Journal of Applied Physiology AJP: Regulatory, Integrative and Comparative Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 72: 712-720, 1992;
8750-7587/92 $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 Baydur, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Baydur, A.

Journal of Applied Physiology, Vol 72, Issue 2 712-720, Copyright © 1992 by American Physiological Society

ARTICLES

Decay of inspiratory muscle pressure during expiration in anesthetized kyphoscoliosis patients

A. Baydur
Chest Medicine Service, Rancho Los Amigos Medical Center, Downey, California 90242.

The decay of pressure developed by the inspiratory muscles during expiration (PmusI) has not been studied in subjects with increased respiratory impedance such as in kyphoscoliosis. PmusI was compared in 11 anesthetized patients with kyphoscoliosis with that in 11 anesthetized normal subjects. PmusI was obtained according to the following equation: PmusI(t) = Ers.V(t) - K1V(t) - K2V2(t), where V is volume and V is airflow at any instant t during spontaneous expiration, Ers is the passive elastance, and K1V + K2V2 is the flow resistance (curvilinear in both groups because of the endotracheal tube and the intrinsic resistance in the kyphoscoliotics) of the total respiratory system. Ers was determined by the relaxation method and resistance from the ensuing V-V relationships during the ensuing relaxed expiration. Changes in impedance due to pliometric work done by the inspiratory muscles during relaxation were neglected. Subjects in both groups showed marked braking of expiratory flow by PmusI. The mean time for PmusI to decrease to 50 and 0% amounted to 17 and 8% less, respectively, in the kyphoscoliosis group. Average values for flow-resistive work in the control and kyphoscoliosis groups both amounted to approximately 40% of the elastic energy stored during inspiration. The remaining portion, used as negative work, amounted to approximately 60% in both groups. Expiratory braking in anesthetized kyphoscoliotic patients appears to be in proportion to their magnitude of elastic recoil and intrinsic flow resistance.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. A. Jo, A. Blasi, E. Valladares, R. Juarez, A. Baydur, and M. C. K. Khoo
Determinants of heart rate variability in obstructive sleep apnea syndrome during wakefulness and sleep
Am J Physiol Heart Circ Physiol, March 1, 2005; 288(3): H1103 - H1112.
[Abstract] [Full Text] [PDF]


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