The physiologic properties of some unsaturated hydrocarbons.

Abstract

The recent introduction of ethylene and acetylene as anesthetics into medical practice has made it appear desirable that a general study of the physiologic properties of the unsaturated hydrocarbons be undertaken. Studies have therefore been carried out on hydrocarbons of the olefine, diolefine and acetylene series. Each hydrocarbon has been studied from the following points of view: 1. Symptoms produced in experimental animals by the inhalation of various concentrations of each hydrocarbon studied. 2. The toxicity of the various hydrocarbons when administered by inhalation. 3. An attempt has been made to relate quantitatively the anesthetic potency and the toxicity of the various hydrocarbons studied.

In order that these studies might be made as strictly comparable as possible a single strain of white rats of uniform weight was used.

The following concentrations of hydrocarbons induce anesthesia in fifteen minutes, and are hence considered to be of equal anesthetic potency : ethylene 90 per cent, propylene 40 per cent, butylene 20 per cent, amylene 6 per cent and acetylene 78 per cent. If the anesthetic potency of ethylene is taken as unity, the potencies of the others then become, propylene =2.25, butylene =4.50, amylene =15.0 and acetylene =1.15. On the blasis of the potency of propylene as unity, the potencies of ethylene, propylene, butylene, amylene and acetylene then become 0.44, 1.0, 2.0, 6.6 and 0.52 respectively. Butylene and amylene cause a marked excitement stage, while ethylene, propylene and acetylene do not. Animals are prostrated by 20 per cent propadiene and by 5 per cent methyl acetylene in about 15 minutes, but the nervous symptoms produced by these hydrocarbons are so violent that they can scarcely be said to possess anesthetic properties.

The following concentrations of hydrocarbons cause respiratory failure in about two hours, and are hence considered to be of equal toxicity: propylene 65 per cent, bvtylene 20 per cent, amylene 6 per cent, acetylene 90 per cent, methyl acetylene 5 per cent and propadierie 15 per cent.