Nitric oxide diffusing capacity versus spirometry in the early diagnosis of emphysema in smokers - 09/08/11
, H.A. Gietema b, P. Zanen c, d, R.J. van Klaveren e, M. Prokop b, J.-W.J. Lammers d, J.M.M. van den Bosch c
Correspondence to: I. van der Lee, Spaarne Ziekenhuis, Department of Pulmonary Diseases, PO Box 770, 2130 AT Hoofddorp, The Netherlands, Tel.: +31 23 8907220; fax: +31 23 8907221.Summary |
The diffusion capacity for nitric oxide (DLNO) is independent of pulmonary capillary blood volume and equals the membrane diffusing capacity. Therefore the DLNO could be more sensitive in detecting alveolar destruction than the DLCO.
We measured flow-volumes curves, DLNO, DLCO, the transfer coefficients KNO (DLNO/VA) and KCO (DLCO/VA) and performed computed tomography (CT) scans in 263 randomly selected heavy smokers. Subjects with areas ≥1% of the total lung volume showing an attenuation <−950 Hounsfield Units were considered to have emphysema.
In 36 subjects emphysema was diagnosed with CT, a low KNO was present in 94 subjects, and in 95 subjects a FEV1/FVC ratio <70% was seen. The area under the ROC curve for detection CT-based emphysema was 0.894 for the KNO, 0.822 for the KCO and 0.795 for FEV1/FVC, meaning that the KNO has a slightly higher sensitivity to detect emphysema than the KCO and FEV1/FVC. The positive predictive value of KNO however was low (34.7%), while the negative predictive value of KNO was very high (98.2%), indicating an emphysema exclusion test. The DLNO/DLCO ratio is significantly higher in the study group compared to normal subjects.
Le texte complet de cet article est disponible en PDF.Keywords : COPD, Emphysema, Diffusion capacity, Spirometry, Nitric oxide
Plan
Vol 103 - N° 12
P. 1892-1897 - décembre 2009 Retour au numéro
Article précédent
- Impairments in balance discriminate fallers from non-fallers in COPD
- M.K. Beauchamp, K. Hill, R.S. Goldstein, T. Janaudis-Ferreira, D. Brooks
- Methacholine challenge – Comparison of an ATS protocol to a new rapid single concentration technique
- Johannes Schulze, Martin Rosewich, Carsten Riemer, Melanie Dressler, Markus A. Rose, Stefan Zielen
Bienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.
Déjà abonné à cette revue ?