Poisoning with toxic chemicals is an acute intoxication caused by transdermal, inhalation or oral intake of toxic substances of this group. The clinical picture depends on which kind of xenobiotic caused the lesion. Common signs include vomiting, nausea, headache and abdominal pain, respiratory disorders, cardiac activity, convulsions, phenomena of multiple organ failure. Pathology is diagnosed on the basis of anamnesis, a characteristic set of symptoms, and a toxicochemical blood test. Treatment methods: administration of antidotes, nonspecific antitoxic measures, post-syndrome therapy.
ICD 10
T60 Toxic effect of pesticides
General information
The term “pesticides” refers to organic or inorganic compounds that are used to control weeds, insects, rodents in fields and indoors. Most of them have high toxicity and the ability to persist in the environment for a long time. Pathology has a certain seasonality. The overwhelming number of cases is registered in the spring-summer period, when people actively use insect repellents, pesticides, zoocides, insecticides, herbicides. Poisoning with toxic chemicals is common among young children and workers of agricultural enterprises engaged in the processing of fields from pests.
Causes
Poisoning with toxic chemicals most often develops with the careless use of these substances for their intended purpose. Agricultural workers and owners of household plots often spray pesticides without using personal respiratory protection equipment. At the same time, the poison enters by inhalation, the clinic of respiratory tract damage prevails. Intoxication can also have the following mechanisms of occurrence:
- Random reception. Occurs when the toxicant is mistakenly ingested. This happens if the substance is stored together with food in containers without a label or labeled with a drinking liquid. The risk group is young children, the elderly, people with significant mental disabilities.
- Suicide. Organophosphorus compounds are commonly used. Poisoning is usually severe, with a high mortality rate. The probability of suicide is maximal in psychiatric patients suffering from schizophrenia, manic–depressive psychosis, clinical depression at the stage of convalescence.
- Improper use of pesticides. The danger of poisoning occurs when people are in closed rooms where insect or rodent treatment has been carried out. In the absence of ventilation, a significant concentration of a toxicant is created in the air and persists for a long time, capable of causing chemical damage.
- Contaminated containers. Intoxication often develops in people who use containers from under pesticides for food storage. It is possible to completely remove the remnants of the substance only by multi-stage processing, which is not always done. The degree of damage in such situations is usually mild.
- Accidents. Leaks of a large amount of toxic substances are possible in case of accidents and explosions at work, in which containers filled with toxic compounds are destroyed. There are intoxications of transdermal and inhalation type, the degree of poisoning is severe. The risk of infection in the zone of a chemical disaster persists for several days or weeks.
Pathogenesis
The pathogenesis of chemical damage varies depending on the type of poison. When poisoning with organochlorine compounds, there is a violation of the transmission of nerve impulses in the brain, toxic encephalopathy occurs. There is damage to the cell membranes of hepatocytes, renal parenchyma cells. Organophosphorus substances block the release of acetylcholine in synapses, contribute to its accumulation in the depot and the development of related clinical effects.
Complexes containing copper ions lead to the formation of dystrophic changes in the parenchyma of internal organs. The result of this process is multiple organ failure and the death of the victim. The intake of organomercury substances into the body is accompanied by damage to nerve trunks, the formation of polyneurites, damage to auditory and visual structures. Carbamic acid derivatives have an anticholinesterase effect similar to organophosphate poisons.
Classification
Poisoning with toxic chemicals can be divided by the type of toxic agent (fungicides, pesticides, zoocides, acaricides, insecticides), by goals (suicidal, accidental, professional), by severity (mild, moderate, severe, lethal). However, the classification according to the affiliation of the toxicant to a particular chemical group is of the greatest clinical importance:
- Organophosphorus substances. Representatives: karbofos, mercaptophos, bromophos. They are one of the most dangerous varieties of insecticides. The share of OPS lesions accounts for about 38% of the total number of cases of poisoning by means of a group of pesticides. The death of patients with a severe degree of chemical trauma occurs by the end of the first day.
- Organochlorine compounds. Representatives: hexachloran, aldrin. They occupy the second place in frequency of occurrence. The volume of such intoxications is about 22%. The victim’s death occurs in 24-36 hours. The consequences of non-fatal lesions persist for 4-10 days or more.
- Organomercury toxicants. Representatives: ethylmercurchloride, agronal. Exotoxicoses usually develop during pickling and sieving of processed grain. The total share of such diseases is about 20%. The poison has a tropism in relation to the kidneys, the central nervous system. Pathological phenomena in workers of agricultural enterprises arise gradually.
- Copper-containing components. Representatives: copper vitriol, kupronaft. They have an irritating effect. Upon contact with body proteins, copper albuminates are formed. Inhalation intoxication with the development of endothelial necrosis of the pulmonary alveoli and systemic signs. Recovery occurs in 10-15 days. The number of cases is 15% of the total volume of toxic chemical lesions.
- Carbamic acid compounds. Representatives: sevin, nexoval, grevenol. The frequency of poisoning does not exceed 5%. Substances of this group are used to destroy pests that are insufficiently sensitive to OPS and organochlorine poisons. They have medium toxicity, rarely cause the death of the victim.
Symptoms
Pathology manifests itself in different ways. There is a direct dependence of symptoms on the type of toxicant and its dose. Organophosphorus compounds lead to the development of myosis, spasm of accommodation. There are cramping pains in the abdomen, vomiting and nausea, sharp weakness. The victims show hypersalivation, paroxysmal cough caused by spasm of the respiratory tract. There is bradycardia, hypertension, which is subsequently replaced by a decrease in blood pressure. In severe cases, paresis, paralysis, blockage of the respiratory center, convulsions are detected.
