Where is potassium cyanide used? What is cyanide? Cyanides and their effect on the human body

There are many legends about a substance called “potassium cyanide”. One of them says that death from cyanide is painful, but instantaneous. This absurd statement was generated by filmmakers who often show the terrible death of movie characters poisoned by this toxic substance.

Potassium cyanide is indeed a very toxic substance. Its lethal dose for humans is 1.7 mg/kg. However, there are people who are able to survive higher doses. In addition, a full stomach and food containing sulfur (eggs, meat, legumes) can significantly slow down the absorption of poison. Just like carbohydrates. A striking example of this is the death of Grigory Rasputin. Filled with cakes, his stomach slowed down the action of the poison so much that the poisoning developed extremely slowly.

Potassium cyanide is a white crystalline powder with a strong odor. It dissolves well in water, poorly in ethanol and does not dissolve at all in carbohydrates. Externally, the powder looks like granulated sugar, which famous poisoners have used more than once. Its properties as a chemical substance are based on the ability of the drug to have a very strong inhibitory effect and block tissue respiration. It happens like this. Once in the body, it reacts with cytochrome c oxidase (this is a cellular enzyme responsible for oxygen transfer). By completely blocking this enzyme, cyanide deprives cells of the ability to absorb oxygen, and a person dies from its lack (more precisely, from interstitial hypoxia).

Andidote (neutralizing) properties for this strongest inorganic poison are substances containing sulfur and carbohydrates that can have a methemoglobin-forming effect. These include amyl nitrite, methylene non blue (popularly known as “blue”), anthicyan.

In private conversations and on Internet forums, you can often come across the question: “Where can I buy potassium cyanide?” The answer will disappoint fans of suicide. Neither potassium cyanide itself nor its antidotes can be purchased. Nowhere: neither in pharmacies, nor in stores. Even in special laboratories, every hundredth of a gram of this substance is counted. Therefore, you should not demonstrate a demonstrative suicide using potassium cyanide: there is a possibility that they simply will not have time to take you to where there is an antidote.

Typically, cyanide is obtained in specialized laboratories by reacting hydrogen cyanide with potassium hydroxide or calcining yellow blood salt at a very high temperature. The resulting compound is used for cyanidation (obtaining precious metals from ore rocks), in jewelry production, and electroplating of certain metals (cadmium, for example, or copper).

Cyanide reserves cannot be created. The hydrocyanic acid corresponding to the cyanide ion is so weak that it is very quickly replaced by any other acids, turning poisonous cyanide into harmless potash. To do this, you don’t even need to carry out chemical reactions: just leave potassium cyanide in the air, allowing carbon dioxide and water to act on it, and it will soon turn into harmless and completely non-toxic potassium carbonate.

So where can you get cyanide? At home.

To make potassium cyanide at home, you need to take (or cyanide acid) and combine it with potash. However, the final product is not always obtained. Firstly, hydrocyanic acid vapors are highly toxic (that is, extremely poisonous to others). Secondly, it can explode from uncontrolled polymerization.

You can use coal tablets, but for it to react, it will have to be heated for a long time (about 300 years).

So it’s best not to engage in amateur activities, and just throw bad thoughts out of your head.

One of the most dangerous poisons is potassium cyanide, whose effect on humans is simply destructive. The toxic substance was repeatedly used in attempts to poison famous figures; it is known from numerous detective stories as the poison of sophisticated killers. Due to the lack of odor and external resemblance to granulated sugar, there is a risk of accidental intoxication.

Potassium cyanide information

The chemical with the formula KCN belongs to the broad group of cyanides. It combines plant toxins and laboratory developments based on them. Potassium cyanide was first obtained in Germany in the middle of the 19th century, and for a long time it was available for free sale in pharmacies. After numerous poisonings, it was banned for household work and was classified as one of the ten most dangerous compounds for humans.

In nature, cyanide is an organic substance found in many fruit acids. In minimal quantities it can be found in the juice and seeds of peach, plum, and some varieties of almonds. The molecules are found in the pulp of pears, apricots and apples. But the potassium cyanide content is so low that poisoning is impossible even if you eat several kilograms of fruit every day. Cyanide ions are included in the vitamin B12 formula and are involved in the process of hematopoiesis.

Potassium cyanide, made synthetically, is a derivative of hydrocyanic acid. It is widely used in printing and developing photographs, and is indispensable in the manufacture of paints and varnishes, chemical solutions and reagents. With its help, jewelers create unique masterpieces from gold, and toxic compounds help get rid of pests and insects on farms.

There is a widespread belief about what cyanide smells like. Many people not involved in chemical production are sure that the toxin has an almond aroma. Therefore, the victim will have a specific smell from the mouth, which will facilitate diagnosis. In reality, there is no such sign, and an attempt to sniff the powder can result in poisoning.

Effect of potassium cyanide on the body

Anyone should know what potassium cyanide looks like in order to prevent a dangerous situation in a timely manner. The structure of the industrially produced composition resembles white sugar crystals. It dissolves easily in liquids without betraying its taste or aroma.

