Increased carbon monoxide concentration in exhaled air after surgery and anesthesia

Masao Hayashi, Toru Takahashi, Hiroshi Morimatsu, Hiromi Fujii, Naoyuki Taga, Satoshi Mizobuchi, Masaki Matsumi, Hiroshi Katayama, Masataka Yokoyama, Masahiro Taniguchi, Kiyoshi Morita

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)


Heme oxygenase-1 (HO-1) is induced by oxidative stress and is thought to confer protection against oxidative tissue injuries. HO-1 catalyzes the conversion of the heme moiety of hemeproteins, such as hemoglobin, myoglobin, and cytochrome P450, to biliverdin, liberating carbon monoxide (CO) in the process. CO reacts with hemoglobin to form carboxyhemoglobin. In this study, to examine the effect of anesthesia and/or surgery on endogenous CO production, we measured the amount of exhaled CO and the arterial carboxyhemoglobin concentration of patients who underwent surgery under general or spinal anesthesia. Both CO and carboxyhemoglobin concentrations were significantly larger on the day after surgery than during the preoperative period (P < 0.05) and in the recovery room (P < 0.05), regardless of anesthesia. However, neither index differed between general and spinal anesthesia. These results suggest that oxidative stress caused by anesthesia and/or surgery may induce HO-1, which catalyzes heme to produce CO, leading to increased exhaled CO concentration.

Original languageEnglish
Pages (from-to)444-448
Number of pages5
JournalAnesthesia and Analgesia
Issue number2
Publication statusPublished - Aug 2004

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine


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