Signs of clinical and biological death of a person. Early signs of biological death

Biological death

Biological death(or true death) represents an irreversible cessation of physiological processes in cells and tissues. See Death. Irreversible cessation usually means “irreversible within the framework of modern medical technologies” cessation of processes. Over time, medicine’s ability to resuscitate dead patients changes, as a result of which the borderline of death is pushed into the future. From the point of view of scientists who support cryonics and nanomedicine, most people who are dying now can be revived in the future if the structure of their brain is preserved now.

Early signs of biological death include:

Lack of eye response to irritation (pressure)
Clouding of the cornea, formation of desiccation triangles (Larche's spots).
The appearance of the “cat’s eye” symptom: with lateral compression of the eyeball, the pupil transforms into a vertical fusiform slit, similar to a cat’s pupil.

Subsequently, cadaveric spots are found localized in sloping areas of the body, then rigor mortis occurs, then cadaveric relaxation, cadaveric decomposition. Rigor mortis and cadaveric decomposition usually begin in the muscles of the face and upper extremities. The time of appearance and duration of these signs depend on the initial background, temperature and humidity of the environment, and the reasons for the development of irreversible changes in the body.

The biological death of a subject does not mean the immediate biological death of the tissues and organs that make up his body. The time until death of the tissues that make up the human body is mainly determined by their ability to survive conditions of hypoxia and anoxia. This ability is different for different tissues and organs. The shortest life time under anoxic conditions is observed in brain tissue, more precisely, in the cerebral cortex and subcortical structures. The stem sections and spinal cord have greater resistance, or rather resistance to anoxia. Other tissues of the human body have this property to a more pronounced extent. Thus, the heart retains its viability for 1.5-2 hours after the onset of biological death. Kidneys, liver and some other organs remain viable for up to 3-4 hours. Muscle tissue, skin and some other tissues may well be viable up to 5-6 hours after the onset of biological death. Bone tissue, being the most inert tissue of the human body, retains its vitality for up to several days. Associated with the phenomenon of survivability of organs and tissues of the human body is the possibility of transplanting them, and the earlier the organs are removed for transplantation after the onset of biological death, the more viable they are, the greater the likelihood of their successful further functioning in another organism.

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A living organism does not die simultaneously with the cessation of breathing and cessation of cardiac activity, therefore, even after they stop, the body continues to live for some time. This time is determined by the brain’s ability to survive without oxygen supplied to it; it lasts 4–6 minutes, on average 5 minutes. This period, when all the extinct vital processes of the body are still reversible, is called clinical death. Clinical death can be caused by heavy bleeding, electrical trauma, drowning, reflex cardiac arrest, acute poisoning, etc.

Signs of clinical death:

1) absence of pulse in the carotid or femoral artery; 2) lack of breathing; 3) loss of consciousness; 4) wide pupils and their lack of reaction to light.

Therefore, first of all, it is necessary to determine the presence of blood circulation and breathing in the patient or victim.

Determination of signs of clinical death:

1. Absence of pulse in the carotid artery is the main sign of circulatory arrest;

2. Lack of breathing can be checked by visible movements of the chest during inhalation and exhalation, or by placing your ear to the chest, hearing the sound of breathing, feeling (the movement of air during exhalation is felt by the cheek), and also by bringing a mirror, a piece of glass or a watch glass, or a cotton swab to your lips or thread, holding them with tweezers. But it is precisely on the determination of this characteristic that one should not waste time, since the methods are not perfect and unreliable, and most importantly, they require a lot of precious time for their determination;

3. Signs of loss of consciousness are a lack of reaction to what is happening, to sound and pain stimuli;

4. The victim’s upper eyelid is raised and the size of the pupil is determined visually, the eyelid lowers and immediately rises again. If the pupil remains wide and does not narrow after lifting the eyelid again, then we can assume that there is no reaction to light.

If one of the first two of the 4 signs of clinical death is determined, then you need to immediately begin resuscitation. Since only timely resuscitation (within 3–4 minutes after cardiac arrest) can bring the victim back to life. Resuscitation is not performed only in the case of biological (irreversible) death, when irreversible changes occur in the tissues of the brain and many organs.

Signs of biological death:

1) drying of the cornea; 2) the “cat’s pupil” phenomenon; 3) decrease in temperature;. 4) body cadaveric spots; 5) rigor mortis

Determination of signs of biological death:

1. Signs of drying out of the cornea are the loss of the iris of its original color, the eye appears to be covered with a whitish film - a “herring shine”, and the pupil becomes cloudy.

