|
|
||||||||
Journal of Applied Physiology, Vol 60, Issue 6 2007-2014, Copyright © 1986 by American Physiological Society
ARTICLES |
P. C. Kosch, P. W. Davenport, J. A. Wozniak and A. R. Stark
We applied graded resistive and elastic loads and total airway occlusions to single inspirations in six full-term healthy infants on days 2-3 of life to investigate the effect on neural and mechanical inspiratory duration (TI). The infants breathed through a face mask and pneumotachograph, and flow, volume, airway pressure, and diaphragm electromyogram (EMG) were recorded. Loads were applied to the inspiratory outlet of a two-way respiratory valve using a manifold system. Application of all loads resulted in inspired volumes decreased from control (P less than 0.001), and changes were progressive with increasing loads. TI measured from the pattern of the diaphragm EMG (TIEMG) was prolonged from control by application of all elastic and resistive loads and by total airway occlusions, resulting in a single curvilinear relationship between inspired volume and TIEMG that was independent of inspired volume trajectory. In contrast, when TI was measured from the pattern of airflow, the effect of loading on the mechanical time constant of the respiratory system resulted in different inspired volume-TI relationships for elastic and resistive loads. Mechanical and neural inspired volume and duration of the following unloaded inspiration were unchanged from control values. These findings indicate that neural inspiratory timing in infants depends on magnitude of phasic volume change during inspiration. They are consistent with the hypothesis that termination of inspiration is accomplished by an "off-switch" mechanism and that inspired volume determines the level of vagally mediated inspiratory inhibition to trigger this mechanism.
This article has been cited by other articles:
![]() |
D. E. O'Donnell, R. B. Banzett, V. Carrieri-Kohlman, R. Casaburi, P. W. Davenport, S. C. Gandevia, A. F. Gelb, D. A. Mahler, and K. A. Webb Pathophysiology of Dyspnea in Chronic Obstructive Pulmonary Disease: A Roundtable Proceedings of the ATS, May 1, 2007; 4(2): 145 - 168. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. A. Hutchison, D. J. Burchfield, J. A. Wozniak, and S. J. Mohrman Laryngeal Muscle Activities with Cerebral Hypoxia-Ischemia in Newborn Lambs Am. J. Respir. Crit. Care Med., July 1, 2002; 166(1): 85 - 91. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. S. Rabbette and J. Stocks Influence of volume dependency and timing of airway occlusions on the Hering-Breuer reflex in infants J Appl Physiol, December 1, 1998; 85(6): 2033 - 2039. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Brown, J. Stocks, C. Aun, and P. S. Rabbette The Hering-Breuer reflex in anesthetized infants: end-inspiratory vs. end-expiratory occlusion technique J Appl Physiol, April 1, 1998; 84(4): 1437 - 1446. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |