Effect of Carbon Dioxide on Ethylene and Nitrous Oxide Anesthesia.

Abstract

As a continuation of the investigation of the effects of CO₂ in anesthesia, this report embodies the results of a study of the effect of this gas on anesthesia by ethylene and by nitrous oxide. As shown in the accompanying graphs, it has been found that CO₂ exerts an effect on anesthesia by these gases of the same nature as on anesthesia with ether recently reported in this bulletin (Klein-dorfer). 1

Thirty-six observations on the effects of mixtures of ethylene and oxygen with or without CO₂ were made on 10 white rats using the same methods employed in the ether series. The results are indicated in Graph I. However, the depth of the anesthesia procurable in these animals by these gases was so slight that it appeared desirable to supplement this series by observations on other animals. Because of the inconsistency of the reactions of rabbits to electrical stimulation of the divided sciatic nerve, which was the criterion used in this series, these animals were found not to be well suited to this type of investigation. While the results were in line with those in the rat series they are not reported in detail.

The results of 87 similar observations on 12 cats are indicated in Graph II.

Results of 64 observations of the effect of CO₂ on nitrous oxide in 15 cats are similarly shown in Graph III.

It is apparent from the results reported that 5 or 10% of CO₂ exerts an unmistakable influence in anesthesia by ethylene or by nitrous oxide. These observations are in line with observations of Nicloux 2 and Henderson 3 and his coworkers. The former reported that he was able to obtain a good anesthesia from the inhalation of ethylene 65% oxygen 15% and CO₂ 20%.