2. The thumb and forefinger squeeze the eyeball; if the person is dead, then his pupil will change shape and turn into a narrow slit - a “cat’s pupil.” This cannot be done in a living person. If these 2 signs appear, this means that the person died at least an hour ago.

3. Body temperature drops gradually, by about 1 degree Celsius every hour after death. Therefore, based on these signs, death can only be confirmed after 2–4 hours or later.

4. Purple cadaveric spots appear on the underlying parts of the corpse. If he lies on his back, then they are identified on the head behind the ears, on the back of the shoulders and hips, on the back and buttocks.

5. Rigor mortis is a post-mortem contraction of skeletal muscles “from top to bottom”, i.e. face – neck – upper limbs – torso – lower limbs.

Full development of signs occurs within 24 hours after death.

The body and signs of biological death

However, the biological death of a specific person does not lead to the simultaneous biological death of all organs and tissues of the body. The lifespan of body tissues depends on their ability to survive hypoxia and anoxia, and this time and ability differ for different tissues. The worst tissues that tolerate anoxia are the brain tissues that die first. The spinal cord and stem sections resist longer and have greater resistance to anoxia. The remaining tissues of the human body can resist lethal effects even more strongly. In particular, it persists for another one and a half to two hours after recording biological death.

A number of organs, for example, kidneys and liver, can “live” up to four hours, and skin, muscle tissue and some tissues are quite viable up to five to six hours after biological death is declared. The most inert tissue is one that is viable for several more days. This property of organs and tissues of the body is used in organ transplantation. The sooner after the onset of biological death organs are removed for transplantation, the more viable they are and the higher the likelihood of their successful engraftment in another organism.

Clinical death

Biological death follows clinical death and there is the so-called “brain or social death”, a similar diagnosis arose in medicine thanks to the successful development of resuscitation. In some cases, cases were recorded where, during resuscitation, it was possible to restore the function of the cardiovascular system in people who were in a state of clinical death for more than six minutes, but by this time in these patients irreversible changes in the brain had already occurred. Their breathing was supported by mechanical ventilation, but brain death meant the death of the individual and the person turned into only a “cardiopulmonary” biological mechanism.

Man, like every living organism on Earth, begins his journey with birth and inevitably ends with death. This is a normal biological process. This is the law of nature. You can extend life, but it is impossible to make it eternal. People dream, create a lot of theories, offer different ideas about eternal life. Unfortunately, so far they are unjustified. And it’s especially offensive when life is cut short not because of old age, but because of illness (see) or an accident. Clinical and biological death: what do they look like? And why doesn’t life always win?

The concept of clinical and biological death

When all the vital functions of the body cease to function, death occurs. But a person, as a rule, does not die immediately. He goes through several stages before completely saying goodbye to life. The dying process itself consists of 2 phases - clinical and biological death (see).

Signs of clinical and biological death give us the opportunity to consider how a person dies and, possibly, save him. Knowing the features and first symptoms of clinical death, as well as early signs of biological death, you can accurately determine the person’s condition and begin resuscitation.

Clinical death is considered a reversible process. This is the intermediate moment between a living organism and an already dead one. It is characterized by cessation of breathing and cardiac arrest and ends with physiological processes in the cerebral cortex, which are considered irreversible. The maximum duration of this period is 4-6 minutes. At low ambient temperatures, the time for reversible changes doubles.

Important! Having discovered that there is no pulse in the carotid artery, immediately begin resuscitation without wasting a minute. You need to remember how it is carried out. Sometimes situations arise when someone's life is in your hands.

Biological death is an irreversible process. Without access to oxygen and nutrients, the cells of various organs die, and it is not possible to revive the body. He will no longer be able to function, the person can no longer be revived. This is the difference between clinical death and biological death. They are separated by a period of only 5 minutes.

Signs of clinical and biological death

When clinical death occurs, all manifestations of life are absent:

no pulse;
no breathing;
the central nervous system is “disabled”;
there is no muscle tone;
skin color changes (pallor).

But unbeknownst to us, at a very low level, metabolic processes are still ongoing, the tissues are viable and can still be fully restored. The time period is determined by the work of the cerebral cortex. Once nerve cells die, there is no way to completely restore a person.

Not all organs die immediately; some retain the ability to live for some time. After a few hours, you can revive the heart and respiratory center. Blood retains its properties for several hours.

Biological death happens:

physiological or natural, which occurs during the aging of the body;
pathological or premature, associated with serious illness or non-life-threatening injuries.

In both cases, it is impossible to bring a person back to life. Signs of biological death in humans are expressed as follows:

cessation of heart rhythm for up to 30 minutes;
lack of breathing;
dilated pupil that does not respond to light;
the appearance of dark blue spots on the surface of the skin.

