Emphysema, Pulmonary

the name for various pathological conditions characterized by an excessive amount of air in the lungs.

Pulmonary emphysema may be congenital or acquired, localized or diffuse, and acute or chronic. In humans, it is caused by a deficiency of the enzyme α₁-antitrypsin. Acute acquired emphysema is caused by acute bronchial obstruction, as in bronchial asthma. Chronic diffuse emphysema often develops as a complication of chronic bronchitis, bronchial asthma, pulmonary fibrosis, pneumoconiosis, and other diseases of the bronchopulmonary system as a result of bronchial obstruction. Exhaling requires increased pressure within the alveoli, which leads to compression of small bronchi, entry of air into collapsed alveoli through the interstitial pores, and merging of the alveoli.

The disease also decreases the elasticity of pulmonary tissue. The volume of the lungs increases, the alveolar septa become attenuated, and the capillaries break down. Patients suffer from a cough, sometimes with sputum, as well as shortness of breath and difficulty in exhaling. The chest is barrel-shaped, and the intercostal spaces are flattened. Characteristic body changes are revealed by percussion and auscultation of the lungs, X-ray examinations, electrocardiograms, and the determination of the lung capacity and other parameters of external respiratory function. Progressive emphysema gives rise to cor pulmonale and pulmonary and cardiac insufficiency.

Treatment depends on the main process in the lungs. It includes the use of antispasmodics, expectorants, oxygen therapy, antibiotics, sulfanilamides, and corrective exercise. Prevention requires the prompt treatment of chronic respiratory diseases, especially chronic bronchitis.