Respiratory Disease

e can go without water for days and do without food even longer, but without air we will die in a matter of minutes. Breathing, along with the beating of our hearts, is one of the body's most essential functions, and any disruption can be deadly. Even a minor cold, by affecting our normal intake and outflow of air, can make us feel miserable.

Respiratory problems are common--indeed the most common of all physical complaints. Almost everyone experiences infections of the head, throat, and chest. These infections range from colds to influenza and pneumonia, which can be mildly debilitating or seriously life-threatening.

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How The Respiratory
System Works

The nose, lungs, and diaphragm are the major respiratory organs. As the diaphragm contracts, the rib cage expands. This action creates negative pressure in the lung cavity, and air is then pulled in through the nose. When the diaphragm stops contracting, the lungs recoil and push the air out. Oxygen is exchanged for carbon dioxide (CO ₂) in the blood that flows through the capillaries in any one of the lung's 300 million alveoli. Circulating blood then delivers the oxygen to the body's cells in exchange for CO ₂ and metabolic waste. This trade is known as internal respiration. The lungs subsequently exhale CO ₂-containing air.

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Colds and Flu

The common cold is aptly named: It ranks as the most prevalent infectious disease in humans. Indeed, the common cold accounts for just about as many trips to the drugstore as any other ailment. And although the common cold tends to be benign and brief, this nuisance illness can lead to more serious bacterial infections.

Colds are almost always caused by viral infections of the upper respiratory tract. Many different families of viruses can cause a common cold, and each family has numerous members. The sheer diversity of causative agents is why it has been impossible to develop a vaccine for the common cold.

Different viruses affect different areas of the respiratory tract and may result in fever, chills, malaise, and lethargy. When a virus causes nasal inflammation, you develop stuffiness or runniness, and sometimes postnasal drip. If the virus travels to the pharynx, you get a sore throat or pharyngitis. If inflammation reaches the vocal cords, you may become hoarse or even lose your voice (laryngitis). If the trachea and main bronchi are involved, you will most likely complain of congestion and coughing, and will also produce sputum. This particular medical condition is called tracheobronchitis or acute bronchitis.

Since there is no cure for colds, treatment focuses on the symptoms. Remedies include aspirin, acetaminophen or ibuprofen, increased fluids, and rest. (Avoid giving aspirin to children. It may be linked with a dangerous condition called Reye's syndrome.) Decongestants, throat lozenges, nasal sprays, cough medicines, and expectorants are all used and may or may not ease the symptoms of a cold. In some instances, antibiotics are needed to wipe out any accompanying bacterial infection. This is often the case with bronchitis.

The influenza virus attacks the respiratory tract with particularly debilitating results. Influenza, often called "flu," commonly causes severe aching in the muscles and joints, chills, headache, fever, discomfort, a dry cough, and exhaustion. The virus typically spreads throughout an entire community, often causing serious complications such as pneumonia, and even death. The good news is that influenza can be prevented if you get an annual vaccination.

The treatment of influenza consists of bed rest, increased fluids, aspirin--or for children, acetaminophen--and an expectorant, such as guaifenesin, to treat the cough. Amantadine, an antiviral agent, has proved helpful in reducing the symptoms and the duration of influenza A, and is also used to help prevent it.
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Pneumonia

Pneumonia, an inflammation of the lungs, is usually caused by viruses, bacteria, fungi, protozoa, mycobacteria, mycoplasma, or rickettsia. Pneumonia is a serious matter because the infection may interfere with the lung's very important function of exchanging oxygen and carbon dioxide in the blood.

Common symptoms of pneumonia are fever, shaking chills, pleuritic (lung) pain, cough, and sputum production. In some cases, the resulting sputum may be minimal and off-white in color. Sometimes the patient produces abundant amounts of yellow, green, or brown sputum.

Viral pneumonia is treated symptomatically with adequate liquids and bed rest. Severe cases may require humidified oxygen therapy and mechanical ventilation. The treatment of bacterial pneumonia must also include appropriate antibiotics. There is a vaccine available to prevent the most common bacterial form of this disease.

A CLOSE-UP VIEW OF OUR AMAZING LUNGS

Though they fill most of the chest, the lungs perform their crucial task at an almost microscopic level. Starting at the trachea, or windpipe, the air passages within the lungs divide and redivide into ever smaller branches, or bronchioles, finally terminating in 300 million minute air sacs called alveoli. It's within these capillary-laced sacs that the air we inhale meets our circulatory system, passing fresh oxygen to the blood and removing waste CO2.

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Chronic Lung Disorders

Chronic obstructive pulmonary disease (COPD), the most common chronic lung disorder, currently afflicts some 17 million Americans. And the incidence of COPD is on the rise. Emphysema, chronic bronchitis, asthma (see chapter on allergies), or any combination of these conditions may result in COPD. Smoking is the most common cause of COPD; recurrent infections and allergies may also predispose an individual to this disorder.

Emphysema actually destroys the lung, causing it to lose its elastic properties. As a result, the lungs have trouble expelling air and thus are unable to move air in and out at a normal rate.

Chronic bronchitis involves an inflammation of the bronchial tubes and is characterized by excessive mucus production. The symptoms of chronic bronchitis are cough and sputum production. The disease begins with a typical smoker's cough. Each morning, coughing helps to clear the excess mucus from the lungs. As the bronchitis progresses, shortness of breath develops and eventually becomes chronic.

