Pulmonary mechanics in patients with diffuse interstitial lung disease and normal lung volume.

Static expiratory pressure-volume curves obtained in 20 patients with diffuse interstitial lung disease and lung volume within normal ranges (i.e. in patients in an early stage of the disease) showed different patterns of abnormal lung elastic recoil: 1) P-V curves with normal shape but shifted to the right, which suggest an overdistension of a reduced number of functioning alveoli ("lung shrinkage") and 2) flattened P-V curves (i.e. with low static compliance) also shifted to the right, which argue for an abnormal distensibility of most alveoli or a more diffuse spreading of lesions. These patterns suggest a multifactorial genesis of the increased elastic recoil in diffuse interstitial lung disease.