Pulmonary mechanics in diffuse fibrosing alveolitis.

The mechanical and the diffusing lung properties have been measured in 19 cases of diffuse fibrosing alveolitis of unknown etiology (proved by histology in 17 cases). The characteristic findings are: a) a striking reduction of DLCO in all the cases; b) a marked reduction of the static and dynamic compliance, in correlation with the reduction of vital capacity; c) an increase in P1max in correlation with the decrease of FRC; d) an increase of the elastic recoil when it is considered at various percentages of the predicted lung volume, but in some cases a normal shape of the V-P curve if the measured lung volume is taken into account; e) a reduction of the maximum expiratory flows suggesting bronchiolar stenosis; f) alterations of DL more marked than those of CL suggesting that DL is a more sensitive test.