Journal of Applied Physiology Ad Instruments
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 75: 1222-1225, 1993;
8750-7587/93 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Series, F.
Right arrow Articles by Marc, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Series, F.
Right arrow Articles by Marc, I.

Journal of Applied Physiology, Vol 75, Issue 3 1222-1225, Copyright © 1993 by American Physiological Society

ARTICLES

Effects of continuous negative airway pressure-related lung deflation on upper airway collapsibility

F. Series and I. Marc
Unite de Recherche, Centre de Pneumologie de l'Hopital Laval, Universite Laval, Quebec, Canada.

Continuous negative airway pressure (CNAP) causes a decrease in lung volume, which is known to increase upper airway resistance by itself. We studied how this lung volume change could modify upper airway collapsibility with five normal awake subjects. In a first trial, pressure in a nasal mask (Pm) was progressively decreased in 3- to 5-cmH2O steps (CNAP). In a second trial, changes in lung volumes resulting from CNAP were prevented by applying simultaneously an equivalent level of negative extrathoracic pressure into a poncho-type respirator [isovolumetric CNAP (CNAPisovol)]. For each trial, we examined the relationship between the maximal inspiratory airflow of each flow-limited inspiratory cycle and the corresponding Pm by least-squares linear regression analysis and determined the critical pressure. We also determined the Pm threshold corresponding to the first Pm value below which flow limitation occurred. Flow limitation was observed in each subject with CNAP but in only two subjects with CNAPisovol. In these two subjects, the Pm threshold values were -20 and -9 cmH2O with CNAP and -39 and -16 cmH2O with CNAPisovol, respectively. Critical pressures for the same two subjects were -161 and -96 cmH2O with CNAP and -202 and -197 cmH2O with CNAPisovol, respectively. We conclude that CNAP-induced decreases in lung volume increase upper airway collapsibility.


This article has been cited by other articles:


Home page
 ChestHome page
S. P. Patil, H. Schneider, A. R. Schwartz, and P. L. Smith
Adult Obstructive Sleep Apnea: Pathophysiology and Diagnosis
Chest, July 1, 2007; 132(1): 325 - 337.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Crit. Care Med.Home page
S. P. Patil, N. M. Punjabi, H. Schneider, C. P. O'Donnell, P. L. Smith, and A. R. Schwartz
A Simplified Method for Measuring Critical Pressures during Sleep in the Clinical Setting
Am. J. Respir. Crit. Care Med., July 1, 2004; 170(1): 86 - 93.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
F. Series and G. Ethier
Assessment of upper airway stabilizing forces with the use of phrenic nerve stimulation in conscious humans
J Appl Physiol, June 1, 2003; 94(6): 2289 - 2295.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
A. M. Lorino, K. Hamoudi, F. Lofaso, E. Dahan, C. Mariette, A. Harf, and H. Lorino
Effects of continuous negative airway pressure on lung volume and respiratory resistance
J Appl Physiol, August 1, 1999; 87(2): 605 - 610.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online