EMS Protocol of the Week - Cyanide Poisoning

Hey all,

This week we invite you to drink the EMS Kool-Aid and learn how our pre-hospital colleagues care for patients with suspected cyanide poisoning 💀


Although popularized by mystery novels and mass murder-suicides, the most common and alarming cause of cyanide poisoning we're likely to see is from smoke inhalation. When apartments catch fire, fumes from burning polyurethane, vinyl, and other nitrile-based polymers react to form the deadly compound which is inhaled and rapidly distributed throughout the body. Cyanide then halts ATP production from the electron-transport chain causing a raging lactic acidosis from exclusive anaerobic respiration, and then... well... Cya-never 👋

Initial management consists of ABC's, supplemental O2, and treating burns. Definitive treatment in the field is based on clinical features: cardiac arrest, respiratory arrest, AMS, coma, seizures, and hypotension without an obvious other cause are indications to give the antidote, hydroxocobalamin or sodium thiosulfate via a Cyanokit. Because mortality is high and lab confirmation takes time, treatment should be initiated ASAP, with repeat doses for persistent symptoms. In general, hydroxocobalamin is the first-line agent and can be followed with sodium thiosulfate for continued therapy.

See the contents of the Cyanokit below that NYC paramedics have for use:

Tubes for blood

- pre-hospital lab collection prior to med administration

3-way stopcocks to mix solutions and IV tubing

Hydroxocobalamin 5 g bottle of crystalline powder

-needs to be mixed with 200cc NS or D5W and then IV wide-open over 15 min for adult dosing

-peds dosing 75 mg/kg IV (3 mL/kg of the mixed solution)

20cc syringe to be used to flush crystalloid fluid after hydroxocobalamin administration

Sodium Thiosulfate 12.5 g bottle

-mixed with 100cc NS or D5W and then IV over 10 min for adults

-peds dosing 250 mg/kg IV (3mL/kg of mixed solution)

And keep in mind, although present in smoke inhalation injuries, cyanide poisoning can also be a result of nitroprusside overdose or used as a weapon of mass destruction in an MCI (stay tuned for that protocol...).

See attached protocol and info from FDNY training; check out https://nycremsco.org/ for more!

Best,

Chris Kuhner, MD

PGY-2 Emergency Medicine