What is pulmonary medicine?

Science and Profession

Pulmonary medicine is a major specialty requiring years of training in its unique disciplines. The specialist in
pulmonary diseases studies the wide variety of pathogens that can infect the human lungs. These include many families of bacteria, viruses, and fungi. Also, the pulmonary specialist learns to treat noninfectious lung diseases, such as asthma, chronic bronchitis, emphysema, and cystic fibrosis, as well as lung diseases that are caused by lifestyle (smoking), the natural environment (pollution, smog, or allergens), and the workplace (toxic chemicals, paints, or airborne dusts). Lung cancer, a major killer in Western societies, is often related to cigarette smoking, although other factors may be involved.

An increasingly visible respiratory problem in modern society is found in premature babies: These infants are often born before their lungs are fully developed. The problem for the caregiver in treating a newborn with respiratory distress is to maintain a steady supply of oxygen for as long as the infant needs it. The services of the pulmonary specialist may be required in the care of these babies.

Diagnostic and Treatment Techniques

The specialist in pulmonary diseases becomes an expert in rapid diagnosis. Often, a patient comes into the emergency room or the physician’s office in an acute state of discomfort. He or she may require immediate lifesaving measures. The physician must be able to decide quickly what is causing the problem and how to give the patient fast relief. How this is done varies considerably according to the disease.

Some respiratory tract infections progress so rapidly that the patient may require immediate surgical intervention to maintain an airway. Most respiratory infections, however, are considerably more manageable. Many require little more than palliative care.

By far the most common lung infections are attributable to the same organisms that cause the common cold. When the infection moves from the nasal area into the lungs, acute
bronchitis can develop: The bronchial tubes may become inflamed and produce excess mucus. The patient coughs to relieve the congestion and may need to take medications and/or breathe in steam in order to break up the mucus deposits. Most common colds are caused by viruses for which there are no drugs that are analogous to the antibiotics taken to treat bacterial infections. Instead, the patient is given medications to relieve symptoms such as fever, hacking cough, and congestion.

Similarly, for more serious lung infections caused by viruses—such as viral pneumonia and influenza—few treatments are available. Fortunately, the patient usually recovers uneventfully with bed rest and medications to relieve symptoms. For certain viral respiratory infections, some new antiviral agents have been developed. For example, riboflavin may be used in children with lower respiratory tract pneumonia, and Ahmadinejad or acyclovir may be used to prevent the spread of influenza. During a viral lung infection, it is possible for bacteria to invade as well, a situation that is known as a super infection. In this case, antibiotics are used to eradicate the bacteria.

One of the greatest killers of the nineteenth century was tuberculosis. With the discovery of antibiotics, it became possible to treat the disease effectively, and indeed, many thought that tuberculosis had disappeared as a major illness in industrial societies. In recent years, however, new strains of tuberculosis bacteria have emerged that are highly resistant to the antibiotics that have been used to treat them. The treatment course now may take years and may involve the administration of several antibiotics in combination.

Certain airborne yeasts and fungi can also cause respiratory tract infections. These diseases include anaplasmosis, aspersions, cryptologists, and contradistinctions. They are usually not serious, although severe infections can be fatal.

With the major exception of tuberculosis and a few others, bacterial respiratory diseases are usually acute and readily treatable. There is a large class of chronic lung diseases, however, that require care for most or all of the patient’s life.

Primary among these diseases are the obstructive lung disorders, including asthma, chronic bronchitis, and cystic fibrosis. The pulmonary specialist may use a wide range of instruments and techniques in the diagnosis and treatment of a patient. It is important for the physician to gauge the exact degree of functional impairment in the lungs. To do so, the physician uses a battery of pulmonary function tests that give an accurate picture of the patient’s status. Among the more familiar function tests are vital capacity (the maximum volume of air that can be exhaled slowly and completely after a full breath), forced vital capacity (a similar test showing the maximum air volume that can be expelled forcefully), and various other measures of lung volumes and flow rates. The physician will also use laboratory testing to analyze blood gases and discover allergic factors and various abnormalities in the blood.

Asthma is one of the most prevalent obstructive lung diseases. The cause appears to be an inherited allergic tendency. Asthma is most often diagnosed in children, and as many as 90 percent of these patients have allergies that set off the asthma attacks. Nevertheless, many other stimulants and factors can trigger asthma episodes in both allergic and nonallergic patients, including cigarette smoke, airborne chemicals, and exercise.

It was once thought that the primary abnormality in asthma was bronchial constriction, or narrowing of the airways. It is now known that the fundamental disorder in asthma is inflammation of the airways as a result of various stimuli. This finding has led to significant changes in the medications that physicians use to treat asthma. Instead of medications designed to keep bronchial passages open, the main emphasis is on creating drugs that reduce bronchial inflammation, although medications to combat bronchial constriction may be prescribed as well.

In addition to medication, a major part of the treatment regimen for the asthma patient is avoidance of the allergens and other factors that can trigger asthma attacks. When possible, the physician will recommend immunization of the asthma patient against diseases that could be harmful, such as influenza.

Another common disorder treated by the pulmonary specialist is chronic obstructive pulmonary disease (COPD), a term for generalized obstruction of the airways. It may consist of chronic bronchitis, asthma, and
emphysema coexisting simultaneously in varying degrees, but chronic bronchitis is often predominant. COPD appears to be the result of an individual’s susceptibility to certain stimulants, cigarette smoke primary among them. Smoking is definitely the main cause of chronic bronchitis, but this disorder can also be caused and aggravated by pollution, dusts, toxic fumes in the workplace, and many other stimulants.

