Boric acid poisoning is an exogenous intoxication caused by the simultaneous intake of 15-20 grams of the substance or its gradual use in smaller doses. For young children, taking 4-5 grams is dangerous. The main symptoms are vomiting and nausea, abdominal pain, diarrhea, impaired function of the excretory systems, heart and blood vessels, collapse, shock. Pathology is diagnosed on the basis of anamnesis, general clinical picture and blood test for electrolytes. Treatment is non-specific, aimed at removing the poison from the body as soon as possible and maintaining vital functions.
T54.2 Caustic acids and acid-like substances
The first mention of poisoning with boric acid dates back to 1881, when a child died as a result of ingestion. Later, several European journals published data on the death of more than 200 children. This became possible due to the large spread of acid and its solutions as means of antiseptic treatment of the skin. Today, this is practically not found. A lot of low-toxic antimicrobial medicines have appeared, which has led to a decrease in the popularity of boron-based drugs. Rare cases are noted in regions with a low level of medical literacy of the population.
Fatal poisoning with boric acid in an adult develops when the concentration of the substance in the blood is more than 70-80 micrograms / ml. Such a volume can simultaneously enter the body only with its targeted intake. The clinic of acute intoxication is noted in people who have attempted suicide using boron-containing drugs. The victim uses the drug in the form of a powder or concentrated aqueous solution. Practice shows that the number of such cases is vanishingly small. Other possible causes include:
- Accidents at work. H3BO3 is actively used in many areas of industry – in the manufacture of soldering fluxes, protective coatings for wood, buffer solutions. If an accident occurs at the enterprise, there is a risk of component leakage and chemical damage to employees. The highly concentrated substance gets on the skin, mucous membranes and respiratory tract, causing their irritation.
- Self-medication. The most common cause of chronic poisoning. Intoxication develops in infants whose mothers treat their nipples with a remedy before feeding or rinse their pacifiers with it. Severe acute forms of exotoxicosis are the result of the use of traditional medicine recipes, implying the ingestion of the drug.
- The use of insecticides. Some insect repellent liquids contain boric acid. Spraying them in the air in the form of an aerosol followed by inhalation can provoke the appearance of symptoms of intoxication. Some fertilizers that are used for fertilizing indoor plants also have toxic properties. Failure to comply with safety regulations while working with them increases the risk of emergency situations.
- An erroneous reception. Externally, the powder resembles a sweetener. In addition, it does not have a bright specific smell and taste that would immediately distinguish it from a food product. Elderly people, patients suffering from impaired sense of smell and taste, as well as patients with psychiatric diseases can consume acid in food, mistaking it for sugar.
The breakdown of acid in the body leads to the release of boron, a general cellular poison that primarily affects the tissues of the nervous, hematopoietic and urinary systems. The cytotoxic effect depresses the brain, reduces vascular tone, and is manifested by hypotension. Boric acid poisoning is accompanied by the development of acidosis, a violation of the activity of all receptor systems, a general disorder of regulation. In severe cases, there is a decrease in kidney and liver function, there are violations of the coronary rhythm. Prolonged consumption of small doses is manifested by a weakening of hematopoiesis.
As a result of inhalation of acidic aerosol in the composition of the air, irritation of the respiratory tract develops with corresponding external manifestations. Pulmonary edema is possible. Chronic poisoning with boric acid leads to infertility in both sexes. Taking the drug by pregnant women is especially dangerous, since the compound has an embryotoxic effect even in dosages that do not harm an adult. There is a risk of congenital deformities, improper formation of the internal systems of the fetus, its death.
There are several classification criteria: for reasons (suicidal, accidental), conditions of occurrence (domestic, industrial), severity of the patient’s condition (mild, moderate, severe, extremely severe). In addition, the pathology is divided according to the ways of penetration of the poison (inhalation, oral, transdermal, injection). One of the main variants of systematization is the nature of intoxication. The following flow variants are distinguished:
- Sharp. It is diagnosed with the simultaneous intake of a large amount of toxicant. It is characterized by a pronounced clinical picture, significant disorders in the work of the body. Creates the highest possible vital risk. As a rule, it occurs with oral use of a saturated drug or being in an area with an acid concentration in the air of more than 10 mg / m3.
- Subacute. A characteristic feature is the appearance of symptoms after consuming several relatively small but toxic doses of a toxic substance for a short period of time (1-3 days), its gradual intensification. It proceeds with pronounced external manifestations, but it is easier than the acute variety.
- Chronic. At the initial stage, the clinical picture is unclear, the signs of pathology are poorly expressed. The existing symptoms may worsen as the xenobiotic accumulates in the body or remain at the same level for a long time. It leads to the gradual formation of renal insufficiency, a decrease in mental abilities, with inhalation administration — to chronic catarrh of the upper respiratory tract.
Clinical manifestations differ depending on the age of the patient, the nature of poisoning and the way the poison enters the body. When working in an infected area and regularly installing the drug in high concentration on the skin, the appearance of eczema, abundant exfoliation of the upper layers of the epidermis is noted. The hairline is completely or partially lost. The substance is able to be absorbed into the bloodstream, so long-term contact with it causes systemic damage.
