Arsenic poisoning and its compounds is an acute or chronic intoxication that occurs when the poison is ingested, as well as its ingestion by inhalation. The main symptoms are severe diarrhea, severe abdominal pain, vomiting, dehydration. A paralytic variant is possible, which is manifested by hearing loss, convulsions, and coma. Pathology is diagnosed on the basis of toxicochemical examination, radiography, clinical picture. Treatment — nonspecific antidotes, antitoxic and symptomatic therapy.
T57.0 Toxic effect of arsenic and its compounds
Arsenic (As) is a metalloid, a transition element of group V of the periodic table. The effect on the human body resembles heavy metals and their salts. There are more than 6 thousand organic and inorganic compounds of this substance with different levels of toxicity. The lethal dose of the component in its pure form, taken orally, is 0.3-0.6 grams. Common compounds are arsenic hydrogen and anhydride, arsenite of sodium, potassium, calcium, osarsol, Paris greens. Poisoning occurs among workers of woodworking and agricultural enterprises.
Arsenic poisoning occurs in employees of organizations that are engaged in the conservation of wood, cotton processing, spraying fields with insecticides containing As. This happens when safety precautions are violated and respiratory protection equipment is abandoned. In addition, chemical injuries are recorded in accidents involving the leakage of arsenic hydrogen. Other possible reasons:
- Outdated medicines. For gargling with angina, potassium arsenite is sometimes used, which has antiseptic properties. This agent is able to be absorbed, penetrate into the systemic circulation and have a negative effect. The risk group is young and middle—aged children whose parents use medications with potentially toxic effects.
- Crime. Representatives of the criminal world mix arsenic for the purpose of murder. In addition, the substance is often used to commit suicide attempts. The effectiveness of such methods is low, since the poison does not have an instant effect, death occurs only after a few hours.
- Household poisoning. Develop with accidental ingestion of arsenic, which looks like sugar. Symptoms of chemical damage occur in children, the elderly, people with mental disabilities who are not aware of their actions. Capable adult representatives of society rarely find themselves in such situations.
The effects of trivalent and pentavalent arsenic compounds differ. As3+ blocks pyruvate dehydrogenase. Arsenic poisoning is accompanied by a violation of glycolytic processes. There is a decrease in the resynthesis of adenosine triphosphate, the formation of oxalic acid, the processes of gluconeogenesis suffer. The consequence is hypoglycemia, lack of hepatic glutathione, weakening of specific resistance of erythrocyte membranes.
As5+ replaces inorganic phosphorus in biochemical reactions. Instead of triphosphoglycerate, which takes part in the formation of ATP, 1-arseno-3-phosphoglycerate is synthesized, which does not have the necessary properties. There is a separation of oxidation from phosphorylation and other disturbances of intracellular processes. The processes of energy formation, the work of antioxidant mechanisms are suppressed, signs of multiple organ failure appear.
Arsenic poisoning is divided according to the form of flow. There are intestinal-toxic and paralytic types of the disease. Pathology is also divided by the type of toxic agent (intoxication with a pure substance, its inorganic or organic complexes). It is possible to systematize according to the severity of the lesion (severe, moderate, lethal, light). Structuring according to the nature of pathology is of the greatest practical importance:
- Acute. It is determined by obvious violations in the work of several internal organs. There are symptoms of damage to the brain, intestines, stomach, respiratory apparatus, kidneys, blood system, cardiovascular structures. It has the greatest lethality in the absence of timely medical care.
- Subacute. There are moderate changes in the activity of nerve tissues without obvious life-threatening symptoms. There is a decrease in intellectual abilities, encephalopathy. Non-lethal failures of the coronary rhythm, breathing difficulties, weight loss, periodic abdominal colic may be detected.
- Chronic. A number of nonspecific symptoms are detected in the victim, which are not always possible to associate with the toxic effect of arsenic. There are complaints of periodic intestinal disorders, implicit elements of damage to the central nervous system and peripheral nerves, cough, skin symptoms. There is no immediate threat to life.
The clinical picture of As intoxication is quite diverse, it depends on the type of damaging agent, its dosage and the period during which the poison entered the victim’s body. 70% of poisoning mainly has symptoms of gastrointestinal tract damage: metallic taste in the mouth, vomiting and nausea, epigastric pain, intestinal colic. Due to copious diarrhea, a picture of dehydration occurs. Signs of damage to other systems:
- Central nervous system: weakness, inappropriate behavior, decreased memory and performance, seizures, coma.
- Peripheral nerves: neuropathy, narrowing of the visual fields, pain in the extremities.
- Respiratory apparatus: cough, swelling of the respiratory tract, wheezing, suffocation.
- Blood system: erythrocyte hemolysis, agranulocytosis, anemia.
- Kidneys: tubular necrosis, decreased functional ability up to acute renal failure.
- Skin: baldness, swelling, hyperemia, rash, hyperpigmentation, keratosis, basal cell carcinoma.
- Heart and blood vessels: rhythm disturbance, hypotension, arrhythmia, cardiomyodystrophy.