In most cases, poisoning is oral; potassium cyanide is absorbed through food and drinks. Airborne intoxication occurs when working with certain types of gouache, inhaling fine powder during an accident in the workshop, or treating the room for rodents. There is a danger of injury if the composition gets on open wounds or hangnails on the fingers.

The effect of potassium cyanide on the body is to block the enzyme cytochrome oxidase. It is involved in all vital processes, stimulates the division of new cells, binds and transports oxygen molecules, saturating soft tissues and mucous membranes. Cyanide blocks this connection with hemoglobin, stopping the functioning of all systems and organs. The mechanism resembles suffocation from lack of oxygen.

Symptoms of Cyanide Poisoning

The severity of symptoms depends on the amount of potassium cyanide consumed, therefore, acute and chronic stages of poisoning are distinguished. The lethal dose of cyanide is 17 mg per 1 kg of body weight. At a concentration of 10 to 15 mg, severe damage to internal organs occurs within 30–40 minutes. With a single dose of 50 mg, a person dies within 1 minute.

The lethal dose depends on the weight, age and health characteristics of the victim. There are several ways to be poisoned by potassium cyanide:

• in case of an emergency leak at the enterprise;
• in case of violation of storage rules in the laboratory or at home;
• when working with powder without protective equipment.

Another common method for producing a high dose of potassium cyanide is based on chemical reactions. Some people unknowingly keep the composition in a room with high humidity. When the critical norm of water in the air is exceeded, decomposition into components occurs, the formula is disrupted, senile hydrogen, sodium and toxic fumes are released, which remain in the room and settle on the mucous membranes and alveoli of the bronchi.

Knowing how potassium cyanide and toxic agents work, acute poisoning can be diagnosed by symptoms. There are several stages of development of intoxication:

1. There is a headache, spasms in the temples, severe dizziness. When measuring the pulse, there is a noticeable increase in heart rate, the heart rhythm is disturbed, the skin on the face and chest turns red from a sudden rush of blood.
2. Breathing becomes frequent and loud, adding a feeling of lack of air. The person tries to take a deep breath, but does not feel relief. The pupils dilate, practically do not react to light, and vomiting may occur.
3. Lack of oxygen in the blood provokes fainting, limb cramps, and smooth muscle spasms. Poisoning with potassium cyanide increases the risk of a seizure with damage to the tongue.
4. The patient is paralyzed, the reaction to pain and irritants completely disappears. As with a stroke, involuntary emptying of the intestines and bladder begins. Death from potassium cyanide occurs after excruciating agony from respiratory paralysis and death of brain cells.

Important! During the Cold War, intelligence officers and secret agents had a miniature cyanide capsule sewn into the inside of their cheeks, which, when bitten, resulted in instant death and helped avoid torture and loss of important information.

Doctors explain what will happen if you drink potassium cyanide in a minimal dosage. The main blow falls on the liver, which diligently neutralizes toxic compounds. It protects hemoglobin cells and destroys their binding with poisons. In this situation, the symptoms are mild, the victim only feels dizziness and malaise.

It is more difficult to detect chronic potassium cyanide poisoning. When entering the blood daily, the particles settle in soft tissues, and the properties appear gradually. A person feels tired, and due to insufficient oxygen supply, he is overcome by drowsiness and absent-mindedness. Blood tests show a decrease in hemoglobin and an increase in liver tests.

First aid for potassium cyanide intoxication

If a person exhibits symptoms of potassium cyanide poisoning, first aid must be provided immediately - the victim’s life may depend on the speed and correctness of actions. The patient must be provided with a flow of fresh air and taken outside from a room saturated with toxic fumes. At the same time, an ambulance is called, following the operator’s recommendations.

Potassium cyanide is a poison that can penetrate through pores and cuts on the skin, so work clothes are removed from the person. Exposed areas of the body are wiped with a towel dipped in soapy water. While maintaining consciousness, it is necessary to rinse the mouth and rinse the nose from dust. To prepare a disinfecting solution, use hydrogen peroxide, baking soda or antiseptics.

It is important to provide proper assistance in case of loss of consciousness:

1. The victim is placed on his side so that he does not choke on the vomit.
2. Constantly check your pulse, monitor your breathing rate and chest contractions.
3. If necessary, perform a cardiac massage.

After hospitalization of the patient, the person who provided assistance must contact a medical facility. He also needs to be given an antidote to prevent secondary potassium poisoning. The following drugs act in this capacity:

• sodium nitrite;
• glucose;
• any hemoglobin converters;
• amyl nitrite;
• sodium thiosulfate.

At home, before the doctor arrives, you can give regular sugar. Sweet glucose perfectly replaces the antidote and breaks down potassium cyanide into compounds k2c2o4 and salts that are safe for the body. It is offered to the patient in the form of a piece of refined sugar, concentrated syrup. If the chewing muscles are weak, pour one spoonful of sweetened tea or water into the mouth and allow a little sand to dissolve. This procedure is strictly prohibited for diabetes mellitus.

