What is an induced coma, what is it for and its consequences

An induced coma is actually a medicated sleep. This state differs from anesthesia in the duration of stay in it.

Under the influence of barbiturates, metabolic processes in the nervous tissue slow down. 60% of oxygen and glucose entering the brain support its bioelectrical activity. 40% of oxygen and glucose ensure metabolic processes and other activities.

In a patient in a state of drug-induced sleep, the bioelectrical activity of the brain is significantly reduced, which leads to an increase in free oxygen and glucose, which are redirected to maintain cellular metabolism in the nervous tissue. This is why a person is put into an artificial coma, in order to reduce the negative effects of oxygen deficiency and avoid hypoxic damage to the brain matter.

Artificial coma - what is it?

An artificial coma is a specific state of the body, also called drug-induced sleep, into which the patient is immersed with the help of special medications. A medically induced coma is different from a typical coma and is more like the deep sleep of anesthesia.

When a patient is placed into a medically induced coma, special drugs are used to temporarily slow down the patient's vital functions. Artificial coma is used in the treatment of serious illnesses to reduce the risk of death of the patient.

When a patient is put into an artificial coma, the work of the subcortical parts of the brain is inhibited, reflexes and pain sensitivity are suppressed, the breathing and heart rate decreases, body temperature decreases and muscles relax.

The patient is put into an artificial coma by administering barbiturates, benzodiazepines, ketamine, and propofol. Subsequently, to maintain an induced coma, the patient is administered doses of drugs that support medicinal sleep.

The patient's condition is constantly monitored by specialists (blood gas composition, electrolyte levels, acid-base balance, biochemical blood parameters are monitored).

For reference. It should be noted that the procedure for introducing a patient into an induced coma and further removing it from it is an extremely complex procedure. Therefore, in practice, drug-induced coma is rarely used, only for health reasons, when the potential benefits justify the possible risks associated with the procedure.

Is it true that you can wake up during anesthesia or not wake up after?

It is theoretically possible to wake up during an operation if the dosage is incorrectly calculated, the anesthetic is selected incorrectly, or the body itself processes the injected drugs too quickly. But in practice this is extremely rare. Usually the doctor monitors the situation well and knows when a “supplement” of the drug is needed so that the patient’s sleep remains restful.

There is also a risk of not waking up after an operation performed under anesthesia, but experts note that the likelihood of death is high only in emergency and neurosurgery. True, in these situations, death more often occurs not because of anesthesia, but because of a serious condition - an acute injury or a life-threatening illness. In the case of planned operations, the probability of not surviving due to the fault of anesthesia is close to zero. In general, if the technique is followed and the necessary control is provided, anesthesia does not pose a threat to health, much less life.

Artificial coma - what for?

Induction into an artificial coma is carried out in severe pathologies, when placing the patient on medication is the only way to prevent the development of irreversible changes in organs and tissues.

For reference. Artificial coma can be used to speed up the patient’s recovery after a serious illness or injury, restore damaged nerve tissue, slow down or prevent the development of necrotic processes in tissues against the background of severe hypoxia.

For example, an induced coma helps slow blood circulation and metabolic processes in brain tissue, and therefore can prevent the development of a necrotic lesion and progressive cerebral edema during a major stroke .

Putting a patient into an artificial coma is used for:

• high risk of developing cerebral edema due to trauma, heart attack, stroke, extensive cranial hematomas of non-traumatic injury, brain tumors ;
• extensive burn damage;
• severe life-threatening intoxications;
• intractable seizures and status epilepticus;
• severe alcohol withdrawal syndrome;
• acute psychosis;
• asphyxia of newborns (severe hypoxia of newborns);
• rabies (medically induced coma is used as part of the experimental treatment of rabies; putting the patient into medicated sleep helps prevent the development of severe life-threatening brain damage).

Also, artificial coma is used when performing complex long-term operations on the heart and brain, with combined severe injuries with intense pain (if the patient requires several reconstructive operations, between which there is no point in restoring his consciousness).

