Altered pulmonary gas transfer capacity and capillary blood volume in pediatric Crohn's disease

Objectives To describe diffusing capacity for carbon monoxide (DLCO) and its components, that is, membrane diffusing capacity (DmCO) and pulmonary capillary blood volume (Vc) in children with Crohn's disease (CD), and to investigate the correlation between these parameters and disease activity. Working Hypothesis The most common lung function abnormalities are a reduced pulmonary DLCO and small airways disorders which are in many instances, clinically silent. No valid explanations have been proposed regarding the modifications in gas transfer capacity in active CD. Methods DLCO, DmCO, and Vc were measured in 25 CD children by the simultaneous single breath lung diffusing capacity method using nitric oxide (NO) and carbon monoxide (CO) transfer. These parameters were analyzed in relation to the CD disease activity index. Results DLCO (90.7 ± 4.5% vs 128.5 ± 4.7%; P