Pulmonary emphysema is defined as a nonuniform pattern of abnormal, permanent distention of the air spaces with destruction of the alveolar walls and eventually a reduced pulmonary capillary bed. It appears to be the end stage of a process that has progressed slowly for many years. Smoking is the major cause. In a few patients, there is familial predisposition associated with a plasma protein abnormality ( deficiency in alpha-1 antitrypsin), making the person sensitive to environmental factors ( air pollution, infectious agents, allergens). Emphysema manifests commonly in the fifth decade of life and is classified as follows:
- Panlobular (panacinar): characterized by destruction of respiratory bronchiole, alveolar duct, and alveoli; air spaces within the lobule are enlarged with little inflammatory disease.
- Centrilobular (centriacinar): cause pathologic changes in the center of the secondary lobule, producing chronic hypoxemia, hypercapnia, polycythemia, and episodes of right-sided heart failure.
Both types of emphysema can occur together.
- Dyspnea with insidious onset progressing to severe dyspnea with slight exertion (major symptom)
- Chronic cough, hyperinflated “barrel chest” due to air trapping, muscle wasting, and pursed-lip breathing
- On ausculatation, diminished breath sounds with crackles, wheezes, rhonchi, and prolonged expiration.
- Hyperresonance with percussion and a decrease in fremitus .
- Anorexia, weight loss, weakness, and inactivity.
- Hypoxemia and hypercapnia, morning headaches in advanced stages.
- Inflammatory reactions and infections from pooled secretions.
Assessment and Diagnostic Method Evaluation entails primarily chest x-rays, chest computed tomography CT) scans, pulmonary function tests, pulse oximetry, blood gases, and complete blood count.
Complications Right-sided heart failure (cor pulmonale) leading to central cyanosis and respiratory failure
Medical ManagementThe major goals of medical management are to improve quality of life, slow progression of the disease, and treat obstructed airways to relieve hypoxia. Treatment is directed at improving ventilation, decreasing work of breathing and preventing infection.
- Smoke cessation
- Physical therapy to conserve and increase pulmonary ventilation
- Maintenance of proper environmental conditions to facilitate breathing
- Psychological support
- Ongoing program of patient education ans rehabilitation
- Bronchodilators and metered-dose inhalers (aerosol therapy, dispensing particles in fine mist)
- Treatment of infection (antimicrobial therapy at the first sign of respiratory infection).
- Oxygenation in low concentrations for severe hypoxemia
Reference: Joyce Young Johnson, Brunner & Suddarth’s Textbook for Medical-Surgical Nursing 11th edition Lippincott Williams & Wilkins pp. 331-333