Ammonia poisoning is a pathological condition provoked by inhalation of vapors of this substance, as well as its ingestion in the form of an aqueous or alcoholic solution. In case of man-made disasters, contact damage to the skin and mucous membranes is possible. The main manifestations include lacrimation, pain in the eyes, shortness of breath, hoarseness of voice, cough, suffocation, tachycardia, chemical burns of the skin. In severe cases, seizures, collapse, cardiac arrest occur. Pathology is diagnosed on the basis of anamnesis, typical aroma emanating from the victim, laboratory examination data. Specific treatment: euphyllin, prednisone, inhalation of salbutamol and oxygen.
ICD 10
T57.8 Other refined inorganic substances
General information
Ammonia is a transparent gas with a recognizable odor or its aqueous solution. It has an irritating effect, can cause pulmonary edema, hyperammonemia, chemical damage to the alveoli and interstitial tissue. Poisoning is rare, their number does not exceed 1% of the total number of hospitalizations for exotoxicosis with pulmotoxic poisons. They are common among representatives of antisocial groups of the population (alcohol-dependent people), fans of non-traditional methods of treatment, employees of chemical industry enterprises whose activities are related to the synthesis and transportation of ammonia.
Causes
The most severe poisoning occurs during industrial disasters with the release of a large volume of gas in a confined space and when large containers with aqueous solutions of ammonia are damaged. The substance evaporates, fills the room, making the air unsuitable for breathing. The maximum permissible concentration of gas in the production room is >20 mg/m3, in the open space > 0.2 mg/m3. Other causes of damage:
- Suicide attempt. In rare cases, suicide attempts using ammonia are recorded. To do this, a 10% aqueous solution is used — the most accessible form in everyday life. The mucous membranes of the gastrointestinal tract, oral cavity, nasopharynx are mainly affected. The severity of the condition depends on the amount of the drug taken.
- Self-medication. The use of untested traditional medicine, as well as the incorrect interpretation of existing recipes, sometimes leads to exceeding the permissible doses of ammonia. This becomes the cause of poisoning, which in the absolute majority of cases occur in a mild or moderate form.
- Leveling the effects of alcohol. There is an opinion that ingestion of several drops of ammonia makes it possible to achieve sobering up of a person who is under the influence of ethanol. According to the recipe, before drinking the substance is dissolved in a glass of pure water. When taking a concentrated solution, a burn of the mucous membranes occurs.
- Improper local use. 10% ammonia is used locally for the purpose of degreasing and antiseptic treatment of the skin, elimination of papillomas. Excessively prolonged application or procedure carried out with a highly concentrated solution is accompanied by the appearance of skin burns.
Pathogenesis
Ammonia poisoning is characterized by the presence of suffocating and neurotropic effects. The effect of gas on the respiratory tract provokes irritation of the mucous membranes, venous stasis and alveolar edema. An autopsy reveals an increased level of tissue hydration, necrotic areas and zones of subpleural hemorrhage. The neurotropic effect manifests itself in the form of a violation of neuromuscular conduction and the activity of the central nervous system. Ataxia, head tremor, clonic seizures are noted.
Death occurs from paralysis of the respiratory musculature, a critical decrease in the functional abilities of the lungs, non-canceling vascular collapse. The use of concentrated solutions through the mouth causes chemical burns, necrosis and perforation of the gastrointestinal tract. In the absence of help, the patient dies from internal bleeding, infectious and toxic shock or damage to the visceral organs by spilled gastric contents. If the amount of the drug consumed is small, only burns of the mouth and esophagus occur, which rarely end fatally.
Classification
Ammonia poisoning can be classified depending on the causes of development (criminal, suicidal, accidental, industrial) or the way the poison enters the body (inhalation, contact, food). Given the fact that NH3 has a high volatility, contact and food poisoning are usually combined with respiratory tract damage. The most significant from a clinical point of view is the division by severity:
- Mild intoxication. There are symptoms of irritation of the mucous membranes, hypersalivation. Shortness of breath is mild. Consciousness is not disturbed, the victim is oriented in the surrounding environment, is critical of his own condition. There are no data on changes in heart rate and hemodynamics. Sometimes there is a slight tachycardia and hypertension due to stress reactions.
- Moderate lesion. There is pulmonary edema with an appropriate clinical and radiological picture. The patient is excited, scared, rushing, partially oriented in what is happening. The behavior is inadequate. Hemodynamic disorders, compensatory increase in heart rate, which is subsequently replaced by bradycardia, are added. Signs of hypoxia are revealed. Reflex respiratory arrest is possible.
- Severe intoxication. A sharp violation of vital processes in the body, the development of metabolic failures, acidosis, massive pulmonary edema with severe respiratory failure. Vascular collapse, coronary arrhythmia may occur. Consciousness is disturbed to a large extent, a sopor or coma is formed.
Symptoms
Inhalation damage is manifested by pain in the eyes, lacrimation, visual impairment and conjunctivitis. There are attacks of suffocating cough, initially dry, later acquiring a productive character. With laryngospasm, the cough becomes barking. On examination, hyperemia of the skin is detected, the patient complains of itching all over the body. The development of pulmonary edema is characterized by the appearance of shortness of breath, chest pain, generalized cyanosis. Wheezing is heard, breathing is not carried out in all departments. Compensatory tachycardia is noted, in the later stages — a violation of the heart rhythm by the type of AV blockades, atrial fibrillation or ventricles.
