Cyanide coma caused

Estimates of toxicity based on accidental and deliberate poisoning in humans indicates that NaCN has a lethal potential of around 2-3 mg kg 1 and KCN at 3-5 mg kg 1 (Ballantyne, 1987b). Ingestion of alkaline CN salts by humans (calcium, sodium and potassium cyanides) may cause symptomatology which is life-threatening in 30 to 60 min (Hall and Rumack, 1998). Rapid progression to coma, seizures, arrhythmias, intractable hypotension and apnoea may occur, and death is common. 

PCC, a common by-product of PCP s illicit manufacture (sometimes accounting for 10-25% of the mixture), causes abdominal cramps, diarrhea, and in sufficient doses, coma. PCC is an unstable compound, degrading to piperidine. Contaminated batches of PCP can sometimes be recognized by a strong fishy odor. When heated, as when it is smoked and inhaled, PCC liberates hydrogen cyanide, so cyanide poisoning in PCP smokers is also a strong possibility. 

Cyanide binds to the in the heme of the cytochrome aaj component of cytochrome c oxidase and prevents electron transport to Oj. Mitochondrial respiration and energy production cease, and cell death rapidly occurs. The central nervous system is the primary target for cyanide toxicity. Acute inhalation of high concentrations of cyanide (e.g., smoke inhalation during a fire) provokes a brief central nervous system stimulation rapidly followed by convulsion, coma, and death. Acute exposure to lower amounts can cause lightheadedness, breathlessness, dizziness, numbness, and headaches. 

In large amounts, cyanide is very harmful to people. Exposure to high levels of cyanide in the air for a short time harms the brain and heart, and may cause coma and death. 

B. Asphyxia and systemic intoxicants may cause dizziness, confusion, syncope, seizures and coma. In addition, carbon monoxide (see p 151), cyanide poisoning (p 177), and methemoglobinemia (p 261) have been documented in victims of smoke inhalation. 

D. Cyanides cause dizziness, dyspnea, confusion, agitation, and weakness, with progressive obtundation and even coma. Seizures and hypotension followed by cardiovascular collapse may occur. 

GI Tract May cause gastrointestinal irritation with nausea, vomiting, and diarrhea. May cause effects similar to those for inhalation exposure. Systemic Effects May cause central nervous system depression. Metabolism may release cyanide, which may result in headache, dizziness, weakness, collapse, unconsciousness, and possible death. May be metabolized to cyanide, which in turn acts by inhibiting cytochrome oxidase, impairing cellular respiration. May cause tissue anoxia, characterized by weakness, headache, dizziness, confusion, cyanosis (bluish discoloration of skin due to deficient oxygenation of the blood), weak and irregular heart beat, collapse, unconsciousness, convulsions, coma, and death. 

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