Cyanide poison | |
---|---|
Other names | Cyanide toxicity, hydrocyanic acid poison[1] |
Cyanide ion | |
Specialty | Toxicology, critical care medicine |
Symptoms | Early: headache, dizziness, fast heart rate, shortness of breath, vomiting[2] Later: seizures, slow heart rate, low blood pressure, loss of consciousness, cardiac arrest[2] |
Usual onset | Few minutes[2][3] |
Causes | Cyanide compounds[4] |
Risk factors | House fire, metal polishing, certain insecticides, eating seeds such as from almonds[2][3][5] |
Diagnostic method | Based on symptoms, high blood lactate[2] |
Treatment | Decontamination, supportive care (100% oxygen), hydroxocobalamin[2][3][6] |
Cyanide poisoning is poisoning that results from exposure to any of a number of forms of cyanide.[4] Early symptoms include headache, dizziness, fast heart rate, shortness of breath, and vomiting.[2] This phase may then be followed by seizures, slow heart rate, low blood pressure, loss of consciousness, and cardiac arrest.[2] Onset of symptoms usually occurs within a few minutes.[2][3] Some survivors have long-term neurological problems.[2]
Toxic cyanide-containing compounds include hydrogen cyanide gas and a number of cyanide salts.[2] Poisoning is relatively common following breathing in smoke from a house fire.[2] Other potential routes of exposure include workplaces involved in metal polishing, certain insecticides, the medication sodium nitroprusside, and certain seeds such as those of apples and apricots.[3][7][8] Liquid forms of cyanide can be absorbed through the skin.[9] Cyanide ions interfere with cellular respiration, resulting in the body's tissues being unable to use oxygen.[2]
Diagnosis is often difficult.[2] It may be suspected in a person following a house fire who has a decreased level of consciousness, low blood pressure, or high lactic acid.[2] Blood levels of cyanide can be measured but take time.[2] Levels of 0.5–1 mg/L are mild, 1–2 mg/L are moderate, 2–3 mg/L are severe, and greater than 3 mg/L generally result in death.[2]
If exposure is suspected, the person should be removed from the source of the exposure and decontaminated.[3] Treatment involves supportive care and giving the person 100% oxygen.[2][3] Hydroxocobalamin (vitamin B12a) appears to be useful as an antidote and is generally first-line.[2][6] Sodium thiosulphate may also be given.[2] Historically, cyanide has been used for mass suicide and it was used for genocide by the Nazis.[3][10]