Cyanide intoxication: protection with oxygen.

Prophylactic protection against cyanide intoxication in mice can be enhanced by the administration of oxygen, especially when it is used in combination with the conventional cyanide antidotes, sodium nitrite and sodium thiosulfate. The LD(50) values were compared in groups of mice premedicated with sodium thiosulfate or sodium nitrite, or both, in air and in oxygen. These results indicate that oxygen alone provides only minimal protection. Although oxygen enhances the protective effect of sodium thiosulfate to a minor degree, it does not enhance the protection of sodium nitrite at all; and yet, it potentiates the effectiveness of a combination of these two antagonists against cyanide intoxication.