What is the benefit

An artificial coma after surgery can be used for restorative purposes.

Most often, coma after surgery is used in the recovery period after extensive neurosurgical operations to provide a neuroprotective effect.

Putting the patient into an induced coma can reduce the risk of severe injuries in patients with prolonged convulsions. With cerebral edema, medicated sleep allows you to slow down metabolic processes in tissues, promotes narrowing of intracranial vessels, normalizes intracranial pressure and allows you to quickly stop the progression of edema.

For reference. Medically induced coma after major surgical interventions can significantly reduce the risk of life-threatening complications and speed up the rehabilitation period.

In case of extensive strokes, putting the patient into an artificial coma helps restore damaged nerve cells, improve the functioning of the central nervous system after general resuscitation, and also prevents the development of necrosis of brain tissue.

If the patient has severe traumatic head injuries, a medically induced coma prevents the development of intracranial hemorrhage.

Introducing medicated sleep to newborns who have suffered severe intrauterine asphyxia allows normalizing metabolic processes in tissues, as well as restoring the functioning of the central nervous system.

Severity of pathology

Classifications of degrees of coma adopted in Russian neurology are largely similar. According to the dynamic approach developed by Bogolepov, the degrees of coma are stages that replace each other as the condition deepens. The basis of staging is the gradual shutdown of brain functions in the process of deepening the coma. First of all, phylogenetically young formations suffer, which is accompanied by a “release” of the functions of underlying structures.

There are:

• moderate first degree coma;
• pronounced second degree;
• deep (third degree).

Moderate coma is marked by the absence of obvious signs of impairment of vital functions, while the patient retains pupillary reactions to light and corneal reflexes. There may be some increase in muscle tone over time. The victim in a coma lies with his eyes closed, and, unlike stupor, he has no involuntary motor activity.

Second degree coma has a slightly different clinical picture:

• impairment of respiratory activity, including the formation of respiratory failure;
• shortness of breath, tachycardia, cardiac arrhythmia;
• unstable hemodynamics;
• sluggish pupillary reactions to light;
• dysphagia;
• decreased muscle tone;
• sluggish tendon reflexes;
• inconstancy of the bilateral Babinski reflex.

Deep coma is also called atonic. In this case, the patient develops respiratory failure, hemodynamic instability and lack of pupillary response to light are noted. The deep type of pathology is dangerous because it can turn into an extreme coma, in which a person’s spontaneous breathing function is disrupted and the bioelectrical activity of the brain stops.

In practice, the clinical division of comatose states into degrees is conditional, since they have a certain level of dynamism, because with adequate treatment, the patient may experience regression of the pathology, and otherwise the comatose state may progress.

Coma of the fourth degree (extraordinary) is equivalent to brain death, in which extensive cell death of its tissue begins. Spontaneous breathing is interrupted, but cardiac activity remains.

Also, all comatose lesions are divided into two general groups:

• primary;
• secondary.

In turn, primary comas are represented by cerebral and structural pathologies, and secondary comas are represented by metabolic and dysmetabolic ones.

Dysmetabolic coma can be:

• endogenous;
• exogenous;
• infectious-toxic;
• toxic.

Features of the use of artificial coma

Introducing the patient into a state of medicated sleep is carried out exclusively in the intensive care unit. The patient is under constant supervision of medical personnel.

To introduce the patient into a state of medicated sleep, the following is used:

• hypnotics used for short-term anesthesia (propofol allows you to put the patient into a state of medical sleep for several hours, and due to its short-term action it has the lowest risk of complications);
• tranquilizers benzodiazepines (diazepam preparations allow you to put the patient into medicated sleep for up to three days);
• barbiturates (provide the best neuroprotective effect for head injuries or strokes, and also help prevent the development of cerebral edema).

The patient's breathing in a state of medicated sleep is supported by ventilation. All functions of internal organs are constantly monitored using hardware and laboratory diagnostics (electrocardiogram, electroencephalogram, blood biochemistry).

