|
|
||||||||
Journal of Applied Physiology, Vol 73, Issue 2 440-445, Copyright © 1992 by American Physiological Society
ARTICLES |
J. E. Clague, J. Carter, M. G. Pearson and P. M. Calverley
Regional Thoracic Unit, Fazakerley Hospital, Liverpool, United Kingdom.
Although inspiratory resistive loading (IRL) reduces the ventilatory response to CO2 (VE/PCO2) and increases the sensation of inspiratory effort (IES), there are few data about the converse situation: whether CO2 responsiveness influences sustained load compensation and whether awareness of respiratory effort modifies this behavior. We studied 12 normal men during CO2 rebreathing while free breathing and with a 10-cmH2O.l-1.s IRL and compared these data with 5 min of resting breathing with and without the IRL. Breathing pattern, end-tidal PCO2, IES, and mouth occlusion pressure (P0.1) were recorded. Free-breathing VE/PCO2 was inversely related to an index of effort perception (IES/VE; r = -0.63, P less than 0.05), and the reduction in VE/PCO2 produced by IRL was related to the initial free-breathing VE/PCO2 (r = 0.87, P less than 0.01). IRL produced variable increases in inspiratory duration (TI), IES, and P0.1 at rest, and the change in tidal volume correlated with both VE/PCO2 (r = 0.63, P less than 0.05) and IES/VE (r = -0.69, P less than 0.05), this latter index also predicting the changes in TI with loading (r = -0.83, P less than 0.01). These data suggest that in normal subjects perception of inspiratory effort can modify free-breathing CO2 responsiveness and is as important as CO2 sensitivity in determining the response to short-term resistive loading. Individuals with good perception choose a small-tidal volume and short-TI breathing pattern during loading, possibly to minimize the discomfort of breathing.
This article has been cited by other articles:
![]() |
M. Raux, C. Straus, S. Redolfi, C. Morelot-Panzini, A. Couturier, F. Hug, and T. Similowski Electroencephalographic evidence for pre-motor cortex activation during inspiratory loading in humans J. Physiol., January 15, 2007; 578(2): 569 - 578. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. S. Pine, J. D. Coplan, L. A. Papp, R. G. Klein, J. M. Martinez, P. Kovalenko, N. Tancer, D. Moreau, E. S. Dummit III, D. Shaffer, et al. Ventilatory Physiology of Children and Adolescents With Anxiety Disorders Arch Gen Psychiatry, February 1, 1998; 55(2): 123 - 129. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |