A narrative review of gas separation and conservation technologies during xenon anesthesia

Xenon gas has significant advantages over conventional general anesthetic agents but its use has been limited by the cost associated with its production. Xenon also has significant potential for medical use in the treatment of acquired brain injuries and for mental health disorders. As the demand for xenon gas from other industries increases, the costs associated with its medical use are only likely to increase. One solution to mitigate the significant cost of xenon use in research or medical care is the conservation of xenon gas. During delivery of xenon anesthesia, this can be achieved either by separating xenon from the other gases within the anesthetic circuit, conserving xenon and allowing other gases to be excluded from the circuit, or by selectively recapturing xenon utilized during the anesthetic episode at the conclusion of the case. Several technologies, including the pressurization and cooling of gas mixtures, the utilization of gas selective membranes and the utilization of gas selective adsorbents have been described in the literature for this purpose. These techniques are described in this narrative review along with important clinical context that informs how these technologies might be best applied. Whilst these technologies are discussed in the context of xenon general anesthesia, they could be applied in the delivery of xenon gas inhalation for other therapeutic purposes.