Signs of clinical death

Since the development and implementation of resuscitation techniques, the main sign of clinical death - cardiac arrest - has come to be called not just death, but "clinical death" to reflect the possibility of resuming its work.

Clinical death is a medical term used to define a condition in which breathing and blood circulation cease. That is, the most important physiological conditions for maintaining the biological life of the human body are disrupted. This occurs when the heart stops beating at a normal rhythm and all external signs of the body's vital activity disappear. Before the advent of cardiopulmonary resuscitation, defibrillation, adrenaline injections, and other types of cardiac resuscitation, the loss of vital functions associated with blood circulation was considered the official definition of the end of life.

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The first signs of clinical death

The starting point of the transition from life to death and the main sign of clinical death is the cardiac arrest syndrome. This syndrome develops as a sudden cessation of the heart's work with the loss of its bioelectrical activity - ventricular asystole. Or it occurs as a complete cessation of blood circulation due to ventricular fibrillation, when their contractions lose synchronicity and the ejection of blood into the bloodstream is disrupted. According to statistics from resuscitation doctors, the cessation of the heart's work in almost 93% of cases is recorded as a consequence of ventricular fibrillation.

At the same time, other signs of sudden clinical death appear in an extremely short time:

• complete loss of consciousness (the terminal state of coma occurs 10-15 seconds after cardiac arrest);
• muscle cramps (possible 15-20 seconds after loss of consciousness);
• absence of pulse (pulse is not palpable in the carotid arteries);
• atonal breathing (with convulsive inhalations), which after one and a half to two minutes turns into apnea - a complete cessation of breathing;
• dilation of the pupils and loss of their reaction to light as a sign of impaired cerebral circulation (2 minutes after cardiac arrest);
• paleness or bluishness (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 for a maximum of 5 minutes. The brain is exposed to ischemic damage much faster than any other human organ. Under 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, there are no clinical signs of brain death that could be detected during a physical examination of a victim or patient in a state of clinical death.

The death of brain cells in clinical conditions is registered after the patient is brought out of this state - with a beating heart and breathing with the help of an artificial lung ventilation apparatus. Brain death, which is equivalent to the actual death of a person, can be a consequence of a craniocerebral injury, disease (hemorrhage, tumor) or surgical intervention. These are primary brain injuries. And in the case of cardiac arrest and clinical death, the damage is secondary.

In both cases, the clinical signs of brain death, according to existing medical standards, take the form of a set of mandatory clinical criteria, on the basis of which a diagnosis of brain death can be established. There are six of these signs:

• the patient is in a coma, that is, there is a long-term stable absence of consciousness;
• the patient is diagnosed with a complete loss of normal tone of the skeletal muscles 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 are absent, including the reaction to pain;
• the patient's pupils do not react to direct bright light, the eyeballs are motionless;
• the absence of an unconditional reflex of closing the eye slit in response to irritation of the cornea of the eye (corneal reflex) was established;
• The absence of oculocephalic reflexes was revealed, that is, the patient's eyes remain motionless when the doctor turns his head.

Clinical signs of brain death are obviously related to the fact that under conditions of acute oxygen starvation, there is a sharp decrease in the synthesis of proteins and nucleic acids in nerve cells, which leads to an irreversible loss of the ability of neurons to conduct nerve impulses and the death of brain cells. Researchers also associate the mechanism of brain failure after clinical death with its reperfusion damage, which occurs after the restoration of blood circulation.

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Signs of biological and clinical death

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

Signs of biological and clinical death agree in that the so-called set of signs of biological death include - as in clinical death - cardiac arrest, absence of breathing, pulse and reflex reactions to all stimuli. As well as paleness (or cyanosis) of the skin and dilated pupils with no reaction to light.

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

• absence of cardiac activity at room temperature - longer than 30 minutes;
• drying of the cornea of the eye (the iris loses color, the pupil becomes cloudy);
• the "cat's pupil" sign (when the eyeball is compressed no less than 60 minutes after death, the pupil takes the form of a narrow slit);
• gradually the body temperature drops (by approximately 1 ^o C every hour);

Doctors consider the appearance of cadaveric spots (2-4 hours after the heart stops) and rigor mortis (begins 2-4 hours after the blood circulation stops, the maximum is observed approximately 24 hours after the heart stops) to be reliable signs of biological death.

Determination of signs of clinical death

Signs of clinical death are usually determined based on the absence of pulse and breathing, loss of consciousness and pupillary response.

The pulse is felt only on the carotid artery, which is located on the side of the neck - in the depression between the large muscle of the neck and the windpipe. If there is no pulse, then there is no blood circulation.

The presence or absence of breathing is checked in several ways. First of all, by visually recorded movements of the chest - rising and falling when inhaling and exhaling, as well as by the noise of breathing when putting your ear to the person's chest. Breathing is checked by the movement of exhaled air, which can be felt when bringing the cheek to the victim's mouth. Breathing can be monitored by holding a mirror, glasses or a watch face to the person's lips. However, doctors advise not to waste precious seconds on this in extreme situations.

Determination of such a sign of clinical death as unconsciousness is carried out by two parameters - complete immobility of a person and the absence of a reaction to any external stimuli. And the reaction of the pupils is determined as follows: the upper eyelid of a person must be raised; note the size of the pupil (it is dilated); the eyelid is lowered and immediately raised again. The loss of reaction to light will be indicated by the fact that after repeated lifting of the eyelid the pupil does not constrict.

Considering that the absolute signs of clinical death are expressed in the fact that a person has no pulse and is not breathing, the absence of other signs is not taken into account, and resuscitation is started without delay. Otherwise, 3-4 minutes after the heart stops and breathing stops, the inevitable result follows - biological death. It occurs when brain cells die from lack of oxygen.

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First aid for signs of clinical death

Providing first aid for signs of clinical death begins with calling an ambulance and checking the pulse and breathing of the person who has lost consciousness. If they are absent - until the doctors arrive - cardiopulmonary resuscitation (CPR) must be performed.

The CPR sequence is 30 chest compressions (indirect heart massage) and 2 mouth-to-mouth rescue breaths.

How to perform cardiopulmonary resuscitation if signs of clinical death are detected:

• the victim is placed on his back, his head is straightened and his chin is lifted upward;
• The person performing CPR should kneel to the left of the victim, with the palms of both hands, straightened at the elbows, placed on the central part of the sternum (but not on the xiphoid process);
• with force and rhythm (at a frequency of at least 100 presses per minute) press on the chest to a depth of approximately 4-6 cm, and the victim's sternum should return to its original position, the number of presses of cardiac resuscitation with chest compressions is 30;
• Open the victim's mouth, pinch his nostrils with your fingers, inhale, bend over and exhale air into his mouth. Number of artificial breaths - 2.

The entire CPR cycle should be repeated at least five times.

Signs of clinical death - cardiac arrest and no breathing - require immediate and decisive action. According to the World Health Organization, in nine cases of cardiac arrest out of ten people die before the arrival of a medical team - due to the lack of first aid. First aid for signs of clinical death, that is, immediate cardiopulmonary resuscitation, doubles a person's chance of survival.

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