Emphysema in chronic bronchitis and asthma; a practical therapeutic approach.

Asthma and chronic bronchitis are characterized by bronchial occlusion in expiration. Acute spasmodic asthma, if prolonged, may bring about changes in thoracic structure and diaphragm position which can result in permanent pulmonary inefficiency unless this tendency is corrected by breathing exercises. As expiratory obstruction becomes more chronic, irreversible emphysema develops. Thereafter therapy for bronchopulmonary insufficiency is necessary. The approaches to such therapy have been outlined and briefly evaluated, with emphasis upon the value of intermittent positive-pressure therapy.