Methanol poisoning: symptoms and first aid
Methanol poisoning is often accompanied by the identification of individual and group incidents of disability and high mortality of the victims.
This is a serious poisoning, occurring with significant complications, often leading to death, so let's examine this type of intoxication in detail.
Methanol: characteristics and latent hazards
Methanol (methyl alcohol) due to its chemical properties is actively used in the chemical and pharmaceutical industries:
- as a component of antifreeze agents;
- as an additive to gasoline;
- as a liquid fuel;
On external grounds, it resembles ethyl alcohol. Most methanol poisoning is caused by taking it inside (swallowing) as a result of substitution and use it as alcoholic beverages, accidentally or with malicious intent. To group of the raised risk of a poisoning belong the persons abusing alcoholic drinks (chronic alcoholics). Applying methanol as a solvent for the glass inside the car, perhaps, the development of poisoning with its penetration through the skin or the respiratory tract.
Methanol and the products of its metabolism in the body - formaldehyde and formic acid, belong to the potent poisons of the nervous and vascular system. His insidiousness is manifested in rapid absorption into the body and very slow excretion. At the heart of pathogenesis, an important role is played by the increase in acidosis (acidity of the organism) and the insufficiency of oxygen saturation of the blood.
Symptoms of methanol poisoning
Symptoms of acute methanol poisoning, depending on the amount of toxic substance, arise from several hours to 1-2 days.
The basic symptoms of methanol poisoning:
- manifestations of general intoxication - dizziness and headache, nausea and vomiting, pain in the muscles and joints, abdominal pain;
- signs of alcoholic influence - confusion (confusion) of consciousness, decreased sensitivity, staggering when walking, drowsiness;
- a specific (specific) effect on the organs of vision - photophobia and fuzzy images of objects, pupillary dilatation, impaired or absent reaction to light;
- results of laboratory tests - the blood levels of hemoglobin and erythrocytes increase, in the urine appears protein and hyaline cylinders.
Methanol causes hyperemia (blood overflow of an organ) and edema of the optic nerve and retina, which result in their atrophy and blindness.
In case of severe poisoning with methanol after the phase of psychomotor agitation:
- pupils dilate and visual acuity decreases;
- breathing becomes deep and ineffective;
- there is cyanosis (blueing) of the skin and mucous membranes;
- the pulse is fixed frequent and weak, the pressure decreases, the likely occurrence of seizures.
With the growth of the pathological process and the lack of first aid, the victim falls into a coma because of cerebral edema. The cause of death is considered to be the stopping of breathing and the work of the cardiovascular system.
Methanol poisoning is characterized by symptoms:
- irritation of the mucous membrane of the conjunctiva and upper respiratory tract;
- a state of intoxication.
Symptoms and clinic of chronic influence of methanol
For methanol, cumulative features are characteristic - 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 for a certain time.
Dangerous to human health and life, not only methanol, but also chemical mixtures that contain more than 2% methanol.
Symptoms of chronic methanol poisoning:
- fatigue and fatigue;
- increased irritability and tearfulness;
- decrease in working capacity and memory;
- pain in the right hypochondrium and gastrointestinal disturbances;
- the boundaries of color vision narrow;
- edema and disturbance of the structure of the vessels of the fundus - the arteries are convoluted and narrowed, the veins are enlarged;
- the optic nerve is pale or atrophied;
- redness of the vascular globule of the eye;
- decrease in platelet count (thrombocytopenia) in a general blood test.
How to help the victim before the arrival of doctors? Emergency first aid to a patient with methanol poisoning consists in maximally rapidly removing the poison from the body and counteracting its metabolism.
Possible list of means of application:
- massive gastric lavage, better through the probe;
- abundant drinking;
- use of a salt laxative;
- reception of ethyl alcohol as an antidote (0.5 ml per 1 kg of weight);
- reception of alkaline solutions (drinking and intravenous sodium bicarbonate).
Ethyl and methyl alcohols in the process of metabolism involve the same enzymes and receptors. Since the decomposition products of ethyl alcohol have low toxicity in comparison with methanol, its use as an antidote is justified.
The methods of treatment and the consequences of methanol poisoning
The patient is treated in a hospital and includes normalization of water-salt metabolism and acid-base correction. Manifestations of metabolic acidosis are eliminated by the appointment of bicarbonate solutions, diuretics are used to prevent cerebral edema.
In case of severe poisoning, difficult-to-correct correction of acidosis, increased symptoms of visual impairment and central nervous system function, blood purification is recommended - the use of hemodialysis. Its purpose is to remove from the body of the affected methanol and the products of its decomposition - formic acid and formaldehyde.
One should remember about increasing the dose of ethanol during hemodialysis, because it is also excreted and will not be able to perform the function of an antidote.
In the absence of necessary medical assistance, death, as a rule, occurs on the third day.
The consequences of methanol poisoning occur even in the provision of medical care and treatment. The most frequent damage is persistent impairment of quality and visual acuity, including blindness, functional damage to the liver and food tract, disorders of the central nervous system.
Prevention of methanol poisoning
The preventive measures of this type of poisoning include:
- sanitation and education of the population;
- detailed instruction of workers in enterprises using methanol;
- application of general and individual protective equipment;
- prevention of the use of methanol for household needs;
- checking the quality of alcoholic beverages and prohibiting the use of surrogates.
Thus, compliance with professional and personal safety requirements will prevent the occurrence of poisoning by toxic substances such as methanol.