Barium and its compounds
Drug name in Chinese: Barium
English name: Barium, Ba
Toxic mechanism: Barium is a soft, silver white luster alkaline earth metal that exists in nature in the form of toxic barite (BaCO3) and barite (BaSO4). Barium compounds are widely used in ceramics, glass industry, steel quenching, medical contrast agents, pesticides, chemical reagent production, etc. Common barium compounds include barium chloride, barium carbonate, barium acetate, barium nitrate, barium sulfate, barium sulfide, barium oxide, barium hydroxide, barium stearate, etc. Barium metal is almost non-toxic, and the toxicity of barium compounds is related to their solubility. Soluble barium compounds are highly toxic, while barium carbonate, although almost insoluble in water, is toxic due to its solubility in hydrochloric acid to form barium chloride. The main mechanism of barium ion poisoning is the blockage of calcium dependent potassium channels in cells by barium ions, which leads to an increase in intracellular potassium and a decrease in extracellular potassium concentration, resulting in hypokalemia; Other scholars believe that barium ions can cause arrhythmia and gastrointestinal symptoms by directly stimulating the myocardium and smooth muscles. The absorption of soluble barium compounds in the gastrointestinal tract is similar to that of calcium, accounting for approximately 8% of the total intake dose. Bones and teeth are the main deposition sites, accounting for over 90% of the total body load. Barium ingested orally is mainly excreted through feces; Most of the barium filtered by the kidneys is reabsorbed by the renal tubules, with only a small amount appearing in urine. The elimination half-life of barium is about 3-4 days. Acute barium poisoning is often caused by ingestion of barium compounds as fermentation powder, salt, alkali flour, flour, alum, etc. There have also been reports of barium poisoning caused by drinking water contaminated with barium compounds. Occupational barium compound poisoning is rare and mainly absorbed through the respiratory tract or damaged skin and mucous membranes. There have also been reports of poisoning caused by exposure to barium stearate, usually with subacute or chronic onset and a latent period of 1-10 months. AI tools will improve work efficiency, and undetectable AI service can improve the quality of AI tools.
Treatment volume
The toxic dose of population taking barium chloride is about 0.2-0.5g
The lethal dose for adults is approximately 0.8-1.0g
Clinical manifestations: 1. The incubation period of oral poisoning is usually 0.5-2 hours, and those with high intake may experience poisoning symptoms within 10 minutes.
(1) Early digestive symptoms are the main symptoms: burning sensation in the mouth and throat, dry throat, dizziness, headache, nausea, vomiting, abdominal pain, frequent diarrhea, watery and bloody stools, accompanied by chest tightness, palpitations, and numbness in the mouth, face, and limbs.
(2) Progressive muscle paralysis: Patients initially present with incomplete and flaccid limb paralysis, which progresses from distal limb muscles to neck muscles, tongue muscles, diaphragm muscles, and respiratory muscles. Tongue muscle paralysis can cause difficulty swallowing, articulation disorders, and in severe cases, respiratory muscle paralysis can lead to difficulty breathing and even suffocation. (3) Cardiovascular damage: Due to the toxicity of barium to the myocardium and its hypokalemic effects, patients may experience myocardial damage, arrhythmia, tachycardia, frequent or multiple premature contractions, diphthongs, triplets, atrial fibrillation, conduction block, etc. Severe patients may experience severe arrhythmia, such as various ectopic rhythms, second or third degree atrioventricular block, ventricular flutter, ventricular fibrillation, and even cardiac arrest. 2. The incubation period of inhalation poisoning often fluctuates between 0.5 to 4 hours, manifested as respiratory irritation symptoms such as sore throat, dry throat, cough, shortness of breath, chest tightness, etc., but the digestive symptoms are relatively mild, and other clinical manifestations are similar to oral poisoning. 3. Symptoms such as numbness, fatigue, nausea, and vomiting can appear within 1 hour after absorption of toxic skin through damaged skin and skin burns. Patients with extensive burns may suddenly develop symptoms within 3-6 hours, including convulsions, difficulty breathing, and significant myocardial damage. The clinical manifestations are also similar to oral poisoning, with mild gastrointestinal symptoms. The condition often deteriorates rapidly, and high attention should be paid in the early stages.
