Pulmonary function measurements

Abstract

1. 1. An accurate evaluation of the degree of pulmonary function impairment may be made from the following physiologic tests: (1) ventilation measurements from spirogram tracings (total vital capacity, three-second vital capacity, maximal breathing capacity and the shape of the exhalation curve following a deep breath); (2) the degree of bronchospasm present; (3) the residual volume and alveolar nitrogen percentage after seven minutes of oxygen breathing; (4) the arterial blood-oxygen saturation at rest and immediately after step-up exercise; (5) the oxygen uptake during step-up exercise; (6) the percentage of oxygen extracted from the inspired air breathed; and (7) the character and duration of dyspnea after step-up exercise. 2. 2. A numerical ventilation factor derived from the three-second vital capacity (a timed measurement), the maximal breathing capacity and the residual percentage of total lung volume, the three most important aspects related to breathing resistance and pulmonary ventilation, has been found to be a useful measurement in pulmonary function evaluation. 3. 3. The great importance of comparing resting and exercise measurements in pulmonary function studies, and especially arterial blood-oxygen saturation, is stressed. 4. 4. Intermittent positive pressure breathing has been found a helpful treatment procedure for oxygen administration in hypercapnia and for giving some relief from the dyspnea of chronic pulmonary insufficiency. The more effective treatment of the bronchospasm, the improved bronchial drainage and the deep-breathing exercise constitute the more important aspects in decreasing breathing resistance and, in turn, the dyspnea.