An early symptom of biological death is the “cat pupil sign.” When you press on the side of the eyeball, the pupil becomes narrow and oblong, like a cat's.

Since organs do not die immediately, they are used in transplantology for organ transplantation. Patients whose kidneys, hearts, and other organs are failing are waiting for their donor. In European countries, people obtain paperwork to allow their organs to be used if they die in an accident.

How to make sure a person is dead?

Diagnosis of clinical and biological death is important; it is carried out by doctors. But everyone should know how to determine it. Irreversible death of a person can be determined by the following signs:

"Symptom of a cat's pupil."
The cornea of the eye dries out and becomes cloudy.
The formation of cadaveric spots due to decreased vascular tone. They usually occur several hours later, when a person has died.
Decreased body temperature.
Rigor mortis also sets in after a few hours. The muscles become hard and the body becomes inactive.

Doctors diagnose a reliable sign of biological death using data from medical equipment, which determines that electrical signals are no longer coming from the cerebral cortex.

In what cases can a person be saved?

Clinical death differs from biological death in that a person can still be saved. An accurate signal of clinical death is considered if the pulse in the carotid artery is not heard and there is no breathing (see). Then resuscitation actions are carried out: indirect cardiac massage, injection of adrenaline. In medical institutions with modern equipment, such measures are more effective.

If the person shows minimal signs of life, immediate revival is performed. If there is any doubt about biological death, resuscitation measures are taken to prevent the person’s death.

It is also worth paying attention to the harbingers of clinical death:

reduction in blood pressure to critical levels (below 60 mm Hg);
bradycardia (pulse below 40 beats per minute);
increased heart rate and extrasystole.

Important! Establishing a diagnosis of clinical death should take no more than 10 seconds for the person providing assistance! Revival measures taken no later than two minutes after the first signs of clinical death appear are successful in 92% of cases.

Will the person be saved or not? At some stage, the body loses strength and stops fighting for life. Then the heart stops, breathing stops and death occurs.

A person is able to live without water and food for some time, but without access to oxygen, breathing will stop after 3 minutes. This process is called clinical death, when the brain is still alive, but the heart does not beat. A person can still be saved if you know the rules of emergency resuscitation. In this case, both doctors and those who are next to the victim can help. The main thing is not to get confused and act quickly. This requires knowledge of the signs of clinical death, its symptoms and the rules of resuscitation.

Symptoms of clinical death

Clinical death is a reversible state of dying in which the heart stops working and breathing stops. All external signs of vital activity disappear, and it may seem that the person is dead. This process is a transitional stage between life and biological death, after which it is impossible to survive. During clinical death (3-6 minutes), oxygen starvation has virtually no effect on the subsequent functioning of organs or general condition. If more than 6 minutes have passed, the person will be deprived of many vital functions due to the death of brain cells.

To recognize this condition in time, you need to know its symptoms. Signs of clinical death are:

Coma - loss of consciousness, cardiac arrest with cessation of blood circulation, pupils do not react to light.
Apnea is the absence of respiratory movements of the chest, but metabolism remains at the same level.
Asystole - the pulse in both carotid arteries cannot be heard for more than 10 seconds, which indicates the beginning of destruction of the cerebral cortex.

Duration

Under conditions of hypoxia, the cerebral cortex and subcortex are able to remain viable for a certain time. Based on this, the duration of clinical death is determined by two stages. The first of them lasts about 3-5 minutes. During this period, provided that the body temperature is normal, there is no oxygen supply to all parts of the brain. Exceeding this time range increases the risk of irreversible conditions:

decortication - destruction of the cerebral cortex;
Decerebration – death of all parts of the brain.

The second stage of the state of reversible dying lasts 10 minutes or more. It is characteristic of an organism with a reduced temperature. This process can be natural (hypothermia, frostbite) and artificial (hypothermia). In a hospital setting, this state is achieved by several methods:

hyperbaric oxygenation – saturation of the body with oxygen under pressure in a special chamber;
hemosorption - blood purification by a device;
drugs that sharply reduce metabolism and cause suspended animation;
transfusion of fresh donor blood.

Causes of clinical death

The state between life and death occurs for several reasons. They can be caused by the following factors:

heart failure;
obstruction of the respiratory tract (lung disease, suffocation);
anaphylactic shock – respiratory arrest due to the body’s rapid reaction to an allergen;
large loss of blood due to injuries, wounds;
electrical damage to tissues;
extensive burns, wounds;
toxic shock - poisoning with toxic substances;
vasospasm;
the body's response to stress;
excessive physical activity;
violent death.

