Signs of clinical death

Since the development and implementation of resuscitative techniques, the main symptom of clinical death - cardiac arrest - has been called not simply death, but "clinical death", to reflect the possibility of its resumption.

Clinical death is a medical term for determining the state at which respiratory arrest and cessation of the circulatory process are observed . That is, the most important physiological conditions for maintaining the biological life of the human body are violated. This happens when the heart stops beating in the usual rhythm and all external signs of the vital activity of the organism disappear. Before the advent of cardiopulmonary resuscitation, defibrillation, epinephrine injections and other types of cardiac restoration, the loss of vital functions related to blood circulation was considered the official definition of the end of life.

[1], [2], [3], [4], [5]

The first signs of clinical death

The starting point of the transition from life and death and the main symptom of clinical death is the cardiac arrest syndrome. This syndrome develops as a sudden cessation of the heart with the loss of its bioelectrical activity - ventricular asystole. Either this occurs as a complete stoppage of blood circulation due to ventricular fibrillation, when their contractions lose synchronism and the discharge of blood into the bloodstream is disturbed. According to the statistics of resuscitation physicians, the cessation of heart function in almost 93% of cases is recorded as a consequence of the fibrillation of its ventricles.

In this case, in a very short time, the remaining signs of sudden clinical death appear:

• complete loss of consciousness (terminal condition of coma occurs 10-15 seconds after cardiac arrest);
• muscle cramps (possible within 15-20 seconds after losing consciousness);
• absence of pulse (pulse not probed on carotid arteries);
• Atonal breath (with convulsive breaths), which after a half or two minutes passes into apnea - a complete stop of breathing;
• dilated pupils and loss of their reaction to light as a sign of impaired blood circulation of the brain (after 2 minutes from the moment of cardiac arrest);
• pallor or cyanosis (cyanosis) of the skin (due to a sharp decrease in the oxygen content in the blood).

Clinical signs of brain death

With the onset of clinical death, brain cells continue to live a maximum of 5 minutes. The brain is exposed to ischemic damage much faster than any other human organ. In conditions of total hypoxia, the neurophysiological state of the dying brain is characterized by necrosis of cerebral neurons and irreversible cessation of brain activity.

As experts note, clinical signs of brain death, which could be detected by physical examination of the victim or a patient in a state of clinical death, are absent.

The death of brain cells in clinical conditions is recorded after the patient leaves this state - with a working heart and breathing with the aid of an artificial lung ventilation device. Death of the brain, which is equivalent to the actual death of a person, can be a consequence of a traumatic brain injury, a disease (hemorrhage, swelling) or surgical intervention. This is the primary damage to the brain. And with cardiac arrest and clinical death, the damage is secondary.

In both cases, the clinical signs of brain death, according to existing medical standards, have the appearance of a set of mandatory clinical criteria, on the basis of which a diagnosis can be made-the death of the brain. These attributes are six:

• the patient is in a state of coma, that is, there is a long-term stable absence of consciousness;
• the patient determines the total loss of normal tone of the muscles of the skeleton and internal organs (muscle atony);
• in the trigeminal zone - at the exit points of the branches of the trigeminal nerve located on the face - all reflexes, including reaction to pain, are absent;
• the reaction of the pupils of the patient to direct bright light is absent, the eyeballs are in a stationary state;
• the absence of an unconditioned reflex of closing the eye gap in response to irritation of the cornea (corneal reflex);
• revealed the absence of oculocephalic reflexes, that is, the patient's eyes remain motionless when the doctor turns his head.

The clinical signs of cerebral death are obviously related to the fact that under conditions of acute oxygen starvation in nerve cells there is a sharp decrease in the synthesis of protein and nucleic acids, which leads to an irreversible loss of the ability of neurons to carry out nerve impulses and death of brain cells. Researchers also link the mechanism of brain failure after clinical death with its reperfusion injuries that occur after the restoration of blood circulation.

[6], [7], [8], [9]

Signs of biological and clinical death

In the absence of resuscitation, as well as in case of its failure, doctors state biological death - the final and irrevocable stop of all biochemical processes at the cellular level, as well as all the physiological functions of the internal organs.

