COPD: Chronic Obstructive Pulmonary Disease

  • What is it? COPD is a progressive, partially reversible respiratory disorder. It includes emphysema and bronchitis.
  • Emphysema: this is an abnormal and permanent enlargement of the air spaces in the lungs. Those alveolar walls are destroyed (that’s where gas exchange occurs) to create larger air spaces (blebs). The lungs can inflate but only partially deflate. Fibrosis occurs. Capillary walls are also destroyed. The airways become narrowed and lungs lose their elasticity. Emphysema can be panlobular (the entire primary lobule is involved whereby destruction and distention occurs distal to the respiratory bronchioles), or centrilobular (the destruction primarily involves the respiratory bronchioles).
  • Chronic Bronchitis: this refers to inflammation of the bronchioles. There is an increase of mucus secreting glands in the trachea and the bronchi, an increase in goblet cells, a disappearance of cilia, and chronic inflammation contributes to the narrowing of small airways. Alveolar macrophages decrease in function, causing an increased risk for infection. The thick, abundant mucus also presents as a perfect medium for bacteria to thrive. It builds up in the lungs overtime, so a chronic productive cough develops as the body attempts to clear it out. The cough must be present for 3 months in 2 successive years to rule out other causes of chronic cough.
  • The difference? Alveolar structures and capillaries are maintained in chronic bronchitis compared to emphysema.
  • Causes: Cigarette smoking is a major contributor to COPD. It stimulates the lungs to produce an inflammatory response, it causes goblet cell hyperplasia, it increases mucus production thus creating sputum accumulation, a chronic cough develops, and airways narrow. Irritants like chemicals, and dusts can also cause COPD. Infections such as respiratory tract infections, the flu, and pneumonia can contribute. Genes may play a role, as can aging. There is a higher prevalence in women, theoretically because they are more sensitive to tobacco smoke.
  • Clinical Manifestations: cough (productive and exacerbated by irritants, respiratory infections, and cold, damp air), sputum production, dyspnea (SOB; perhaps on exertion), barrel chest, prolonged expiratory phase on respiration, wheezes, decreased breath sounds, weight loss or anorexia (increased energy use in effort to breathe), hypoxemia (later stage), increased hemoglobin, polycythemia (RBC production increases in attempt to compensate for hypoxemia), fatigue, limited activity levels
  • Complications: cor pulmonale ~ venous congestion alveolar hypoxia leads to pulmonary hypertension which leads to increased pressure trying to push blood into the heart which eventually means right sided heart failure; acidosis from CO2 buildup stimulates erythropoeisis which means the blood is more viscous which means it’s hard to push blood into the heart which again means eventual right sided heart failure. This venous congestion manifests as peripheral edema, weight gain, and distended neck veins. Acute exacerbations of COPD lead to dyspnea, cough, and sputum production. Acute respiratory failure can occur, as can depression, anxiety, and panic.
  • To Diagnose: listen to lung sounds, note reported symptoms, confirm with spirometry. FVC/FEV1…This refers to the forced vital capacity (largest amount of air one can blow out) and the forced expiratory volume (the amount of air one can blow out in one second). If the value is less than 70%, it is indicative of COPD. Normal values are around 80%.
  • Therapy: stop smoking!!!!!! Bronchodilators (long and short acting). Oxygen therapy for hypoxemia (high or low flow? Administer with humidification. Warn about combustion, O2 toxicity, risks of infection, absorption atelectasis, and CO2 narcosis). Surgery (it’d have to be quite severe though for someone to get a lung transplant or reduce hyperinflation). Breathing retraining (blowing candles; using the abdomen). Effective coughing (to expel secretions). Nutrition therapy (to promote weight loss).
  • As a nurse: health promotion (smoking cessation, avoiding irritants), COPD education, encourage exercise, teach about bronchodilators, encourage sleep, note psychosocial needs (anxiety? teach relaxation techniques such as yoga or music), and discuss end of life issues.

Bottom picture obtained from: http://www.nhlbi.nih.gov/health/health-topics/topics/copd/

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