Anesthesia-Related Carbon Monoxide Exposure: Toxicity and Potential Therapy

Abstract

Exposure to carbon monoxide (CO) during general anesthesia can result from volatile anesthetic degradation by carbon dioxide absorbents as well as re-breathing of endogenously produced CO. Although adherence to the Anesthesia Patient Safety Foundation guidelines reduces the risk of CO poisoning, patients may still experience a sub-toxic CO exposure during low-flow anesthesia. The consequences of such exposures are relatively unknown. In contrast to the widely recognized toxicity of high CO concentrations, the biological activity of low concentration CO has recently been shown be cytoprotective. As such, low dose CO is being explored as a novel treatment for a variety of different diseases. Here we review the concept of anesthesia-related CO exposure, identify the sources of production, detail the mechanisms of overt CO toxicity, highlight the cellular effects of low dose CO, and discuss the potential therapeutic role for CO as a part of routine anesthetic management.

Carbon monoxide ameliorates lipopolysaccharide-induced acute lung injury via inhibition of alveolar macrophage pyroptosis

“…This study may be instructive for ALI therapy. Though many studies have demonstrated the therapeutic effect of CO on various diseases, including ALI, the toxicity of CO limits its extensive application [ 32 ]. Therefore, clarification of its therapeutic mechanism and identification of critical targets are important.…”

The Role of Heme Oxygenase-1 in Remote Ischemic and Anesthetic Organ Conditioning

“…Interestingly, elevated intraoperative carboxyhemoglobin (COHb) levels in patients have been associated with the application of volatile halogenated ether anesthetics. CO is produced during a reaction of desiccated carbon dioxide absorbents within anesthesia machine apparatuses [55,56,57]. Thus, in addition to effects on HO-1 expression resulting in increased production of protective heme metabolites, the release of biologically relevant concentrations of CO might contribute to the cytoprotective mechanisms of these substances [58].…”

Predicting cost of inhalational anesthesia at low fresh gas flows: impact of a new generation carbon dioxide absorbent

“… 3 In response to these issues new carbon dioxide absorbents have been introduced which decrease the possibility of accumulation of these toxic products. 4 5 6 One benefit of newer CO 2 absorbents is safety. New CO 2 absorbents, such as Amsorb, have been demonstrated to effectively completely eliminate the potential risk of compound A.…”