Carbon monoxide poisoning

Only a few people know what carbon monoxide poisoning is. Another term is "carbon monoxide poisoning", which is exactly the same thing. Such intoxication is very dangerous and often ends in death if not acted upon in time. And the main danger is that a person does not feel the presence of gas in the air, quickly loses consciousness and dies.

Carbon monoxide is a substance produced as a result of under-combustion of carbon, which often occurs when there is limited access to oxygen. Initially, it is a gaseous substance without a characteristic aroma and color. Because of its lightness, the gas tends to accumulate in the upper air layers - for example, closer to the ceiling.

Carbon monoxide poisoning is popularly known as "carbon monoxide poisoning": it is easy to get it if you use gas and especially stove heating with violations, ignore safety precautions when working with a car in the garage, as well as during fires, and so on. [1]

Epidemiology

Carbon monoxide poisoning is one of the most common intoxication injuries caused by exposure to gaseous substances. For example, in the United States, more than 2,000 people die from such poisoning each year, and this does not include cases related to fires. From 2001 to 2003, more than fifteen thousand victims were hospitalized in intensive care units with a diagnosis of carbon monoxide poisoning. At the same time intoxication was both accidental and intentional - with the purpose of suicide. More than half of the patients suffered as a result of malfunction of the stove heating exhaust system.

Nearly one in two survivors of carbon monoxide poisoning has a long-term psychiatric disorder. [2]

Causes of the carbon monoxide poisoning

The most common sources of carbon monoxide poisoning are considered to be: [3], [4]

• running cars;
• gas-fired water heaters;
• gas-fired furnaces;
• ovens and gas-fired domestic stoves;
• charcoal grilling devices;
• canned blood products used for transfusion;
• units used for pouring ice;
• boats, motorized gear, generators;
• Anesthesia devices that use a reversible absorbent circuit;
• propane loaders;
• active fire zones, coal mines.

Risk factors

At present, carbon monoxide poisoning is much less frequent than, for example, a hundred years ago, when houses were predominantly heated by stoves. Nevertheless, there are many sources of possible intoxication even nowadays:

• dwellings heated by gas stoves, fireplaces;
• bathhouses;
• auto repair shops, garages;
• manufacturing plants that use carbon monoxide;
• fires in confined spaces - e.g. Elevators, shafts, basements, etc.

People living in houses with stove heating, motorists and car mechanics, miners, firemen are at particular risk. Often victims of carbon monoxide poisoning are persons with unstable psyche and those who regularly abuse alcohol.

Pathogenesis

The density of carbon monoxide is 0.968 of the specific gravity of air under natural conditions. The substance can easily penetrate into the bloodstream, where it combines with hemoglobin: carboxyhemoglobin is formed. The degree of affinity of hemoglobin and carbon monoxide is high, so CO is present mainly in the blood, and only in small amounts - up to 15% in tissues.

Carbon monoxide is released by intrahepatic decomposition of methylene chloride, with a maximum detectable concentration eight or more hours after the onset of intoxication. [5]

The defining effect of carbon monoxide in poisoning is the failure of the oxygen binding property of hemoglobin. As a result, even with an adequate partial pressure of oxygen, its content in the arterial flow is strongly reduced. In addition, carbon monoxide shifts the dissociation curve of _HbO2 to the left side, which leads to a decrease in the transfer of oxygen to tissues. The toxic effect of the gas is not only due to the formation of carboxyhemoglobin, but also due to the formation of carboxymyoglobin of the compound myoglobin with carbon monoxide. The compound is known to directly alter the processes of cellular respiration. After time, oxidative degradation of lipids develops and brain activity is disturbed. [6]

Symptoms of the carbon monoxide poisoning

The clinical picture of carbon monoxide poisoning has several degrees of severity, which are characterized by different manifestations and their intensity.

The mild degree is characterized by these early signs:

• a general state of weakness;
• increasing pain in the head (more often in the forehead and temples);
• the sensation of pulse beats in the temple area;
• auditory noise;
• dizziness;
• visual impairment, blurring, blurring;
• dry cough;
• a feeling of shortness of breath, difficulty breathing;
• tear production;
• nausea;
• redness of the skin of the face, extremities, conjunctiva of the eyes;
• heart palpitations;
• "spike" in blood pressure.

