Airway mechanics and lung tissue viscoelasticity effects of altered blood hematocrit in the pulmonary circulation /

The contribution of the hematocrit (Hct) of the blood in the pulmonary vasculature to the overall lung mechanics has not been characterized. We therefore set out to establish how changes of the Hct level in the pulmonary circulation affect the airway and lung tissue viscoelastic properties. The Hct...

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Bibliographic Details
Main Authors: Peták Ferenc
Fodor Gergely
Babik Barna
Habre Walid
Format: Article
Published: American Physiological Society 2016
Series:JOURNAL OF APPLIED PHYSIOLOGY 121 No. 1
doi:10.1152/japplphysiol.01103.2015

mtmt:3094056
Online Access:http://publicatio.bibl.u-szeged.hu/11010
Description
Summary:The contribution of the hematocrit (Hct) of the blood in the pulmonary vasculature to the overall lung mechanics has not been characterized. We therefore set out to establish how changes of the Hct level in the pulmonary circulation affect the airway and lung tissue viscoelastic properties. The Hct level of the blood in an isolated perfused rat lung model was randomly altered. Intermediate (26.5%), followed by low (6.6%) or normal Hct (43.7%) were set in 2 consecutive sequences. The pulmonary capillary pressure was maintained constant throughout the experiment and the pulmonary hemodynamic parameters were monitored continuously. The airway resistance (Raw), the viscous (G) and elastic (H) parameters and the hysteresivity (eta=G/H) of the lung tissues were obtained from measurements of forced oscillatory input impedance data. Raw was not affected by the alterations of the Hct levels. As concerns the lung tissues, the decrease of Hct to intermediate or low levels resulted in close to proportional decreases in the viscoelastic parameters G (16.5+/-7.7%, 12.1+/-9.5%, p<0.005) and H (13.2+/-8.6%, 10.8+/-4.7%, p<0.001). No significant changes in eta were detected in a wide range of Hct, which indicates that coupled processes cause alterations in the resistive and elastic properties of the lungs following Hct changes in the pulmonary circulation. The diminishment of the viscous and elastic parameters of the pulmonary parenchyma following a reduction of blood Hct demonstrate the significant contribution of the red blood cells to the overall lung viscoelasticity.
Physical Description:261-267
ISSN:8750-7587