DISABILITY IN PATIENTS WITH OBSTRUCTIVE PULMONARY DISEASE

Abstract

The purpose of the investigation was to relate the decrease in exercise tolerance and the inability to work in patients with obstructive pulmonary disease to specific alterations in pulmonary function. Thirty men, aged 32 to 51 years, were studied. Pulmonary function tests included spirometry and the measurement of lung volumes, single-breath diffusing capacity, and arterial blood gases at rest and with exercise. Exercise performance was studied by means of a treadmill exercise test. Tests which measured the degree of obstruction correlated with exercise performance; of these, the 1-second forced expiratory volume test showed the best correlation. The degree of variation, however, was such that individual exercise tolerance could not be reliably predicted from any of the standard pulmonary function tests. The exercise tolerance test proved more reliable than the usual pulmonary function tests for selecting patients unable to maintain full time employment. It could not be clearly demonstrated that ability to tolerate abnormal blood gases or ability to limit ventilation favorably influenced exercise tolerance.