Posted on 12 April 2011
The lungs are essential organs of respiration.
Each human has two lungs which are between 10 and 12 inches long. The two lungs are separated by a structure called the mediastinum, which contains the heart, trachea, esophagus, and blood vessels. The lungs are covered by a protective membrane called the pulmonary pleura. The function of the lungs is to maintain the body’s respiration, which means that the lungs bring oxygen to the bloodstream via alveoli (tiny sacs in the lungs). Oxygen provides the body with energy. When oxygen enters the blood, hemoglobin (a protein in red blood cells) picks it up and transports it throughout the body. The lungs also remove carbon dioxide which is a bodily waste produced by cellular metabolism that collects in the tissue of the body. When the lungs do not work properly, it means that oxygen is not getting to the body and that they need to work harder to function. Problems with the lungs, such as pneumonia, lung disease, asthma or other problems put more stress on bodily functions.
Results from pulmonary function tests are necessary for establishing a diagnosis for lung disease and for determining the severity of the disease. Pulmonary function testing with routine spirometry is recommended for all smokers over the age of 45 and in any person presenting with dyspnea (shortness of breath), chronic cough, wheezing, or excessive mucus production. Spirometry is a relatively simple and noninvasive test that can be performed easily. Although many spirometric tests are available, the most commonly used include the forced vital capacity (FVC), the forced expiratory volume in 1 second (FEV1), and the FEV1/FVC ratio. Results from these tests can be used in the early identification of patients at risk for the development of both restrictive and obstructive pulmonary disease before symptoms.
Restrictive lung disease is a group of diseases characterized by the inability to normally inflate the lungs. There are various symptoms of restrictive lung disease that acts as warning. They include shortness of breath after exercise, cough, difficulty in inhaling and exhaling, and wheezing.
Chronic Obstructive pulmonary disease (COPD) is a common disorder characterized by progressive expiratory airflow obstruction. Symptoms develop insidiously over years or decades and include dyspnea, cough, and sputum production. The obstructive airway diseases include emphysema, chronic bronchitis, and asthma.
EMPHYSEMA is a disease of the lung parenchyma (respiratory bronchioles and alveolar walls) that secondarily affects the smaller airways. The lung loses its elasticity and its elastic recoil pressure. Small airways lose traction with the surrounding alveolar walls and become easily collapsible during expiration. Patients with emphysema alter their pattern of breathing in an attempt to perform the work necessary to breath. Patients with emphysema can minimize air trapping by breathing through pursed lips.
CHRONIC BRONCHITIS is a clinical diagnosis for patients who have chronic cough and sputum production. It is defined by the American Thoracic Society as the presence of a productive cough most days during three consecutive months in each of two successive years. The cough is a result of hyper-secretion of mucus, which in turn is the result of an enlargement of the mucus-secreting glands. Unlike emphysema, which primarily involves abnormalities within the lung parenchyma and smaller airways, chronic bronchitis primarily involves the large airways.
ASTHMA is characterized by increase airway reactivity to a variety of stimuli, resulting in widespread reversible narrowing of the airways. Its episodic nature and reversibility are important features separating it from the two other major types of obstructive airways disease. Asthma is related to inflammation and is often initiated by an antigen (any substance that causes your immune system to produce antibodies against it) presented to the airway. An antibody response results in the release of various chemical mediators from mast cells which promotes inflammation of the airway walls and airway smooth muscle. The clinical symptoms of a patient with asthma are similar to that of the other obstructive lung diseases. Shortness of breath and wheezing are commonly present. A diagnosis is made by using a combination of the patients history, clinical examination, and pulmonary function tests. In some, asthma is only present during or after exercise
TREATMENT AND MANAGEMENT
Once a diagnosis of COPD has been made, a multi-faceted approach to the treatment and management of the patient should be adopted. Comprehensive treatment of the patient should include smoking cessation, oxygen therapy, pharmacological therapy, and pulmonary rehabilitation which includes exercise training. Participation in pulmonary rehabilitation program that includes at least 4 weeks of exercise training can result in improvements that are significant for COPD patients. The improvements realized by patients who participate in exercise are in the realm of quality of life specifically in the relief of dyspnea and improvement in patients perception of how well they can cope with their disease. Exercise can improve musculoskeletal and psychological factors that typically limit exercise in persons with pulmonary disease. Because pulmonary disease is commonly associated with Coronary artery disease (CAD), exercise training can reduce the risk of CAD in persons with pulmonary disease.
In general, four approaches are recommended for improving respiratory and skeletal muscle dysfunctions. These include lower extremity aerobic exercise training, ventilatory muscle training, upper extremity strength, and whole-body strength training. The American College for Sports Medicine recommends that the mode of exercise should be any aerobic exercise that involves large muscle groups, such as walking or cycling. The minimal recommendation for frequency is three to five times per week with a minimal duration goal of 20 to 30 minutes of continuous activity.
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