It should be remembered that to neutralize potassium cyanide, a direct reaction with a product containing glucose and its derivatives is necessary. Therefore, the sweet medicine should be obtained as early as possible to ensure contact of the chemicals in the stomach. If the poison gets into the blood and several hours have passed, it will be impossible to correct the situation.

Upon admission to the hospital, the first action of toxicologists is to administer the drugs Lobelin or Cititon. They are designed to stimulate the parts of the brain responsible for breathing. Additionally, the victim is transferred to artificial ventilation, and the concentration of oxygen ions is increased. The following steps can help make potassium cyanide safer:

In the case of the patient, the patient is kept under constant observation. On the second day, potassium cyanide intoxication often causes kidney dysfunction, liver damage and other life-threatening complications. Complete rehabilitation takes several months.

Possible consequences

Whether potassium cyanide kills quickly or slowly depends on the dose taken. But a person rarely manages to fully recover: the chemical and oxygen starvation provoke the death of brain cells. The victim has problems with memory, assimilation of information, and coordination of movements is impaired. Health consequences may include:

• decreased liver function;
• hormonal imbalance;
• deterioration of the thyroid gland;
• problems with conception.

Half of those affected by potassium cyanide develop long-term neuroses, characterized by uncontrolled surges in blood pressure, arrhythmia, and frequent. The person experiences mood swings, becomes irritable and inattentive.

Prevention when working with cyanides

At enterprises that actively use the chemical as a reagent, the emphasis is on respiratory and skin protection. All actions must be carried out in special clothing and gloves using masks and respirators. Considering that when there is a leak, the smell of potassium cyanide is not noticeable, professionals resort to a trick: they put a piece of sugar in the cheek. When the toxin gets into the mucous membranes of the nasopharynx, it is instantly neutralized. To reduce the risk of poisoning, you should follow the recommendations:

1. In workshops where potassium cyanide or hydrocyanic acid is contained, carry out preventive training for neutralization.
2. Visit your therapist regularly for examinations and tests.
3. Do not try powder of unknown origin on your tongue, do not check what cyanide smells like.

At home, toxicologists do not recommend consuming apricot kernels for food or medicinal purposes. If you are going to work with paints based on potassium cyanide at home, you should purchase an antidote and familiarize yourself with the specifics of first aid.

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Poisoning a person can happen accidentally or intentionally. Many have heard of such a poison as potassium cyanide. It acts on humans quite quickly and cyanide poisoning often results in severe consequences or death. This toxic substance is used only in production (jewelry making, mining of precious metals); it is not often found in everyday life.

How to determine potassium cyanide

Potassium cyanide, or potassium cyanide, is a substance that is a compound of hydrocyanic acid and potassium hydroxide. It is very toxic. However, it should be noted that this toxic substance is not particularly resistant to decay. That is, under certain conditions (concentrated glucose solution, high environmental humidity), oxidation and decomposition of a dangerous compound occurs.

Is it possible to detect this poison? This is quite difficult, since it does not have any special distinctive features, and when it gets into food and drinks it is not distinguishable.

Characteristics of potassium cyanide:

• Type of this substance. It appears as small colorless crystals. Looks like regular refined sugar;
• Solubility. Poison crystals dissolve well in water. At the same time, the liquid does not change its color and consistency;
• Smell. We can say that potassium cyanide has no smell at all. Although some people, due to their genetic predisposition, can detect a slight almond aroma.

How can you get poisoned?

Potassium cyanide can be found in some plant foods:

• Almonds, cassava;
• Fruit tree seeds (cherry, apricot, peach, plum).

If these products are consumed in large quantities, symptoms of mild intoxication may occur.

Industries and industries that use cyanide:

Causes of potassium cyanide poisoning:

• Violation of safety precautions and rules of use when working with toxic substances at work;
• Failure to comply with the rules for handling rodent poison;

• Industrial accidents;
• Eating tassels of fruiting plants(more often in children). Canned compotes with pits, as well as frozen cherries, tend to accumulate this dangerous substance. Therefore, it is not recommended to store these stocks longer than 12 months;
• Intentional use for the purpose of suicide (recently practically not registered).

Ways of penetration of poison into the body:

• Airborne - inhalation of poison vapors;
• Food – penetration into the body with food and drinks;
• Contact household, that is, poisoning with potassium cyanide through the skin and mucous membranes.

The effect of potassium cyanide on the human body

The speed of action of potassium cyanide on the body directly depends on the route of its penetration. If the poison enters the air, the body’s reaction is lightning fast. When this substance is inhaled, it quickly penetrates the blood, from which it spreads throughout the body. When penetrated by other routes, pathological signs increase gradually.

Cyanide disrupts the functioning of the body at the cellular level.

Cyanide has a negative effect on humans. As soon as the toxic substance has entered the body, it begins to block the cells. That is, the body's cells lose the ability to absorb oxygen, which is so necessary for life and activity.

Oxygen enters the cells, but they cannot absorb it, which is why hypoxia develops, and then asphyxia. First of all, brain cells, which vitally need oxygen to function, are affected.

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Venous and arterial blood are compared in terms of oxygen concentration. Therefore, the color of venous blood changes. She turns scarlet. The skin becomes hyperemic.