In moderately severe carbon monoxide poisoning, the symptomatology increases and worsens:

• clouds the mind, to the point of losing it;
• there's vomiting;
• auditory and visual hallucinations;
• there's a loss of coordination;
• there's a feeling of pressure behind the sternum.

In severe cases, other serious symptoms are added:

• decreases in muscle function to the point of paralysis;
• the person loses consciousness, coma may develop;
• you get seizures;
• pupils dilating;
• there may be involuntary discharge of urine and feces;
• pulse is weak and rapid;
• skin and mucous membranes acquire a livid color;
• respiratory movements become shallow and intermittent.

As can be seen, the color of the skin in carbon monoxide poisoning varies depending on the degree of intoxication, ranging from deep red to bluish. In the fainting form, which refers to atypical manifestations of poisoning, the skin and mucous membranes can be pale and even grayish.

Less often, acute carbon monoxide poisoning manifests itself in the so-called euphoric form: the victim has psychomotor excitement, there is unreasonable laughter or crying, behavior becomes inadequate. Then signs of respiratory and cardiac failure increase, the person loses consciousness.

Chronic carbon monoxide poisoning is characterized by complaints of constant pain in the head, fatigue, apathy, sleep problems, poor memory, periodic "failures" in orientation, frequent and unstable heartbeat, pain behind the sternum. Vision is disturbed: color perception changes, the visual field narrows, accommodation is disturbed. Increasing symptoms of malfunctions on the part of the CNS, which manifests itself as asthenia, dysfunction of the autonomic nervous system, vascular spasms, hypertension, myocardiodystrophy. When conducting an ECG, focal and diffuse pathologic signs, coronary changes are detected. In women, failures of the monthly cycle, problems with pregnancy are noted. Men note sexual weakness. [7]

Chronic poisoning can be a trigger in the development of atherosclerosis, endocrine disorders: patients are often found to have thyrotoxicosis.

Complications and consequences

The long-term consequences of carbon monoxide poisoning are difficult to predict, because the compounds formed in the blood are quite strong. In addition, carbon monoxide can change the structure of hemoglobin, which negatively affects the mechanism of oxygen transfer to tissues. Transport properties of blood are disturbed, chronic hypoxia develops, which adversely affects the functional capacity of the brain, cardiovascular system, liver and kidneys.

Carbon monoxide has a long-lasting toxic effect on all tissues in the body. This compound binds to myoglobin, impairs myocardial contractile function, which leads to impaired blood circulation and lack of oxygen in organs.

If you look at the statistics of intoxication, a person who has experienced carbon monoxide poisoning may die years later from a heart attack associated with myocardial damage.

Other adverse effects may include:

• memory impairment;
• mental deterioration;
• myopathies;
• migraines;
• chronic dyspepsia.

According to experts, even after intensive treatment of persons poisoned by carbon monoxide, neurological disorders are present for at least three years. The possibility of irreversible disorders in cellular structures is not excluded. [8]

Causes of death in carbon monoxide poisoning

Comatose state and death of the victim usually occurs as a result of paralysis of the respiratory center. In this case, heartbeats may be recorded for some time after breathing stops. There are many cases of death from the effects of intoxication even weeks after the incident.

Some patients develop complications in the form of inflammatory processes in the airways and lungs. Death from such complications is second only to respiratory depression and paralysis.

As a rule, the severe form of carbon monoxide poisoning is fatal. In the long term, negative consequences may develop even after a moderate form of intoxication.

Diagnostics of the carbon monoxide poisoning

Since the clinical picture of carbon monoxide poisoning is most often vague, without diverse and specific symptoms, it is easy for a medical professional to make a mistake and misdiagnose. There are many cases when a moderately severe poisoning with vague symptoms was mistaken for a viral infection. Therefore, doctors are advised to be very careful, and at the slightest suspicion of carbon monoxide poisoning to conduct a thorough diagnosis using all necessary procedures. For example, gas intoxication can never be ruled out if patients living in the same dwelling show nonspecific virus-like signs - especially if the house has stove or fireplace heating.

