CJA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Submit a scholarly reply
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 Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by KEENAN, R. L.
Right arrow Articles by BOYAN, C. P.
Right arrow Search for Related Content
PubMed
Right arrow Articles by KEENAN, R. L.
Right arrow Articles by BOYAN, C. P.

Canadian Journal of Anesthesia, Vol 25, 117-121, Copyright © 1978 by Canadian Anesthesiologists' Society

How Rebreathing Anaesthetic Systems Control Pacoco2: Studies with a Mechanical and a Mathematical Model

RICHARD L. KEENAN M.D.1 and C. PAUL BOYAN M.D.1

1 Department of Anesthesiology, Medical College of Virginia, Richmond, Virginia, 23298

Results from a proposed equation for re-breathing systems, were compared with results from a mechanical model "lung" ventilated either with a Bain Breathing Circuit, or a circle system (Eger- Ethans type A) without soda lime. When values for carbon dioxide excretion (VCO2), dead spacetidal volume ratio (VD/VT), minute volume ventilation (V·E), and fresh gas flow (V·F) were varied over a wide range, the model and the equation yielded identical values of Pacoco2.

When V·CO2 = 2.25 ml/kg, VD/VT = 0.5, and V·E = 140 ml/kg, then fresh gas flows (V·F) with both the equation and the model produced values of Pacoco2 which were very close to those found by Bain and Spoerel in anaesthetized, artificially ventilated humans. It is concluded that the equation is an accurate mathematical representation of how rebreathing anaesthetic systems control Pacoco2.

It is expected that the equation will be useful in the clinical application of rebreathing anaesthetic systems, allowing the selection of minute volumes and fresh gas flows which will yield predictable Pacoco2 values.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1978 by the Canadian Anesthesiologists' Society.