The heart and lungs also suffer from hypoxia. The heart rhythm is disturbed, ischemia occurs. Lung cells do not absorb oxygen, which leads to suffocation and asphyxia (stopping breathing).

Symptoms of potassium cyanide poisoning

In the clinical picture of poisoning, there are 4 stages, which depend on the concentration of the poison that has entered the body.

The first stage is prodromal. This is a mild poisoning, which is manifested by the following pathological signs:

The second stage is dyspneic. It develops with further contact with the toxic substance. The dyspnoetic stage is characterized by the presence of the following symptoms of cyanide poisoning:

• The victim's anxiety;
• Feeling of fear of death;
• Bradycardia (pulse becomes rare);
• Impaired coordination of movements;
• Dizziness;
• Redness of the skin, perspiration;
• Trembling limbs (tremor);
• The eyeballs are bulging, the pupils are dilated. Their reaction to light is preserved;
• Severe shortness of breath, tachypnea.

The third stage is convulsive:

• Vomit;
• Convulsions;
• Loss of consciousness;
• The bullet is weak, thread-like;
• Body temperature is sharply increased;
• Reduced blood pressure.

At this stage of intoxication, immediate qualified medical assistance is required.

Fourth stage paralytic:

• Bright blush;
• Stopping seizures;
• There is no sensitivity of the skin;
• Paresis and paralysis, including the respiratory center;
• Lack of breathing.

First aid and treatment after poisoning

In case of poisoning with potassium cyanide, it is necessary to call an ambulance team, which will ensure hospitalization of the patient. Before doctors arrive, first aid should be provided to the victim to alleviate his condition:

Antidotes are:

• 5 or 40% glucose solution;
• 2% sodium nitrite solution;
• 1% solution of methylene blue;
• 25% sodium thiosulfate solution;
• Amyl nitrite. This solution is applied to a cotton swab and the victim is allowed to breathe.

The victim is hospitalized in the intensive care unit, where appropriate treatment is carried out:

Consequences and complications

When working with cyanide, chronic poisoning may develop, which appears:

• Severe headaches;
• Dizziness;
• Irritability;
• Decreased memory;
• Sleep disturbance;
• Unpleasant sensations and pain in the heart area.

With a long course of chronic intoxication, severe pathologies of various systems (nervous, cardiovascular, digestive, excretory) develop.

Complications of cyanide poisoning include:

• Persistent memory impairment (difficulty remembering new information, disappearance of certain moments of the past from memory);
• In severe poisoning, severe brain damage is observed, which is manifested by a decrease in intellectual and cognitive abilities;
• Chronic headaches;
• Nervous breakdowns and depression;
• Changes in blood pressure;
• Change in heart rate;
• Coma and convulsions are early complications that are life-threatening for the victim;
• In severe cases, death.

Death from potassium cyanide: lethal dose and causes of death

Death from potassium cyanide is very real. This is a very toxic substance, which even in small doses has extremely negative effects.

17 milligrams of potassium cyanide per 1 kilogram of human weight is a lethal dose.

When this concentration enters the body, death occurs in a matter of minutes. In this case, the person does not even have time to provide first aid to the victim.

Why does death occur from potassium cyanide poisoning? Death occurs when there is a high concentration of the toxic substance in the body, as well as when medical care is not provided in a timely manner. In this case, a paralytic stage quickly occurs, which often ends in the death of the patient. Many organs and systems stop working.

The causes of death are:

• Brain damage. Paralysis of the respiratory center occurs. In this case, respiratory arrest is of central origin;
• Hypoxia of brain and heart tissue;
• Respiratory and cardiac arrest are the leading causes of death.

It is impossible to avoid death when a lethal dose is administered.

In all other cases, in order to save the patient, it is necessary to provide him with assistance and administer antidotes as quickly as possible.

In 1945, the novel Sparkling Cyanide by Agatha Christie was published. The detective story turned out to be exciting and interesting. However, not everyone knows that such cyanide does not exist. So what is this substance and how does it affect the human body?

What is cyanide?

Cyanides are a class of fast-acting substances that have harmful effects on the human body. In other words, these are poisons. Their toxicity can easily be explained by the negative impact of some of their components on the body. In turn, the functioning of the entire organism is disrupted. The cells simply stop functioning. After this, important systems of the body cease to perform their functions, and a pathological serious condition occurs, which most often ends in death.

So what is cyanide? First of all, these are derivatives of hydrocyanic acid. The formula is quite simple: KCN. This substance was first obtained by the German chemist Robert Wilhelm Bunsen. In addition, the scientist also developed industrial methods for its synthesis. This happened in 1845.

Some properties of matter

Potassium cyanide is a white powder with a crystalline structure. The substance dissolves perfectly in water. The poison has a peculiar smell, but about 50% of the population of our planet can smell it. It is worth noting that potassium cyanide is an unstable substance. It oxidizes in solutions containing glucose and at a sufficient level of humidity.

