[Obstructive pulmonary emphysema. Evolution of various parameters of pulmonary function and its correlation].

A follow-up study was carried on in a series of 20 patients with chronic obstructive pulmonary disease. The parameters analyzed were forced expiratory volume in the first second (FEV1), maximum voluntary ventilation (MVV), forced expiratory flow (FEF), vital capacity (VC), and diffusing capacity of lung (DL). Considering the importance of the parameter changes observed, each of these parameters were divided in three groups. The period of observation was of two and a half years in 9 patients, and between two years and seven months to four years in 11 patients. The follow-up was characterized by stability of the parameters in cases with the greatest degree of changes, and a definite deterioration of the parameter values in patients with minor degree of basal changes. It was observed an excellent correlation between FEV1 and MVV and FEF. As to CV and DL, the relationship was only good. These findings lead us to believe that MVV and FEF values can be predicted about from the FEV1 results.