The general symptoms are diverse. In subacute forms, there is pain in the stomach, cephalgia, nausea, vomiting, a feeling of palpitation, impaired thinking abilities. Erythematous rashes on the skin, pallor caused by the occurrence of anemia are objectively determined. Acute varieties are manifested by a pronounced clinic: hyperpyrexia of central origin, tonic convulsions, psychomotor agitation, alternating depression of mental activity, tachycardia, decreased blood pressure, acute cardiac arrhythmias, collapse.
Focal symptoms of inhalation poisoning are hyperemia, swelling of the mucous membranes of the nose, mouth, larynx, bronchi, dry irritating cough, turning into a productive form. Possible bronchoobstructive syndrome with the occurrence of expiratory or mixed dyspnea, a decrease in oxygen partial pressure, moderate hypoxia phenomena. The most severe variant of the course – pulmonary edema is characterized by the occurrence of wet wheezing, cough, signs of respiratory failure (forced position, diffuse cyanosis of the skin, pronounced shortness of breath).
The main danger is the development of multiple organ failure with damage to the kidneys, liver and cardiovascular system. Oliguria or anuria occurs, metabolic products accumulate, and a high concentration of boron persists for a long time. Then there is a cascade of interrelated pathological reactions, the result of which is the death of the victim. MOF is accompanied by 10-15% of cases of timely treated boric exotoxicosis and 50-60% of severe poisoning in the absence of detoxification. The average period of development of vital complications is 5-7 days of the disease.
The primary diagnosis is made by an emergency medical doctor, a therapist or a pediatrician to whom the patient turned. It is not always possible to accurately determine the toxic agent. Laboratory and instrumental examination is carried out in the hospital. It is required to differentiate pathology with other poisoning, cardiogenic pulmonary edema, skin diseases, acute cardiovascular insufficiency of non-toxic genesis. The following methods of assessing the condition are shown:
- Physical. Pulse rate >90-95 beats/min, filling and tension are weak, blood pressure is sharply reduced, RR is 18-25 or more per minute, the skin is pale, dry to the touch when dehydrated. Turgor is reduced, a decrease in the criticality of thinking is determined, there is depression of consciousness or psychomotor agitation. With edema of the lung, large-bubbly wheezes are heard, the patient is frightened, covered with sweat, the skin is cyanotic.
- Laboratory. The hemoglobin level is less than 110-115 g/liter in women and 130 g/l in men. Saturation index <94-95%, blood creatinine >120-122 mmol, urea >8-10 mmol. There are electrolyte disorders, a shift in pH to the acidic side. AlAT >40, AsAT >26, LDG >200-280. The concentration of boron in the blood plasma significantly exceeds the maximum allowable figure of 100 mcg/l.
- Instrumental. The ECG shows a reduction in the RR interval, the time difference between ventricular complexes is more than 0.3 seconds, shape transformation, conduction blockages. With chronic intoxication, changes occur on the EEG: the predominance of alpha rhythms in the parietal-occipital leads, a decrease in their amplitude. With pulmonary edema, focal shadows merging with each other are viewed on the survey radiography.
There is no specific treatment. Measures are being taken to maintain the patient’s vital activity. At the prehospital stage, the stomach is cleaned with a large amount of water, the mucous membranes are washed with a 4% sodium bicarbonate solution. With convulsions or psychomotor agitation, benzodiazepines are administered. Respiratory failure is an indication for transferring the victim to a ventilator. In case of pulmonary edema, the respiratory mixture is passed through ethyl alcohol vapors. It may be necessary to use antiarrhythmic drugs, cardiotonics, glucocorticosteroid hormones.
The main method of detoxification is forced diuresis. Some of the acid is excreted in the feces, so the introduction of laxatives is justified. Severe poisoning requires extracorporeal purification — hemo- and peritoneal dialysis. In anemia, transfusion of erythrocyte mass is performed. During dehydration, a volumetric infusion of saline solutions is carried out. In some cases, freshly frozen plasma is used. At the recovery stage, as well as with mild intoxication, treatment is carried out with the help of copious drinking, the introduction of diuretics, enteral sorbents.
Prognosis and prevention
The prognosis is favorable for poisoning of mild and moderate severity. Timely treatment measures can prevent the development of complications. The increased concentration of boron persists for 8-10 weeks, after which the indicator returns to normal. Severe poisoning increases the probability of multiple organ failure by up to 50%, and mortality — up to 70% of all cases of PON. Delayed consequences associated with damage to the central nervous system are noted in 20% of cases.
To prevent poisoning with boric acid, it is necessary to observe safety precautions when working with chemical compounds, use respiratory protection during spraying plants with insecticides and fertilizers. At home, acid should be stored in closed cabinets, where children, the elderly, and people with mental illnesses do not have access. Do not use the drug to treat large body surfaces. For this purpose, it is advisable to use modern and safe solutions based on chlorhexidine.