Clinical significance of small airway obstruction markers in patients with asthma

• DOI: 10.1111/cea.12257
• Publication Date: 2013-12-16T17:07:10Z
• Authors: S. Gonem; S. Natarajan; D. Desai; S. Corkill; A. Singapuri; P. Bradding; P. Gustafsson; R. Costanza; R. Kajekar; H. Parmar; C. E. Brightling; S. Siddiqui
• Keywords: Airway obstruction; Plethysmograph; Clinical Significance; Vital capacity; Air trapping; Small airways

The role of small airway obstruction in the clinical expression asthma is incompletely understood.We tested hypotheses that markers are associated with (i) increased severity, (ii) impaired control and quality life (iii) frequent exacerbations.Seventy-four adults 18 healthy subjects underwent impulse oscillometry (IOS), multiple breath inert gas washout (MBW), body plethysmography, single-breath determination carbon monoxide uptake spirometry. Patients completed six-point Asthma Control Questionnaire (ACQ-6) standardized Quality Life [AQLQ(S)]. severity was classified according to Global Initiative for (GINA) treatment steps.The putative Sacin , resistance at 5 Hz minus 20 (R5-R20) reactance area (AX) were not independently control, or exacerbations. In contrast, total (R5) mean large airways (R20) significantly higher severe group compared mild-moderate (0.47 vs. 0.37, P < 0.05 R5; 0.39 0.31, 0.01 R20). strongest independent contributors ACQ-6 score R20 forced expiratory volume one second (% pred.), AQLQ(S) vital capacity pred.). A history more exacerbations within previous year R20.Previously reported do appear be disease expression. IOS parameter R20, a marker both airways, appears have significance. These observations require confirmation prospective longitudinal studies.