Effects of pulmonary vascular pressures and flow on airway and parenchymal mechanics in isolated rat lungs

Petak, F., Habre, W., Hantos, Z., Sly, P.D. and Morel, D.R. (2002) Effects of pulmonary vascular pressures and flow on airway and parenchymal mechanics in isolated rat lungs. Journal of Applied Physiology, 92 1: 169-178.

Author Petak, F.
Habre, W.
Hantos, Z.
Sly, P.D.
Morel, D.R.
Title Effects of pulmonary vascular pressures and flow on airway and parenchymal mechanics in isolated rat lungs
Journal name Journal of Applied Physiology   Check publisher's open access policy
ISSN 8750-7587
1522-1601
Publication date 2002-01
Sub-type Article (original research)
Volume 92
Issue 1
Start page 169
End page 178
Total pages 10
Place of publication Bethesda, MD, United States
Publisher American Physiological Society
Language eng
Formatted abstract
Changes in pulmonary hemodynamics have been shown to alter the mechanical properties of the lungs, but the exact mechanisms are not clear. We therefore investigated the effects of alterations in pulmonary vascular pressure and flow (Q̇p) on the mechanical properties of the airways and the parenchyma by varying these parameters independently in three groups of isolated perfused normal rat lungs. The pulmonary capillary pressure (Pcest), estimated from the pulmonary arterial (Ppa) and left atrial pressure (Pla), was increased at constant Q̇p (n = 7), or Q̇p was changed at Pcest = 10 mmHg (n = 7) and at Pcest = 20 mmHg (n = 6). In each condition, the airway resistance (Raw) and parenchymal damping (G) and elastance (H) were identified from the low-frequency pulmonary input impedance spectra. The results of measurements made under isogravimetric conditions were analyzed. The changes observed in the mechanical parameters were consistent with an altered Pla: monotonous increases in Raw were observed with increasing Pla, whereas G and H were minimal at Pla of ∼7-10 mmHg and increased at lower and higher Pla. The results indicate that Pla, and not Ppa or Q̇p, is the primary determinant of the mechanical condition of the lungs after acute changes in pulmonary hemodynamics: the parenchymal mechanics are impaired if Pla is lower or higher than physiological, whereas airway narrowing occurs at high Pla.
Keyword Respiratory mechanics
Forced oscillations
Pulmonary circulation
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Medicine Publications
 
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Created: Wed, 17 Nov 2010, 11:41:36 EST