A importância do estudo da difusão alvéolo-capilar, como complemento da pletismografia, na avaliação funcional de fumadores The importance of diffusing capacity as a complementary study to plethysmography in smokers

This study comprised 194 male and female heavy smokers or ex-smokers (≥ 1 pack-year) aged between 20 and 82, whose symptoms varied. Cases were only selected from patients with normal whole-body plethysmography. Subjects with any significant pathology and occupational risk factors were excluded from the study. Varying degrees of symptoms were found and a range of results from normal plethysmography examination, with abnormal levels of alveolar-capillary transfer, determined by the single-breath method to analyse CO (TL CO and TL CO -VA) coefficients. Using the chi-square test for statistical analysis of the sample revealed a significant variation in sensitivity between both parameters (p=0.0001). Possible limitations of using the single-breath method, of were reduced in this study (ventilatory restriction