differentiating between cyanide and carbon monoxide toxicity

• related: cyanide toxicity, carbon monoxide poisoning
• tags: #literature #icu

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The low level of carboxyhemoglobin detected by CO-oximetry makes carbon monoxide poisoning less likely the cause of his marked lactic acidosis. Carbon monoxide and cyanide poisoning are similar in presentation, and either or both can occur in victims of smoke inhalation. Clinicians should be careful to not solely focus on easily obtainable carbon monoxide levels and fail to manage coexistent cyanide poisoning. Cyanide poisoning should be considered in any patient with at least two of the following: soot in the oropharynx, elevated anion gap metabolic acidosis, neurological dysfunction, or serum lactate >72.07 mg/dL (8 mmol/L).¹²³⁴⁵

Links to this note

• cyanide toxicity
  • differentiating between cyanide and carbon monoxide toxicity

Footnotes

1. SEEK Questionnaires ↩

2. Baud FJ, Barriot P, Toffis V, et al. Elevated blood cyanide concentrations in victims of smoke inhalation. N Engl J Med. 1991;325(25):1761-1766. PubMed ↩

3. Mokhlesi B, Leikin JB, Murray P, et al. Adult toxicology in critical care: Part II: specific poisonings. Chest. 2003;123(3):897-922. PubMed ↩

4. Parker-Cote JL, Rizer J, Vakkalanka JP, et al. Challenges in the diagnosis of acute cyanide poisoning. Clin Toxicol (Phila). 2018;56(7):609-617. PubMed ↩

5. Shepherd G, Velez LI. Role of hydroxocobalamin in acute cyanide poisoning. Ann Pharmacother. 2008;42(5):661-669. PubMed ↩