[Usefulness of an exercise pulmonary function test for differential diagnosis or treatment evaluation of restrictive...

To simplify its applications in patients in poor condition such as cases of idiopathic interstitial pneumonia (IIP), we chose a simple method of exercise test instead of the usual method. The method consisted of the single Master's two-step test and instant blood-gathering without keeping a needle in a vessel. By this method, PaO2 after exercise was estimated approximately 7 torr less than with the usual method, but tendencies of PaO2 changes were accurately observed. In a study on 8 patients with IIP, 20 collagen vascular disease cases with pulmonary changes (CVD), 11 hypersensitivity pneumonitis cases, and 5 sarcoidosis cases, the parameters such as delta PaO2 or delta AaDO2 differentiated the different physiological conditions of the 4 disease groups accurately. However, the exercise test was noted to be less sensitive in terms of differential diagnosis than the at-rest test after a multiple discriminant analysis in the 4 disease groups. For the estimate of patient prognosis delta AaDO2 was most useful in a study of IIP and CVD patients. We conclude that this simple exercise test is useful for the diagnosis or evaluating treatment of such restrictive pulmonary disease.