Tests are the basis for the diagnosis of carbon monoxide poisoning. First of all, the carboxyhemoglobin content in the blood should be determined: a CO-oximeter is used for this purpose. It is possible to take both venous and arterial blood for the study. A high level of carboxyhemoglobin is a hundred percent indicator of carbon monoxide intoxication. But there are known situations when this level is underestimated due to its rapid fall. For example, this happens if the victim is evacuated from the gas center, or on the way to the hospital inhalation of oxygen (before taking blood for analysis).

Instrumental diagnostics is not determinative, but only acts as a supplement to the diagnosis, as it helps to detect some auxiliary signs - for example, electrocardiography in case of chest pain, and in case of neurological symptoms - a CT scan of the brain. Changes in the CT image can be seen as early as 12 hours after the carbon monoxide poisoning, which was accompanied by loss of consciousness. Usually symmetrical foci of rarefaction are visualized in the area of the pale globe, shell and caudate nucleus. Such changes, which appeared within the first day, indicate an unfavorable prognosis. Conversely, the absence of pathologic changes indicates a probable positive outcome.

Differential diagnosis is carried out with influenza and other viral infections, alcohol intoxication, overdose of sedative and hypnotic drugs.

Treatment of the carbon monoxide poisoning

The main focus of treatment in carbon monoxide poisoning is the establishment of gas exchange processes. First, the patient is provided with breathing 100% oxygen, using a mask or endotracheal tube. Such a measure helps to increase the concentration of dissolved oxygen in the bloodstream, while stimulating the dissociation of carboxyhemoglobin. If hospitalization and oxygenation are followed in a timely manner, the incidence of mortality is reduced to 1-30%.

Primary treatment interventions may include:

• oxygen mask placement;
• breathing a mixture of oxygen and carbon dioxide (called carbogen);
• artificial ventilation;
• barochamber therapy.

In addition, it is mandatory to administer an antidote.

After stabilizing the condition of the victim proceed to general treatment, in order to restore the basic functions of the body and prevent the negative effects of hypoxia.

In addition to the main treatment, a diet is prescribed: the diet is enriched with vitaminized foods rich in antioxidants. The diet should include a dominant amount of fruits and berries: blueberries, red and blue grapes, cranberries, currants, pomegranate are recommended. Freshly squeezed juices of citrus and carrots, green tea, puerh have a good effect. [9]

First aid for carbon monoxide poisoning

From the speed and timeliness of first aid directly depends on the prognosis for the patient, so even if you suspect carbon monoxide poisoning, you should immediately contact the "ambulance".

General emergency care measures are as follows:

• Eliminate and neutralize the source of carbon monoxide emissions, and remove or remove the poisoned person to fresh air.
• Maximize oxygen access by loosening the collar, unbuckling the belt, etc.
• Try to activate blood circulation: rub the chest, give hot tea or coffee.
• In every possible way to prevent loss of consciousness victims: bring ammonia, sprayed with cool water, slapped on the cheeks.
• If the victim's breathing has stopped or pulse is lost, you should resort to emergency measures: artificial respiration, manual heart massage.

Antidote for carbon monoxide poisoning

The antidote is the drug Acizol, which is administered in the amount of 60 mg as an intramuscular injection three times during the first 24 hours of poisoning, then once a day in the amount of 60 mg for two consecutive days. Antidote administration is combined with fibrobronchoscopy in case of respiratory system damage.

If the victim can take the drug himself, it is prescribed in the form of capsules: one capsule 4 times in the first day, then - one capsule twice a day for a week. The maximum permissible dosage of the antidote for an adult is 4 capsules (or 480 mg).

Acisol enhances the effect of general pathogenetic treatment, inhibits the formation of carboxyhemoglobin by affecting the combined interaction of hemoglobin subunits. As a result, the degree of relative affinity of hemoglobin and carbon monoxide is reduced, and the oxygen-binding and gas-transport abilities of blood are optimized. In addition, the antidote reduces the degree of oxygen starvation, increases hypoxic resistance of the body. [10]

Medicines that your doctor can prescribe

Carbon monoxide poisoning always requires urgent hospitalization, even if it seems that the victim feels satisfactory. In addition to oxygen therapy, the patient is given an intravenous infusion of drugs, depending on which organs and systems first failed. Cardiovascular drugs, vitamins, anticonvulsants, etc. Are often prescribed.

