Xenon: anesthesia for the 21st century.

: Xenon is a naturally occurring, gaseous element that comprises 0.000008% of air, or 0.05 parts per million. It was discovered by Ramsey and Travers in 1898. Xenon is found on the Periodic Table in group 0, which is the group commonly referred to as the noble or inert gases. It is obtained by fractionally distilling liquefied air. Xenon has been studied sporadically within the discipline of anesthesia as a replacement for nitrous oxide. Because it is a naturally occurring element, xenon is not a pollutant. It is not an occupationally hazardous gas. It is neither teratogenic nor fetotoxic, as is nitrous oxide; it does not contribute to the depletion of stratospheric ozone, as do chlorofluorocarbons and nitrous oxide. Xenon does not contribute to global warming and the greenhouse effect, as does nitrous oxide. Xenon provides excellent anesthesia and analgesia at its minimum alveolar concentration, 71%, as well as excellent analgesia at "subanesthetic" concentrations. Xenon also provides excellent cardiovascular and hemodynamic stability and offers both rapid induction and emergence. Because of the relatively high cost of xenon, a low-flow, closed-system technique is needed to be most cost effective.