Journal of Applied Physiology http://www.adinstruments.com/labchart/faseb
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 17: 417-420, 1962;
8750-7587/62 $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 Larson, C. P.
Right arrow Articles by Severinghaus, J. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Larson, C. P., JR.
Right arrow Articles by Severinghaus, J. W.

Postural variations in dead space and CO2 gradients breathing air and O2

C. P. Larson JR. 1 and J. W. Severinghaus 1

1 Department of Anesthesia and Cardiovascular Research Institute, University of California School of Medicine, San Francisco, California

Effects of postural changes on anatomic and physiologic dead space and arterial-alveolar CO2 gradients were studied in 11 healthy, adult subjects breathing air and O2. Results indicate that, on moving from the supine to the sitting position, Vads and Vpds increased by corresponding amounts (42 and 37 ml) with no increase in alveolar dead space or volume of lung which is nonperfused. Arterial-alveolar CO2 gradients were unaffected by posture, but more than doubled with O2 breathing, suggesting that O2 may relax the pulmonary vascular bed and diminish perfusion of highest lung segments. Isoproterenol aerosol (0.5%) produced significant bronchodilatation (27 ml increase in Vads), but only small and inconsistent increases in alveolar dead space and CO2 gradients. The PDS/Vt ratio in these subjects while sitting, breathing air, averaged 31 ± 6%, which is higher than the normally accepted value of 30%. As a result, the upper normal limit for PDS/Vt has been increased to 40% in our laboratories.

Submitted on January 22, 1962




This article has been cited by other articles:


Home page
 J. Physiol.Home page
S. Ito, A. Mardimae, J. Han, J. Duffin, G. Wells, L. Fedorko, L. Minkovich, R. Katznelson, M. Meineri, T. Arenovich, et al.
Non-invasive prospective targeting of arterial PCO2 in subjects at rest
J. Physiol., August 1, 2008; 586(15): 3675 - 3682.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
H. J. Mummery, B. W. Stolp, G. deL. Dear, P. O. Doar, M. J. Natoli, A. E. Boso, J. D. Archibald, G. W. Hobbs, H. E. El-Moalem, and R. E. Moon
Effects of age and exercise on physiological dead space during simulated dives at 2.8 ATA
J Appl Physiol, February 1, 2003; 94(2): 507 - 517.
[Abstract] [Full Text] [PDF]


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