How is acute cyanide poisoning treated?

Cyanide poisoning may occur via inhalation, dermal absorption, or oral ingestion. In cases of inhalational exposure, immediately don a gas mask and rapidly remove the patient from the contaminated environment. For dermal exposure, promptly remove contaminated clothing and thoroughly irrigate the affected skin. If respiratory arrest occurs, initiate artificial respiration immediately and administer respiratory stimulants.Concurrently, administer specific antidotes without delay: crush one or two ampoules of amyl nitrite into a handkerchief and hold it near the patient’s nose and mouth for inhalation for 15–30 seconds; repeat every 2–3 minutes until intravenous administration of 3% sodium nitrite is initiated.These two agents—amyl nitrite and sodium nitrite—are effective only during initial on-site emergency treatment. Following intravenous sodium nitrite administration, inject 50% sodium thiosulfate (also known as “hypo”); in mild cases, 50% sodium thiosulfate alone may suffice.

In cases of oral cyanide ingestion—which results in extremely rapid absorption—gastric lavage should generally be performed only after antidotal therapy has been initiated. Lavage solutions may include large volumes of 5% sodium thiosulfate solution, 1:5,000 potassium permanganate solution, or 3% hydrogen peroxide solution. Activated charcoal is contraindicated. After lavage, administer ferrous sulfate solution to render cyanide non-toxic. Additionally, provide high-concentration oxygen supplementation and initiate hyperbaric oxygen therapy as early as possible.