Chronic Airflow Limitation And Chronic Obstructive Pulmonary Disease Biology Essay

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Chronic airflow limitation (CAL) was formerly called chronic obstructive pulmonary disease (COPD). This term is used to describe a condition that is common in three diseases which are pulmonary emphysema, chronic bronchitis, and bronchial asthma. There are differences in each of these diseases like the clinical history, course of each disease, and origin of the specific illness. There is a common condition to all three of the diseases and this condition is an obstruction of the small airways. It can also be called chronic obstructive lung disease (COLD) or chronic airway obstruction (CAO). There is an estimated 20% to 30% of the adults in the United States that are affected by COPD and there are about 20 million Americans that suffer from COPD. COPD is the fourth leading cause of morbidity and death in the United States and it is projected to rank 5th in 2020 in burden of disease worldwide.

There is a dramatic increase in the rate of death and morbidity due to COPD with the increases in smoking and the increase with air pollution. The main risk factor for COPD is due to chronic smoking, The likelihood of developing COPD increases with age and the exposure to cigarette smoke and the lifers that do smoke will eventually develop COPD. The other factor is a genetic susceptibility to the destruction of lung tissue, which is a lack of a serum protein called AAT and is genetic. The protein inhibits the activity of an enzyme called elastase which breaks down lung tissue. So when there is no AAT the lung tissue is destroyed by this enzyme, and they have a greater risk of developing this at an early age.

Pulmonary emphysema is a permanent distension of the bronchioles and a destruction of the walls of the alveoli. It is a disease of the terminal respiratory units. The air that is inhaled will become trapped which will cause them to work harder to exhale the air rather than inhale it. As the pulmonary emphysema progresses they will loose the elasticity of the lungs. The diaphragm will become permanently flattened by the over distention of the lungs, the muscles of the rib cage will become rigid, and the ribs can flare outward. Many of the people with COPD will look like they have a barrel chest. People with COPD will start to use other muscles, such as the neck and shoulders, to compensate for loss of the normal muscles that are used for respiration. They will hold there shoulders high in attempt to enlarge the space where the lungs can expand. They will feel anxiety and tension because of the struggle to get enough air into lungs. If they have pure emphysema without any asthma or bronchitis, they have very little mucus, the skin may still have a pink color even when there is hypoxia. The carbon dioxide is usually not retained so there would not likely be an acid base imbalance.

Chronic Bronchitis is inflammation of the bronchi and is chronic when there is a recurrent cough for at least three months out of the year for at least two years. Chronic bronchitis can be a mild cough in the morning with small amounts of sputum to a severe disabling condition. It is characterized by an increase resistance to airflow, hypoxia, and frequently hypercapnia and cor pulmonale. The clinical characteristics of chronic bronchitis is a productive cough that is due to hyperplasia of the bronchial glands and an increase in the secretion of mucus. There is also breathing difficulties that are normal for obstructive lung disease. There is testing such as a pulmonary function test that will reveal an increase in the residual volume which is from the premature closure of the narrowed airways when we exhale. They will have an increase in the PaCO2 levels and a decrease in the PaO2 levels. The skin will have a reddish blue color because of the retention and deficiency of oxygen. The reddish color is also from an increase in the red blood cell count which is also called polycythemia. There is also elevated hemoglobin and hematocrit levels. The body is trying to compensate for the chronic hypoxia by increasing the red blood cells.

Asthma is a chronic lung disease that is characterized by a reversible airway obstruction, airway inflammation from edema or swelling, and the airway is sensitive to a variety of stimuli. There is also a hypersensitivity in the trachea and bronchi from various kinds of stimuli. There is no single cause for the group of symptoms that cause asthma but allergens, viruses, toxins, exercise, and psychological disturbances can make it worse. The symptoms of asthma are from the constriction of the bronchi, inflammatory changes in the mucosa, secretion buildup in the lumen of the bronchi, and changes in the elastic recoil of the lungs. To know what a person goes through when they have an asthma attack is to try to breath through a straw. Some of the people with asthma have no symptoms between attacks, but the pulmonary function test will reveal abnormalities even when there are no signs such as wheezing or coughing. Coughing is a common symptom in adults with asthma and it indicates an obstruction of the larger airways. Dyspnea is another symptom and it indicates edema or mucus in the smaller airways.

Bronchiectasis is another chronic respiratory disorder where one or more of the bronchi are permanently dilated. Some people think that it is from a lot of respiratory infections as a child. Cystic fibrosis is a major cause of bronchiectasis and it will eventually result in COPD. It is a genetic disease where there is an excessive mucus production because there is a dysfunction with the endocrine gland. There are many organs that are affected such as the lungs, intestines, sinuses, reproductive tract, sweat glands, and pancreas. The lung damage is from an excessive amount of abnormally thick mucus, an impairment of the ciliary action of the lungs, an airway obstruction and repeated infections. This use to be a childhood disease because the children usually died before adulthood, but today about 20% of the patients with cystic fibrosis are adults.

Many of the people with COPD have a combination of emphysema, chronic bronchitis, and asthma and the treatment is aimed at managing the underlying symptoms. The goal is to minimize irritation of the air passages and relieve the obstructions of secretions, edema, or bronchospasms. They also try to prevent or control infection and allergies, try to increase the ability of activity, and get the right drug combinations that can control the symptoms. They may need oxygen for moderate or severe hypoxemia to raise the PaO2 above 60 mm Hg, this is used with patients who have consistent PaO2 levels less than 55 to 59 mm Hg. Because the patient has adjusted themselves to have high levels of CO2 and low oxygen levels, giving them too much oxygen can make the patient stop breathing.

There is no cure for this disease but there are treatment options to slow the progression of the disease and help with the side effects. Smoking cessation is the most important thing if you do smoke. There are more medications out there to help people to quit smoking. People who have an infection that is associated with COPD are treated with antimicrobials. There are also drugs that can relax the airway wall muscles that help you to breath better and this class of drugs is known as bronchodilators. Corticosteroids are also used to manage acute exacerbation of COPD because they shorten the recovery time, they also improve the lung function and hypoxemia. They are not used as wildly because of the dangerous side effects. There is also aerosol therapy which is medication in the form of a mist that used by a nebulizer. These nebulized aerosols relieve spasms in the lungs, decrease swelling and make the secretions easier to cough up. Pulmonary rehabilitation is used with people that have debilitating symptoms. They use a team of specialists such as doctors, nurses, respiratory therapists, physical therapists, occupational therapists and psychologists. They all help the patient cope with the disease through the physical, psychological and social standpoint. This has been proven to help the patient. Another treatment option is oxygen therapy, flu shots, pneumonia vaccines, and surgery. There are three types of surgery that can be an option with patients that have end stage emphysema. They are bullectomy, lung volume reduction surgery and lung transplantation.