Signs of biological and clinical death agree that the so-called set of signs of biological death include - as in the case of clinical death - cardiac arrest, lack of breathing, pulse and reflex reactions to all stimuli. And also pallor (or cyanosis) of the skin and dilated pupils with no response to light.

In addition, among the set of signs of biological death are:

• absence of cardiac activity at room temperature of air - longer than 30 minutes;
• drying of the cornea of the eyes (the iris loses color, the pupil becomes cloudy);
• the sign of the "cat's pupil" (when the eyeball contracts at least 60 minutes after death, the pupil acquires the appearance of a narrow crack);
• gradually the body temperature drops (approximately 1 ^o C every hour);

To the number of reliable signs of biological death, physicians refer to the appearance of cadaveric spots (2-4 hours after the cardiac arrest) and rigor mortis (begins 2-4 hours after the circulatory arrest, the maximum occurs approximately 24 hours after cessation of the heart).

Determination of signs of clinical death

Signs of clinical death are usually determined on the basis of lack of pulse and respiration, loss of consciousness and reaction of pupils.

The pulse is palpated only on the carotid artery, which is located on the side of the neck - in the deepening between the big neck muscle and the windpipe. If there is no pulse, then there is no circulation.

The presence or absence of breath is tested in several ways. First of all, visually fixed movements of the chest - raising and lowering with inspiration-exhalation, as well as by noise of breathing when applying the ear to the human chest. Conduct a breath test on the movement of the exhaled air, which can be felt when the cheek approaches the victim's mouth. Breathing can be controlled if a mirror, a glass of glasses or a dial of a wrist watch are brought to the lips of a person. However, doctors advise in extreme situations not to spend precious seconds on it.

The definition of such a symptom of clinical death as an unconscious state is carried out in two parameters: total immobility of a person and absence of reaction to any external stimuli. And the reaction of the pupils is defined as follows: the upper eyelid of the person should be raised; notice the size of the pupil (it is enlarged); the eyelid should be lowered and immediately raised again. The loss of reaction to light will be evidenced by the fact that after repeated lifting of the eyelid the pupil did not narrow.

Given that the absolute signs of clinical death are expressed in the fact that a person does not have a pulse, and he does not breathe, the absence of other signs is not taken into account, and without delay begins resuscitation. Otherwise, 3-4 minutes after cardiac arrest and cessation of breathing, the inevitable result is a biological death. It comes when the cells of the brain die from lack of oxygen.

[10], [11], [12],

First aid for signs of clinical death

First aid for signs of clinical death begins with an emergency call and a check of the pulse and breath of a person who has lost consciousness. In their absence - before the arrival of doctors - you need to conduct cardiopulmonary resuscitation (CPR).

The sequence of CPR is 30 compressions on the sternum (indirect heart massage) and 2 artificial mouth-to-mouth inhalations.

How to do cardiopulmonary resuscitation if there are signs of clinical death:

• the victim is put on his back, his head is unbent, and his chin is raised upward;
• Conductive CPR should kneel to the left of the victim, palms of both hands straightened in elbows, put on the central part of the sternum (but not on the xiphoid process);
• with an effort rhythmically (with a frequency of at least 100 strokes per minute) to press on the chest to a depth of about 4-6 cm, with the victim's breast should return to its original position, the number of strokes of the cardiac retreatment by chest compressions is 30;
• open the victim's mouth, clasp his nostrils with his fingers, inhale, bend and exhale the air in his mouth. The number of artificial breaths - 2.

The whole cycle of CPR should be repeated at least five times.

Signs of clinical death - cardiac arrest and lack of breathing - require immediate and decisive action. According to the World Health Organization, in nine cases, cardiac arrest of ten people dies before the arrival of a team of doctors - due to the lack of first-aid first aid. The first aid at signs of clinical death, that is an urgent carrying out of cardiopulmonary resuscitation, doubles the chance of a person to survive.

[13], [14], [15], [16], [17]