Structure and Function

The respiratory system is responsible for supplying oxygen to the body and removing carbon dioxide (a waste product) from the body. The structures in this system include the nose, pharynx, larynx, trachea, bronchial tree and lungs.

Most breathing occurs through the nose. The nose also contains the smell receptors. Air travels through the pharynx. The pharynx is commonly referred to as the throat. The pharynx is located behind the nose and mouth, and above the larynx. The larynx is the voice box. The larynx is composed of cartilage and when air is exhaled, the vocal cords vibrate, producing sound. On top of the larynx is a lid called the epiglottis. During swallowing, the epiglottis seals off the larynx so that food and fluids do not enter the lungs. Damage to the epiglottis can cause aspiration of substances into the lungs. Below the larynx is the trachea. The trachea is often called the windpipe. The trachea is located within the chest cavity and divides into two branches (bronchi) just behind the heart. The bronchi continue to branch and divide within each lung like branches of a tree. The final branches end in structures called alveoli. Alveoli are tiny air sacs.

The gases oxygen (O2) and carbon dioxide (CO2) are exchanged between the lungs and the blood at the alveoli. The lungs fill the chest cavity, expanding and deflating each time we breathe. This allows air to move into and out of the lungs. Cells within the body will die within a matter of minutes without oxygen. Surrounding the lungs is the pleura. The pleura is a double-layered sac that reduces friction on the lungs during breathing.

Age-Related Changes

Long-term exposure to air pollutants, as well as the normal aging process, causes a decline in lung function. With age, the alveoli tend to lose their elasticity, and their walls thin and tear. Alveoli become more fragile and enlarge. The cartilage connecting to the ribs becomes more rigid and stiff, and the muscles between the ribs weaken, which makes breathing more difficult. With age, people exhale less air. The air left in the lungs has less oxygen than fresh air, which can reduce the amount of oxygen readily available. With age, people are less responsive to oxygen needs and can become oxygen-deprived more easily. The ability to cough effectively also decreases with age, which leads to an increased susceptibility to infections. The incidence of chronic lung problems is more prevalent in the elderly than the general population.

Upper Respiratory Infection

The most common disorder of the respiratory tract is an upper respiratory infection (uri). A URI is caused by a virus or bacteria. Symptoms include fever, body aches, stuffy nose, irritated and itchy eyes, cough, and sore throat. Most people average 2-3 per year. A URI lasts 7-10 days and usually goes away without complications. The elderly person, however, is more susceptible to complications such as pneumonia. Treatment consists of treating the symptoms.

Influenza

Influenza is a highly contagious viral infection. It is similar to URI; however, the symptoms can be much more severe. In the elderly, the chances of complications are greatly increased. Your employer probably offers you and every resident a flu shot each fall. Flu vaccination can greatly reduce the incidence of the infection and/or minimize complications. Antiviral drugs may be prescribed to reduce the severity of the infection.

Pneumonia

Pneumonia is an inflammation of the lungs. It is one of the most frequent causes of death in the elderly. An infection or some irritant to the lung tissue, such as food entering the lung, can cause pneumonia. In residents with pneumonia, the alveoli fill with pus and cause the lungs to solidify. This decreases oxygen exchange and frequently requires hospitalization. Pneumonia is often caused by bacteria or a virus. Aspiration pneumonia occurs when something is inhaled or dropped into the lungs. Elderly persons often do not show the usual signs of pneumonia such as fever and cough. Elderly people are more likely to show signs of increased respiratory rate and heart rate, confusion, agitation, or dehydration before other signs appear. Residents who have limited physical activity, chronic illnesses, difficulty swallowing or feeding tubes are more likely to contract pneumonia.

Treatment of pneumonia includes monitoring the person’s breathing, swallowing and fatigue. If a person develops difficulty swallowing, he or she should be evaluated for possible aspiration. Antibiotics are given for bacterial pneumonia. Expectorants may be given to help expel mucus if the person has an adequate cough. Antitussives are given to prevent coughing in people who are not required to cough to expel secretions, such as a resident who has a dry, nonproductive, weak cough causing pain and fatigue.

Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible condition that diminishes the ability of the lungs to exchange oxygen and carbon dioxide. Diseases that fall under this group include emphysema and chronic bronchitis. Common symptoms include dyspnea, fatigue and persistent cough.

Emphysema causes damage to the structure of the alveoli. With emphysema the walls of the lungs are destroyed, resulting in large air spaces where gas exchange cannot occur. Less oxygen is available to the blood. The ability of the lungs to expand and contract is reduced. Exhalation becomes increasingly difficult. The person with emphysema may use the muscles of the neck, jaw and abdomen to breathe. With emphysema, the chest may enlarge and become barrel-shaped. Cigarette smoking is a common cause of emphysema. The symptoms of emphysema include difficulty breathing, chronic cough and frequent respiratory infections.

The goal of treatment for COPD is to slow the progression of the disease. There is no cure for the disease. Symptoms are controlled with oxygen therapy and medications. A variety of medications are used by different routes such as aerosol mists, inhalers, oxygen therapy and oral routes. Prevention of infection is important.

Bronchodilators relieve muscle spasms of the airways and assist in raising sputum. Bronchodilators allow more air to enter the lungs. Handheld, metered dose inhalers are often used to deliver bronchodilators directly into the air passages.

Drugs that Affect the Respiratory System

1. Antituberculosis agents treat tuberculosis.
2. Antiviral medications treat viral infections.
3. Vaccinations contain weakened or dead diseasecausing organisms, given to allow an individual to develop immunity.
4. Oxygen supplements the room air and increases the amount of oxygen available to the lungs, blood and cells.
5. Corticosteroids reduce inflammation in lung tissue.
6. Antitussives control coughing. Codeine is a narcotic antitussive that is very effective but can cause drowsiness and constipation. Non-narcotic antitussives include dextromethorphan (Robitussin DM) or diphenhydramine (Benadryl) and are commonly found in over-the-counter cough medicines.
7. Expectorants thin the secretions in the lungs, making them easier to cough out. Common expectorants include guaifenesin (Robitussin), potassium iodide and terpin hydrate. Common side effects include stomach upset and allergic reactions. Expectorants are frequently combined with other drugs such as antihistamines, antitussives and decongestants.
8. Antihistamines block the action of histamine. Histamine is the chemical made by the body that produces the symptoms of stuffy nose and sneezing. Antihistamines may produce side effects such as sedation, dry mouth, constipation, blurred vision and urinary retention. They should not be given to persons with glaucoma, prostate problems or emphysema. Common antihistamines include diphenhydramine (Benadryl), loratadine (Claritin) and cetirizine (Zyrtec).
9. Decongestants reduce swelling in the nose, slow the formation of mucus and permit the drainage of mucus. They can be administered orally, by inhalation, or topically to the lining of the nose. Decongestants may elevate blood pressure. Common decongestants include phenylephrine (Neosynephrine and Sudafed).
10. Bronchodilators dilate the bronchi so there is more room for air to travel into and out of the lungs. Some of these drugs may be given either orally or by inhalation. There are many sub-classifications of bronchodilators, and common bronchodilators include albuterol sulfate (Ventolin), theophylline (Theodur), triamcinolone (Azmacort) and montelucast (Singulair).
11. Antipyretics reduce fever. Most antipyretics are also analgesics. Recommended doses of antipyretics are the same whether for fever or pain. Many medications contain acetaminophen, and care should be taken to prevent overdose.
12. Antibiotics (anti-infectives, antibacterials) inhibit or kill bacteria. Antibiotics treat infection anywhere in the body. There are many different types of bacteria, and each antibiotic works on a different type of bacteria. The most common side effects of antibiotic therapy include allergic reactions, nausea, vomiting, diarrhea, sensitivity to sunlight, and secondary infections such as a vaginal yeast infection or fungal infection of the mouth (thrush).
13. Antineoplastic drugs treat cancer. Antineoplastic drugs act by interfering with the growth, reproduction and/or other activities in cancer cells. Common side effects include nausea, vomiting, hair loss, diarrhea, exhaustion, tingling in the extremities and abnormal blood count. Antineoplastics should be carefully handled and should not be touched by bare skin.