Pulmonales kapilläres Blutvolumen und Membrankomponente der pulmonalen Diffusionskapazität bei Patienten mit chronisch obstruktiver Bronchitis (COPD)

Abstract

Reduced pulmonary diffusion capacity is a hallmark of COPD, although the relative contribution of the subcomponents of pulmonary diffusion--membranous component (Dm) and capillary volume (Vc)--is unknown. These components can be measured with the method of NO single-breath diffusion (DLNO). In a prospective study, pulmonary function tests including spirometry, body plethysmography and single-breath measurements of diffusion capacity with CO and NO were performed in 183 patients with COPD of varying severity. There was a severity-dependent decrease in DLCO. Furthermore, Dm as well as Vc was positively correlated with the severity of COPD measured by FEV1. In all stages of COPD, reduction of Vc was more pronounced than constriction of Dm. In patients with most severe COPD, the preponderance of the reduction of Vc was significantly more marked than in milder stages.We conclude that Dm as well as Vc contributes to the reduction of DLCO in COPD, with a predominance of Vc at all stages of COPD. This confirms the idea that the loss of pulmonary capillaries in COPD is functionally relevant.

Membrane and Capillary Components of Lung Diffusion in Infants with Bronchopulmonary Dysplasia

“…Researchers in studies of children and adults with a prior history of BPD have reported lower DL CO (25)(26)(27) than healthy controls; however, we are not aware of any previous study evaluating the DM and Vc in subjects with a history of BPD. Studies in adults with differing pulmonary diseases, including chronic obstructive pulmonary disease (28), pulmonary hypertension (29), and idiopathic interstitial pneumonia (30), have demonstrated reductions in both DM and Vc. However, DM/Vc ratios were increased in chronic obstructive pulmonary disease, reduced in pulmonary hypertension, and unchanged in idiopathic interstitial pneumonia, which may reflect the differing pathophysiology of these diseases.…”