamox, Sumox, Trimox).

Chronic Bronchitis

The treatment of chronic bronchitis is complex. It depends on the stage of the disease and whether other health problems are present. An important first step is giving up smoking and avoiding second-hand smoke (smoke from other people's cigarettes) and air pollutants. A regular program of controlled exercise is also important.

Drug therapy begins with bronchodilators (pronounced brong-ko-die-LATE-urs). These drugs relax the muscles of the bronchial tubes and allow air to flow more freely. Common bronchodilators include albuterol (pronounced al-BYOO-tuh-rol, trade names Ventolin, Proventil, Apo-Salvent) and metaproterenol (pronounced met-uh-pro-TER-uh-nol, trade names Alupent, Orciprenaline, Metaprel, Dey-Dose). They can be taken by mouth or inhaled with a nebulizer. A nebulizer is a device that delivers a carefully measured amount of medication to the airways.

Anti-inflammatory medications are used to reduce swelling of airway tissues. Corticosteroids (pronounced kor-tih-ko-STIHR-oids), such as prednisone (pronounced PRED-nih-zone), can be taken by mouth or by injection. Other steroids are inhaled. Long-term steroid use can have serious side effects and should be avoided.

Drugs are available to reduce the amount of mucus produced. Ipratropium (pronounced ip-ruh-TRO-pee-uhm, trade name Atrovent) is one such drug. In the late stages of the disease, patients may need extra oxygen supplied from an oxygen tank through a mask. Hospitalization may also be required to provide the medical care needed in the last stages of the disease.

Alternative Treatment

The focus of alternative treatments is a healthy diet that strengthens the immune system. A number of herbal medicines have also been recommended for the treatment of bronchitis. These treatments include the inhaling of eucalyptus (pronounced yoo-kuh-LIP-tus) or certain other oils in warm steam and drinking a tea made of mullein, coltsfoot, and anise seed. Hydrotherapy, the use of water and water vapors, may also help clean out the chest and stimulate the immune system.

PROGNOSIS

With treatment, acute bronchitis usually clears up in one to two weeks. The cough that accompanies the disease may last for several more weeks, however. By contrast, chronic bronchitis is a progressive disease. Brief improvements may be seen, but in the long term, no cure is available. The disease often develops into emphysema or other lung diseases, all of which are eventually fatal.

PREVENTION

The best way to prevent bronchitis is not to begin smoking or to stop smoking. Smokers are ten times more likely to die of bronchitis and other lung disorders than are nonsmokers. Other irritants in the environment, such as chemicals and air pollutants, should also be avoided. Immunizations (shots) can also help protect against certain diseases of the lungs, such as pneumonia and the flu.

FOR MORE INFORMATION

Books

Adams, Francis V. The Breathing Disorders Sourcebook. Los Angeles, CA: Lowell House, 1998.

Haas, Francois, and Sheila Sperber Haas. The Chronic Bronchitis and Emphysema Handbook. New York: John Wiley & Sons, 1990.

Shayevits, Myra, Berton Shayevits, and the editors of Consumer Reports Books. Living Well with Chronic Asthma, Bronchitis, and Emphysema. Yonkers, NY: Consumer Report Books, 1991.

Smolley, Laurence A., Debra Fulghum Bruce, and Rob Muzzio. Breathe Right Now : A Comprehensive Guide to Understanding and Treating the Most Common Breathing Disorders. New York: W. W. Norton & Company, 1998.

Organizations

American Lung Association. 1740 Broadway, New York, NY. (800) LUNGUSA. http://www.lungusa.org

National Heart, Lung, and Blood Institute Information Center. PO Box 30105, Bethesda, MD 20824–0105. (301) 251–1221.

National Jewish Center for Immunology and Respiratory Medicine. 1400 Jackson Street, Denver, CO 80206. (800) 222–5864.