Cyanide poisoning: Rapid overview of emergency management

To obtain emergency consultation with a medical toxicologist, in the United States, call 1-800-222-1222 for the nearest regional poison control center. Contact information for poison control centers around the world is available at the WHO website and in the UpToDate topic on regional poison control centers (society guideline links).

General information

Cyanide poisoning is rapidly lethal unless treated with antidote

Clinical features

History

Ascertain if patient has access to cyanide or if patient was part of a high-risk event (eg, fire, industrial exposure)

Initial symptoms are nonspecific: headache, anxiety, confusion, abdominal pain

Physical examination

Vital signs: initial hypertension/tachycardia/tachypnea progresses to respiratory and circulatory collapse

Skin: may be flushed with "cherry red" color

Neurologic: seizures and coma as poisoning progresses

Laboratory evaluation

Obtain the following:

Fingerstick glucose, acetaminophen and salicylate concentrations, electrocardiogram, and pregnancy test (when appropriate)

Basic chemistries and serum lactate

Elevated anion gap acidosis, with elevated lactate, expected in cyanide poisoning
Venous blood appears bright red

Central venous blood gas with concomitant arterial blood gas

Narrowed venous-arterial PO₂ gradient supports diagnosis of cyanide toxicity

Carboxyhemoglobin and methemoglobin levels

Rule out other dyshemoglobinemias
Use nitrites (refer below) cautiously or not at all in presence of dyshemoglobinemias

Cyanide poisoning can cause: renal failure, hepatic failure, rhabdomyolysis, pulmonary edema; obtain relevant studies as indicated

General treatment

Secure airway, breathing, and circulation. Intubation is usually required. Administer high-flow oxygen by nonrebreather face mask regardless of pulse oximetry reading.

Do NOT perform mouth-to-mouth resuscitation in cases of suspected cyanide toxicity. Patients with dermal exposure must be decontaminated using proper precautions.

Give a single dose of activated charcoal if the airway is adequately protected (50 g in adults; 1 g/kg in children with maximum dose of 50 g).

Treat hypotension with rapid IV boluses of isotonic fluid and vasopressors as needed. Treat seizures with a benzodiazepine (eg, diazepam 5 mg IV).

Obtain assistance from medical toxicologist or poison control center.

Antidotal treatment

Administer cyanide antidote when cyanide poisoning is clinically suspected. Hydroxocobalamin is the preferred antidote.

If hydroxocobalamin is available, give the following:

Hydroxocobalamin 5 g (adults) or 70 mg/kg IV (pediatric patients, maximum 5 g)

If hydroxocobalamin is not available, cyanide toxicity is known or strongly suspected in an adult patient, and there are no contraindications to nitrites, give the following:

Sodium nitrite (3% solution) 10 mL IV (300 mg) at 2.5 to 5 mL per minute; may repeat once
Sodium thiosulfate (25% solution) 50 mL IV (12.5 g) immediately following sodium nitrite administration; may repeat once

If hydroxocobalamin is not available and cyanide toxicity is possible but not certain in an adult patient, or the patient has contraindications to nitrites, give the following:

Sodium thiosulfate (25% solution) 50 mL IV (12.5 g); may repeat once

Refer to UpToDate topic for details about nitrite treatment for children and patients with anemia, and for treatment in cases of unlikely cyanide poisoning.

PO₂: partial pressure of oxygen; IV: intravenously.

Graphic 65052 Version 15.0

خرید پکیج

Cyanide poisoning: Rapid overview of emergency management