Basic steps and first aid methods

Before taking first aid measures, you must be sure that a state of temporary death has occurred. If all of the following symptoms are present, it is necessary to proceed to emergency assistance. You should make sure of the following:

the victim is unconscious;
the chest does not make inhalation-exhalation movements;
there is no pulse, the pupils do not react to light.

If there are symptoms of clinical death, it is necessary to call an ambulance resuscitation team. Until the doctors arrive, it is necessary to maintain the victim’s vital functions as much as possible. To do this, apply a precordial blow to the chest with a fist in the area of the heart. The procedure can be repeated 2-3 times. If the victim’s condition remains unchanged, then it is necessary to move on to artificial pulmonary ventilation (ALV) and cardiopulmonary resuscitation (CPR).

CPR is divided into two stages: basic and specialized. The first is performed by a person who is next to the victim. The second is by trained medical workers on site or in a hospital. The algorithm for performing the first stage is as follows:

Lay the victim on a flat, hard surface.
Place your hand on his forehead, tilting his head back slightly. At the same time, the chin will move forward.
With one hand, pinch the victim’s nose, with the other, stretch out your tongue and try to blow air into your mouth. Frequency – about 12 breaths per minute.
Go to indirect cardiac massage.

To do this, use the palm of one hand to press on the area of the lower third of the sternum, and place the second hand on top of the first. The chest wall is pressed to a depth of 3-5 cm, and the frequency should not exceed 100 contractions per minute. Pressure is performed without bending the elbows, i.e. straight position of the shoulders over the palms. You cannot inflate and compress the chest at the same time. It is necessary to ensure that the nose is tightly pinched, otherwise the lungs will not receive the required amount of oxygen. If insufflation is done quickly, air will enter the stomach, causing vomiting.

Resuscitation of a patient in a clinical setting

Resuscitation of a victim in a hospital setting is carried out according to a certain system. It consists of the following methods:

Electrical defibrillation - stimulation of breathing by exposure to electrodes with alternating current.
Medical resuscitation through intravenous or endotracheal administration of solutions (Adrenaline, Atropine, Naloxone).
Circulatory support by administering Gecodez through a central venous catheter.
Correction of acid-base balance intravenously (Sorbilact, Xylate).
Restoration of capillary circulation by drip (Reosorbilact).

If resuscitation measures are successful, the patient is transferred to the intensive care unit, where further treatment and monitoring of the condition is carried out. Resuscitation is stopped in the following cases:

Ineffective resuscitation measures within 30 minutes.
Statement of the state of biological death of a person due to brain death.

Signs of biological death

Biological death is the final stage of clinical death if resuscitation measures are ineffective. Tissues and cells of the body do not die immediately; it all depends on the organ’s ability to survive hypoxia. Death is diagnosed based on certain signs. They are divided into reliable (early and late), and orienting - immobility of the body, absence of breathing, heartbeat, pulse.

Biological death can be distinguished from clinical death using early signs. They occur 60 minutes after death. These include:

lack of pupillary response to light or pressure;
the appearance of triangles of dried skin (Larchet spots);
drying of the lips - they become wrinkled, dense, brown in color;
symptom of “cat's eye” - the pupil becomes elongated due to the lack of eye and blood pressure;
drying of the cornea - the iris becomes covered with a white film, the pupil becomes cloudy.

A day after dying, late signs of biological death appear. These include:

the appearance of cadaveric spots - localized mainly on the arms and legs. The spots have a marbled color.
rigor mortis is a condition of the body due to ongoing biochemical processes that disappears after 3 days.
cadaveric cooling - states the completion of biological death when the body temperature drops to a minimum level (below 30 degrees).

Consequences of clinical death

After successful resuscitation measures, a person returns to life from a state of clinical death. This process may be accompanied by various violations. They can affect both physical development and psychological state. The damage caused to health depends on the time of oxygen starvation of important organs. In other words, the sooner a person returns to life after a short death, the fewer complications he will experience.

Based on the above, we can identify temporary factors that determine the degree of complications after clinical death. These include:

3 minutes or less – the risk of destruction of the cerebral cortex is minimal, as is the appearance of complications in the future.
3-6 minutes - minor damage to parts of the brain indicates that consequences may occur (impaired speech, motor function, coma).
More than 6 minutes - destruction of brain cells by 70-80%, which will lead to a complete lack of socialization (the ability to think, understand).

At the level of the psychological state, certain changes are also observed. They are usually called transcendental experiences. Many people claim that while in a state of reversible death, they floated in the air and saw a bright light and a tunnel. Some accurately list the actions of doctors during resuscitation procedures. After this, a person’s life values change dramatically, because he escaped death and received a second chance at life.