Hydrogen cyanide

CAS RN: 74-90-8

Clinical Signs and Symptoms

Signs Symptoms

Clinical Signs and Symptoms

Hydrogen cyanide acts as a cellular asphyxiant. By binding to mitochondrial cytochrome oxidase, it prevents the utilization of oxygen in cellular metabolism. The CNS and myocardium are particularly sensitive to the toxic effects of cyanide.

Children exposed to the same level of cyanide agents as adults will usually receive higher doses because they have greater lung surface area: body weight ratios and increased minute volume: weight ratios.

  • CNS - Initial signs and symptoms especially with lower dose exposures are nonspecific and include excitement, dizziness, nausea and vomiting, headache and weakness. Progression of symptoms (pending exposure levels) can include increased lethargy, tetany, convulsions, and loss of consciousness. Young children, especially under the age of four, are more prone to develop seizure disorders secondary to hypoxia, or other CNS insult.
  • Cardiovascular - Arrhythmias can occur in cases of severe poisoning. Bradycardia, hypotension followed by death can occur. Transient hypertension and tachycardia may be early findings.
  • Respiratory - Initial patient findings may include shortness of breath, chest tightness, and increased respiratory rate. With progression of poisoning, respirations become slow and gasping. Central cyanosis may or may not occur. Pulmonary edema may occur.
  • Metabolic - Acidosis occurs secondary to increased anaerobic respiration.
  • Dermal - Systemic absorption can occur. High ambient temperate, relative humidity results in increased absorption. Children are more vulnerable to these toxicants being absorbed through the skin because their skin is thinner, contains more moisture, and they have a larger surface area to weight ratio than adults. Pregnant women also will have increased absorption through the skin because of the increased vascularity and vasodilatation associated with pregnancy.
  • Ocular - Direct contact to liquid cyanide can result in eye irritation and swelling.
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