Organochlorine poisons provoke the appearance of tremor, increased salivation and sweating, increased nervous excitability. The victims are diagnosed with convulsive readiness, often replaced by tonic-clonic convulsions. There is a violation of coordination, ataxia, difficulty breathing. Pupils dilate, exophthalmos may be present. The digestive system reacts with the development of vomiting, nausea, abdominal pain, localized mainly in the epigastric zone.
Intoxication with organomercury substances is accompanied by the appearance of general weakness, a metallic taste in the mouth. There is a headache, diarrhea with an admixture of blood or mucus, vomiting, abdominal pain. The victim is very thirsty. Hypotension, compensatory tachycardia, cardiac arrhythmias are determined. The patient is unstable in the Romberg pose. In chronic poisoning, there is bleeding gums, arthralgia, myalgia. There are psychoses, hallucinations, epileptimorphic seizures.
The defeat of copper compounds is characterized by difficulty breathing, the appearance of a taste of metal in the mouth, a dry debilitating cough. There is burning in the eyes, lacrimation, severe headache, which is accompanied by nausea. Hyperthermia, unpleasant sensations in muscles and joints are diagnosed. Vomit masses of bluish color, sometimes with streaks of blood or an admixture of hydrochloric acid hematin (coffee grounds). It is possible to develop epipripadki, multiple organ failure.
Carbamate damage is accompanied by the appearance of nicotine-like and muscarinoid syndrome. A similar, but more pronounced pattern is observed in OPS poisoning. Carbamates are metabolized relatively quickly in the body, which significantly reduces the time of reconvalescence compared to organophosphate toxicants. Fatal outcomes occur mainly with targeted oral administration of a toxic liquid.
Diagnostics
A preliminary diagnosis is made by the ambulance team that arrived at the scene. Its confirmation is carried out by toxicologists of specialized hospitals or an ICU resuscitator. During the examination, auxiliary consultations of a therapist, gastroenterologist, cardiologist may be required. It is necessary to differentiate poisoning with toxic chemicals from other exotoxicoses with similar clinical symptoms. The following methods are used for this:
- Physical. They are implemented at the pre-hospital stage and in a hospital setting. Blood pressure at the time of hospitalization is more often reduced, tachycardia is determined to 100-110 beats / minute. The skin is pale or cyanotic, sweating is possible. With respiratory insufficiency, diffuse cyanosis occurs, with coronary symptoms — acrocyanosis of the earlobes and lips. There is a characteristic clinical picture.
- Laboratory. According to the results of toxicological examination, the presence of a toxicant is detected in the biological fluids of the patient. Such an analysis is not effective in all cases. Against the background of damage to internal organs, an increase in the activity of AST, ALT, urea, creatinine is determined. Electrolyte disturbances and a shift in pH to the acidic side are possible.
- Hardware. They are used to diagnose complications. Pulmonary edema provokes the appearance of vague diffuse shadows. Coronary failures lead to the appearance of specific phenomena on the film (loss of QRS complexes, different R-R distance, sharpening of the T-wave). CT scans show areas of necrosis of internal organs. Bronchial damage is accompanied by a decrease in the volume of forced exhalation.
Treatment
Pathology requires immediate first aid to the victim. If a person is conscious, before the arrival of the ambulance, the stomach should be rinsed with a probe-free method, then give 6-8 tablets of activated charcoal. Attempts at washing in a coma or a soporotic state are prohibited. If the blood pressure is lowered, it is necessary to lay the patient on a horizontal surface, install a roller 40-50 cm high under his feet, provide fresh air.
First aid
The medical team that arrived on the call immediately begins antidote therapy. The antidote for the defeat of OPS and carbamates is atropine, intoxication with organochlorine xenobiotics requires intravenous infusion of gluconate or calcium chloride. Exotoxicoses with mercury and copper compounds are stopped by non-specific antidotes. The drug of choice is unithiol. Symptomatic treatment, active infusion therapy with crystalloids is indicated. Correction of acidosis is carried out with buffer solutions. The development of respiratory failure is the reason for the beginning of hardware respiratory support.
Hospital treatment
Therapeutic measures are aimed at the speedy removal of the poison from the body and correction of existing disorders. The introduction of specific and non-specific antidotes continues, forced diuresis is used. Severe poisoning with toxic chemicals requires extracorporeal detoxification: hemodialysis, peritoneal dialysis, hemosorption. The drug regimen usually includes multivitamins, cardiac support products, bronchodilators and respiratory analeptics, drugs that allow to stop seizures and relieve psychomotor agitation, if any.
Rehabilitation
The average time of hospitalization is 7-14 days in the absence of complications and 1-3 months in their presence. A specialized diet is not indicated, but it is necessary to adhere to the general principles of healthy nutrition: fractional food intake, rejection of excessively salty, sour, spicy dishes, the optimal ratio of proteins, carbohydrates, fats.
Prognosis and prevention
The prognosis for moderate and mild intoxication is favorable, complete recovery is achieved in 93% of cases. Severe lesions often cause multiple organ failure, which is accompanied by high mortality. If more than two systems are affected, the number of deaths reaches 60% of the total number of victims. Organophosphorus substances are considered extremely dangerous. The second place is occupied by organochlorine xenobiotics, which have moderate toxicity.
To prevent poisoning with toxic chemicals, respirators or insulating gas masks should be used during the processing of plant crops and premises. The use of chemical protection suits or thick waterproof clothing is recommended. Poisons must be stored in locked rooms where there is no access for children and the elderly. The container must be factory-made, with the appropriate marking. It is forbidden to use pesticide bottles for food storage, regardless of the quality and methods of their processing.