JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS
AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
A&A International Anesthesia Research Society
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a colleague
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
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 Google Scholar
Google Scholar
Right arrow Articles by Adachi, T.
Right arrow Articles by Hara, Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Adachi, T.
Right arrow Articles by Hara, Y.
Related Collections
Right arrow Patient Safety
Right arrow Monitoring (Non-cardiac)
Right arrow Technology

Anesth Analg 2007;105:696-699
© 2007 International Anesthesia Research Society
doi: 10.1213/01.ane.0000278118.60543.7a

TECHNOLOGY, COMPUTING, AND SIMULATION

Exhaled Carbon Monoxide Levels Change in Relation to Inspired Oxygen Fraction During General Anesthesia

Takehiko Adachi, MD, PhD*, Kiichi Hirota, MD, PhD*{dagger}, Tomoko Hara, MD*, Yukiko Sasaki, MD, PhD*, and Yasufumi Hara, MD*

From the *Department of Anesthesiology, Kitano Hospital, The Tazuke Kofukai Medical Research Institute; and {dagger}Department of Anesthesia, Kyoto University Hospital, Osaka, Japan.

Address correspondence to Takehiko Adachi, MD, PhD, Department of Anesthesiology, Kitano Hospital, The Tazuke Kofukai Medical Research Institute, 2-4-20 Ohgimachi, Kita-ku, Osaka 530-8480, Japan. Address e-mail to t-adachi{at}kitano-hp.or.jp.

BACKGROUND: Heme oxygenase produces carbon monoxide (CO) during the breakdown of heme molecules. A variety of stressors upregulate this enzymatic activity and can increase exhaled CO levels. Recently, exhaled CO levels have been reported to increase in critically ill patients and after anesthesia and surgery. To use this measurement during mechanical ventilation, it is important to clarify the effects of factors which interfere with exhaled CO levels. The fraction of inspired oxygen (Fio2) is often changed during artificial ventilation. To investigate the effect of changes of Fio2 on exhaled CO, we measured exhaled CO levels during general anesthesia.

METHODS: Thirty patients who underwent elective operations were enrolled in this study. Anesthesia was maintained with sevoflurane and fentanyl. All patients were tracheally intubated and ventilated with a non-rebreathing ventilator. Exhaled CO levels were measured in gas sampled from the expired limb of the respiration circuit using a CO monitor. The effects of sequential changes of Fio2 on exhaled CO levels, and the effects of long-term inhalation of Fio2 0.75 and Fio2 0.35 on exhaled CO levels and arterial carboxyhemoglobin concentrations were investigated.

RESULTS: Exhaled CO levels changed rapidly in response to changes of Fio2. Long-term inhalation of Fio2 0.75 initially increased and then gradually decreased exhaled CO to basal levels, concomitant with a decrease of arterial carboxyhemoglobin. Long-term inhalation of Fio2 0.35 did not elicit any significant change in the observed variables.

CONCLUSION: When monitoring exhaled CO levels during mechanical ventilation, it is important to consider the effects of Fio2.






Lippincott, Williams & Wilkins Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999 HighWire Press
Copyright © 2007 by the International Anesthesia Research Society.