The neurotropic effect of the poison manifests itself in the form of delirium, psychomotor agitation, convulsive syndrome. A pathognomonic sign is a decrease in the auditory threshold to the limits when even weak sounds are unbearable for the patient. In many cases, it is the auditory stimulus that becomes the provoking factor of seizures. The phenomenon persists for several hours after the removal of the victim from the infected area and the start of medical care. In the future, the functions of the nervous system may not be fully restored.
In contact with liquid forms of ammonia, the clinic of inhalation poisoning is usually absent. In the area in contact with the solution, a chemical burn of the II degree develops. There is a lesion of the epidermis and upper layers of the skin, the appearance of blisters. When taking the drug inside, similar processes are noted in the esophagus and stomach. The clinic includes pain in the damaged area, vomiting, nausea, signs of chemical burns of the oral mucosa and the skin around the mouth. There is a risk of internal bleeding, accompanied by vomiting the color of coffee grounds or with an admixture of scarlet blood.
Complications
Ammonia poisoning with pulmonal symptoms in 80% of cases leads to the development of secondary pneumonia. Acute respiratory failure is possible, occurring in severe form and requiring artificial respiratory support. Delayed consequences (decreased intelligence, personality change) occur in 20-25% of cases, are the result of hypoxia and toxic effects of hydrogen nitride on the tissues of the central nervous system. They can be diagnosed several months or years after discharge from the hospital. They are irreversible, against the background of ongoing nootropic treatment, the psyche is restored to a small extent.
Diagnostics
A preliminary diagnosis is established by an ambulance doctor who arrived at the scene, confirmed by a toxicologist or resuscitator of the specialized department. Differential diagnosis is carried out with pulmonary edema of another origin, as well as with the defeat of combat gases and other inhalation chemicals. Burns caused by ingestion of ammonia should be distinguished from poisoning with cauterizing liquids (acetic essence, household alkalis). The following types of examination are shown:
- Physical. The signs of acute intoxication with hydrogen nitride are determined: psychomotor agitation, RR > 18-20 per minute, suffocating cough, copious saliva, tearfulness. Heart rate above 90, in severe cases less than 60 beats/min. At the point of contact of liquid ammonia with the skin, areas of pronounced hyperemia or blisters filled with serous contents are found.
- Instrumental. Pulmonary edema is diagnosed based on radiography data. The main symptoms are: root dilation, “deer antlers”, curling lines, thickening of interstitial crevices, vague focal shadows. A more accurate method is positron emission and computed tomography. Darkening by the type of frosted glass in places of accumulation of liquid is viewed. MRI in the diagnosis of OL is ineffective.
- Laboratory. The ammonium content in the blood is determined above 32 mmol / liter. There are non-specific changes in biochemical parameters and ABB: an increase in the concentration of carbon dioxide, a decrease in oxygen levels, acidosis, an increase in the content of oligopeptides, the activity of alkaline phosphatase. With a massive lesion of the body surface with liquid solutions, an insufficient amount of proteins, water, and glucose is determined.
Treatment
Ammonia poisoning requires immediate measures to save the victim. Before the arrival of doctors, it should be removed from the infected area, provide fresh air, give a semi-sitting position. It is permissible to rinse the eyes with a weak phosphate buffer solution or clean water, then drip 1 drop of albucide. The ambulance employees who arrived at the scene of the events treat the affected areas of the body with 5% ascorbic acid. Further actions depend on the available clinical picture.
With laryngospasm, inhalation of dexamethasone or naphthyzine through a nebulizer is necessary. Intravenous bronchodilators, including salbutamol. Pulmonary edema is an indication for fractional administration of morphine, strophanthin, droperidol. Psychomotor agitation is stopped with the help of benzodiazepines. Severe respiratory failure requires intubation of the trachea with the transition to a ventilator. In case of shock, infusion therapy with crystalloid and colloidal solutions is performed, adrenaline, cardiotonics, sodium bicarbonate are injected.
In the hospital, specific therapy is carried out aimed at restoring the functioning of the respiratory system. The most effective remedy is prednisone. Routes of administration: intravenous, inhalation through a nebulizer. The second place is taken by eufillin, which is prescribed intramuscularly. Pedifen, salbutamol, combined drugs, ascorbic acid are also used. If necessary, the patient is placed in the ICU for resuscitation benefits.
Prognosis and prevention
Ammonia poisoning has a favorable prognosis if the victim was in the zone of infection for no more than 3-5 minutes. The concentration of gas in the air should also be taken into account. The higher it is, the shorter the time it takes to get a toxic dose. In severe intoxication accompanied by alveolar edema, mortality is 50% in the absence of therapy, 20% in the treatment with prednisone and euphyllin, 30-60% when using less effective drugs. The course of pathology worsens in the presence of concomitant lung diseases.
Prevention consists in observing safety precautions while working in chemical production. With a high probability of man-made disasters, preventive treatment can be practiced. Prednisone is used as a drug that reduces the risk of severe damage to the respiratory system as much as possible. To prevent poisoning with aqueous solutions, they should be kept in a tightly closed and labeled container, in places inaccessible to children, separately from food products.