For reference. With prolonged drug-induced sleep, the patient is transferred to parenteral (intravenous) nutrition. Mandatory prevention of the development of bedsores and concomitant bacterial infections is also carried out.

Use in resuscitation therapy

An artificial coma is often performed for pneumonia, when acute respiratory failure develops against the background of pneumonia. More often, such pathologies are detected in patients with complicated influenza, who quickly develop viral or bacterial pneumonia and respiratory distress syndrome (a life-threatening condition characterized by diffuse infiltration and hypoxemia - a decrease in the concentration of oxygen in the blood).

Patients are placed in the intensive care unit, where they are sedated with medication and connected to a ventilator. In some cases, patients may remain in this condition for longer than 2 weeks. Typically, the drugs used for sedation are sodium oxybutyrate and benzodiazepines, and for muscle relaxation - Pipecuronium bromide.

In the case of an ischemic stroke , the patient is placed in an induced coma if a large lesion is detected, which is associated with a high risk of progression of neurological disorders - this measure in some cases can improve the outcome of stroke. Severe traumatic brain injuries resulting from an accident, bruise, or attack are associated with acute disruption of blood flow, cerebral edema, dislocation and compression of the brain matter.

For reference. If the patient lies in a coma, cerebral edema decreases, which often leads to stabilization of brain functions; how long the patient needs to remain in this state will be determined by the attending physician. Medication-induced sleep after complex neurosurgery reduces the risk of brain damage.

Often, a comatose state develops spontaneously as a protective reaction of the body to a negative external influence - head injury, impaired cerebral blood flow, taking a large dose of alcohol or a narcotic substance, impaired respiratory and cardiac activity due to complicated, acute somatic pathology.

Your doctor will tell you how to get out of a coma in such cases. Typically, therapeutic measures are reduced to maintaining the vital functions of the body.

The patient regains consciousness on his own or enters a vegetative state (minimal consciousness). The patient can fall asleep and wake up, swallow food, blink, but does not respond to speech at all, does not speak, and does not walk independently.

The duration of the vegetative state, like the coma itself, is difficult to predict. It can last for years and even a lifetime.

Features of carrying out in childhood

Psycho-emotional reactions of patients often complicate the treatment process and negatively affect recovery. Drug sedation as an alternative to local anesthesia is indicated for some types of dental treatment. Painful manipulations, stress, and unfamiliar surroundings negatively affect the child’s psycho-emotional status.

Usually in such cases, adequate doses of hypnotics (hypnotics) or anxiolytics (tranquilizers, psychotropic drugs that eliminate anxiety) are administered. The disadvantage of sedation is that children are unable to answer important questions during sleep that the doctor may have during treatment.

For reference. Deep medicated sleep is indicated in cases where a child is connected to a ventilator. The procedure of tracheal intubation (insertion of a breathing tube into the tracheal cavity) and the lack of speech contact cause discomfort and fear in pediatric patients, which is accompanied by an increase in the concentration of cortisol, a hormone involved in the development of stress reactions.

In parallel, reactions such as increased blood pressure, increased heart rate, and tachypnea (rapid, shallow breathing) occur. In these cases, sodium thiopental or Midazolam is usually used.

Is dental anesthesia safe during pregnancy?

Implantologist Mikhail Popov emphasizes that local anesthesia not only does not threaten the health of the fetus, but is also recommended for dental treatment, especially in the second and early third trimester of pregnancy. The anesthetic is absorbed into the blood in minute quantities and does not penetrate the placenta, so it will not affect the course of pregnancy and the condition of the fetus. Yuri Timonin adds that local anesthesia allows you to “turn off” a fairly large area of ​​the jaw associated with the blocked nerve for 1–1.5 hours. Moreover, the harm from it is always less than from the source of infection in the mouth.