People with COPD can live relatively normal lives for years. Sooner or later, though, they will notice a growing inability to exercise or do strenuous work, along with the onset of a productive cough. The symptoms tend to get worse as time goes by, and the individual becomes more and more prone to respiratory infections, shortness of breath, and reduced pulmonary function.

Treatment consists of relieving the symptoms of COPD, preventing complications, educating smokers to stop, and encouraging all patients to eliminate any airborne irritants. Patients are also taught deep breathing exercises to strengthen muscles used in respiration and are trained to cough effectively. Oxygen therapy is sometimes necessary as well. The medications prescribed for COPD are bronchodilators such as theophylline (Theo-Dur), antibiotics for infections, diuretics (water pills) to eliminate the fluid retention, and corticosteroids (for chronic bronchitis and asthma).

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The Resurgence of TB

Tuberculosis was declining for many years in America; but, unfortunately, this infection is back and on the rise. Some people who contract tuberculosis fail to take their medication properly. It is this lack of compliance that is often cited as the reason for the increasing spread of this dread disease.

Tuberculosis is a serious, chronic infection. In about five percent of those exposed, tuberculosis develops within one year. However, the infection may also lie dormant for years, emerging as tuberculosis when the person is weakened by another serious illness, such as diabetes, leukemia, or Hodgkin's disease, or when immunity is compromised by immunosuppressive drugs or AIDS. Tuberculosis is transmitted through the air, particularly after an infected person coughs.

The initial infection with TB generally does not produce any symptoms. When symptoms do appear, infected individuals are likely to complain of fever, night sweats, loss of appetite, weight loss, and fatigue. In its reactivated phase, TB may be signaled by a cough with discolored sputum production and sometimes pain in the chest. Patients may also cough up blood. Tuberculosis is caused by Mycobacterium tuberculosis and as such is treated with daily oral doses of antibiotics for at least nine months. The drugs used most often are isoniazid and rifampin (Rifadin, Rimactane).

The diagnostic test for tuberculosis is called a Tine test or PPD skin test. A positive reading indicates that a person has been exposed to tuberculosis but does not necessarily predict who will ultimately develop active infection. People with positive skin test results can often prevent subsequent illness by faithfully taking a one-year course of antituberculosis antibiotics.

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Childhood Respiratory Diseases

Croup, a childhood disease more common in boys than girls, typically occurs between the ages of three months and three years. This disease usually follows a viral infection and is associated with a harsh, grating, creaking sound upon breathing; hoarse or muffled vocal sounds; labored breathing; and the characteristic sharp, barking cough. Depending on the type of infection, croup may also be accompanied by a sore throat, hoarseness, runny nose, rapid pulse, clammy skin, and breathing marked by sharp inward and outward movement of the spot above the sternum and muscles of the rib cage--like a balloon quickly filling and then losing air.

Treatment for croup usually consists of rest, cool humidification while sleeping, and acetaminophen. If the child has severe respiratory distress, hospitalization and oxygen therapy may be necessary. If a bacterial infection is a factor, the child must also take antibiotics.

Epiglottitis is a disorder in which the epiglottis becomes inflamed--often to the point of blocking breathing. Epiglottitis typically strikes children between the ages of two and eight years. It is a critical condition, one that can prove fatal if appropriate emergency treatment is not implemented.

Epiglottitis may begin as a respiratory infection, progressing to complete upper airway obstruction within two to five hours. Symptoms include difficulty in breathing and swallowing, a harsh, grating or creaking sound when breathing, high fever, sore throat, restlessness, irritability, and drooling. Emergency treatment is necessary and includes endotracheal intubation or a tracheotomy, oxygen therapy, and the administration of fluids to prevent dehydration. Patients always receive antibiotics.

For more on childhood diseases, including whooping cough, turn to Chapter 12.

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Other Serious Respiratory Illnesses

Legionnaires' disease got its name from the highly publicized outbreak that occurred in 1976 during an American Legion convention in Philadelphia. Legionnaires' disease is usually an acute bronchopneumonia accompanied by diarrhea, malaise, body aches and headaches, loss of appetite, recurrent chills, and a fever that occurs within 12 to 48 hours and rises as high as 105 degrees. Patients subsequently develop a dry cough that may later produce grayish and sometimes blood-streaked sputum. Other possible symptoms of legionnaires' disease include disorientation, vomiting, nausea, mental sluggishness, and mild, temporary amnesia.

As soon as legionnaires' disease is suspected, antibiotics should be administered immediately. Erythromycin (E-Mycin), alone or in combination with rifampin (Rifadin), is the preferred treatment for legionnaires' disease. If the patient cannot tolerate erythromycin, the doctor may prescribe doxycycline (Vibramycin)--alone or with rifampin-- instead. Treatment may also consist of aspirin or acetaminophen; drugs that increase blood pressure if necessary; fluid replacement; and oxygen therapy.

Pleurisy is an inflammation of the tissue that lines the lungs and the inner surface of the chest wall. Pleurisy is usually a complication of pneumonia, but may also result from viruses, tuberculosis, chest trauma, rheumatoid arthritis, systemic lupus erythematosus (a collagen vascular disease), cancer, pulmonary infarction (a blood clot in the lungs), and Dressler's syndrome (a complication of heart attack). Pleurisy is characterized by a sharp, stabbing pain that intensifies with breathing. The pain may at times inhibit movement on the affected side. Breathing is labored. Treatment involves anti-inflammatory drugs, painkillers, bed rest, and, in severe cases, a nerve block.

Asthma , a grave respiratory disorder affecting millions, is discussed in the chapter on allergies. To learn about lung cancer, turn to Chapter 7.

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