Journal article
Single-Breath Washout Tests to Assess Small Airway Disease in COPD.
- Boeck L Clinic of Respiratory Medicine and Pulmonary Cell Research, University Hospital Basel, Switzerland.
- Gensmer A Division of Respiratory Medicine, University Children's Hospital Basel, Switzerland.
- Nyilas S Division of Respiratory Medicine, University Children's Hospital Basel, Switzerland; Pediatric Respiratory Medicine, University Children's Hospital Bern, University of Bern, Switzerland.
- Stieltjes B Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Switzerland.
- Re TJ Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Switzerland.
- Tamm M Clinic of Respiratory Medicine and Pulmonary Cell Research, University Hospital Basel, Switzerland.
- Latzin P Division of Respiratory Medicine, University Children's Hospital Basel, Switzerland; Pediatric Respiratory Medicine, University Children's Hospital Bern, University of Bern, Switzerland.
- Stolz D Clinic of Respiratory Medicine and Pulmonary Cell Research, University Hospital Basel, Switzerland. Electronic address: daiana.stolz@usb.ch.
- 2016-06-04
Published in:
- Chest. - 2016
COPD
lung function
physiology
small airway disease
Adult
Aged
Cross-Sectional Studies
Disability Evaluation
Female
Humans
Male
Middle Aged
Pulmonary Disease, Chronic Obstructive
Reproducibility of Results
Respiratory Function Tests
English
BACKGROUND
Current functional assessments do not allow a reliable assessment of small airways, which are a major site of disease in COPD. Single-breath washout (SBW) tests are feasible and reproducible methods for evaluating small airway disease. Their relevance in COPD remains unknown.
METHODS
We performed a cross-sectional study in 65 patients with moderate to severe COPD. Phase III slope of nitrogen (SIIIN2) and double tracer gas (SIIIDTG) SBW tests were used as a measure of ventilation inhomogeneity. The association of both markers with established physiological and clinical features of COPD was assessed.
RESULTS
Ventilation inhomogeneity as measured by SIIIN2 and SIIIDTG was increased in patients with COPD compared with healthy subjects (P < .001 and P < .001, respectively). SIIIN2 was associated with FEV1 predicted, residual volume (RV)/total lung capacity (TLC) and diffusing capacity of the lung for carbon monoxide (Dlco) (all P < .001). Furthermore, SIIIN2 was related to dyspnea, exercise-induced desaturation, and exercise capacity (P = .001, P < .001, and P = .047, respectively). SIIIDTG was associated with TLC, Dlco, and cough (P < .001, P = .001, and P = .009, respectively). In multivariate regression models, we demonstrated that these associations are largely independent of FEV1 and mostly stronger than associations with FEV1. In contrast, FEV1 was superior in predicting emphysema severity.
CONCLUSIONS
SIIIN2 and SIIIDTG, two fast and clinically applicable measures of small airway disease, reflect different physiological and clinical aspects of COPD, largely independent of spirometry.
TRIAL REGISTRY
ISRCTN99586989, Ethics committee Beider Basel (approval number 295/07).
Current functional assessments do not allow a reliable assessment of small airways, which are a major site of disease in COPD. Single-breath washout (SBW) tests are feasible and reproducible methods for evaluating small airway disease. Their relevance in COPD remains unknown.
METHODS
We performed a cross-sectional study in 65 patients with moderate to severe COPD. Phase III slope of nitrogen (SIIIN2) and double tracer gas (SIIIDTG) SBW tests were used as a measure of ventilation inhomogeneity. The association of both markers with established physiological and clinical features of COPD was assessed.
RESULTS
Ventilation inhomogeneity as measured by SIIIN2 and SIIIDTG was increased in patients with COPD compared with healthy subjects (P < .001 and P < .001, respectively). SIIIN2 was associated with FEV1 predicted, residual volume (RV)/total lung capacity (TLC) and diffusing capacity of the lung for carbon monoxide (Dlco) (all P < .001). Furthermore, SIIIN2 was related to dyspnea, exercise-induced desaturation, and exercise capacity (P = .001, P < .001, and P = .047, respectively). SIIIDTG was associated with TLC, Dlco, and cough (P < .001, P = .001, and P = .009, respectively). In multivariate regression models, we demonstrated that these associations are largely independent of FEV1 and mostly stronger than associations with FEV1. In contrast, FEV1 was superior in predicting emphysema severity.
CONCLUSIONS
SIIIN2 and SIIIDTG, two fast and clinically applicable measures of small airway disease, reflect different physiological and clinical aspects of COPD, largely independent of spirometry.
TRIAL REGISTRY
ISRCTN99586989, Ethics committee Beider Basel (approval number 295/07).
- Language
-
- English
- Open access status
- closed
- Identifiers
-
- DOI 10.1016/j.chest.2016.05.019
- PMID 27256720
- Persistent URL
- https://sonar.ch/global/documents/278519
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