Artificial coma

An artificial coma, from the point of view of clinical medicine, is a temporary immersion of the patient in the unconscious state, in which there is a deep inhibition of the activity of the cortex and subcortex of the brain and a complete disconnection of all reflex functions.

[1], [2]

Causes of the artificial coma

An artificial coma is an extreme measure. To such extent, they resort only when doctors see no other way to protect the patient's body from the occurrence of irreversible brain changes that threaten his life. These include compression effects on brain tissue and their edema, as well as hemorrhages or bleeding that accompany severe craniocerebral trauma or cerebral vascular disease.

In addition, an artificial coma can replace general anesthesia in cases of urgent urgent operations of large volume or in complex surgical interventions directly on the brain.

[3], [4]

Symptoms of the artificial coma

Why enter into an artificial coma? To slow the metabolism of brain tissue and reduce the intensity of cerebral blood flow. As a result, the vessels of the brain narrow, and intracranial pressure drops. In this condition, you can remove the swelling of the brain tissue and avoid their necrosis (necrosis).

Introduction to the state of artificial coma is carried out in intensive care units by intensive administration of a controlled dose of special drugs. Most often these are barbiturates or their derivatives, which depress the central nervous system. For immersion in medicamentous patients, high doses are selected, corresponding to the stage of surgical anesthesia.

After the onset of the drug, symptoms of an artificial coma appear:

• complete relaxation of muscles and immobilization;
• the absence of all reflexes (deep unconsciousness);
• a drop in body temperature;
• lowering blood pressure;
• a significant decrease in heart rate (heart rate);
• retardation of atrioventricular (atrioventricular) conduction;
• blocking the activity of the gastrointestinal tract.

It should be noted that in order to compensate for the oxygen deficiency that the brain would have to experience due to a decrease in the heart rate, patients are immediately connected to the ventilator (IVL). That is, the respiratory mixture is forced into the lungs from the compressed dried air and oxygen. As a result, the blood is saturated with oxygen, and carbon dioxide from the lungs is removed.

During the patient's stay in a state of artificial coma, the indices of all his vital functions are fixed by special equipment and are constantly monitored by an anesthesiologist and intensive care physicians in the intensive care unit.

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Complications and consequences

Neurosurgeons note that the effects of an artificial coma depend on the cause, which caused the need to introduce the patient into this state.

But many consequences of an artificial coma are due to the fact that prolonged artificial ventilation (IVL) has a lot of side effects. The main complications affect the respiratory system and are expressed in tracheobronchitis, pneumonia, obstruction of the bronchi by adhesions, pneumothorax, constrictions of the trachea, bedsores of its mucosa, fistula in the walls of the trachea and esophagus.

In addition, the effects of an artificial coma are expressed in violations of blood flow through the vessels (hemodynamics), pathological changes in the long-term gastrointestinal tract, renal insufficiency, etc. Numerous cases of neurologic disorders in patients after leaving the medically induced coma are also documented.

[6], [7]

Diagnostics of the artificial coma

To date, the diagnosis of an artificial coma is carried out using a whole set of methods.

A mandatory method for determining the functional parameters of the brain is monitoring the activity of the cerebral cortex by electroencephalography. Actually, the artificial coma itself is possible only under the condition of constant monitoring of the electroencephalograph, to which the patient is permanently connected.

The method of measuring cerebral blood flow (cerebral hemodynamics) has such methods of evaluation of microcirculation as local laser fluometry (with the introduction of a sensor into the brain tissue) and a radioisotope measurement of cerebral circulation.

The state of the brain of the patient in a state of artificial coma is carried out by measuring intracranial pressure in the ventricles of the brain - with the installation of a ventricular catheter in them. The method of assessing metabolism in the brain tissues allows you to determine the degree of oxygen saturation and the content of certain components in the venous blood flowing from the brain - by periodically performing a blood test from the jugular vein.

Also in the diagnosis of an artificial coma, visualization methods are used, including computed tomography (CT), magnetic resonance imaging (MRI), and positron emission computer tomography (PECT). Together with the methods of measuring the cerebral blood flow, CT and MRI are used in neuroreanimatology in determining the prognosis of the outcome of an artificial coma.

Experts argue as to when to consider the state of a coma hopeless. In the clinical practice of many Western countries, patients with traumatic brain damage who are permanently in a vegetative state for more than six months are considered hopeless. At the same time, such diagnosis is established on the basis of identification of the cause of the syndrome, clinical assessment of the patient's condition and duration of stay in a coma.

[8], [9], [10],

Treatment of the artificial coma

In this context, the phrase "artificial coma treatment" seems more appropriate to us, since an artificial coma is not a disease, but a purposeful clinical action for medical reasons.

Such indications are caused by an artificial coma after surgery, an artificial coma with pneumonia or an artificial coma in stroke.

So, an artificial coma after the operation was applied against the famous German race driver Michael Schumacher, after he, skiing in the Alps, in late December 2013, received a severe craniocerebral injury. First, he was given two complicated neurosurgical operations, and then put into a state of artificial coma.

A month later the doctors of the clinic in Grenoble began to withdraw from the artificial coma - by reducing the dose of drugs administered. However, the athlete still, almost half a year, is in a coma.

And on March 18, 2014, the 50-year-old brother of the Belgian monarch, Prince Laurent, went to hospital with signs of acute pneumonia. For more effective treatment, physicians put him in intensive care and put him in a state of artificial coma with pneumonia. After a two-week coma, during which treatment was performed, he was withdrawn from the coma in a satisfactory condition.

Among the causes of artificial coma as a way to reduce the risk of severe consequences of cerebral circulation disorders is a brain stroke (ischemic or hemorrhagic). With this disease, a focal brain lesion occurs, the irreversible effects of which appear in just a few hours. To avoid this, as well as to carry out the removal of thrombus, the patient can enter into an artificial coma. However, this method of treatment is rather risky.

The duration of an artificial coma (not caused by a preliminary surgical intervention) is related to the nature and severity of the injury or illness and can range from several days to several months. And the withdrawal from an artificial coma begins only after the disappearance of the consequences of trauma or signs of disease - based on a comprehensive examination of the patient.

Forecast

The most disappointing prognosis of an artificial coma is observed with subarachnoid hemorrhage (which occurs due to rupture of arterial aneurysm or craniocerebral trauma) and stroke. And the longer a person remains in an artificial coma, the better his chances of recovering.

In the UK, a study was conducted according to which the effects of an artificial coma lasting up to one year look like this: 63% of patients died or left coma with irreversible cognitive impairment (at "plant level"), 27% after getting out of a coma received a severe or moderate disability and only 10% of patients have restored a fairly good condition. This study made it possible to identify four important clinical features that help determine the prognosis of an artificial coma: bradycardia, coma depth, duration, and clinical signs such as the results of stem somatosensory brain reflexes on the electroencephalogram, blood glucose level, biochemical parameters of cerebrospinal fluid,

[11], [12]