Women should warn the dentist about pregnancy before starting treatment: this information will allow them to make a choice in favor of drugs without adrenaline, which are best suited for expectant mothers. It is worth postponing the solution of non-urgent dental problems at 35-40 weeks of pregnancy - but in case of urgent treatment, for example, for inflammatory processes and ulcers, local anesthesia is given throughout the entire pregnancy. As for sedation, this method is contraindicated in pregnant women: the effect of drugs on the fetus has not been fully studied.

How long does an induced coma last?

The duration of drug-induced sleep is different for each patient and depends on the initial severity of his condition and diagnosis. Since the likelihood of complications directly depends on the duration of the induced coma, doctors try to reduce its duration as much as possible.

In most cases, the patient is put into medicated sleep for several hours or days. Less commonly, a medically induced coma can last up to several months.

Epidural anesthesia: pros and cons

Thanks to epidural anesthesia, when an anesthetic is injected into the space along the spinal canal, contractions become less painful and labor is noticeably calmer - while the woman is conscious. With a good dose calculation, sensitivity disappears almost only in the pelvic area, but sensations in the legs and the ability to move them remain. This anesthesia is also called walking epidural, although in fact you won’t be able to walk - your legs will be weak, and sensors or catheters on different parts of the body will not allow you to go far. The psychological aspect is also important: when you know in advance that it won’t hurt, it’s much easier to relax and not worry.

According to Oleg Karmanov, with epidural anesthesia already performed, it is faster and easier to proceed to an emergency caesarean section, if necessary: ​​you will not have to waste time on pain relief. But you can’t always rely on epidural anesthesia; at a certain stage of labor it is already too late to perform it. The method has a number of contraindications, including intervertebral hernia and serious circulatory and coagulation disorders. Dangerous complications of epidural anesthesia are extremely rare.

Coma state

During a medically induced coma, the following occurs:

• slow breathing;
• decreased heart rate;
• reduction in blood and intracranial pressure;
• muscle relaxation;
• decrease in body temperature;
• slowing down metabolic processes in tissues;
• vasoconstriction;
• decreased kidney function;
• decrease in the amount of fluid in the body;
• decrease in cerebral blood flow rate.

Another indicative manifestation of drug-induced sleep is the patient’s lack of consciousness.

For reference. Breathing during an induced coma is supported by a ventilator.

Diagnosis for coma

It should be noted that coma can cause disability and even death.

A patient in an induced coma is maximally vulnerable to the effects of any negative factors. Therefore, his condition is constantly carefully monitored by medical personnel.

To monitor the effectiveness of treatment, the quality of maintaining medicated sleep and the state of vital signs, the following is used:

• electroencephalogram (allows you to constantly monitor the state of the patient’s cerebral cortex);
• CT and MRI to monitor the patient’s condition and make a further prognosis;
• electrocardiogram (monitoring the state of the patient’s cardiovascular system);
• cerebral angiography (allows for the most accurate assessment of the state of blood circulation in the brain);
• a ventricular catheter that allows you to measure intracranial pressure and the degree of oxygen saturation of the body;
• biochemical blood test, general blood test, assessment of blood oxygen saturation, assessment of acid-base balance and blood electrolyte levels.

For reference. Constant monitoring of the patient’s condition helps prevent the development of complications and promotes timely recovery from drug-induced sleep.

Why is an induced coma dangerous?

The most common complications of an induced coma are bedsores. In order to avoid their development, the patient’s relatives and medical personnel must periodically change the position in which the patient is, give him a gentle massage, and carefully monitor skin hygiene.

Attention. Due to muscle relaxation, lack of consciousness and impaired swallowing, an induced coma can be complicated by severe aspiration pneumonia associated with the reflux of gastric contents into the lungs.

It is also possible to develop:

• laryngeal stenosis and pulmonary edema (against the background of constant mechanical ventilation (artificial ventilation));
• acute cardiovascular failure;
• collapse;
• renal failure;
• infectious and inflammatory processes in internal organs;
• sepsis.

After the patient is brought out of a medically induced coma, there may be a temporary decrease in memory, impaired speech and motor activity, and lethargy.

