Ventilation Heterogeneity and Airway Hyperreactivity in Children with Well Controlled Asthma
- *Corresponding Author:
- Stephanie D. Davis, MD
Section of Pediatric Pulmonology
Allergy and Sleep Medicine, Riley Children’s Hospital
705 Riley Hospital Drive, ROC 4270, Indianapolis
Tel: (317) 948-7769
Fax: (317) 944-7247
E-mail: [email protected]
Received date: January 23, 2016; Accepted date: February 22, 2016; Published date: February 25, 2016
Citation:Assaf SJ, Clem CC, Jewett LB, Schornick L, Tiller CJ, et al. (2016) Ventilation Heterogeneity and Airway Hyperreactivity in Children with Well Controlled Asthma. J Pulm Respir Med 6:321. doi:10.4172/2161-105X.1000321
Copyright: © 2016 Assaf SJ, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Rationale: In asthma, airway inflammation, obstruction and reactivity may lead to ventilation heterogeneity; our understanding of this process is limited in asthmatic children.
Objectives and Methods: The study’s objective was to measure ventilation heterogeneity, by the lung clearance index (LCI), in children with well controlled asthma and assess the association of LCI with airway reactivity through methacholine challenge tests. LCI and spirometry were measured in 24 children with asthma and 21 healthy controls between 4 and 10 years of age. Sixteen children with asthma and 11 healthy controls also performed methacholine challenge tests.
Results: LCI was higher in children with asthma compared to healthy controls (7.58 vs 6.79, p=0.004); no differences in FEV1 or FEF25-75 were noted between groups. Ages were similar (p=0.54); however, the slope of LCI versus age differed between groups (p=0.001). The LCI slope increased with age in asthmatics. Further, higher LCI values were associated with decreasing PC20 (provocative concentration of methacholine to decrease baseline FEV1 by 20%) values in children with asthma (p=0.02), but not healthy controls (p=0.16).
Conclusions: Ventilation heterogeneity is present from preschool age in children with well controlled asthma. The relationship between ventilation heterogeneity and airway reactivity suggests that normalizing ventilation heterogeneity may be an important therapeutic target for treating children with asthma.