| Title: |
Precise Control of End-tidal Carbon Dioxide Levels Using Sequential Rebreathing Circuits |
| Authors: |
Somogyi, R. B.; Vesely, A. E.; Preiss, D.; Prisman, E.; Volgyesi, G.; Azami, T.; Iscoe, S.; Fisher, J. A.; Sasano, H. |
| Source: |
Anaesthesia and Intensive Care ; volume 33, issue 6, page 726-732 ; ISSN 0310-057X 1448-0271 |
| Publisher Information: |
SAGE Publications |
| Publication Year: |
2005 |
| Description: |
Anaesthesiologists have traditionally been consulted to help design breathing circuits to attain and maintain target end-tidal carbon dioxide (P ET CO 2 ). The methodology has recently been simplified by breathing circuits that sequentially deliver fresh gas (not containing carbon dioxide (CO 2 )) and reserve gas (containing CO 2 ). Our aim was to determine the roles of fresh gas flow, reserve gas PCO 2 and minute ventilation in the determination of P ET CO 2 . We first used a computer model of a non-rebreathing sequential breathing circuit to determine these relationships. We then tested our model by monitoring P ET CO 2 in human volunteers who increased their minute ventilation from resting to five times resting levels. The optimal settings to maintain P ET CO 2 independently of minute ventilation are 1) fresh gas flow equal to minute ventilation minus anatomical deadspace ventilation, and 2) reserve gas PCO 2 equal to alveolar PCO 2 . We provide an equation to assist in identifying gas settings to attain a target PCO 2 . The ability to precisely attain and maintain a target PCO 2 (isocapnia) using a sequential gas delivery circuit has multiple therapeutic and scientific applications. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1177/0310057x0503300604 |
| DOI: |
10.1177/0310057X0503300604 |
| Availability: |
https://doi.org/10.1177/0310057x0503300604; https://journals.sagepub.com/doi/pdf/10.1177/0310057X0503300604 |
| Rights: |
https://journals.sagepub.com/page/policies/text-and-data-mining-license |
| Accession Number: |
edsbas.DBB69932 |
| Database: |
BASE |