Coma
Coma is a special type of disturbance of consciousness that occurs due to damage to entire structures of the brain. The main manifestation of coma is the complete absence of human contact with the outside world.
The content of the article:
Causes of coma
Classification of coma
Symptoms of coma
Diagnosis of coma
Characteristic signs of coma
Coma Treatment
Prognosis for coma
Coma
The causes of this physiological condition can be very different, but they are all divided into:
metabolic (arising from poisoning of the body by metabolic products or chemicals);
organic (due to the destruction of certain areas of the brain).
As for external manifestations, the main symptomatology is considered to be unconsciousness and a complete lack of reaction to the outside world (the pupil of the eye does not react to external stimuli in any way).
The main diagnostic methods are CT and MRI, as well as laboratory tests. Treatment of this condition is aimed, first of all, at eliminating the cause that caused this pathological process.
Coma is such a deep pathological disorder of consciousness that it is impossible to bring the patient out of it even after intensive stimulation. A person in a coma always stays with his eyes closed, without opening or reacting to pain, sound, light, or a change in ambient temperature. This is the main distinguishing feature of coma.
Among other signs of coma:
presence (absence) of unconscious body movements;
preservation (extinction) of reflexes;
saving (absence) ability to breathe independently; in the absence of such ability, the patient is connected to an artificial respiration apparatus; the latter will depend on the cause of the patient falling into a coma, as well as on the degree of depression of the nervous system.
It should be said that it is not always with traumatic brain injuries that a person falls into a coma. Coma is a condition caused by damage to special areas of the brain responsible for wakefulness.
Causes of coma
Coma is not considered an independent pathology, in medicine it is defined as a severe complication of the central nervous system, which is based on damage to the nerve pathways.
As is known, the cerebral cortex is able to receive signals coming from the environment through the so-called reticular formation, which is directed through the entire brain. It will be a filter that systematizes and passes nerve impulses of various kinds. In case of damage to the cells responsible for the reticular formation, there is a complete loss of communication between the brain and the environment. The patient falls into a coma.
Damage to nerve fibers occurs both due to physical exposure and due to the influence of chemicals. Physical damage can even occur with strokes, traumatic brain injuries, brain hemorrhage and other injuries.
As for the chemicals that cause a comatose state, they include:
internal (products of metabolic processes formed as a result of pathologies of internal organs);
external (entering the body from the environment).
Internal damaging factors include: a decrease in the level of oxygen in the blood (which is also called hypoxia), low or elevated glucose levels, the presence of acetone bodies (which is often found in diabetes mellitus) or ammonia (in the case of severe liver diseases).
If we talk about external intoxication of the nervous system, then it happens in the case of an overdose of narcotic substances or the abuse of sleeping pills, as well as poisoning with neurotropic poisons. Interestingly, the external type of intoxication can also be caused by the action of toxins of a bacterial nature, which is often observed in the spread of infectious diseases.
The most common cause of coma will be a combination of signs of chemical and physical damage related to the reticular formation. This is expressed in a characteristic increase in intracranial pressure. The latter is often observed in the case of traumatic brain injuries or brain tumors.
Classification of coma
Usually, a coma is classified according to two criteria: depending on the cause that caused it, and the level of depression of consciousness.
Classification of coma depending on the cause that caused it:
traumatic (observed in the case of traumatic brain injuries);
epileptic (is a complication of an epileptic nature);
apoplexy (a consequence of a stroke);
meningial (as a result of the development of meningitis);
tumor (with volumetric neoplasms in the brain);
endocrine (manifested in the case of suppressed thyroid function);
toxic (in case of kidney failure, it may also be the result of liver diseases).
It should be said that this classification is rarely used in neurology, since it does not always express the real condition of the patient.
Most often in neurology, the classification of a comatose state is used, based on the severity of the violation of consciousness. This classification is called the Glazko scale. It is used to determine the severity of the disease, to prescribe further treatment and predict recovery. The basis of the Glazko scale is an analysis of three indicators: speech, the ability to move and open eyes. Depending on how strong the deviations are for each of the indications, the specialist puts an assessment in the form of points:
15 points corresponds to clear consciousness;
13-14 points — moderate degree of stun;
10-12 points indicate deep stunning;
8-9 points is a sopor;
from 7 and below points, a comatose state begins.
Another classification of coma speaks of its 5 degrees:
Precoma (pre-coma state);
Coma I (or stupor);
Coma II (or sopor);
Coma III (atonic degree);
Coma IV (extreme, extreme degree).
