Bronchodilator Response Assessment of the Small Airways Obstructive Pattern

Plamen Bokov1, 2, Clémence Martin1, Sémia Graba1, Karine Gillet-Juvin1, Mohamed Essalhi1, Christophe Delclaux1, 2, *
1 AP-HP ; Hôpital Européen Georges Pompidou ; Service de Physiologie, Paris. France
2 Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris. France

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 4593
Abstract HTML Views: 3190
PDF Downloads: 1212
ePub Downloads: 843
Total Views/Downloads: 9838
Unique Statistics:

Full-Text HTML Views: 2363
Abstract HTML Views: 1360
PDF Downloads: 770
ePub Downloads: 524
Total Views/Downloads: 5017

Creative Commons License
© 2017 Bokov et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Service de Physiologie Pédiatrique, Université Paris Diderot, Hôpital Robert Debré, 48, boulevard Sérurier, 75019 Paris, France; Tel: 33140034190; E-mail: christophe.delclaux@aphp.fr



A concomitant decrease in FEV1 and FVC with normal FEV1/FVC ratio and TLC defines small airways obstructive pattern (SAOP) and constitutes a classic pitfall of pulmonary-function-tests interpretation.


To evaluate the prevalence of flow- (FEV1 increase≥12% and 200 mL), volume- (FVC or inspiratory capacity [IC] increase≥12% and 200 mL), flow and volume-, and non-response to bronchodilation in patients with SAOP. An additional objective was to assess whether impulse oscillometry (IOS) parameters allow the diagnosis of SAOP and its reversibility.


Fifty consecutive adult patients with SAOP (FEV1 and FVC < lower limit of normal, FEV1/FVC and TLC > lower limit of normal) diagnosed on spirometry and plethysmography underwent the assessment of reversibility (400 µg salbutamol) on FEV1, FVC, IC and IOS parameters.


The diseases most frequently associated with SAOP were COPD and asthma (26 and 15 patients, respectively). Six patients were flow-responders, 20 were volume-responders, 9 were flow and volume-responders and 15 patients were non-responders. Overall, 26 patients had a significant improvement of IC, and 35 / 50 (70%, 95%CI: 57-83) exhibited a significant bronchodilator response. The difference between Rrs5Hz and Rrs20Hz was increased in 28/50 patients (56%, 95%CI: 42-70 with value higher than upper limit of normal) and its decrease after bronchodilator significantly correlated to FEV1 increase only, suggesting proximal airway assessment.


A significant reversibility, mainly assessed on IC increase, is frequent in Small Airways Obstructive Pattern. Impulse oscillometry is of limited value in this context because of its low sensitivity.

Keywords: Pulmonary function testing, Bronchodilator response, Impulse oscillometry, Obstructive defect, Inspiratory capacity, Distal airways.