Sodium cyanide is also common. The formula of this substance is NaCN. Sodium cyanide appears as white plasticine, powder, paste or hygroscopic crystals. The substance is also unstable. It dissolves quickly in menthol and water. Sodium cyanide itself is not flammable. However, upon contact with moist air, the substance releases a gas that is highly flammable. When burned, sodium cyanide releases toxic and irritating fumes. They can cause serious poisoning. The hydrolysis of cyanide also produces volatile substances.

Cyanide in plants

We figured out what cyanide is. But how do you get it and why? Cyanides are not only produced synthetically. These substances are also found in nature. This increases the risk of intentional or accidental poisoning. The poison can be obtained from certain foods and plants. It is for this reason that you should know all sources of cyanide.

The list of dangerous foods includes Lima beans, almonds and cassava. In addition, cyanide is found in the seeds of pears, plums, apricots, cherries, peaches and even apples. Poisoning occurs only in cases where an excessive amount of dangerous products enters the body. At risk are those people who have individual intolerance.

Use of cyanide

Cyanide solutions are used in many industries. These substances are commonly used to make paper, plastics and some types of textiles. As a rule, poison is present in many reagents that are used to develop photographs. In metallurgy, the substance we are considering is used to purify galvanics and metals, as well as to separate gold from ores.

In addition, cyanide is used in gas form in combination with other substances to disinfect grain storage facilities. Such compositions allow you to kill rodents.

Effect on the body

When cyanide enters a living organism, a special enzyme, cytochrome oxidase, is blocked. As a result, the tissues do not receive the required amount of oxygen. This leads to the development of asphyxia.

First of all, tissue hypoxia affects the brain. As a result, central nervous system paralysis develops. All this leads to rapid poisoning. As for the symptoms of poisoning, they appear almost instantly.

The severity of the patient’s condition depends primarily on how the poison entered the body. When inhaling vapors and gases, poisoning occurs instantly. It is extremely rare that cyanide penetrates the skin and gastrointestinal tract. In such cases, symptoms of poisoning may appear gradually.

When do signs of poisoning appear?

As already mentioned, the signs of poisoning and the degree of their manifestation depend on how the poison entered the body and in what quantity. For humans, the lethal dose of cyanide is only 0.1 mg/l. Death occurs within an hour. If 0.12-0.15 mg/l enters the body, then the person dies within half an hour.

If the concentration of the toxic substance is increased to 0.2 mg, then death occurs within 10 minutes. It is worth considering that a person can withstand cyanide poisoning under certain conditions. This is possible if the concentration does not exceed 0.55 mg/l and the effect of the poison is no more than one minute.

If cyanide enters the body along with the gas, then symptoms are observed after a couple of seconds. If the toxic substance enters through the stomach, the clinical picture develops after a few minutes.

Main symptoms of poisoning

Cyanide is a poison that begins to act immediately as soon as it enters the human body. At high dosages of a toxic substance, symptoms of poisoning appear instantly. Here are the main signs:

1. First of all, the victim loses consciousness.
2. Paralysis of the respiratory system occurs instantly. In addition, the work of the heart muscles is blocked.
3. Death.

With small dosages, symptoms appear gradually:

1. The initial stage of cyanide poisoning is characterized by dizziness, acute and rapidly increasing headache, rapid heartbeat and breathing, a feeling of heaviness in the frontal lobes,
2. The second stage is shortness of breath. At the same time, breathing becomes noisy, deep and rare. The victim's pulse slows down, nausea and vomiting occur, and the pupils dilate.
3. At the next stage, the person loses consciousness. Often, tetanic spasms cause spasms of the masticatory muscles, which can result in biting the tongue.
4. The next stage is paralysis. The victim loses not only reflexes, but also sensitivity. Breathing is very rare. In addition, involuntary bowel movements and urination may occur. If you do not provide first aid to the victim, cardiac activity will stop and death will occur.

In conclusion

Now you know what cyanide is and how it affects the human body. Alas, this substance was not always used for peaceful purposes. during the Second World War, it was part of such poisonous gas as Zyklon-B. This weapon was widely used by German troops. There is also an opinion that this poisonous gas was also used in 1980 during the war between Iran and Iraq.