Symptoms of coma
The main symptoms, by the presence of which a comatose state is determined, are:
absence of any contact with the environment;
the absence of even minimal mental activity;
body temperature rise;
change in respiratory rate;
pressure spikes and changes in heart rate;
blueness or redness of the skin.
Let’s take a closer look at each of the symptoms.
Changes in body temperature can be caused by overheating of the body. Body temperature can rise up to 43 ° C, accompanied by dry skin. If the patient has been poisoned by alcohol or sleeping pills, then his condition is accompanied by a decrease in temperature to 34 C⁰.
As for the respiratory rate, slow breathing is characteristic in the case of coma, accompanied by hypothyroidism, that is, a low level of thyroid hormone release. Also, slow breathing can be a consequence of poisoning with a sleeping pill or narcotic (for example, a substance from the morphine group). If the coma is caused by bacterial intoxication or is a consequence of severe pneumonia, brain tumor, acidosis or diabetes mellitus, then deep breathing is inherent in the patient.
Changes in blood pressure and heart rate are also an important symptom of a comatose state. If the patient has bradycardia (in other words, a decrease in the number of heart contractions per unit of time), then we are talking about a coma that occurs as a result of acute cardiac pathology. An interesting fact is that with a combination of tachycardia (or an increase in the number of heart contractions) and high blood pressure, there is an increase in intracranial pressure.
Arterial hypertension is a symptom of a coma, which could occur on the background of a stroke. In the case of diabetes-based coma, a person is accompanied by low blood pressure, which is also a symptom of severe internal bleeding or even myocardial infarction.
A change in skin color from natural to dark red can be a sign of carbon monoxide poisoning. Cyanotic fingers or nasolabial triangle indicate a lack of oxygen in the blood (for example, in case of suffocation). A coma that has arisen due to a traumatic brain injury can also express itself with subcutaneous bruising from the nose or ears. In addition, bruises may be present under the eyes. If the skin is pale in color, then they talk about a coma caused by severe blood loss.
Another important criterion of a comatose state is the absence of contact with the environment. In the case of a sopor or with a mild coma, vocalization may be observed, that is, involuntarily making different sounds to patients. This sign is considered favorable, it indicates a successful outcome. The deeper the comatose state, the less the patient’s ability to make various sounds.
Other characteristic signs of a comatose state, indicating a successful outcome, are the ability of the patient to make grimaces, pull the upper and lower limbs, reacting to pain. All this is inherent in a mild form of coma.
Diagnosis of coma
Diagnosis of a comatose state involves performing 2 tasks: determining the cause that caused this condition, and conducting direct diagnosis and differential diagnosis in order to exclude other coma-like conditions.
To determine the causes of coma, a survey conducted among the relatives of the patient or people who witnessed this case will help. Conducting such a survey, they clarify whether the patient had previously had complaints from the cardiovascular or endocrine systems. Witnesses are being questioned on whether there were blisters or other packages of medicines next to the patient.
Of great importance in the diagnosis of coma is the ability to determine the rate of developing symptoms and the age of the patient himself. If a coma is diagnosed to a young person, then often its cause is drug poisoning or an overdose of sleeping pills. For older people, coma is characteristic in the presence of cardiovascular diseases, heart attack or stroke.
Upon examination of the patient, it is possible to presumably determine the cause contributing to the onset of a comatose state. The presence of a coma is determined by the following signs:
pulse rate;
blood pressure level;
presence or absence of respiratory movements;
characteristic bruises;
bad breath;
body temperature.
Characteristic signs of coma
Doctors should also pay attention to the position of the patient’s body. Usually, the appearance of a patient with his head thrown back and increased muscle tone indicates the beginning of an irritated state of the cerebral membrane. The latter is characteristic of meningitis or cerebral hemorrhage.
Convulsions in the body or in individual muscles indicate that the cause of the coma was most likely an epileptic seizure or a state of eclampsia (manifested in pregnant women).
Mild paralysis of the upper or lower extremities clearly indicates a stroke. In the case of the complete absence of any reflexes, they speak of a strong, deep damage to a large type of cortical surface or spinal cord injury.
The most important thing in the differential diagnosis of coma is to establish the patient’s ability to open his eyes or respond to sound (pain, light) irritation. If the reaction to a painful or light stimulus manifests itself as an arbitrary opening of the eyes, then there is no question of a coma in the patient. And, on the contrary, if the patient, despite the efforts and efforts of doctors, does not react and does not open his eyes, then they talk about a comatose state present.
