RT Journal Article
SR Electronic
T1 Comparison of different measurement methods of gas diffusion in the lung
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P253
VO 40
IS Suppl 56
A1 Alexandra M. Preisser
A1 Maxi Seeber
A1 Xaver Baur
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P253.abstract
AB Background:Lung fibrosis results in decreases of oxygen diffusion and oxygen arterial partial pressure (Pa,O2) especially during exercise. Obstructive airway diseases are often associated with a mismatch of ventilation and perfusion. We investigated the validity of the CO diffusion capacity (DL,CO) in comparison with Pa,O2 and alveolo-arterial oxygen gradient (AaDO2) in different lung diseases.Methods:250 subjects (52.3±12.5 yrs) were examined, out of 206 there were: 13 with VC<LLN (normal FEV1/VC, DL,CO normal or reduced); 19 with normal VC but DL,CO<LLN; 86 with mild or moderate bronchial obstruction (FEV1/VC<LLN, VC>LLN), and 88 healthy controls. Pearson correlation coefficient of DL,CO with Pa,O2 and AaDO2 were analyzed in each group.Results:DL,CO (%pred.), Pa,O2 at rest, and AaDO2, respectively, showed low correlation in all groups (0.25**; -0.19*)(**=p<0.001, *=p<0.01). DL,CO and Pa,O2 during exercise revealed moderate correlation in the group with bronchial obstruction (0.55**), but there were strong correlations in the groups with reduced VC and/or DL,CO (0.82**; 0.68*). Correlations between DL,CO and AaDO2 during exercise were the best in the latter two groups (-0.84**; -0.64*), medium in the group with bronchial obstruction (-0.47**), but not significant in healthy controls (0.19).Conclusions: Only in patients with reduced VC and/or impaired DL,CO all three parameters are likely to objectify impaired gas exchange in the lungs. AaDO2 relates to the ventilation, this may be the cause of the good correlation with DL,CO. In the group with bronchial obstruction DL,CO seems to be influenced by other pathophysiological aspects, resulting in only moderate correlation between the different parameters.