Acute arsenic poisoning manifests itself after 30-120 minutes that have elapsed from taking the poison. The death of the victim often occurs within the first hour after the occurrence of a characteristic clinic or after 1-3 days. The reason is the phenomenon of cardiovascular insufficiency caused by dehydration. With a paralytic course, the lethal outcome is provoked by the paralysis of the respiratory and vasomotor centers.
The main complication in As lesions is severe exicosis. Massive fluid loss leads to a decrease in preload on the heart, a drop in coronary output and blood pressure, a collapse of the circulatory system, and the occurrence of hypovolemic shock. If help was not provided on time, similar symptoms are detected in 80-85% of patients. With the timely start of infusion therapy, dehydration can be avoided.
The second problem is considered to be a critical weakening of the function of several organ systems — multiple organ failure. Usually there is damage to the kidneys, liver, and heart. At the same time, the process of metabolism and excretion of the toxic substance slows down, which contributes to an increase in the severity of the pathology. PON is diagnosed in 15-20% of victims with acute intoxication, delivered to the hospital a few hours after taking xenobiotic.
The presumed diagnosis of “arsenic poisoning” is made by the ambulance team that arrived at the scene. Its employees are based on information that they managed to get from the victim himself or his relatives. Confirmation is made in a toxicological hospital, which has a toxicochemical and biochemical laboratory, an X-ray room. Consultations of a gastroenterologist, a therapist, and, according to indications, a resuscitator are required. Survey methods:
- Physical. Psychomotor agitation, inadequate assessment of reality is noted. The skin is pale, cold, the pulse is rapid, blood pressure is reduced or within normal limits. The patient complains of indomitable vomiting, soreness along the course of the intestine. Pulmonary wheezing, deaf heart tones can be heard. A specific sign is the smell of garlic from the mouth.
- Laboratory. The level of the toxicant in the urine at a single measurement exceeds 50 micrograms / liter. Chronic arsenic poisoning is characterized by its appearance in the composition of hair and nails. Blood test reveals a decrease in the number of red blood cells. There is an increased level of glycated hemoglobin, a general decrease in the volume of solid fractions. Urine contains protein, blood elements. Its daily amount is reduced.
- Hardware. The electrocardiogram shows symptoms of rhythm disturbance. Lung x-ray and abdominal organs allows you to visualize phenomena similar to the introduction of barium suspension, since arsenic has a certain radiopacity.
Before the arrival of doctors, the victim should be induced to vomit. To do this, they give him 0.5-1 liter of pure water to drink, after which they press their fingers on the root of the tongue. The manipulation is carried out several times until a clean washing liquid begins to flow away, in which there are no foreign impurities. Next, the patient must be laid down, provide fresh air. For people without consciousness, gastric cleansing is contraindicated.
Acute arsenic poisoning requires first aid on the spot. The patient is shown a probe gastric lavage using at least 10 liters of water with an admixture of adsorbent. After the procedure, the patient is given 8-10 tablets of activated charcoal and 50-100 ml of magnesium sulfate as a laxative. The alternative is unithiol injected into the stomach through a probe. The same drug is injected intramuscularly.
At the pre-hospital stage, other activities aimed at maintaining vital activity are also carried out. To eliminate hypovolemia and correct the electrolyte balance, infusion therapy is started. Anticonvulsants are used for convulsions. In order to reduce pain, antispasmodics and analgesics are prescribed. It may be necessary to transfer to a ventilator, titrated supply of vasopressors.
Unithiol therapy continues in a hospital setting. The drug is prescribed in a course of 5-6 days. In its absence, the patient should receive N-acetylcysteine, acting as a donor of monotile groups. When affected by arsenic hydrogen, mecaptide is added to the scheme. Active detoxification methods are needed: intestinal lavage with the introduction of 8-10 liters of enteral salt solution into the intestine, hemodialysis, repeated gastric lavage.
After the completion of intestinal lavage, the patient is given an antidiarrheal remedy to drink. Infusion of saline solutions is mandatory, with severe dehydration – colloids. Adult patients can receive oral fluids (rehydration solutions) if this does not provoke vomiting. Additionally, glucocorticoids, ascorbic and nicotinic acid are prescribed. Pronounced metabolic acidosis is eliminated with sodium bicarbonate.
After discharge from the hospital, the patient is recommended to be monitored by a district therapist in order to exclude the development of delayed consequences of chemical trauma. It is possible to visit gastroenterological sanatoriums. Restrictions must be observed until the complete stabilization of the gastrointestinal tract.
Prognosis and prevention
Arsenic poisoning has a favorable prognosis for mild and moderate uncomplicated course. Timely medical assistance helps to avoid complications in 89% of cases. The symptoms of a severe lesion increase the likelihood of developing multiple organ failure, with a mortality rate of 60-70%. There is a high risk of depression of the vasomotor and respiratory structures of the brain.
Preventive measures consist in taking care when working with pesticides and other substances containing arsenic. It should be borne in mind that even insignificant amounts of it that regularly enter the body can cause intoxication. Do not keep the poison in food containers or in the reach of children, the elderly. Workers of enterprises dealing with As should be provided with gas masks, insulating clothing.