Bronchitis

Definition

Bronchitis is inflammation of the walls that line the tube-like bronchial passages (bronchi, bronchioles) that carry air in and out of the lungs.

Description

Inflammation of the bronchial tubes in the lungs means that the lining of the bronchials (mucous membrane) is swollen and tender, usually occurring after an acute cold or respiratory infection in the nasal passageways, sinuses, or throat. Bronchitis occurs most often as a single illness (acute bronchitis), but it can sometimes become chronic bronchitis in which the inflammation occurs several months during the year for at least two consecutive years. Smoking cigarettes or being frequently exposed to other irritants may cause acute bronchitis to develop into a chronic condition. In both acute and chronic bronchitis, inflammation is accompanied by infection, resulting in reduced airflow and causing a cough. The source of infection can be bacterial or viral.

Acute bronchitis can usually be treated effectively in people who are otherwise healthy. Chronic bronchitis is a more serious and potentially long-term illness in which the individual will have a mucus-producing cough for most days in three or four months out of each year. It may act like a cold that will not clear up, but the inflammation gradually scars the lining of the bronchi and bronchioles so that mucus production is continuous and the condition develops again and again. As a result the walls that line the bronchial tubes become thicker, reducing airflow and causing constant inflammation, mucus production and coughing. This may become the permanent condition of the lungs, especially in smokers. Chronic bronchitis may also lead to emphysema , a condition that reduces the lungs' ability to exhale air. Both chronic bronchitis and em-physema are classified as chronic obstructive pulmonary disease (COPD) and often occur together.

Demographics

Acute bronchitis occurs commonly among people of both sexes and all ages, with as many as 34 million doctor visits each year by people seeking care for bronchitis or upper respiratory infection (URI). Acute bronchitis develops in 60% of individuals who have the flu (influenza ). More than 12 million individuals are reported to have chronic bronchitis. Among adults, chronic bronchitis occurs twice as often in men than in women and most often in smokers.

Causes and symptoms

Breathing (respiration) is the main function of the lungs on either side of the chest, each composed of lobes, three in the right lung and two in the left. They exchange oxygen and carbon dioxide, bringing in oxygen from the outside environment into the blood, and releasing carbon dioxide from blood that has circulated. Between the lungs is a central airway, the trachea, which then branches into the two larger bronchi that lead into each lung and divide again into smaller bronchi called bronchioles. Finally, the branching ends in small tube-like passages, the terminal bronchioles, which are composed of air-filled sacs (alveolar sacs) that contain even smaller air sacs (alveoli) that exchange oxygen and carbon dioxide through tiny blood vessels surrounding them. Moisture levels inside the lungs make it a perfect environment for bacterial growth, one of the reasons for development of bacterial and viral infections in lungs that are compromised by disease

Acute bronchitis

Acute bronchitis usually follows a cold or viral infection, especially flu virus, and typically lasts no more than six weeks. In acute bronchitis, passageways that are inflamed during an infection return to normal fairly quickly in normally healthy individuals after the infection is treated. However, acute bronchitis can become worse or recur if the individual smokes.

The first symptom of acute bronchitis after having a cold or upper respiratory infection will be a sore throat that leads to a cough, either dry or with coughing up of sputum. Symptoms may also include tightness in the chest and some mild difficulty breathing. Usually there is no fever and symptoms subside in a week or so, except for a lingering cough.

Chronic bronchitis

Smoking cigarettes is the most common cause of chronic bronchitis. When someone smokes, bronchitis recurs frequently, becoming a chronic condition because the lining of the bronchial tract is continuously

irritated. Likewise, when chronic bronchitis is accompanied by smoking, the lining of the bronchial tract stays inflamed and small fibers (cilia) that normally move irritants and mucus out of the passage-ways stop functioning. Because the lungs are then filled with mucus most of the time, they are more subject to bacterial and viral infections. This cycle of inflammation and infection can cause permanent damage to the lungs and severely limit lung function. At this point the condition becomes chronic obstructive lung disease (COPD), which requires regular medical care and treatment to help maintain lung function.

Other irritants that may cause chronic bronchitis include environmental pollutants (e.g., sulfur dioxide) and industrial pollutants found in certain occupations such as coal mining, metal work, and work in grain mills.

Chronic cough is the most noticeable symptom of chronic bronchitis. Symptoms will also include coughing up (expectoration) of significant amounts of sputum, wheezing and difficulty breathing. Sputum is typically thick, yellow to green, and may have tinges of blood. Coughing and expectoration are worse on arising from sleep. Breathing difficulty may be worse after physical activity. The most characteristic pattern includes severe colds and upper respiratory infections, especially in cold weather months, followed by periods of sputum-producing cough with difficult breathing. Several months may pass before another acute infection occurs, but coughing persists in between. Symptoms become progressively worse with each year.

Diagnosis

A comprehensive history will be taken by the doctor, including childhood illnesses such as asthma , injuries, and medications taken; use of drugs, alcohol and tobacco; and any known pattern of coughs, colds or flu followed by a lasting cough. The doctor may ask if anyone in the family has a history of lung disease. Examination of nose, sinuses and throat may reveal signs of recent infection or irritation. A stethoscope may reveal wheezing or crackling sounds in the chest related to excess production of mucus. If sputum is present, it will be tested for the presence of blood and cultured to identify the presence of specific types of bacteria. Testing for viruses may be done as well. Blood tests, including complete blood count and blood chemistries, may be done to investigate overall health, immune system status, and presence of other possible diseases or conditions. Pulmonary function tests will be performed to measure air volume released by the lungs (forced expiratory volume or FEV) and air capacity of the lungs (forced vital capacity or FVC). X rays may also be ordered to check for increased lung volume, which can occur due to inflation of the lungs. The heart may also be enlarged in individuals with advanced chronic bronchitis.

