01.12.2015 | Research article | Ausgabe 1/2015 Open Access
Different KCO and VA combinations exist for the same DLCO value in patients with diffuse parenchymal lung diseases
- Zeitschrift:
- BMC Pulmonary Medicine > Ausgabe 1/2015
Wichtige Hinweise
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
JP, DIB and CD2 designed the cohort design and analysis plan. Analyses were performed by CD2. All authors (JP, LP, CP, RB, HN, CD2 and DIB) contributed to recruitment, data collection, discussion of results and final approval of the submitted manuscript.
Abstract
Background
DLCO is the product of the CO transfer coefficient (KCO) by the “accessible” alveolar volume (VA). In theory, the same DLCO may result from various combinations of KCO and VA values, each of which reflect different injury sites and mechanisms. We sought to determine in this study the potential variability of both VA and KCO for fixed values of DLCO in diffuse parenchymal lung diseases (DPLD).
Methods
To this end, we designed a retrospective, cross-sectional study of three distinct types of DPLD and analysed pulmonary function test (PFT) datasets.
Results
We show here that for the same value of DLCO (50 % predicted), KCO varied from 60 to 95 % predicted and VA from 55 to 85 % predicted in various types of DPLD idiopathic pulmonary fibrosis, sarcoidosis and connective tissue disease-associated DPLD, indicating distinct pathogenic mechanisms in these diseases. In addition, a comparison of VA with total lung capacity may help to evidence the distal airway obstruction sometimes associated with certain DPLD particularly sarcoidosis.
Conclusion
Clinicians should take into account not only DLCO but also VA and KCO values when managing patients with DPLD.
