Differential inspiratory muscle pressure contributions to breathing during dynamic hyperinflation.

Details

Serval ID
serval:BIB_01A55FD17FD5
Type
Article: article from journal or magazin.
Collection
Publications
Title
Differential inspiratory muscle pressure contributions to breathing during dynamic hyperinflation.
Journal
American Journal of Respiratory and CriticalCare Medicine
Author(s)
Yan S., Kayser B.
ISSN
1073-449X (Print)
ISSN-L
1073-449X
Publication state
Published
Issued date
1997
Peer-reviewed
Oui
Volume
156
Number
2 Pt 1
Pages
497-503
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
During dynamic hyperinflation, the ventilatory pump is facing increased demand because it must overcome the intrinsic positive end-expiratory pressure (PEEPi) and decreased capacity since it must operate at a dynamically increased end-expiratory lung volume (EELV). The aim of this study was to evaluate the relative pressure contribution by the diaphragm and inspiratory rib cage muscles (RCMs) during dynamic hyperinflation. In six healthy subjects, dynamic hyperinflation was induced by limiting expiratory flow. The global inspiratory muscle pressure (delta Pmus,i) and transdiaphragmatic pressure (delta Pdi) were partitioned into the portion used to overcome PEEPi and the portion used to inflate the respiratory system. The delta Pdi/delta Pmus,i ratio was used to estimate the pressure contribution of RCMs relative to that of the diaphragm. Our results suggest that (1) with increasing severity of dynamic hyperinflation, there is a significant increase in the inspiratory pressure contribution of RCMs relative to that of the diaphragm for inflating the respiratory system; (2) during dynamic hyperinflation, especially at high EELV, the major pressure contribution of the diaphragm is to overcome the PEEPi-imposed inspiratory threshold load, whereas the inspiratory pressure needed for the subsequent task of inflating the respiratory system is largely contributed by RCMs. This arrangement is consistent with the change in mechanical advantages of RCMs and the diaphragm during the development of dynamic hyperinflation.

Keywords
Humans, Least-Squares Analysis, Lung/physiology, Lung Volume Measurements, Positive-Pressure Respiration, Intrinsic/physiopathology, Pressure, Reference Values, Respiration/physiology, Respiratory Mechanics/physiology, Respiratory Muscles/physiology
Pubmed
Web of science
Create date
30/10/2017 14:56
Last modification date
20/08/2019 12:23
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