Management of acute sulfide poisoning. Effects of oxygen, thiosulfate, and nitrite

Oxygen (100% at 1 atmosphere) did not protect mice against death from acute sulfide poisoning as compared with animals maintained under air at 1 atmosphere. Sodium thiosulfate had a small, but statistically significant (P less than .05) protective effect against death due to sodium sulfide, whether the mice were maintained under air or oxygen. Pretreatment with sodium nitrite, however, increased the acute intraperitoneal lethal dose for 50% survival of the group (LD50) of sodium sulfide 2.5 times. Neither oxygen, thiosulfate, nor the combination potentiated the protective effects of nitrite against sulfide poisoning. Antidotal effects of nitrite in acute sulfide poisoning were demonstrated in rats. The therapeutic efficacy of nitrite in acute poisoning is clearly superior to that of oxygen, which is the more widely recommended antidote.