Cyanide may be taken deliberately for suicide. Accidental exposures occur in fumigation, fires, the electroplating industry, in some laboratory procedures. They are also produced from the combustion of plastics, polyurethane, wool, silk, nylon, nitriles, rubber, and even some paper products. Additionally, some traces of cyanide may be found in well water.
Either inhaled or ingested, cyanide blocks cell metabolism by binding to the ferric ion on cytochrome A3, which is a molecule that cells need to use oxygen. The cells starve for oxygen and the anaerobic metabolism that cells use to try to function at all creates lactate acidosis.
Benefits From Hyperbaric Oxygen Treatment
In a cyanide poisoned animal model, immediate oxygen administration on cardiac tissue was shown to be effective and to augment the effectiveness of the antidotes - sodium nitrite and sodium thiosulfate.
Oxygen has an antidotal potency when the dose of cyanide is at or just over the critical level for cell respiratory function. HBOT is recommended particularly when supportive measures and other cyanide antidotes fail. Increased plasma-dissolved oxygen offers a direct benefit.
Skene et al (1966) Drop in mortality from 96% to 20% in a group of mice treated with HBOT at 2 ATA compared with those treated at 1 ATA.
Ivanov (1959) showed that HBOT restored normal activity of the brain in mice poisoned with cyanide.