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8 Cards in this Set
- Front
- Back
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What is the mechanism of toxicity of cyanide? |
1. Inhibits oxidate metabolism = lactic acidosis 2. CVS: Stimulates amine release causing pulmonary and coronary vasospasm 3. Neuro: Releases NDMA causing seizures |
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What are the clinical features of cyanide toxicity? |
1. CNS: Rapid loss of consciousness if inhaled 2. CVS: HTN, Tachycardia, 3. CNS: Headache, seizures, 4. GI:N/V 5. Progresses to HypoTN, Bradycardia, Confusion - Drowsiness - coma. Resp depression 6. Delayed parkinsonism in survivors |
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What investigations will you do? |
1. Serum lactate correlates with cyanide poisoning 2. Cyanide levels - confirm Dx, don't aid Mx |
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What is the toxic and lethal dose of cyanide? |
Symptomatic - 20umol/L Toxic = 40umol/L Lethal = 100umol/L |
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What is the antidote and dose for cyanide? |
Hydroxycobalamin 2.5g IV x2 Paeds 50mg/kg IV (give before cyanide levels are back - EARLY) Also Thiosulfate |
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How will you manage this person immediately? |
1. Immediate intubation and ventilation with 100% O2 2. Resuscitation: IVF, vasopressors 3. Decontamination: remove clothes (bagged), wash skin |
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How does the antidote work? |
Hydroxycobalamin chelates cyanide to from cyanocobalamin. Cyanide has a high affinity for it. |
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What features and sources of cyanide poisoning? |
Sudden collapse with sustained lactic acidosis Smoke inhalation - product of combustion Industrial exposure - Metal and ore works - Fumigant (planes, buildings, ships) - Manufacturing plastics & fibres Natural: Amygdalin (apple, apricot, pips) Iatrogenic - warfare/gas chambers - sodium nitroprusside |