Anti-inflammatory drugs to relieve airway inflammation
Pulmicort	A glucocorticosteroid drug with strong anti-inflammatory properties, reducing the degree of bronchial obstruction. The dosage for an adult patient is up to 800 mcg per day, taken in 2-4 inhalations. The amount of the drug can be changed at the discretion of the doctor. Among the possible side effects: allergies, sleep disturbance, cough, irritability.
Budesonide	An active synthetic glucocorticoid drug that prevents and cures inflammatory diseases of the respiratory tract. Can be administered in amounts ranging from 200 to 1600 mcg per day, in 2-4 inhalations. Possible side effects: oral and throat candidiasis, hypersensitivity reactions, coughing, wheezing, throat irritation.
Anticonvulsants to reduce muscle hypertonicity
Levodopa and carbidopa	Anticonvulsant antiparkinsonian drug, prescribed in individual doses. Can be used from the age of 18 years.
Amantadine	Antiviral and at the same time antiparkinsonian drug. It is taken orally, after meals, in an individually selected dosage. Treatment may be accompanied by nausea, dry mouth, dizziness. Simultaneous administration of alcohol and Amantadine is prohibited.
Pain relievers for relief
Novigan	Analgesic and antispasmodic. It is prescribed between meals, one tablet three times a day. Contraindicated in children under 16 years of age. Possible side effects: abdominal pain, allergic reactions, dyspepsia.
Ibuprofen	Non-steroidal anti-inflammatory drug, taken after meals, 200-400 mg, three times a day. Duration of treatment - not more than three days. Side effects: abdominal pain, digestive disorders.
Vitamin preparations to accelerate the destruction of carboxyhemoglobin
Cocarboxylase	A vitamin B1 preparation used as part of complex treatment. It is administered intramuscularly at 50-100 mg per day for 15-30 consecutive days. Allergic reactions in the form of redness, itching, swelling are possible during treatment.
Sorbent means to neutralize toxins
Polysorb	Colloidal silicon dioxide preparation with enterosorbing activity. It is taken between meals, in individual doses. Treatment can last up to two weeks. It is possible to conduct several courses with an interval between them of 2-3 weeks. Side effects are rarely registered: it can be constipation, allergies.

Prevention

In order to reduce the risk of carbon monoxide poisoning, it is recommended to follow the following simple rules:

• stoves and fireplaces must be operated in compliance with all safety regulations;
• It is necessary to regularly inspect and test the ventilation system in the house, check the flow of the chimney and ventilation ducts;
• stoves and fireplaces should only be installed, repaired and maintained by professional specialists;
• turn on the car engine only in an open garage (according to statistics, staying in a closed space with the engine running for five minutes is enough to get carbon monoxide poisoning);
• Do not stay in a parked, closed, running vehicle for long periods of time and, moreover, do not sleep in it;
• At any sign of carbon monoxide spread and poisoning, it is important to fill the room with fresh air as soon as possible and, if possible, go outside.

Carbon monoxide is an insidious and dangerous substance that has a rapid and almost imperceptible effect. Therefore, it is much easier to prevent the problem in advance by simply following all the rules and recommendations. [11]

Forecast

What do experts say about the prognosis of the clinical course of acute carbon monoxide poisoning? In most cases, such a prognosis depends on how affected the respiratory tract is, as well as on the recorded limit level of carboxyhemoglobin in the blood of the victim. Doctors assess the condition of the victim using the following criteria:

• general state of health, individual features of the patient's physiology (the worst prognosis is voiced for weakened patients suffering from chronic pathologies, for the elderly, pregnant women and children);
• duration of exposure and concentration of carbon monoxide in the air breathed by the victim;
• active activity during intoxication (high physical activity, intensive respiratory movements contribute to a faster development of poisoning).

Unfortunately, acute carbon monoxide poisoning is often fatal: this is due to both the vagueness of clinical symptoms and the lack of or untimely provision of first aid to the victim.