The study of the reaction of the pupils in case of suspicion of coma will be mandatory. The features of the pupils will help determine the estimated location of the damage in the brain, as well as determine the cause that caused this condition. It is the “testing” of the pupillary reflex that is one of the most reliable diagnostic studies, which is able to give almost 100% prognosis. If the pupils are narrow and do not react to light, then this indicates a possible poisoning of the patient with alcohol or drugs. If the patient’s pupils are of different diameters, then this indicates an increasing cranial pressure. Wide pupils are a sign of an affected condition of the middle part of the brain. If the diameter of the two pupils dilates the same way, and there is no reaction to light completely, then they talk about an exorbitant type of coma, which is considered a very bad sign, which most often indicates a possible imminent death of the brain.
Modern medicine has made a breakthrough in instrumental diagnostics, making it possible to correctly identify the causes that contributed to the comatose state. It is also possible to correctly identify any other type of violation of consciousness. With the help of CT or MRI, it is possible to determine with the greatest accuracy the structural changes that have occurred in the brain, to determine the presence or absence of tumors of a volumetric type, as well as to establish the characteristic signs of increased intracranial pressure. Depending on what the pictures show, the doctor decides on further therapy, which can be conservative or operative.
If there are no opportunities and conditions to carry out CT and MRI diagnostics to the patient, then practice radiography of the craniocerebral box (or take a picture of the spinal column). Taking a biochemical blood test will help characterize the metabolic process of coma. In some cases, an analysis can be carried out to determine the level of glucose and urea present in the blood. Separately, an analysis is carried out for the presence of ammonia in the blood. In addition, it will be important to determine the percentage of gases and electrolytes in the blood.
If CT and MRI do not reveal a clear violation on the part of the central nervous system, then the reasons that could put the patient into a coma disappear by themselves. Next, doctors examine the blood for the presence of hormones such as insulin, thyroid and adrenal hormones. In addition, a separate analysis is carried out that can determine the presence of toxic substances (sleeping pills, drugs, etc.) in the blood. This is a bacterial blood culture.
EEG is considered one of the important diagnostic studies that can differentiate coma from other types of disorders of consciousness. To carry it out, an electrical type of brain potential is registered, which helps to determine who, distinguishing it from a brain tumor, drug poisoning or hemorrhage.
Coma Treatment
Treatment of a comatose state should take place in two directions: on the one hand, the maintenance of vital functions of the human body in order to prevent possible brain death; on the other hand, treatment is aimed at eliminating the underlying cause that contributed to the development of the comatose state.
The first path aimed at maintaining vital functions usually begins in an ambulance. First aid is provided to all patients without exception, long before the results of the tests are received.
This implies performing procedures aimed at maintaining normal airway patency:
correction of a sunken language;
cleansing of the oral and nasal cavities from the vomit present in them;
application of an oxygen mask (if required);
the use of a breathing tube (in the most severe cases).
In addition, it is necessary to establish normal blood circulation by administering antiarrhythmic drugs that will help normalize blood pressure. The patient can also be given a heart massage.
In the intensive care unit, the patient can be connected to an artificial respiration machine, which is done in extremely severe comatose states. In the presence of convulsive characteristics, the introduction of glucose into the blood and normalization of body temperature will be mandatory. To do this, the patient is covered with a warm blanket or wrapped around with hot water bottles. In case of suspected poisoning of the patient with narcotic or hypnotic substances, the stomach is washed.
The second stage of treatment involves performing a thorough examination using highly qualified tactics, which will depend on the root cause that caused the comatose state. If such a cause is a brain tumor or a hematoma that has arisen, then the operation should be immediate. If the patient has been diagnosed with a diabetic coma, then mandatory monitoring of sugar and insulin in the patient’s blood is prescribed. Hemodialysis will be prescribed if the cause of the coma is kidney failure.
Prognosis for coma
What the outcome of this condition will be depends on the degree of brain damage, as well as on the nature of the causes that caused it. In practice, the chances of coming out of a coma are high in those patients who were in a light comatose state. So, for example, in the case of a precoma or coma of the first degree, the outcome of the disease will most often be favorable with the full recovery of the patient. In the case of grade II and III coma, the favorable outcome is already in doubt: the probability of recovering or not coming out of the coma is the same. The most unfavorable prognosis is in a coma of the IV degree, which in almost all cases ends in a fatal outcome of the patient.
Among the main preventive actions of a comatose state is timely diagnosis, the correct appointment of treatment, and, if necessary, correction of pathological conditions, its timely implementation.