The duration of the rehabilitation period in this case will depend on the duration of the induced coma and the severity of the resulting disorders.

For reference. It should be noted that during the first year after drug-induced sleep, approximately every 10 patient manages to return to normal life. In other cases, the period of complete recovery takes a longer period of time.

Possible complications

The probability of developing complications after an artificially induced coma is quite high, and is determined by its duration. Most often, patients develop:

• heart failure;
• heart failure;
• bedsores;
• blood flow disorders;
• sudden changes in blood pressure;
• renal failure;
• neurological disorders;
• infectious processes in the body.

A significant danger is posed by the gag reflex, as a result of which the contents of the stomach can enter the respiratory tract and cause breathing problems. Sometimes there are difficulties with emptying the bladder, which can provoke its rupture, or the development of peritonitis.

If the patient has a weakened respiratory system, complications such as inflammation, pulmonary edema, and tracheobronchitis are possible after recovery from a coma. It is possible that stenosis, pathological changes in the functioning of the gastrointestinal tract, fistulas in the lining of the esophagus,

Severe complications after emerging from a medically induced coma can first lead to clinical and then biological death of the patient.

How to be brought out of an induced coma

Bringing a patient out of an induced coma is an extremely complex procedure that requires special training. The administration of medications that support the patient's medicated sleep is stopped gradually.

Relatives of the patient need to understand that recovery from a coma and further rehabilitation can last many months.

The patient's consciousness is restored gradually, periods of delirium, memory impairment, speech impairment and motor activity are possible.

For reference. During rehabilitation, patients gradually learn to eat, get out of bed, and walk on their own. Restoring memory, speech and motor activity can take from several months to a year.

Forecast for recovery

The prognosis is always extremely serious. First of all, due to the fact that patients are put into an artificial coma only in the presence of severe pathologies.

The further prognosis for rehabilitation and recovery depends on the main diagnosis, the duration of the medically induced coma, the patient’s age, the presence of concomitant pathologies and complications.

Important. The longer the patient is in an induced coma, the longer the further recovery period and the lower the likelihood of full recovery.

The most optimistic prognosis is observed in patients who were put into a short-term medical coma - up to several hours. There is also a good prognosis for complete rehabilitation in patients who have been in a medical coma for up to several days.

METHOD OF LAST HOPE

“ECMO is the method of last hope for COVID-19 (and not only for this disease. - Ed.), ” writes a cardiac surgeon, head of the operating department of the Center for Cardiovascular Surgery of the Main Military Clinical Hospital named after. N.N.Burdenko Alexey Fedorov. And he explains: the ECMO (extracorporeal membrane oxygenation) device combines an artificial heart and an artificial lung.

This is a relatively small device with a set of hollow tubes called cannulas. The device has two main “units”: a pump and an oxygenator. The first methodically pumps the blood, the second saturates it with oxygen, Fedorov describes. In fact, life is maintained through mechanisms outside the body: the patient’s blood is driven through the apparatus, enriched with oxygen and returned back. To do this, cannulas are inserted into the vessels (into the veins and arteries or only into the veins, depending on medical indications), and the device itself works while located nearby.

The procedure for connecting and managing a patient on ECMO is extremely complex and requires high skill and long-term experience. We need a large team of specialists. “In a regular hospital, it is unreasonable to connect the device. The risk of error and fatal outcome is too high,” notes Alexey Fedorov. According to his calculations, in all of Russia today there are approximately 100 ECMO devices, which are located in specially created centers. One of these centers is equipped in the 52nd City Clinical Hospital of Moscow, where Marina Abrosimova (singer MakSim) has been staying for more than a month and a half. At the same time, about 5% of people with Covid, that is, approximately every twentieth, end up on mechanical ventilation and ECMO. What happens to the body connected to special equipment in intensive care - we talked about this with an experienced resuscitator working in the red zone of one of the Covid hospitals, Candidate of Medical Sciences Georgiy Arbolishvili .

Singer MakSim.

Photo: Evgenia GUSEVA