Treatment of industrial methanol alcohol poisoning

The article was consulted professionally by Master, Dr. Nguyen Le Duc Hoang – Emergency Resuscitation Doctor – Emergency Resuscitation Department – Share99 Da Nang International Hospital.

Methanol, commonly known as industrial alcohol, has many different uses: paint making, solvents …, but this substance is very toxic to the body and is not used at all as food alcohol such as ethanol.

Methanol is rapidly and completely absorbed through the gastrointestinal tract, with a distribution of 0.7L/kg, not tied to plasma proteins. Most are converted through the liver but slowly. The parent substance methanol itself works like ethanol ("drunken" type manifestations), but then methanol converts into formic acid, then into formate, causing metabolic acidosis, toxic to organs, especially neurological and visual. When in drinking alcohol there is both ethanol and methanol, the toxic chemical of methanol appears more slowly and manifests late intoxication, patients and physicians may pay attention only to ethanol-type poisoning at first and easily miss the later stage of true poisoning of methanol. Methanol poisoning is often severe, prone to death if not detected in time and actively treated.

When drinking alcohol with industrial methanol alcohol, this substance will be easily absorbed through the intestines and skin into the lungs. Methanol in the body will reach peak concentrations in plasma in just 30-60 minutes. It takes a long time for the liver to convert this chemical. About 3% of methanol introduced into the body is eliminated through the lungs or intact discharge does not change through urine.

Industrial methanol alcohol will be oxidized to form formaldehyde in the body. Formaldehyde then continues to be oxidized to form formic acid – ant acid, the main component of ant venom. The new formic acid is considered the culprit for poisoning in cases of methanol alcohol poisoning. And to be eliminated through the lungs and kidneys, formic acid will be converted into CO2 and water.

Formaldehyde converts into formic acid and this oxidation occurs rapidly, so formic acid will accumulate in the serum, causing toxicity and acidification. When formic acid accumulates in the retina causing damage to the retina, damage to the visual nerve, which leads to blindness. Not only that, the case of formic acid coming to the brain will damage and can lead to death.

Symptoms of intoxication usually appear within 30 minutes of instalion but may be later, depending on the number and if the patient drinks ethanol (if symptoms appear more slowly). There are usually two stages, the discreet one (the first few hours to the first 30 hours) and the next clear stage of poisoning. Since symptoms are usually discreet and mild at first (mild inhibition of nerves, sedatives, insymities) it is often ignored or young children are not detected. Common manifestations are:

• Nerve: methanol is a central nervous inhibitor, similar to ethanol poisoning but to a milder extent, sedative and insympressive. Patients who come to the hospital are usually conscious but have headaches, dizziness, then may experience symptoms: forgetfulness, restlessness, mania, drowsiness, confusion, coma, convulsions. When severe poisoning may have hemorrhages or infarction of the rafts, cerebral drops.
• Eyes: At first look normal, then 12-24 hours of blurred vision, double vision, feeling like clouds covering the eyes, fear of light, haunting points, eye pain, parallel vision, haunting the central point, narrowing the market, reducing or losing vision, vision loss (bright light, dancing dots, tunnel vision …). The homage that reacts poorly to light or fixed dilated is a sign of severe poisoning and a bad dosing. The bottom of the eye sees hemolytic spines, then retinal edema spreads along the blood vessels to the center of the eye, hematoma blood vessels, visual edema, retinal hemorrhage. The signs seen when looking at the bottom of the eye do not match the patient's visible signs but actually correspond to the degree of severe poisoning.
• Neurological symptoms: consciousness disorders, coma, parkinson's syndrome, perception device, cross-sectional mastitis, poly-neurological pathology, visual disc atrophy, hypophysiosis of the eye.
• Cardiovascular: varicose dilator, hypotension and heart failure.
• Breathing: weak breathing, apnea; rapid, deep breathing if there is metabolic acidosis.
• Digestion: hemorrhagic gastritis, acute purulent inflammation manifests itness of aphal pain, vomiting, diarrhea. Medium or severe poisoning may alter liver function.
• Kidneys: renal failure, low urination, anuria, red or dark urine if there is diarrhea.
• May have back pain, torso, stiffness of the neck (like meningeal hemorrhage), muscle stiffness, skin can be cold, sweating.

3.1 General testing

• Arterial blood gas test: As soon as the drinker contains methanol showing signs of drunkenness and severe metabolic acidosis, acidosis is not caused by ceton and lactic;
• Ion testing: Helps calculate anion gaps;
• Osmosis pressure gap measurement (ALTT) = measured ALTT – ALTT estimation[ALTT ước tính = 2Na + Ure (mmol/l) + Glucose (mmol/l)] ;
• Blood and urinary ceton testing: Helps rule out other diagnoses (diabetic ceton infection, alcohol,due to long-term hunger);
• Measure the concentration of ethanol, methanol, ethylene glycol in the blood;

CT scans and brain MRI scans to detect edema lesions and necrosis of the baslia, characterized by the gray nuclei (Putamen). These signs may explain a symptom of methanol poisoning if saved may have Parkinson's syndrome with manifestations: stiffness, mild muscle jerky, slow movement, phlegm or mild insane dementia.

3.2. Methanol Test

Measure methanol directly by gas chrowatography. If the concentration > 20mg/dL is poisoning, if > 40 mg/dL is very severe poisoning.

