Barbiturate poisoning is a pathological condition that occurs when ingesting toxic doses of barbamil, phenobarbital, barbital sodium and other drugs of this pharmacological group. It is manifested by the development of a comatose state, respiratory, cardiovascular, renal insufficiency, trophic disorders. At the prehospital stage, the diagnosis is made by the presence of appropriate clinical manifestations, anamnesis and indications for taking medications (empty blisters from pills, stories of relatives). Specific treatment includes hemosorption, intestinal lavage, gastric lavage and other methods of active detoxification.
T42.3 Barbiturate poisoning
Poisoning by means of the barbiturate group occupies a leading place among other drug intoxications. In specialized toxicological centers, their number reaches 20% of the total flow of patients. They have a high mortality rate: 3% in moderate forms and 15% in severe pathology. The frequency of occurrence increases in spring and autumn during the period of exacerbation of mental illness. The ratio of affected men and women is 3:7. The most complex poisoning occurs after taking short- and medium-acting pills. Prolonged funds are absorbed longer, so there is no sharp rise in the concentration of barbiturates in the blood.
Barbiturate poisoning is almost always the result of taking increased amounts of medication. Sometimes therapeutic doses of the drug lead to the development of a poisoning clinic. A psychiatrist and a toxicologist are engaged in determining the causes of pathology. If there is evidence of a criminal component, this is reported to law enforcement agencies. The main causes of poisoning include:
- Suicide attempts. In 85% of cases, a person is pushed to take sleeping pills by the desire to die independently and painlessly. Such desires arise against the background of serious psychoemotional injuries, incurable pathology, exacerbation of diseases, difficult life situations, unrequited love. The age of patients committing suicide ranges from 15 to 30 years. The next wave of victims falls on the category of 70-85 years. Suicide attempts end in the most severe poisoning, because the volume of the drug taken is many times higher than the therapeutic dosage.
- Incorrect dosage. It usually results from illiterate self-medication. To enhance and accelerate the effect, a person takes pills in an amount 2-3 times higher than the maximum allowable. Cases of iatrogenism are extremely rare. They occur only with intravenous administration of the drug, if the medical staff made a mistake when calculating the required amount of drugs.
- Violation of excretion. Renal or hepatic insufficiency leads to a slowdown in the rate of metabolism and excretion of medications. With the daily intake of sleeping pills, they accumulate in the body. At some point, the concentration becomes critical, the clinic of poisoning develops. In such situations, symptoms occur gradually, which allows you to recognize what happened in a timely manner and take the necessary rescue measures.
- Anesthesia. The drugs of this pharmacological group have some intoxicating effect. Sometimes they try to use them as a drug. Tolerance to the drug is rapidly developing, which requires a constant increase in the number of medications. Critical dosages for barbituromania are achieved after 4-6 months of regular use of the drug.
- Crime. There are known situations when sleeping pills were used to bring a person into unconsciousness for robbery, rape and other illegal actions. The goal of the criminal is to achieve the fastest and deepest possible sleep of the victim. Therefore, the volume of the drug used is very high. Criminal poisoning with barbiturates is usually comparable in severity to suicidal.
After absorption of the drug in the small intestine, it penetrates into the bloodstream, partially binds to plasma proteins. The active portion of the drug passes through the blood-brain barrier, enters the internal lipid layers of neurons, changing their structure and aggregate state. There is a suppression of the production of acetylcholine, stimulation of the synthesis of gamma-aminobutyric acid, which has an inhibitory effect. The process is characterized by a general depression of the central nervous system, a violation of the process of impulse transmission in synapses.
At the macro level, barbiturate poisoning is manifested by paralysis of the vasomotor center, hyporeflexia, impaired breathing, consciousness, decreased myocardial contractility, increased vascular permeability. The latter causes edema of the lungs and brain. These clinical manifestations are due to the toxic effect of the drug on the medulla oblongata and the trunk. The metabolic component of intoxication consists in the induction of liver enzymes, the activity of which increases. This is most noticeable when taking barbiturates for a long time.
The division of drug intoxication into groups can be carried out using various principles: for reasons (accidental, intentional, criminal), time of development (acute, chronic, subacute). However, the most common is the clinical classification, which is based on the severity and level of violation of vital functions of the body. According to it , there are the following degrees of poisoning:
- Easy. There is no suppression of consciousness, there are changes that do not significantly affect vital processes. There may be a clinic of intoxication, nausea, increased effects of the drug. Hospitalization is usually not required. Negative phenomena pass within 1-2 days from the moment of drug withdrawal.
- Medium. Moderate disturbances of consciousness are noted: more often sopor or delirium, in rare cases, superficial coma. There are no generalized symptoms of hypoxia. Muscle tone and tendon reflexes are weakened. The concentration of the drug in the blood is less than 100 micrograms / ml. Hospitalization to the department of the toxicology center is indicated.
- Heavy. There are significant changes in the work of the body. Respiratory insufficiency is pronounced. Deep coma, miosis, hypothermia develops. With long-term exposure before the arrival of doctors, positional compression syndrome occurs. The plasma content of the drug exceeds 100 micrograms/ml. Treatment is carried out in the toxicological intensive care unit.
- Extremely heavy. All signs of poisoning are expressed as much as possible. The patient loses the ability to breathe adequately, vascular collapse develops, a critical decrease in blood pressure. On the Glasgow scale, the coma is in the range of 4-8 points (severe damage). In the absence of immediate help, it ends with cardiac arrest and death of the patient after 1-2 hours.
The clinic of barbiturate poisoning goes through 4 main stages. At the first of them, apathy, drowsiness, weakening of the victim’s reaction to stimuli are noted. Contact with a person is preserved, but gradually lost. There are no other visible signs of violations. When taking a large number of tablets at the same time, nausea and vomiting may occur. The duration of the stage depends on the dose of the medication and ranges from 20-60 minutes in acute poisoning.