INJURIES BY POISONIC SUBSTANCES WITH GENERAL TOXIC EFFECT: PYROCYCAL ACID AND POTASSIUM CYANIDE

Hydrocyanic acid and potassium cyanide are generally toxic substances, as are sodium, cyanogen chloride, cyanogen bromide, and carbon monoxide.
Hydrocyanic acid was first synthesized by the Swedish scientist Karl Scheele in 1782. History knows of cases of the use of cyanide for mass destruction of people. During the First World War (1916 on the Somme River), the French army used hydrocyanic acid as a poisonous substance; in Hitler’s extermination camps, the Nazis (1943-1945) used poisonous gases, cyclones (esters of cyanacetic acid), and American troops in South Vietnam. (1963) used toxic organic cyanides (CS type gases) against civilians. It is also known that in the United States the death penalty is used by poisoning convicts with hydrocyanic acid fumes in a special chamber.
Due to their high chemical activity and ability to interact with numerous compounds of various classes, cyanides are widely used in many industries, agriculture, and scientific research, and this creates many opportunities for intoxication.
Thus, hydrocyanic acid and a large number of its derivatives are used in the extraction of precious metals from ores, in electroplating gilding and silvering, in the production of aromatic substances, chemical fibers, plastics, rubber, organic glass, plant growth stimulants, and herbicides. Cyanides are also used as insecticides, fertilizers and defoliants. Hydrocyanic acid is released in gaseous form during many industrial processes. There may also be cyanide poisoning due to eating large quantities of almond, peach, apricot, cherry, plum and other plants of the Rosaceae family or infusions from their fruits. It turned out that they all contain the glycoside amygdalin, which decomposes in the body under the influence of the emulsin enzyme to form hydrocyanic acid, benzaldehyde and 2 glucose molecules. The largest amount of amygdalin is found in bitter almonds (up to 3%) and apricot seeds (up to 2%).
Physicochemical properties and toxicity of hydrocyanic acid
Hydrocyanic acid - HCN - is a colorless, easily boiling (at 26 ° C) liquid, with the smell of bitter almonds, with a specific gravity of 0.7, freezes at - 13.4 ° C. Cyanide poisoning develops when inhaling vapors of a toxic substance when entering through the skin and through the mouth. In wartime, the most likely route of entry into the body is inhalation. According to WHO, Lt50 of hydrocyanic acid is 2 g/min/m3. In case of poisoning by mouth, lethal doses for humans are: HCN - 1 mg/kg, KCN - 2.5 mg/kg; NaСN - 1.8 mg/kg.
Mechanism of toxic action
The mechanism of action of hydrocyanic acid has been studied in some detail. It is a substance that causes oxygen starvation of tissue type. In this case, a high oxygen content is observed in both arterial and venous blood and thus a decrease in the arteriovenous difference, a sharp decrease in oxygen consumption by tissues with a decrease in the formation of carbon dioxide in them.
It has been established that cyanide interferes with redox processes in tissues, disrupting the activation of oxygen by cytochrome oxidase. (The lecturer can dwell in more detail on modern concepts of cellular respiration).
Hydrocyanic acid and its salts, dissolved in the blood, reach the tissues, where they interact with the trivalent form of iron, cytochrome oxidase. By combining with cyanide, cytochrome oxidase loses its ability to transfer electrons to molecular oxygen. Due to the failure of the final link of oxidation, the entire respiratory chain is blocked and tissue hypoxia develops. Oxygen is delivered to the tissues in sufficient quantities with arterial blood, but is not absorbed by them and passes unchanged into the venous bed. At the same time, the processes of formation of macroergs necessary for the normal functioning of various organs and systems are disrupted. Glycolysis is activated, that is, the metabolism is rearranged from aerobic to anaerobic. The activity of other enzymes - catalase, peroxidase, lactate dehydrogenase - is also suppressed.
The effect of cyanide on various organs and systems
Effect on the nervous system. As a result of tissue hypoxia, which develops under the influence of hydrocyanic acid, the functions of the central nervous system are primarily disrupted. Cyanides in toxic doses initially cause excitation of the central nervous system, and then its depression. In particular, at the beginning of intoxication, excitation of the respiratory and vasomotor centers is observed. This is manifested by a rise in blood pressure and the development of severe shortness of breath. An extreme form of excitation of the central nervous system is clonic-tonic convulsions. Severe excitation of the nervous system is replaced by paralysis (of the respiratory and vasomotor centers).
Effect on the respiratory system. In the picture of acute poisoning, there is a pronounced increase in the frequency and depth of breathing. Developing shortness of breath should apparently be considered as a compensatory reaction of the body to hypoxia. The stimulating effect of cyanide on respiration is due to the stimulation of the chemoreceptors of the carotid sinus and the direct effect of the poison on the cells of the respiratory center. The initial excitation of breathing as intoxication develops is replaced by its suppression until it stops completely. The causes of these disorders are tissue hypoxia and depletion of energy resources in the cells of the carotid sinus and in the centers of the medulla oblongata.
Effect on the cardiovascular system. In the initial period of intoxication, a slowdown in heart rate is observed. An increase in blood pressure and an increase in cardiac output occurs due to cyanide stimulation of the chemoreceptors of the carotid sinus and cells of the vasomotor center, on the one hand, the release of catecholamines from the adrenal glands and, as a result, vasospasm, on the other. As poisoning progresses, blood pressure drops, pulse quickens, acute cardiovascular failure develops, and cardiac arrest occurs.
