Oscillation mechanics of the human lung periphery in asthma
(2004) In Journal of Applied Physiology 97(5). p.1849-1858- Abstract
- To more precisely measure the mechanical properties of the lung periphery in asthma, we have developed a forced oscillation technique that applies a broad-band flow signal through a wedged bronchoscope. We interpreted the data from four healthy and eight mildly asthmatic subjects in terms of an anatomically accurate computer model of the wedged segment. There was substantial overlap in impedance between the two groups, with resistance ( R) showing minimal frequency dependence and elastance (E) showing positive and negative frequency dependence across subjects. After direct instillation of methacholine, R rose in both groups, but compared with healthy subjects, the asthmatic subjects displayed upward, parallel shifts in their dose-response... (More)
- To more precisely measure the mechanical properties of the lung periphery in asthma, we have developed a forced oscillation technique that applies a broad-band flow signal through a wedged bronchoscope. We interpreted the data from four healthy and eight mildly asthmatic subjects in terms of an anatomically accurate computer model of the wedged segment. There was substantial overlap in impedance between the two groups, with resistance ( R) showing minimal frequency dependence and elastance (E) showing positive and negative frequency dependence across subjects. After direct instillation of methacholine, R rose in both groups, but compared with healthy subjects, the asthmatic subjects displayed upward, parallel shifts in their dose-response curves. The baseline frequency-response patterns of E were enhanced after methacholine. Frequency dependencies of R and E were well reproduced in two normal subjects by a computational model that employed rigid airways connected to constant-phase tissue units but were better reproduced in the other two normal and three asthmatic subjects when the model employed heterogeneous, peripheral airway narrowing and compliant airways. To capture the frequency dependencies of R and E in the remaining five asthmatic subjects, the model was modified by increasing airway wall stiffness. These results indicate that the lung periphery of mildly asthmatic subjects is not well distinguished from that of healthy subjects by measurement of mechanical impedance at baseline, but group differences are seen after challenge with methacholine. Modeling of the response suggests that variable contributions of airway narrowing and wall compliance are operative in determining overall mechanical impedance of the lung periphery in humans with asthma, likely reflecting the functional consequences of airway inflammation and remodeling. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/265379
- author
- Kaminsky, DA ; Irvin, CG ; Lundblad, Lennart LU ; Moriya, HT ; Lang, S ; Allen, J ; Viola, T ; Lynn, M and Bates, JHT
- organization
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- forced oscillation technique, impedance, airway remodeling
- in
- Journal of Applied Physiology
- volume
- 97
- issue
- 5
- pages
- 1849 - 1858
- publisher
- American Physiological Society
- external identifiers
-
- wos:000224361700040
- pmid:15220299
- scopus:7044270909
- pmid:15220299
- ISSN
- 1522-1601
- DOI
- 10.1152/japplphysiol.00300.2004
- language
- English
- LU publication?
- yes
- id
- 559d3a4c-66a1-463b-8d50-76cc6a34285e (old id 265379)
- date added to LUP
- 2016-04-01 12:04:23
- date last changed
- 2023-09-01 18:19:43
@article{559d3a4c-66a1-463b-8d50-76cc6a34285e,
abstract = {{To more precisely measure the mechanical properties of the lung periphery in asthma, we have developed a forced oscillation technique that applies a broad-band flow signal through a wedged bronchoscope. We interpreted the data from four healthy and eight mildly asthmatic subjects in terms of an anatomically accurate computer model of the wedged segment. There was substantial overlap in impedance between the two groups, with resistance ( R) showing minimal frequency dependence and elastance (E) showing positive and negative frequency dependence across subjects. After direct instillation of methacholine, R rose in both groups, but compared with healthy subjects, the asthmatic subjects displayed upward, parallel shifts in their dose-response curves. The baseline frequency-response patterns of E were enhanced after methacholine. Frequency dependencies of R and E were well reproduced in two normal subjects by a computational model that employed rigid airways connected to constant-phase tissue units but were better reproduced in the other two normal and three asthmatic subjects when the model employed heterogeneous, peripheral airway narrowing and compliant airways. To capture the frequency dependencies of R and E in the remaining five asthmatic subjects, the model was modified by increasing airway wall stiffness. These results indicate that the lung periphery of mildly asthmatic subjects is not well distinguished from that of healthy subjects by measurement of mechanical impedance at baseline, but group differences are seen after challenge with methacholine. Modeling of the response suggests that variable contributions of airway narrowing and wall compliance are operative in determining overall mechanical impedance of the lung periphery in humans with asthma, likely reflecting the functional consequences of airway inflammation and remodeling.}},
author = {{Kaminsky, DA and Irvin, CG and Lundblad, Lennart and Moriya, HT and Lang, S and Allen, J and Viola, T and Lynn, M and Bates, JHT}},
issn = {{1522-1601}},
keywords = {{forced oscillation technique; impedance; airway remodeling}},
language = {{eng}},
number = {{5}},
pages = {{1849--1858}},
publisher = {{American Physiological Society}},
series = {{Journal of Applied Physiology}},
title = {{Oscillation mechanics of the human lung periphery in asthma}},
url = {{http://dx.doi.org/10.1152/japplphysiol.00300.2004}},
doi = {{10.1152/japplphysiol.00300.2004}},
volume = {{97}},
year = {{2004}},
}