The second stage is characterized by the development of a superficial coma. There is a loss of consciousness, a complete loss of contact with the patient. There is a sinking of the tongue, which leads to respiratory disorders. There is hyporeflexia, in which, first of all, the swallowing and coughing reflex disappears. The reaction to pain is weakened, pupil dilation appears, slight motor activity. The body temperature rises to 39-40 °C due to toxic damage to the thermoregulatory center.
Aggravation of the situation leads to the emergence of a deep coma, in which there are no reflexes, reaction to physical impact, independent breathing. Hemodynamics is unstable, blood pressure is sharply reduced, medication support is required. There is tachycardia, hypersalivation, bronchorrhea. Pupils are dilated. The skin temperature decreases. With prolonged stay in a coma, the patient develops bedsores, congestive pneumonia. It is possible to weaken the function of urinary excretion up to acute renal failure.
The post-comatose period is characterized by a gradual restoration of consciousness, mental disorders (tearfulness, inadequate perception of reality, delirium), lack of sleep. Depression, emotional lability, shaky gait and other neurological symptoms may occur. If there was a clinical death, signs of post-resuscitation disease are detected in a person. In some cases, they are retained for life. There may be persistent residual changes on the part of the cardiovascular, urinary, respiratory system, disorders of the liver, cerebral structures.
The most dangerous complication of barbiturate intoxication is posthypoxic brain damage. It occurs in 35% of cases of severe and extremely severe poisoning. It is manifested by a weakening of mental abilities, paralysis, paresis, violation of the function of internal organs and executive motor systems. Developing brain edema sometimes leads to the death of the patient or irreversible damage to the central nervous system. It occurs in about 10% of cases, characterized by a number of stem and focal symptoms. Patients who are on a ventilator for a long time and in a stationary state are susceptible to the development of severe pneumonia of the stagnant type. This happens in 40% of victims if artificial respiratory support is carried out for more than 2-3 days.
In most cases, the diagnosis of “barbiturate poisoning” is made by an emergency medical doctor arriving at the scene. Its confirmation is carried out by toxicologists or resuscitators, based on the results of laboratory and hardware examination. Differential diagnosis is carried out with comas of a different etiology, including hypoglycemic, caused by poisoning with other drugs or drugs, traumatic (TBI), infectious genesis. The main search methods include:
- Physical. There is no or weakened reaction to external stimuli, the skin is pale, blood pressure is reduced, pulse is frequent, weak tension and filling. There is an increased saliva secretion, wheezing during breathing. In severe lesions, signs of hypoxia are detected: diffuse cyanosis, sweating. RR varies between 8-10 per minute, heart rate 90-120. At the terminal stage, bradycardia occurs. Lateral nystagmus, diplopia may be detected.
- Laboratory. The presence of barbiturates in a toxic dose is detected in plasma. The pH value is reduced, which indicates the development of metabolic acidosis. The oxygen content in the blood decreases, the partial pressure of carbon dioxide increases above 40 mm Hg. There are changes in the electrolyte composition, when massive edema occurs, the CBV decreases with a corresponding decrease in the central venous pressure of less than 4 cm of the water column.
- Hardware. It is mainly used to clarify secondary changes. During radiography, symptoms of pulmonary edema or brain edema may be detected. On the ECG — sinus tachycardia, diffuse myocardial transformations. The use of electroencephalography detects characteristic barbiturate swirls.
Gastric lavage is considered the basis of first aid. It is carried out both at the pre-hospital stage and in the hospital. In patients in a coma, the procedure is implemented through a thick gastric tube. It is permissible for people with preserved consciousness and swallowing reflex to remove gastric contents in a non-probe way. Manipulation is carried out to clean washing waters. In addition, the ambulance team carries out activities aimed at maintaining vital functions: intubation, transfer to a ventilator, introduction of cardiotonics, infusion solutions.
Hospital treatment is aimed at the speedy removal of the toxic agent. Intestinal lavage, forced diuresis, hemo- or peritoneal dialysis are used. Symptomatic therapy is carried out, aimed at eliminating severe disorders of the heart, kidneys, lungs. Respiratory support is continued until independent breathing is restored. It is mandatory to introduce 4% sodium bicarbonate, which is necessary for the correction of acidosis and accelerated removal of barbiturates from the blood.
In moderate poisoning, an infusion of analeptics (cordiamine, caffeine) is indicated. They have a stimulating effect on the nervous system, which allows partially leveling the effects of sleeping pills. Deep depression of the central nervous system is a contraindication to the use of stimulants due to the ineffectiveness of the latter. Specific barbiturate antidotes — bemegrid, flumazenil (anexate) are injected in a jet, until consciousness is restored or the maximum allowable single dose is reached. In the absence of an instant effect, several injections are prescribed daily, several times a day.
Prognosis and prevention
Severe barbiturate poisoning has an unfavorable prognosis. About 15% of patients die, and 40% of the survivors after recovery undergo some kind of changes in the psyche or internal organs (kidneys, liver). The situation further worsens if there was pulmonary edema or brain, kidney failure. Poisoning with barbiturates of small and medium degree does not lead to such deplorable consequences, in the absolute majority of cases it is completely cured. Symptoms can be eliminated within a week.
Prevention on the part of the patient consists in taking the drug strictly according to the doctor’s prescription and in a dose not exceeding the therapeutic one. Iatrogenic poisoning can be avoided if the patient’s medical history is carefully collected and the presence of contraindications to the drug is found out. It is necessary to limit independent access to medicines for people prone to tantrums, depression, mental breakdowns, suffering from mental illnesses.