Hydrocyanic acid poisoning
Hydrocyanic acid (hydrogen cyanide, HCN) is a colorless volatile liquid with a specific smell of bitter almonds. Easily soluble in water and organic solvents.
Source: depositphotos.com
This compound is often found because it is found in the seeds of almonds, peaches, apricots, cherries, plums and other plants of the Rosaceae family or in tinctures from their fruits. All seed kernels of the listed plants contain the glycoside amygdalin, which is metabolized in the body to form hydrocyanic acid. The largest amount of amygdalin is found in bitter almonds, about 3%, slightly less (up to 2%) is present in apricot pits.
There is evidence of the presence of cyanides (hydrocyanic acid salts) in the human body under physiological conditions. Cyanides of endogenous origin are found in some biological fluids, in exhaled air, in urine. It is believed that their normal level in blood plasma can reach 140 μg / l.
Hydrocyanic acid and its salts (sodium cyanide (NaCN), potassium cyanide (KCN), ammonium cyanide (NH4CN) and others) have found wide application in industry and agriculture. Hydrogen cyanide is an indispensable component in the production of synthetic rubbers, acrylic polymers, chemical fibers, plastics, fragrances, plexiglass, pesticides. Cyanides are used for the extraction of gold and silver from ore, hardening and liquid carburizing of metals, for electroplating cadmium plating, zinc plating, etc., in the production of pharmaceuticals, in photography, lithography.
In agriculture, hydrocyanic acid and its derivatives are used to control rodents, plant pests, for the purpose of disinfection.
Hydrogen cyanide is extremely toxic: if taken orally at a dose of 50 mg or more, or if inhaled at a concentration of more than 0.4 mg / l, it causes poisoning, which ends in death. If the concentration of a substance in the air exceeds 11 mg / l, then intoxication with hydrocyanic acid vapors is possible even percutaneously. In this case, the penetration of the poison into the interior is facilitated by the high temperature of the air in the production premises and severe physical stress, which cause increased blood circulation in the upper layers of the skin.
How does hydrocyanic acid poisoning occur?
The widespread use of hydrocyanic acid and its compounds in production conditions, along with its specific characteristics and high toxicity, leads to a high risk of acute or chronic intoxication. Most often, poisoning occurs in the following cases:
- inhalation of hydrocyanic acid vapors or its contact with the skin in case of violation of safety measures at the workplace (0.2-0.3 mg / l for 5-10 minutes);
- the ingress of concentrated aerosols into the digestive tract;
- inhalation of vapors or contact of substances on the skin when working with herbicides without personal protective equipment;
- eating large quantities of peach, apricot, cherry, almond, etc. seeds;
- the use of homemade liqueurs, wines, liqueurs, prepared on the seeds of the fruits of the listed plants.
Once in the body, acid and its compounds significantly reduce the activity of tissue respiration enzymes - cytochromes and catalase enzyme, which stimulates the breakdown of hydrogen peroxide. As a result, acute hypoxia develops when arterial and venous blood is oversaturated with oxygen, but its absorption by tissues at an adequate level is not possible due to blocking of key enzymes. Stopping the degradation of hydrogen peroxide leads to its accumulation and damage to cells and tissues of the body. The central nervous system is most sensitive to tissue hypoxia.
Poisoning symptoms
According to the intensity of the lesion, lightning and protracted forms of hydrocyanic acid poisoning are distinguished.
The fulminant form develops within a few minutes when a large amount of toxin enters the body:
- instant loss of consciousness;
- shallow pathological breathing;
- threadlike arrhythmic pulse;
- tonic and clonic seizures;
- death, usually from paralysis of the respiratory center.
With this form of poisoning, it is not possible to provide specialized medical care due to the violent and transient symptoms.
With a delayed form, the clinical manifestations of intoxication develop in the interval from 15 to 60 minutes, while it can proceed in a mild, moderate and severe degree.
Mild poisoning
It is characterized by the following symptoms:
- unpleasant taste in the mouth, bitterness;
- sharp muscle and general weakness;
- dizziness, headache;
- numbness of the oral mucosa;
- increased salivation;
- nausea, vomiting;
- dyspnea.
After the cessation of the action of the poison, the phenomena self-stop after 1-3 days.
Source: depositphotos.com
Average degree of poisoning
With moderate intoxication, the initial manifestations are similar to those with a mild degree, and later the symptoms grow, join:
- psycho-emotional excitement, a feeling of fear of death;
- staining of mucous membranes and skin in an intense scarlet color;
- decrease in heart rate (HR);
- increased blood pressure (BP);
- shallow unproductive breathing;
- the smell of bitter almonds from the mouth;
- incoming short-term neurological symptoms: confusion, convulsions, disorientation.