The diagnostic
criteria are based on the history of exposure to barium compounds in the respiratory tract, digestive tract, and skin mucosa. Clinical manifestations such as flaccid muscle paralysis and myocardial damage may occur, and laboratory tests may indicate refractory hypokalemia, which can be diagnosed. Hypokalemia is the pathological basis of acute barium poisoning. Muscle strength decline should be differentiated from diseases such as hypokalemic periodic paralysis, botulinum toxin poisoning, myasthenia gravis, progressive muscular dystrophy, peripheral neuropathy, and acute polyradiculitis; Gastrointestinal symptoms such as nausea, vomiting, and abdominal cramps should be distinguished from food poisoning; Hypokalemia should be differentiated from diseases such as trialkyltin poisoning, metabolic alkalosis, familial periodic paralysis, and primary aldosteronism; Arrhythmia should be differentiated from diseases such as digitalis poisoning and organic heart disease.
Principle of treatment:
1. For those who come into contact with the skin and mucous membranes to remove toxic substances, the contact area should be thoroughly washed with clean water immediately to prevent further absorption of barium ions. Burn patients should be treated with chemical burns and given 2% to 5% sodium sulfate for local flushing of the wound; Those who inhale through the respiratory tract should immediately leave the site of poisoning, rinse their mouth repeatedly to clean their mouth, and take an appropriate amount of sodium sulfate orally; For those who ingest through the digestive tract, they should first wash their stomach with a 2% to 5% sodium sulfate solution or water, and then administer 20-30 g of sodium sulfate for diarrhea. 2. Detoxification drug sulfate can form insoluble barium sulfate with barium ions to detoxify. The first choice is to inject 10-20ml of 10% sodium sulfate intravenously, or 500ml of 5% sodium sulfate intravenously. Depending on the condition, it can be reused. If there is no sodium sulfate reserve, sodium thiosulfate can be used. After the formation of insoluble barium sulfate, it is excreted through the kidneys and requires enhanced fluid replacement and diuresis to protect the kidneys. 3. Timely correction of hypokalemia is the key to rescuing severe cardiac arrhythmia and respiratory muscle paralysis caused by barium poisoning. The principle of potassium supplementation is to provide sufficient potassium until the electrocardiogram returns to normal. Mild poisoning can generally be administered orally, with 30-60ml of 10% potassium chloride available daily in divided doses; Moderate to severe patients require intravenous potassium supplementation. Patients with this type of poisoning generally have a higher tolerance for potassium, and 10~20ml of 10% potassium chloride can be intravenously infused with 500ml of physiological saline or glucose solution. Severe patients can increase the concentration of potassium chloride intravenous infusion to 0.5%~1.0%, and the potassium supplementation rate can reach 1.0~1.5g per hour. Critical patients often require unconventional doses and rapid potassium supplementation under electrocardiographic monitoring. Strict electrocardiogram and blood potassium monitoring should be performed when supplementing potassium, and attention should be paid to urination and renal function. 4. To control arrhythmia, drugs such as cardiolipin, bradycardia, verapamil, or lidocaine can be used for treatment according to the type of arrhythmia. For patients with unknown medical history and low potassium electrocardiogram changes, blood potassium should be tested immediately. Simply supplementing potassium is often ineffective when lacking magnesium, and attention should be paid to supplementing magnesium at the same time. 5. Mechanical ventilation respiratory muscle paralysis is the main cause of death in barium poisoning. Once respiratory muscle paralysis appears, endotracheal intubation and mechanical ventilation should be performed immediately, and tracheotomy may be necessary. 6. Research suggests that blood purification measures such as hemodialysis can accelerate the removal of barium ions from the blood and have certain therapeutic value. 7. Other symptomatic supportive treatments for severe vomiting and diarrhea patients should be promptly supplemented with fluids to maintain water and electrolyte balance and prevent secondary infections.
Post time: Sep-12-2024