Changes in the blood system. The content of red blood cells in the blood increases, which is explained by the reflex contraction of the spleen in response to developing hypoxia. The color of venous blood becomes bright scarlet due to excess oxygen not absorbed by the tissues. The arteriovenous difference in oxygen decreases sharply. When tissue respiration is suppressed, both the gas and biochemical composition of the blood changes. The CO2 content in the blood decreases due to less formation and increased release during hyperventilation. This leads at the beginning of the development of intoxication to gas alkalosis, which changes to metabolic acidosis, which is a consequence of the activation of glycolytic processes. Under-oxidized metabolic products accumulate in the blood. The content of lactic acid increases, the content of acetone bodies increases, and hyperglycemia is noted. The development of hypothermia is explained by disruption of redox processes in tissues. Thus, hydrocyanic acid and its salts cause the phenomenon of tissue hypoxia and associated disorders of respiration, blood circulation, metabolism, and the function of the central nervous system, the severity of which depends on the severity of intoxication.
CLINICAL PICTURE OF CYANIDE POISONING
Cyanide poisoning is characterized by the early appearance of signs of intoxication, the rapid development of oxygen starvation, primary damage to the central nervous system and probable death in a short time.
There are lightning-fast and delayed forms. When poison enters the body in large quantities, death can occur almost instantly. The affected person immediately loses consciousness, breathing becomes rapid and shallow, the pulse becomes faster, arrhythmic, and convulsions occur. The convulsive period is short-lived, breathing stops and death occurs. In the delayed form, the development of poisoning can extend over time and occur in various ways.
Mild degree of poisoning characterized mainly by subjective disorders: irritation of the upper respiratory tract, conjunctiva of the eyes, an unpleasant burning-bitter taste in the mouth, the smell of bitter almonds, weakness, dizziness. Somewhat later, a feeling of numbness in the oral mucosa, drooling and nausea occurs. With the slightest physical effort, shortness of breath and severe muscle weakness, tinnitus, difficulty speaking, and possible vomiting appear. After the action of the poison ceases, all unpleasant sensations subside. However, headaches, muscle weakness, nausea and a general feeling of weakness may remain for several days. With a mild degree of intoxication, complete recovery occurs.
In case of intoxication medium degree First, the subjective disorders described above are noted, and then a state of excitement arises, and a feeling of fear of death appears. The mucous membranes and skin become scarlet in color, the pulse is slow and tense, blood pressure rises, breathing becomes shallow, and short clonic convulsions may occur. With timely assistance and removal from the contaminated atmosphere, the poisoned person quickly regains consciousness. Over the next 3-6 days, weakness, malaise, general weakness, headache, discomfort in the heart area, tachycardia, and restless sleep are noted.
In the clinical picture severe intoxication There are four stages: initial, dyspnoetic, convulsive and paralytic. The initial stage is characterized mainly by the subjective sensations outlined above when describing mild poisoning. It is short-lived and moves on to the next one. For the dyspnoetic stage, some signs of oxygen starvation of the tissue type are typical: scarlet color of the mucous membranes and skin, gradually increasing weakness, general anxiety, discomfort in the heart area. The poisoned person develops a feeling of fear of death, the pupils dilate, the pulse slows down, breathing becomes frequent and deep. In the convulsive stage, the condition of the affected person deteriorates sharply. Consciousness is lost, the corneal reflex is sluggish, the pupils do not respond to light. Exophthalmos appears, breathing becomes arrhythmic and rare, blood pressure rises, and the pulse rate decreases. Widespread clonic-tonic convulsions occur. The scarlet color of the skin and mucous membranes remains. The duration of this stage can vary from several minutes to several hours. With further deterioration of the affected person's condition, the paralytic stage develops. By this time, the convulsions have stopped, but the patient is in a deep comatose state with complete loss of sensitivity and reflexes, muscle adynamia, involuntary urination and defecation are possible. Breathing is rare, irregular. Then a complete cessation of breathing occurs, the pulse quickens, becomes arrhythmic, blood pressure drops and after a few minutes cardiac activity stops.
Consequences and complications characteristic of severe intoxication. For several weeks after the injury, persistent and profound changes in the neuropsychic sphere may persist. As a rule, asthenic syndrome persists for 10-15 days. Patients complain of increased fatigue, decreased performance, headache, and poor sleep. Impaired motor coordination, persistent cerebellar disorders, paresis and paralysis of various muscle groups, difficulty speaking, and mental disorders may be observed. From co-
Pneumonia ranks first among the most common complications. Its occurrence is facilitated by aspiration of mucus, vomit, and prolonged stay of patients in a supine position. Changes are also observed in the cardiovascular system. Within 1-2 weeks, unpleasant sensations in the heart area, single extrasystoles, tachycardia, lability of pulse and blood pressure are observed, ECG changes are observed (signs of coronary insufficiency).
DIAGNOSIS OF PYROCANIC ACID POISONING
The diagnosis of damage by hydrocyanic acid is based on the following signs: sudden onset of symptoms of damage, the sequence of development and transience of the clinical picture, the smell of bitter almonds in the exhaled air, scarlet coloring of the skin and mucous membranes, wide pupils and exophthalmos.
TREATMENT OF POISONING WITH PRYANIC ACID
The effect of helping those poisoned by cyanide depends on the speed of use of antidotes and agents that normalize the functions of vital organs and systems.
