Methanol poisoning: symptoms and first aid
Methanol poisoning is often accompanied by the identification of individual and group cases of the onset of disability and high mortality of victims.
This is a serious poisoning that occurs with significant complications, often fatal, so let's take a look at this type of intoxication in detail.
Methanol: characteristic and hidden dangers
Methanol (methyl alcohol) due to its chemical properties is widely used in the chemical and pharmaceutical industries:
- as a component of antifreeze;
- as an additive to gasoline;
- as a liquid fuel;
In appearance, it resembles ethyl alcohol. Most methanol poisoning occurs due to ingestion (swallowing) as a result of the substitution and its use as alcoholic beverages, accidentally or with malicious intent. Persons who abuse alcoholic beverages (chronic alcoholics) belong to the group at increased risk of poisoning. Using methanol as a solvent for the glass inside the car, it is possible the development of poisoning with its penetration through the skin or respiratory tract.
Methanol and its metabolic products, formaldehyde and formic acid, are potent poisons of the nervous and vascular systems. Its cunning is manifested in rapid absorption into the body and very slow elimination. The basis of the pathogenesis is played by a significant increase in acidosis (acidity of the body) and insufficient oxygen saturation of the blood.
Symptoms of methanol poisoning
Symptoms of acute methanol poisoning, depending on the amount of toxic substances occur from several hours to 1-2 days.
Basic symptoms of methanol poisoning:
- manifestations of general intoxication - dizziness and headache, nausea and vomiting, pain in the muscles and joints, pain in the abdomen;
- signs of alcohol influence - clouding (confusion) of consciousness, decrease in sensitivity, staggering when walking, drowsiness;
- characteristic (specific) effect on the organs of vision - photophobia and fuzzy image of objects, pupil dilation, impaired or absent reaction to light;
- results of laboratory tests - the level of hemoglobin and red blood cells increases in the blood, protein and hyaline cylinders appear in the urine.
Methanol causes hyperemia (blood overflow of any organ) and edema of the optic nerve and retina, which as a result lead to their atrophy and blindness.
In case of severe methanol poisoning after the phase of psychomotor agitation:
- pupils dilate and visual acuity decreases;
- breathing becomes deep and ineffective;
- cyanosis (blue) of the skin and mucous membranes appears;
- pulse is fixed frequent and weak, pressure decreases, the likelihood of seizures.
With an increase in the pathological process and the absence of first aid, the victim falls into a coma due to brain swelling. The cause of death is considered respiratory arrest and cardiovascular system.
Methanol vapor poisoning is characterized by symptoms:
- irritation of the conjunctival mucosa and upper respiratory tract;
Symptoms and clinic of the chronic effects of methanol
Methanol is characterized by cumulative features - the ability to accumulate in the body. Therefore, there is a high probability of developing chronic poisoning as a result of the action of small doses of this poison over a period of time.
Not only methanol, but also chemical mixtures that contain more than 2% methanol are dangerous to human health and life.
Symptoms of chronic methanol poisoning:
- fatigue and weakness;
- increased irritability and tearfulness;
- decrease in working capacity and memory;
- pain in the right hypochondrium and gastrointestinal disturbances;
- boundaries of color vision are narrowed;
- edema and violation of the structure of the fundus vessels - the arteries are convoluted and narrowed, the veins are dilated;
- the optic nerve is pale or atrophied;
- redness of the vascular sphere of the eye;
- decrease in platelet count (thrombocytopenia) in the general blood count.
How to help the victim before the arrival of the doctors? Emergency first aid to the patient in case of poisoning with methanol consists in the most rapid removal of the poison from the body and counteracting its metabolism.
Possible list of means of application:
- massive gastric lavage, better through the probe;
- drink plenty of water;
- the use of saline laxatives;
- taking ethanol as an antidote (0.5 ml per 1 kg of weight);
- reception of alkaline solutions (drinking and intravenous administration of sodium bicarbonate).
Ethyl and methyl alcohols in the process of metabolism use the same enzymes and receptors. Since the decay products of ethyl alcohol have low toxicity compared with methanol, its use as an antidote is justified.
Treatment methods and effects of methanol poisoning
Treatment of the patient is carried out in the hospital and includes the normalization of water-salt metabolism and correction of acid-base. Manifestations of metabolic acidosis are eliminated by the appointment of bicarbonate solutions, diuretic drugs used to prevent cerebral edema.
In case of severe poisoning, difficult to correct correction of acidosis, increasing symptoms of visual damage and function of the central nervous system, blood purification is recommended - hemodialysis. Its purpose is to extract from the body of the affected methanol and its decay products - formic acid and formaldehyde.
It should be remembered about increasing the dose of ethanol during hemodialysis, because it also appears and can not perform the function of antidote.
In the absence of necessary medical care, death occurs, as a rule, on the third day.
The consequences of methanol poisoning occur even when providing medical care and treatment. The most frequent injuries are persistent violations of quality and visual acuity, including blindness, functional damage to the liver and the alimentary tract, disorders of the central nervous system.
Methanol poisoning prevention
The preventive measures of this type of poisoning include:
- sanitary and educational work and increasing the alertness of the population;
- detailed instruction of workers in enterprises using methanol;
- the use of general and personal protective equipment;
- prevention of the use of methanol for household needs;
- quality control of alcoholic beverages and the prohibition of the use of surrogates.
Thus, compliance with the requirements of professional and personal safety will prevent the occurrence of poisoning by such toxic substances as methanol.