Journal article
Compressive air trapping in asthma: effects of age, sex, and severity
Journal of applied physiology (1985), Vol.126(5), pp.1265-1271
03/07/2019
DOI: 10.1152/japplphysiol.00924.2018
PMCID: PMC6589814
PMID: 30844338
Abstract
Air trapping due to airway closure has been associated with unstable asthma. In addition to airway closure that occurs at lower lung volumes during slow expiration, there may be further closure during a forced expiration because of airway compression. The purpose of this study was to define a reference range from a nonasthmatic population and investigate the characteristics of compressive air trapping in asthma. Spirometry and plethysmography were performed in 117 nonasthmatic subjects (ages 18–87 yr) and 153 asthma subjects (ages 12–72 yr). Air trapping was assessed as residual lung volume and the ratio of forced expiratory vital capacity (FVC) to slow inspiratory vital capacity (iVC) (FVC/iVC). There were no significant age or sex effects on the FVC/iVC ratio in the nonasthmatic subjects, and a fifth percentile lower limit of normal (LLN) of 0.93 was computed. An FVC/iVC ratio less than LLN defined compressive air trapping. Asthma subjects exhibited an age-related decline in the FVC/iVC ratio of 0.0027 per year (
P
< 0.0001) in a mixed effects model, with additional decreases associated with severe asthma and male sex. FVC/iVC ratios< LLN were infrequent in subjects <30 yr but evident in most asthma subjects >50 yr. Lung residual volumes followed similar patterns of greater elevations in subjects with severe asthma, older age, and male sex. Compressive air trapping occurs frequently in older asthmatics, appearing to be a feature of the natural history of asthma that is greater in severe asthma and men. This component of premature airway closure affects spirometric assessment of airway function and may contribute to asthma symptoms during physical exertion.
NEW & NOTEWORTHY
Premature airway closure during exhalation is a component of airway obstruction that is associated with asthma severity and instability. Compressive air trapping is airway closure that is more extensive during a forced exhalation than with a slow, passive exhalation. We report that compressive air trapping occurs in most people > 50 yr with asthma, affects men more than women, and persists after bronchodilator treatment. This component of obstruction appears to be part of the natural history of asthma.
Details
- Title: Subtitle
- Compressive air trapping in asthma: effects of age, sex, and severity
- Creators
- Ronald L. Sorkness - University of Wisconsin–MadisonCasey Kienert - University of Wisconsin–MadisonMatthew J. O’Brien - University of WisconsinSean B. Fain - University of Wisconsin–MadisonNizar N. Jarjour - University of Wisconsin–Madison
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.126(5), pp.1265-1271
- Publisher
- American Physiological Society
- DOI
- 10.1152/japplphysiol.00924.2018
- PMID
- 30844338
- PMCID
- PMC6589814
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Grant note
- R01-HL069116 / ; U10-HL109168 / ;
- Alternative title
- COMPRESSIVE AIR TRAPPING IN ASTHMA
- Language
- English
- Date published
- 03/07/2019
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Electrical and Computer Engineering; Health and Human Physiology
- Record Identifier
- 9984275056702771
Metrics
10 Record Views