NURS 251 Portage Study Guide 7

main function of the respiratory system - (1) to deliver oxygen to the cells of the body (2) remove carbon dioxide from the body. upper respiratory tract (URT) - outside the chest cavity and includes the nose, and nasopharynx (down to the larynx). lower respiratory tract (LRT) - includes the organs within the chest including the trachea, bronchial tree, and lungs. alveoli - microscopic sacs in lungs, that oxygen diffuses across when a person breathes and is exchanged for carbon dioxide Asthma - - general term for recurrent and reversible shortness of breath resulting from the narrowing of the bronchi and bronchioles - The narrowing of the bronchioles can be caused by bronchospasm, inflammation, edema and the production of mucus. This ultimately obstructs airflow meaning that the carbon dioxide cannot get out and the oxygen cannot get in. allergic asthma - caused by outside factors such as allergens intrinsic asthma - caused by unknown factors. In some cases, certain factors have precipitated the asthma attack such as respiratory infections, stress, or cold weather. COPD/chronic obstructive pulmonary disease - Consists of both emphysema and chronic bronchitis: Emphysema is a disease process involving inflammation of the alveoli. Chronic Bronchitis is characterized by chronic inflammation or irritation on the lower respiratory tract, specifically the bronchi. primary drugs used in the treatment of both asthma and COPD - bronchodilators and a variety of anti-inflammatory and antiallergic agents. similarity between these diseases: - all involve obstruction of airflow through the airways Chemical Mediator - - a substance released from mast cells and white blood cells during inflammation and allergic reactions. - responsible for most of the symptoms and complications associated with asthma and COPD. - Only chemical mediator with known involvement where drug therapy has been shown to help symptoms is leukotrienes. Leukotrienes - - potent bronchoconstrictors with a long duration of action. - stimulate receptors responsible for bronchoconstriction, edema and other inflammatory actions. - Class of drugs that inhibit these actions and have an important role in treating asthma specifically--leukotriene inhibitors Emphysema - - occurs when the air spaces within the bronchioles enlarge as a result of the destruction of the alveolar walls. - As walls are destroyed, there is less surface area available for oxygen and carbon dioxide exchange. - The cause appears to be enzymes that are released in response to inflammation. - These enzymes are increased by air pollution, tobacco smoke, and other irritants to the respiratory tract. - Hyperinflation is the result of the air spaces being enlarged. - These patients have difficulty expelling air from the lungs. - This results in a reduction in gas exchange and the feeling of shortness of breath. - Emphysema causes irreversible lung damage over time. Chronic Bronchitis - - Chronic irritation, usually from cigarette smoke or other environmental pollutants, can lead to chronic bronchitis. - The irritants cause mucus secretions to increase and thicken which can then begin to interfere with gas exchange within the lungs. - Patients often present with a chronic cough, difficulty breathing, and increased respiratory infections. - Drug therapy can provide relief, but it cannot reverse the damage. treatment of both asthma and COPD - Historically: bronchodilation Now: also includes anti-inflammatory component Drug classes: Beta2 adrenergic agonist (bronchodilators) Anticholinergic (bronchodilators) Xanthine derived bronchodilator Inhaled corticosteroids (ICS) (Anti-inflammatory) Leukotriene Inhibitors (anti-inflammatory) Beta2 adrenergic agonist (bronchodilators) - Examples: - Short Acting Beta agonist (SABA)- albuterol, levalbuterol - Long acting Beta Agonists (LABA)- salmeterol, formoterol Administration: - Inhalation- inhaler or nebulizer Use: SABA- Rescue medication LABA- long term controller Asthma and COPD Anticholinergic (bronchodilators) - Examples: - Ipratropium (Atrovent)- short acting