[Carbon monoxide alveolar-capillary diffusion: considerations on inter-personal variability].

: Twenty three male subjects 21 to 53 aged were undergone to lung diffusion test using breath holding method. Each subject was tested three times in different days. The results were evaluated by Bartlett's Chi-square test and by Kendall's coefficient of concordance. Correlation between the CO distribution and diffusion index (R&DCO), the Helium distribution index (RHe), the time of breath holding and the volume of "single breath" was found. It seems it will be possible to improve the inter-personal estimation to 1.25% about.