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Airway distensibility in normal and asthmatic subjects and partitioning of the Fowler dead space


Johns, DP and Burns, G and Reid, DW and Walls, JT and Maskrey, M and Walters, EH, Airway distensibility in normal and asthmatic subjects and partitioning of the Fowler dead space, Applied Physiology Nutrition and Metabolism-Physiologie Appliquee Nutrition Et Metabolisme , 31, (4) pp. 460-466. ISSN 1715-5312 (2006) [Refereed Article]

DOI: doi:10.1139/H06-019


Anatomical dead space measured by the Fowler method (VDF) is the sum of 2 serial volume compartments (VDF = VDp1 + VD p2). VDF has been shown to increase linearly with end-inspiratory lung volume (EILV) and the gradient of the relationship ("VDF) has been used as an index of airway distensibility. The aim of this study was to partition VDF into its serial compartments VDp1 and VDp2 to test the hypothesis that, given the greater distensibility of distal airways, VDp2 would demonstrate greater volume dependence than VDp1. The relationships between each measure of VD (VDF, VDp1, and VDp2) and EILV were studied in 16 healthy subjects and 16 mildly asthmatic subjects. Significant (p < 0.05) linear relationships were obtained between each measure of VD and EILV in both subject groups. Changes in VDp1 with EILV ("VDp1) accounted for 78.6% ± 5.6% (mean ± SEM) and 72.6% ± 6.3% of AVDF in the healthy and asthmatic groups, respectively. AVDp1 was greater in the healthy subjects than in asthmatic subjects (18.4 versus 13.1 mL/L, p = 0.005). We conclude that in both asthmatic and healthy subjects, the major component of AVDF was AVDp1 and not AVDP2, as originally hypothesized. We believe our results are reflecting the degree of asynchronous airway emptying. © 2006 NRC Canada.

Item Details

Item Type:Refereed Article
Research Division:Biomedical and Clinical Sciences
Research Group:Cardiovascular medicine and haematology
Research Field:Respiratory diseases
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Johns, DP (Associate Professor David Johns)
UTAS Author:Reid, DW (Dr David Reid)
UTAS Author:Walls, JT (Professor Justin Walls)
UTAS Author:Maskrey, M (Associate Professor Michael Maskrey)
UTAS Author:Walters, EH (Professor Haydn Walters)
ID Code:40458
Year Published:2006
Web of Science® Times Cited:2
Deposited By:Medicine
Deposited On:2006-08-01
Last Modified:2011-09-20

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