Methemoglobin-forming substances, substances containing sulfur and carbohydrates have antidote properties. Methemoglobin formers include anthicyanin, amyl nitrite, sodium nitrite, and methylene blue. They oxidize the iron in hemoglobin, converting it into methemoglobin. Methemoglobin, containing ferric iron, is able to compete with cytochrome oxidase for cyanide. It should be borne in mind that methemoglobin is not able to bind with oxygen, therefore it is necessary to use strictly defined doses of these agents, since when hemoglobin is inactivated by more than 25-30%, hemic hypoxia develops. Methemoglobin binds primarily to cyanide dissolved in the blood. When the concentration of cyanide in the blood decreases, conditions are created to restore the activity of cytochrome oxidase and normalize tissue respiration. This is due to the reverse flow of cyanide from the tissues into the blood - towards its lower concentration. The formed cyanogen-methemoglobin complex is an unstable compound. After 1-1.5 hours, this complex begins to gradually disintegrate with the formation of hemoglobin and cyanide. Therefore, relapse of intoxication is possible. However, the dissociation process is extended over time, which makes it possible to neutralize the poison with other antidotes.
The standard antidote from the group of methemoglobin formers is anticyan.
In case of hydrocyanic acid poisoning, the first administration of anthicyanin in the form of a 20% solution is made in a volume of 1.0 ml intramuscularly or 0.75 ml intravenously. When administered intravenously, the drug is diluted in 10 ml of 25-40% glucose solution or saline, the injection rate is 3 ml per minute. If necessary, after 30 minutes. the antidote can be repeated in a dose of 1.0 ml, but only intramuscularly. After another 30-40 minutes. You can carry out a third administration in the same dose, if there are indications for this.
Sodium nitrite is a powerful methemoglobin-forming agent. Aqueous solutions of the drug are prepared ex tempore, since they are unstable during storage. When providing assistance to poisoned people, sodium nitrite is administered intravenously slowly in the form of a 1-2% solution in a volume of 10-20 ml.
Amyl nitrite and propyl nitrite have a methemoglobin-forming effect. Methylene blue has a partial methemoglobin-forming effect.
Substances containing sulfur. When substances containing sulfur interact with cyanide, non-toxic rhodanium compounds are formed. Sodium thiosulfate turned out to be the most effective of the sulfur donors. 20-50 ml of a 30% solution is administered intravenously. It reliably neutralizes chemical agents. The disadvantage is the relatively slow action.
The next group of antidotes has the property of converting cyanogen into non-toxic cyanohydrins. This property is observed in carbohydrates. Glucose has a pronounced antitoxic effect, which is recommended to be administered in a dose of 30-50 ml of a 25% solution. In addition, glucose has a beneficial effect on respiration, cardiac function and increases diuresis.
An antidote effect is observed when using cobalt salts, which, when interacting with cyanides, lead to the formation of non-toxic cyanide-cobalt compounds.
The effect of antidotes is enhanced when used against the background of oxygen barotherapy. It has been shown that oxygen under pressure promotes a more rapid restoration of cytochrome oxidase activity.
There is information about the beneficial therapeutic effect of unithiol, which, without being a sulfur donor, activates the enzyme rhodonase, and thus accelerates the detoxification process. Therefore, it is advisable to introduce unithiol along with sulfur donors.
Antidote therapy for lesions with hydrocyanic acid is usually carried out in combination: first, methemoglobin formers are used, then sulfur donors and substances that promote the formation of cyanohydrins.
In addition to the use of antidotes, it is necessary to carry out all the general principles of treating poisoned people (removal of unabsorbed and absorbed poison, prevention of further entry of poison into the organs - by forced removal, symptomatic therapy, resuscitation measures).
STAGE TREATMENT
Poisoning develops quickly, so medical care is urgent.
First aid in an outbreak includes putting a gas mask on the poisoned person. Then evacuation outside the outbreak is carried out. Those affected in an unconscious state and in the convulsive stage of intoxication need to be evacuated while lying down.
First aid is carried out outside the outbreak, which allows you to remove the gas mask. Anticyan is administered - 1 ml intramuscularly, if necessary, cordiamine, mechanical ventilation.
First medical aid. The anticyant is reintroduced. If it was not prescribed at the stage of first aid, it is advisable to carry out the first administration intravenously with 10 ml of 25-40% glucose solution. Subsequently, 20-50 ml of 30% sodium thiosulfate solution is injected intravenously. According to indications, 2 ml of etimizol and cordiamine solution are used intramuscularly, mechanical ventilation.
Further evacuation is carried out only after the elimination of convulsions and normalization of breathing. Along the route, it is necessary to provide assistance for relapses of intoxication.
Qualified therapeutic care consists primarily of emergency measures: repeated administration of antidotes (anticyanin, sodium thiosulfate, glucose), injections of cordiamine, etimizol, mechanical ventilation (hardware method). Delayed measures of qualified therapeutic care include the administration of antibiotics, sulfonamides, desensitizing agents, and vitamins.
Those affected in a comatose and convulsive state are not transportable. Evacuation of the seriously injured is carried out in the VPTG, in the presence of neurological disorders - in the VPNG, those who have suffered mild intoxication remain in the medical hospital (OMO).
Specialized care is provided in the appropriate therapeutic hospitals (VPTG, VPNG) in full. At the end of treatment, convalescents are transferred to the VPGRL; in the presence of persistent changes in the nervous, cardiovascular, and respiratory systems, patients are subject to referral to VVC.