Podcast 574: Cyanide Toxicity

Contributor: Nick Tsipis, MD

Educational Pearls:

• Significant cyanide exposure most commonly occurs from fire/smoke exposure particularly when plastics are involved
• Cyanide binds to cytochrome oxidase leading to the use of anaerobic metabolism which causes a profound lactic acidosis
• Classic toxicity includes a rapid loss of consciousness, hypotension, bradycardia, respiratory depression, and seizures
• Mild exposures can lead to nausea/vomiting, headaches, and other nonspecific symptoms.
• Sometimes patients will complain of an almond taste.
• Cyanide toxicity will manifest on labs by a profound anion gap acidosis with elevated lactate (but don't wait for them to ponder the diagnosis)
• Antidote is hydroxocobalamin and sodium thiosulfate
• Severe cyanide exposure will likely need ICU level care until the blood gas levels return to their baselines and the lactic acidosis resolves

References

Nickson Chris C, Australian Centre for Health Innovation at Alfred Health. Cyanide Poisoning • LITFL • CCC Toxicology. Life in the Fast Lane • LITFL • Medical Blog. https://litfl.com/cyanide-poisoning-ccc/. Published April 2, 2019. Accessed June 11, 2020.

Parker-Cote JL, Rizer J, Vakkalanka JP, Rege SV, Holstege CP. Challenges in the diagnosis of acute cyanide poisoning. Clin Toxicol (Phila). 2018;56(7):609‐617. doi:10.1080/15563650.2018.1435886

MacLennan L, Moiemen N. Management of cyanide toxicity in patients with burns. Burns. 2015;41(1):18‐24. doi:10.1016/j.burns.2014.06.001

Summarized by Jackson Roos, MS4 | Edited by Erik Verzemnieks, MD