With timely assistance, the condition is normalized, complaints disappear in 4-6 days.
Severe poisoning
Severe poisoning develops sequentially, going through several stages: the stage of initial symptoms, respiratory failure, convulsive and paralytic stages.
- Initial stage. Symptoms are nonspecific, similar to the manifestations of mild to moderate poisoning. This condition is short-lived, it quickly turns into a stage of shortness of breath.
- Dyspnoetic stage (dyspnea stage). Signs of acute tissue hypoxia are the leading ones: scarlet color of visible mucous membranes and skin, severe weakness, a state of stunning, increasing pain in the heart. Objectively: the pupils are dilated, the victim is restless, the pulse is rapid, arrhythmic, breathing is unproductive, frequent, the inhalation is shortened, a persistent smell of bitter almonds from the mouth.
- Convulsive stage. Deterioration of the general condition progresses, shortness of breath increases, pulse becomes rare, blood pressure rises. Clonic and tonic convulsions develop with the reduction of the chewing muscles and, often, by biting the tongue, when frequent rhythmic muscle contractions turn into a long persistent generalized muscle spasm; the victim has no consciousness. This condition lasts from several minutes to several hours, transforming into the terminal paralytic stage.
- Paralytic stage. Convulsions stop, a coma develops, breathing stops, a critical drop in blood pressure and cessation of cardiac activity.
First aid for poisoning with hydrocyanic acid
- Evacuate the victim from the place of contamination (break off contact with the poison).
- Provide access to fresh air (open windows, doors, unfasten tight clothing).
- If the victim is unconscious, put him on his side or on his back with his head turned to one side to prevent aspiration of vomit in case of vomiting.
- When using hydrogen cyanide inside - rinse the stomach (drink 1-1.5 liters of warm water, a weak solution of potassium permanganate or 1% hydrogen peroxide, press on the root of the tongue, provoking vomiting).
- Take sorbent (Enterosgel, Polyphepan, Polysorb).
- In the presence of symptoms of clinical death (lack of consciousness, breathing, pulse on the carotid arteries and pupil response to light), immediately proceed to basic cardiopulmonary resuscitation of the victim, performing an indirect heart massage. Artificial ventilation of the lungs by mouth-to-mouth or mouth-to-nose method should not be carried out, since this can lead to the development of poisoning in the rescuer.
When is medical attention required?
Medical attention is needed in 100% of cases of hydrocyanic acid poisoning. Since it is not always possible to assess the degree of impact and the severity of the lesion at the initial stage, the victim should be under round-the-clock medical supervision.
The antidotes of hydrocyanic acid are Glucose, sodium thiosulfate, ethyl nitrite, methylene blue with tetrathiosulfate (joint administration), amyl nitrite with thiosulfate (joint administration). The most strongly opposed to hydrocyanic acid is the joint introduction of sodium nitrite with thiosulfate.
After the introduction of the antidote, measures are taken to maintain critical life support systems. When stabilization is achieved, further treatment is symptomatic.
Possible consequences
The consequences of the postponed poisoning with hydrocyanic acid can be persistent, sometimes irreversible changes in the central nervous system (parkinsonism, symptoms of cerebellar damage, disturbances of the emotional sphere, toxic encephalopathy, paresis and muscle paralysis), astheno-neurotic conditions, toxic pneumonia, acute heart failure.
Prevention
Since the bulk of hydrocyanic acid poisoning is of an industrial nature, preventive measures are primarily aimed at optimizing production processes:
- compliance with safety requirements at the workplace;
- prevention of violations of the technological process;
- mandatory use of personal protective equipment (gloves, respirator, gas mask, protective clothing).
Poisoning in everyday life can be avoided, bearing in mind the high danger of consuming a large number of pits and seeds of apricots, cherries, almonds, peaches, etc. and products made from them.
Olesya Smolnyakova Therapy, clinical pharmacology and pharmacotherapy About the author
Education: higher, 2004 (GOU VPO "Kursk State Medical University"), specialty "General Medicine", qualification "Doctor". 2008-2012 - Postgraduate student of the Department of Clinical Pharmacology, KSMU, Candidate of Medical Sciences (2013, specialty "Pharmacology, Clinical Pharmacology"). 2014-2015 - professional retraining, specialty "Management in education", FSBEI HPE "KSU".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