Treatment

In acute bronchitis, the only treatment is to relieve symptoms. Anti-inflammatory drugs may be prescribed as well a decongestants and drugs to thin bronchial secretions and assist in removing material from the lungs (expectorant). Antibiotics are only given when an individual does not respond to treatment of symptoms and when specific bacteria have been identified in sputum.

For chronic bronchitis, the most important treatment for smokers is to stop smoking. Doctors will often recommend nicotine patches or counseling to help an individual stop smoking. Otherwise, specific treatment is not usually effective. Antibiotics may be given when acute flare-ups of infection occur and specific bacterial causes have been identified. Drug therapy may be used to reduce bronchial secretions and reduce inflammation in the airways. Medications may be given by nebulizers that allow

QUESTIONS TO ASK YOUR DOCTOR

• What caused this condition to develop?
• Can I prevent my symptoms from getting worse?
• Are there things I can do for myself to decrease coughing and to breath more easily?
• How many of your patients have chronic bronchitis?
• What medication or treatment has worked best for your patients with chronic bronchitis?

inhalation of a mist, or by metered dose inhalers (MDIs) that are easy for the individual to carry with them at all times. Types of medication will differ from patient to patient, depending on which medication produces the best response. Sometimes inhaled steroids (corticosteroid drugs) are most effective in reducing inflammation in the bronchial passages, helping to reduce secretions and improve breathing. Corticosteroids have numerous side effects in some individuals, however, including osteoporosis , obesity and problems with glucose (sugar) metabolism. If side effects can be controlled, inhaled steroids can continue to be used to relieve symptoms. In advanced cases, regular testing of oxygen levels may be necessary to determine if oxygen administration should be part of treatment, either at night only or continuously.

Prognosis

Acute bronchitis in otherwise healthy individuals is usually short-term. Chronic bronchitis is long-term, with progressive worsening of symptoms. Respiratory failure can occur in chronic bronchitis that has become severe obstructive lung disease, resulting in a life-threatening situation. Death and disability from chronic bronchitis occur primarily in adults over age 55; some deaths are due directly to complications of COPD and others are due to associated heart and/or lung failure.

Prevention Although any adult can develop acute bronchitis due to colds or flu, preventing repeated infections in the bronchial tract from becoming chronic bronchitis is possible. Preventive measures include:

• Don't smoke.
• Avoid inhaled irritants such as second-hand smoke, chemical fumes and environmental toxins.
• Take supplements to support the immune system (Vitamin C with bioflavanoids), destroy harmful toxins (Vitamin E), heal and improve tissues (Vitamin A) and improve circulation and breathing (Coenzyme Q10).
• Include garlic and onions in meals. Both have an anti-inflammatory enzyme and garlic has natural antibiotic properties against infection.
• Maintain good fluid balance in the body (hydration) by drinking plenty of water and other clear fluids.
• Treat any cold or respiratory infection immediately.

KEY TERMS

Bacterial culture —Planting samples of body fluids (e.g., blood, urine or sputum) in a special broth to determine if bacteria are present. Bacteria will then be stained and identified to help select proper antibiotic treatment.

Bronchi —Larger tubular divisions stemming from the main airway (trachea) into the lungs. Bronchi help carry air to and from the lungs and branch into smaller tubular divisions of the lung.

Bronchial —Any function or condition relating to the bronchi.

Corticosteroid drug —A medication that acts like a type of hormone (cortisol) produced by the adrenal gland of the body. Corticosteroids produced by the body stimulate specific types of functional activity. As a drug, a corticosteroid (sometimes just called steroid) provides extra cortisol, which helps treat infection or trauma to the body.

Emphysema —A chronic obstructive pulmonary disease (COPD) characterized by respiratory airspace enlargement that affects lung function and breathing ability.

Nebulizer —A device that holds and dispenses medications in mist-form. Nebulizers help deliver medication to break up congestion in airways or lungs and to improve breathing ability.

Respiratory failure —Loss of lung (pulmonary) function, which can be an acute or chronic disturbance of breathing ability.

Caregiver concerns

An adult with acute bronchitis will not need special care. Individuals with chronic bronchitis may need assistance with nebulizers or other devices that dispense medications or oxygen. The caregiver must be especially alert to breathing difficulty and understand what actions to take if breathing becomes seriously labored. If the individual has advanced chronic bronchitis, the caregiver must be aware of signs and symptoms of lung and heart failure and understand when to call for help since hospitalization may be needed.

Resources

BOOKS

“Bronchitis.” Infectious Diseases, 2nd ed. J. Cohen et al. eds. Philadelphia: Mosby, 2004.

“Pulmonary Disorders: Bronchitis.” The Merck Manual of Diagnosis and Therapy, Section 6. R.S. Porter, ed. White House Station, NJ: Merck Research Laboratories, 2007. Available at www.merck.com. Accessed Feb 1, 2008.

Balch P A. “Bronchitis.” Prescription for Nutritional Healing. Garden City Park, NY: Avery, 1997.

OTHER

“Bronchitis Causes, Symptoms, Diagnosis, Treatment, and Prevention.” MedicineNet. Available at http://www.medicinenet.com. Accessed Feb.3, 2008.

ORGANIZATIONS

American Lung Association, 61 Broadway, 6th floor, New York, NY, 10006, 212-315-8700, 800-LUNG-USA (800-586-4872), www.lungusa.org.

L. Lee Culvert