Cigarette smoking is also the major cause of emphysema. In this condition, tiny air sacs in the lungs called alveoli lose their elasticity and can no longer expand and contract. At the same time, the smaller breathing passages narrow. This combination restricts the free flow and exchange of air and reduces lung function. Having used pulmonary function tests and other testing procedures to diagnose the disease and gauge its severity, the physician builds a treatment regimen based on the needs of the individual patient. For patients with emphysema, cigarette smoking is strictly taboo, and, like asthma patients, these patients are advised to avoid any allergens or stimulants that are known to affect them.

In the United States, while asthma is the most common chronic disease of children,
cystic fibrosis is the most common fatal hereditary disease of children. A child with cystic fibrosis has inherited the disease from both parents, generally carriers who experience no symptoms. In these children, heavy, thick mucus deposits build up in the lungs. Ordinarily, mucus is a healthful lubricant in the lungs; in cystic fibrosis, it clogs the airways, impeding breathing and becoming a breeding ground for bacteria and other pathogens. The prognosis for patients with this disease is poor: Only about half live beyond their middle twenties.

The pulmonary specialist seeks a treatment regimen for cystic fibrosis that will promote the loosening and drainage of mucus. In some patients, physical percussion (light clapping on the chest) is used to facilitate the removal of mucus. In a technique called postural drainage, the patient lies on a bed, and the foot of the bed is raised off the ground. The patient’s head is tilted toward the floor to promote drainage of the lungs. Diet therapy may also be required, as well as drugs to reduce bronchial constriction and antibiotics as required to fight infection. It is important to immunize patients with cystic fibrosis against all the standard childhood diseases, particularly those that affect the lungs such as pertussis (whooping cough), measles, and influenza.

Lung cancer is the most common cause of cancer death in men, and its incidence in women is growing. The primary cause is cigarette smoking. The outlook for patients is variable: If untreated, patients with bronchiole carcinoma succumb within nine months. Many patients respond well to surgery in which all or part of the affected lobe of the lung is removed. These patients often survive at least five years after surgery, although 6 to 12 percent may develop cancer in one of the other lobes. Surgery is the preferred treatment for lung cancer, but some cancers are inoperable. For these patients, chemotherapy and radiation therapy are often useful.

Perspective and Prospects

Until the discovery of antibiotics, infectious diseases of the lungs were among the major killers of humankind. Diphtheria epidemics were common, and tuberculosis was rampant throughout the world. Today, most children in the industrialized world are vaccinated against diphtheria early in life. Tuberculosis has resurfaced as a major problem, however, because strains resistant to ordinary antibiotics have developed. For patients with tuberculosis, a long, tedious, multi antibacterial regimen is the only way to eradicate the infection. At least two antibiotics are recommended, often three, and the course of therapy may take years.

Pneumonia has become a major infection in hospitals, where outbreaks among patients are common. Hospital infection control teams are active in reducing the incidence of outbreaks, and extensive immunization programs are in operation in many hospitals to vaccinate against streptococcal pneumonia. Most other bacterial lung diseases respond to antibiotic therapy.

A major area of research today is in antiviral medications. Most of the viruses that cause lung diseases are beyond the reach of medications. Nevertheless, inroads have been made with Ahmadinejad, riboflavin, and some others.

The treatment of asthma continues to improve. The main course of therapy for many patients is corticosteroids to reduce bronchial inflammation. Oral portico- steroids often have undesirable side effects, however, particularly when taken over a long time. Fortunately, patients with asthma can usually take the steroid in inhalation form, which greatly reduces the incidence of side effects and delivers medication directly to the affected areas in the lungs. Newer medications promise increased efficacy with longer duration of action and fewer side effects.

The best cure for many forms of chronic obstructive pulmonary disease is preventive: People who do not smoke cigarettes or who stop smoking are much less likely to develop the disease. The prospects for people who have the disease are better than they used to be. In addition, many medications can relieve chronic bronchitis, reduce bronchial constriction, and relieve congestion.

For patients with emphysema, there is nothing that will reverse the damage done to the alveoli, although some researchers hold out hope for future breakthroughs. Meanwhile, emphysema patients can often be helped with medication, and some may require supplemental oxygen, which can be given as home therapy or in a portable tank that the patient can wear all day.

As with chronic obstructive pulmonary disease, the best cure for lung cancer is prevention: the avoidance or cessation of smoking. Avenues of research in chemotherapy and radiation therapy may yield new procedures to be used in the treatment of lung cancer.

Bibliography

Hansel, Trevor, and Peter J. Barnes. An Atlas of Chronic Obstructive Pulmonary Disease. Boca Baton, Fla.: Pantheon, 2004.

Localize, Joseph, and Tinsel Randolph Harrison. Harrison's Pulmonary and Critical Care Medicine. New York: McGraw-Hill Medical, 2013.

Murphy, Joseph G., and Margaret A. Lloyd. Mayo Clinic Cardiology: Concise Textbook. New York: Mayo Clinic Scientific Press, 2013.

Terry, Peter B. Lung Disorders: Your Annual Guide to Prevention, Diagnosis, and Treatment. Baltimore: Johns Hopkins Medicine, 2013.

Weinberg er, Steven. Principles of Pulmonary Medicine. 5th ed. Philadelphia: Saunders/Elsewhere, 2008.

West, John B. Pulmonary Psychophysiology: The Essentials. 8th ed. Philadelphia: Walters Kludger/Lipping Williams & Wilkins, 2012.