|
|
||||||||
Journal of Applied Physiology, Vol 78, Issue 5 1910-1920, Copyright © 1995 by American Physiological Society
ARTICLES |
G. F. Rafferty, J. Evans and W. N. Gardner
Department of Physiology, King's College London, United Kingdom.
Combinations of 17 normal awake humans breathed mildly hyperoxic and hypercapnic gas mixtures via a pneumotachograph into an open circuit. Respiratory pattern was measured for each breath in real time by computer. Use of computer-controlled auditory feedback at a constant end-tidal PCO2 (PETCO2) allowed prolonged changes of 1) inspiratory time (TI) at constant inspired tidal volume (VTI), 2) VTI up and down in repeated steps at constant TI, and 3) expiratory time (TE) at constant VTI. The remaining variables were free to be determined by the subjects' automatic respiratory control mechanisms. We showed that TE changed in parallel with the change in TI despite constant VTI, TE did not change in response to step changes in VTI at constant TI, and large changes in TE had no influence on the subsequent TI, but VTI increased slightly as TE lengthened despite clamping. Time for expiratory flow (TE--end-expiratory pause) changed in parallel with TE in all protocols. Thus, in conscious humans, inspiratory timing has a direct influence on expiratory timing, independent of volume change and chemical drive, but expiratory timing has no influence on the inspiratory timing of the subsequent breath but has a small influence on volume.
This article has been cited by other articles:
![]() |
T. Brack, A. Jubran, and M. J. Tobin Dyspnea and Decreased Variability of Breathing in Patients with Restrictive Lung Disease Am. J. Respir. Crit. Care Med., May 1, 2002; 165(9): 1260 - 1264. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Kowallik, I. Jacobi, A. Jirmann, M. Meesmann, M. Schmidt, and H. Wirtz Breath-to-Breath Variability Correlates With Apnea-Hypopnea Index in Obstructive Sleep Apnea Chest, February 1, 2001; 119(2): 451 - 459. [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] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |