Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease

Background The prevalence of small airway dysfunction (SAD) in patients with chronic obstructive pulmonary disease (COPD) across different ethnicities is poorly understood. This study aimed to estimate the prevalence of SAD in stable COPD patients. Methods We conducted a cross-sectional study of 196...

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Main Authors: Amit K. Rath, Dibakar Sahu, Sajal De
Format: Article
Language:English
Published: The Korean Academy of Tuberculosis and Respiratory Diseases 2024-04-01
Series:Tuberculosis and Respiratory Diseases
Subjects:
Online Access:http://e-trd.org/upload/pdf/trd-2023-0139.pdf
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author Amit K. Rath
Dibakar Sahu
Sajal De
author_facet Amit K. Rath
Dibakar Sahu
Sajal De
author_sort Amit K. Rath
collection DOAJ
description Background The prevalence of small airway dysfunction (SAD) in patients with chronic obstructive pulmonary disease (COPD) across different ethnicities is poorly understood. This study aimed to estimate the prevalence of SAD in stable COPD patients. Methods We conducted a cross-sectional study of 196 consecutive stable COPD patients. We measured pre- and post-bronchodilator (BD) lung function and respiratory impedance. The severity of COPD and lung function abnormalities was graded in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. SAD was defined as either difference in whole-breath resistance at 5 and 19 Hz > upper limit of normal or respiratory system reactance at 5 Hz < lower limit of normal. Results The cohort consisted of 95.9% men, with an average age of 66.3 years. The mean forced expiratory volume 1 second (FEV1) % predicted was 56.4%. The median COPD assessment test (CAT) scores were 14. The prevalence of post-BD SAD across the GOLD grades 1 to 4 was 14.3%, 51.1%, 91%, and 100%, respectively. The post-BD SAD and expiratory flow limitation at tidal breath (EFLT) were present in 62.8% (95% confidence interval [CI], 56.1 to 69.9) and 28.1% (95% CI, 21.9 to 34.2), respectively. COPD patients with SAD had higher CAT scores (15.5 vs. 12.8, p<0.01); poor lung function (FEV1% predicted 46.6% vs. 72.8%, p<0.01); lower diffusion capacity for CO (4.8 mmol/min/kPa vs. 5.6 mmol/min/kPa, p<0.01); hyperinflation (ratio of residual volume to total lung capacity % predicted: 159.7% vs. 129%, p<0.01), and shorter 6-minute walk distance (367.5 m vs. 390 m, p=0.02). Conclusion SAD is present across all severities of COPD. The prevalence of SAD increases with disease severity. SAD is associated with poor lung function and higher symptom burden. Severe SAD is indicated by the presence of EFLT.
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spelling doaj.art-6521efd45326495f80894f1ee534cf972024-04-01T07:30:27ZengThe Korean Academy of Tuberculosis and Respiratory DiseasesTuberculosis and Respiratory Diseases1738-35362005-61842024-04-0187216517510.4046/trd.2023.01394854Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary DiseaseAmit K. Rath0Dibakar Sahu1Sajal De Department of Pulmonary Medicine, All India Institute of Medical Sciences, Raipur, India Department of Pulmonary Medicine, All India Institute of Medical Sciences, Raipur, IndiaBackground The prevalence of small airway dysfunction (SAD) in patients with chronic obstructive pulmonary disease (COPD) across different ethnicities is poorly understood. This study aimed to estimate the prevalence of SAD in stable COPD patients. Methods We conducted a cross-sectional study of 196 consecutive stable COPD patients. We measured pre- and post-bronchodilator (BD) lung function and respiratory impedance. The severity of COPD and lung function abnormalities was graded in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. SAD was defined as either difference in whole-breath resistance at 5 and 19 Hz > upper limit of normal or respiratory system reactance at 5 Hz < lower limit of normal. Results The cohort consisted of 95.9% men, with an average age of 66.3 years. The mean forced expiratory volume 1 second (FEV1) % predicted was 56.4%. The median COPD assessment test (CAT) scores were 14. The prevalence of post-BD SAD across the GOLD grades 1 to 4 was 14.3%, 51.1%, 91%, and 100%, respectively. The post-BD SAD and expiratory flow limitation at tidal breath (EFLT) were present in 62.8% (95% confidence interval [CI], 56.1 to 69.9) and 28.1% (95% CI, 21.9 to 34.2), respectively. COPD patients with SAD had higher CAT scores (15.5 vs. 12.8, p<0.01); poor lung function (FEV1% predicted 46.6% vs. 72.8%, p<0.01); lower diffusion capacity for CO (4.8 mmol/min/kPa vs. 5.6 mmol/min/kPa, p<0.01); hyperinflation (ratio of residual volume to total lung capacity % predicted: 159.7% vs. 129%, p<0.01), and shorter 6-minute walk distance (367.5 m vs. 390 m, p=0.02). Conclusion SAD is present across all severities of COPD. The prevalence of SAD increases with disease severity. SAD is associated with poor lung function and higher symptom burden. Severe SAD is indicated by the presence of EFLT.http://e-trd.org/upload/pdf/trd-2023-0139.pdfchronic obstructive pulmonary diseasesmall airway dysfunctionoscillometryexpiratory flow limitation at tidal breathscopd assessment test score
spellingShingle Amit K. Rath
Dibakar Sahu
Sajal De
Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease
Tuberculosis and Respiratory Diseases
chronic obstructive pulmonary disease
small airway dysfunction
oscillometry
expiratory flow limitation at tidal breaths
copd assessment test score
title Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease
title_full Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease
title_fullStr Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease
title_full_unstemmed Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease
title_short Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease
title_sort oscillometry defined small airway dysfunction in patients with chronic obstructive pulmonary disease
topic chronic obstructive pulmonary disease
small airway dysfunction
oscillometry
expiratory flow limitation at tidal breaths
copd assessment test score
url http://e-trd.org/upload/pdf/trd-2023-0139.pdf
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