4.1. Basic treatments

• Deep coma, convulsions, extensive sputum stagnation, tongue drops, respiratory failure, weak breathing, apnea: lying on your side, placing oral canuns, sucking sputum, breathing oxygen, intoc administration, mechanical breathing with increased ventilation mode (depending on the degree).
• Hypotension: infusions, vascular medications if necessary.
• Nutrition: Glucose infusion 10-20% if hypoglycemia, (infusion of preferred glucose for energy replenishment), it is possible to immediately bolus 25-50 g of sugar 50-100 mL type of glucose 50% if hypoglycemia initially.
• Vitamin B1 intramuscularly 100-300mg (adult) or 50mg (children), before glucose infusion.
• Heavy vomiting: anti-vomiting injections, oral gastric mucosa cover, injections of de-secreting drugs, electrolytization rehydration by intravenous infusion.
• Nebula: infusion according to CVP, electrolysis balance, ensuring urine 150-200 mL/hour.
• Hypothermia: warming.
• Note the detection and handling of injuries and other complications.

4.2. Treatment of detoxification and increased detoxification of toxins:

• Place the gastric sonde and suck the solution if the patient arrives within 1 hour and the patient vomits less. Patients arriving later but drinking in large quantities may still consider smoking.
• Increase toxic waste:
  • Ensure urine flow: ensure blood pressure and patients do not lack volume, increase urine flow, intravenously, adults the total dose can be up to 1 g/day, child dose 0.5-1.5mg/kg/day.
  • Dialysis of the body: decisive.
• In dinh: patients diagnosed with methanol poisoning have:
  • Blood methanol concentration is > 50mg/dL or ALTT gap > 10mOsm/kg.
  • Acidification is clear regardless of methanol levels.
  • Patients with vision disorders.
  • Renal failure does not respond to routine treatment.
  • Methanol poisoning in alcoholics regardless of blood methanol levels.
• Filter method:
  • Dialysis dialysis (hemodialysis): for patients with stable hemolysis (normal blood pressure, without severe heart failure). There may be a re-distribution of methanol from organizations back to the blood, so altt gaps, blood gases, methanol levels should be monitored immediately after filtration for further filtration.
  • Continuous dialysis: applied to patients with hemolysis is unstable, continuous filtration avoids the redefining of methanol until methanol is negative and blood gas is normal.

4.3. Specific antid poisons

Ethanol and fomepizole (4-methylpyrazole): prevents methanol from converting into toxins (formic acid and format), free methanol will be eliminated from the body through the kidneys or dialysis. When these drugs are discontinued or taken insufficiently and the patient is not dialysis, methanol continues to be converted and toxic.

4.3.1. Specify:

History of methanol, and ALTT gaps of >10 mOsm/kg when no concentration test results have been available.

Methanol concentration is > 20mg/dL.

A suspected history of methanol poisoning and has at least 2 of the following standards: pH <7,3; HCO3 <20mmHg; khoảng="" trống="" altt="">10mOsm/kg.</20mmHg;>

Metabolic acidosis does not explain the cause and has altt gaps of >10mOsm/kg. Ethanol or fomedizole should be taken in patients who will and are receiving continuous dialysis or while waiting for dialysis to prevent the continued toxic conversion of methanol while not yet removed from the body.

4.3.2. Medications used:

Ethanol is effective, inexpensive but has a number of side effects (effects on the central nervous system, hypoth glucose, electrolytological water disorders. Intravenous ethanol is easier to take for patients, easier to monitor and adjust doses than oral ethanol.

Fomepizole is efficient, easy to use and track but very expensive.

How to take ethanol orally:

Type of ethanol used: drinking alcohol, products that ensure safety and clearly state the alcohol content (%).

How to brew: mix into alcohol with a concentration of 20% (1ml contains 0.16 grams of ethanol). + Initial dose: 800 mg/kg (4ml/kg), taken (sugar or juice can be added) or dripped via gastric sonde.

Maintenance dose: Non-alcoholic: 80 – 130 mg/kg/hour (0.4 to 0.7ml/kg/hour), in alcoholics: 150 mg/kg/hour (0.8 mL/kg/hour), orally or via gastric sonde.

Maintenance dosage during and after dialysis: 250 to 350 mg/kg/hour (1.3 to 1.8 mL/kg/hour), orally or via gastric sonde.

track:

Blood ethanol concentration (if conditional), maintaining 100-150mg/dL.

Monitoring of sensation, vomiting, medication, respiratory condition, pulse, blood pressure, blood sugar, blood electrolysis. Handling accidents and ensuring patients are given enough glucose, especially children.

Ethanol should be discontinued when the following standards are reached:

Normal blood osmosis gaps or blood methanol levels <10m/dL.

Metabolic acidosis as described above and clinical (especially central nervous) has improved.

4.3.3. Supportive drugs

• Folic acid or leucovorin, promotes the body's detoxifying process (formic acid conversion and format), 1-2mg/kg/time, taken every 4-6 hours, in dialysis patients take an additional dose before and 1 dose at the end of dialysis.
• Sodiumbicarbonate: for metabolic acidosis, dose 1-2mEq/kg for both children and adults, adjusted to pH >7.25.

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SEE MORE:

• Alcohol production: Dangerous diseases
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