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Poisoning with cyanides


The ion of cyanide is extremely strong and high-speed poison. It is among those poisons against which there is a specific and effective antidote.

Poisoning with cyanides symptoms:

Excessive toxicity of cyanide is caused by its ability to react with trivalent iron of cytochrome oxydase. Formation of a complex cytochrome oxydase cyanide blocks transport of electrons, oppressing thereby oxygen utilization. It leads to dysfunction of cells and death. Inhalation of cyanhydric acid can cause death within 1 min. Orally applied poison works much more slowly, symptoms of poisoning appear in a few minutes, and death comes in several hours. The first effect of cyanide is increase in ventilation owing to blockade of metabolism of oxygen in cells of chemoceptors. In process of absorption of bigger amount of cyanide there are a headache, dizziness, nausea, drowsiness, hypotonia, heavy short wind, characteristic changes on an ECG, a coma and spasms.

Poisoning with cyanides reasons:

Poisoning with cyanide results from inhalation of cyanhydric acid or a proglatyvaniye of soluble inorganic salts of cyanide or tsianidvysvobozhdayushy substances, such as cyanamide, циаиогенхлорид and нитроируссид. Parts of some plants also contain substances, such as dl-mandelonitrile gentiobioside which release cyanide at digestion. These are seeds of the Virginia bird cherry, pennsylvanian bird cherry, the Virginia cherry, peaches, apricots, almonds ordinary, roots of a cassava, berry of a chernoyagodny bush, leaves and escapes of elder and all parts of a hydrangea. Laetrit medicine which part extract of grains of an apricot was, was the cause of fatal poisoning with cyanide. Cyanides are widely applied in the industry and in life in the form of reactants to photography or means of a dlyachistka of silver. Even 300 mg of potassium cyanide can cause a lethal outcome.

Treatment of the Poisoning with cyanides:

Patients with poisoning with cyanide demand urgent medical intervention. Timely begun treatment is very effective. In points of rendering emergency medical service always there have to be necessary chemical antidotes. The diagnosis can be made on the characteristic smell of bitter almonds defined at breath of the victim. As cyanide does not influence hemoglobin saturation by oxygen, cyanosis does not develop until there is respiratory depression. Treatment is directed to formation of a metgemoglobulin at administration of nitrite. Trivalent iron of a methemoglobin competes with cytochrome oxydase for a cyanide ion. A complex cytochrome oxydase dissociates cyanide, function of enzyme and cellular respiration are recovered. The further detoxication is carried out by administration of thiosulphate. Enzyme of a rodanaz catalyzes reaction of thiosulphate with the cyanide released at dissociation of a tsianmetgemoglobin; thiocyanate which is rather non-toxical and eksretirutsya easily in urine is formed.

As speed is a determinal factor, nitrite needs to be entered immediately by means of amyle nitrite inhalation, on one breath every 2 min. if arterial pressure is not less than 80 mm of mercury. Then whenever possible quickly it is necessary to enter intravenously 10 ml of 3% of solution of sodium nitrite within 3 min. For maintenance of a normal amount of arterial pressure during this injection intravenous injection of noradrenaline can be required. Within 10 min. after administration of sodium nitrite it is necessary to enter intravenously 50 ml of 25% of solution of sodium thiosulphate. The supporting actions, especially artificial respiration pure oxygen, it is necessary to hold as soon as possible, but if immediately not to cause development of a metglobinemiya, all other types of treatment are not of value. Administration of sodium nitrite and sodium thiosulphate can be repeated. The size of the entered doses should be based on determination of level of a methemoglobin; it should not exceed 40%. If the patient survives during 4 h, then, most likely, will recover, but at him residual brain symptoms can be observed.

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