Partitioning of airway and respiratory tissue mechanical impedances by body plethysmography

• Published in: Journal of applied physiology (1985) 1998-02, Vol.84 (2), p.553-561
• Main Authors: Peslin, R, Duvivier, C
• Format: Article
• Language: English
• Subjects: Adult; Aged; Air breathing; Airway Resistance - physiology; Biological and medical sciences; Computer Simulation; Female; Fundamental and applied biological sciences. Psychology; Humans; Lung - physiology; Male; Middle Aged; Models, Biological; Plethysmography, Whole Body; Respiratory Mechanics - physiology; Respiratory system: anatomy, metabolism, gas exchange, ventilatory mechanics, respiratory hemodynamics; Space life sciences; Vertebrates: respiratory system
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1998.84.2.553

Unité 14 de Physiopathologie Respiratoire, Institut National de la Santé et de la Recherche Médicale, Université H. Poincaré Nancy I, 54500 Vandoeuvre-les-Nancy, France Peslin, R., and C. Duvivier. Partitioning of airway and respiratory tissue mechanical impedances by body plethysmography. J. Appl. Physiol. 84(2): 553-561, 1998. We have tested the feasibility of separating the airway (Zaw) and tissue (Zti) components of total respiratory input impedance (Zrs,in) in healthy subjects by measuring alveolar gas compression by body plethysmography (Vpl) during pressure oscillations at the airway opening. The forced oscillation setup was placed inside a body plethysmograph, and the subjects rebreathed BTPS gas. Zrs,in and the relationship between Vpl and airway flow (Hpl) were measured from 4 to 29 Hz. Zaw and Zti were computed from Zrs,in and Hpl by using the monoalveolar T-network model and alveolar gas compliance derived from thoracic gas volume. The data were in good agreement with previous observations: airway and tissue resistance exhibited some positive and negative frequency dependences, respectively; airway reactance was consistent with an inertance of 0.015 ± 0.003 hPa · s 2  · l 1 and tissue reactance with an elastance of 36 ± 8 hPa/l. The changes seen with varying lung volume, during elastic loading of the chest and during bronchoconstriction, were mostly in agreement with the expected effects. The data, as well as computer simulation, suggest that the partitioning is unaffected by mechanical inhomogeneity and only moderately affected by airway wall shunting. respiratory mechanics; methods; forced oscillations; alveolar pressure; airway impedance; tissue impedance The Journal of Applied Physiology 84(2):553-561 8750-7587/98 $5.00 Copyright © 1998 the American Physiological Society