Biological death

Biological death is an irreversible stop of biological processes. Let's consider the main signs, causes, types and methods of diagnosing the fading of the body.

Death is characterized by cardiac and respiratory arrest, but does not occur immediately. Modern methods of cardiopulmonary resuscitation allow us to prevent dying.

A distinction is made between physiological, that is, natural death (gradual fading of the main life processes) and pathological or premature death. The second type can be sudden, that is, occur within a few seconds, or violent, as a result of murder or an accident.

ICD-10 code

The International Classification of Diseases, 10th revision, has several categories in which death is considered. Most deaths are caused by nosological units that have a specific ICD code.

• R96.1 Death occurring less than 24 hours after onset of symptoms, not otherwise explained

R95-R99 Uncertain and unknown causes of death:

• R96.0 Instant death
• R96 Other sudden death of unknown cause
• R98 Death without witnesses
• R99 Other ill-defined and unspecified causes of death
• I46.1 Sudden cardiac death, so described

Thus, cardiac arrest caused by essential hypertension I10 is not considered the main cause of death and is indicated in the death certificate as concomitant or background damage in the presence of nosologies of ischemic diseases of the cardiovascular system. Hypertensive disease can be identified according to ICD 10 as the main cause of death if the deceased has no indications of ischemic (I20-I25) or cerebrovascular diseases (I60-I69).

Causes of biological death

Establishing the cause of biological cardiac arrest is necessary for its confirmation and identification according to the ICD. This requires determining the signs of the action of damaging factors on the body, the duration of the damage, establishing thanatogenesis and excluding other damage that could cause a fatal outcome.

The main etiological factors:

Primary causes:

• Injuries incompatible with life
• Profuse and acute bleeding
• Compression and shaking of vital organs
• Asphyxia by aspirated blood
• State of shock
• Embolism

Secondary causes:

• Infectious diseases
• Intoxication of the body
• Non-infectious diseases.

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Signs of biological death

Signs of biological death are considered a reliable fact of death. 2-4 hours after the heart stops, cadaveric spots begin to form on the body. At this time, rigor mortis occurs, which is caused by the cessation of blood circulation (it spontaneously passes on the 3-4th day). Let's consider the main signs that allow us to recognize dying:

• Absence of cardiac activity and respiration - the pulse is not palpable in the carotid arteries, heart sounds are not heard.
• There is no cardiac activity for more than 30 minutes (assuming the ambient temperature is room temperature).
• Maximum dilation of the pupils, no reaction to light and no corneal reflex.
• Postmortem hypostasis, that is, dark blue spots on the sloping parts of the body.

The above-described manifestations are not considered to be the main ones for establishing death when they occur under conditions of deep cooling of the body or with the depressing effect of drugs on the central nervous system.

Biological dying does not mean the instantaneous death of the body's organs and tissues. Their time of death depends on their ability to survive in conditions of anoxia and hypoxia. All tissues and organs have different abilities. The tissues of the brain (the cerebral cortex and subcortical structures) die the fastest. The spinal cord and brainstem are resistant to anoxia. The heart is viable for 1.5-2 hours after death is confirmed, and the kidneys and liver for 3-4 hours. Skin and muscle tissue are viable for up to 5-6 hours. Bone tissue is considered the most inert, as it retains its functions for several days. The phenomenon of the survival of human tissues and organs makes it possible to transplant them and continue to work in a new organism.

Early signs of biological death

Early signs appear within 60 minutes of death. Let's look at them:

• There is no pupillary response when pressure is applied or when light is stimulated.
• Triangles of dry skin (Larchet spots) appear on the body.
• When the eye is compressed from both sides, the pupil takes on an elongated shape due to the absence of intraocular pressure, which depends on arterial pressure (cat's eye syndrome).
• The iris of the eye loses its original color, the pupil becomes cloudy, covered with a white film.
• The lips become brown, wrinkled and dense.

The appearance of the above symptoms indicates that resuscitation measures are pointless.

Late signs of biological death

Late signs appear within 24 hours of death.

• Cadaveric spots appear 1.5-3 hours after cardiac arrest, have a marbled color and are located in the underlying parts of the body.
• Rigor mortis is one of the reliable signs of death. It occurs due to biochemical processes in the body. Complete rigor mortis occurs after 24 hours and disappears on its own after 2-3 days.
• Corpse cooling is diagnosed when the body temperature has dropped to the air temperature. The rate of body cooling depends on the ambient temperature, on average it decreases by 1°C per hour.

Reliable signs of biological death

Reliable signs of biological death allow us to state death. This category includes phenomena that are irreversible, that is, a set of physiological processes in tissue cells.

• Drying of the white of the eye and cornea.
• The pupils are dilated and do not react to light or touch.
• Change in the shape of the pupil when squeezing the eye (Beloglazov's sign or cat's eye syndrome).
• Lowering body temperature to 20 °C, and in the rectum to 23 °C.
• Cadaveric changes – characteristic spots on the body, rigor mortis, drying out, autolysis.
• No pulse in the main arteries, no spontaneous breathing or heartbeat.
• Hypostasis blood spots are pale skin and blue-violet spots that disappear when pressed.
• Transformation of cadaveric changes – rotting, adipocere, mummification, peat tanning.

If the above symptoms appear, resuscitation measures are not carried out.

Stages of biological death

The stages of biological death are stages characterized by the gradual suppression and cessation of basic vital functions.

• Pre-agonal state – sharp depression or complete loss of consciousness. Pale skin, pulse is weakly felt on the femoral and carotid arteries, pressure drops to zero. Oxygen starvation rapidly increases, worsening the patient's condition.
• Terminal pause is an intermediate stage between life and death. If resuscitation measures are not carried out at this stage, death is inevitable.
• Agony – the brain stops regulating the functioning of the body and life processes.

If the body has been exposed to destructive processes, all three stages may be absent. The duration of the first and last stages can be from several weeks-days to a couple of minutes. The end of agony is considered to be clinical death, which is accompanied by a complete cessation of vital processes. From this moment, cardiac arrest can be stated. But irreversible changes have not yet occurred, so there are 6-8 minutes for active resuscitation measures to bring a person back to life. The last stage of dying is irreversible biological death.

Types of biological death

Types of biological death is a classification that allows doctors to establish the main signs in each case of death that determine the type, genus, category and cause of death. Today, medicine distinguishes two main categories - violent and non-violent death. The second sign of dying is the genus - physiological, pathological or sudden death. In this case, violent death is divided into: murder, accident, suicide. The last classifying feature is the type. Its definition is associated with the identification of the main factors that caused death and are united by the impact on the body and origin.

The type of death is determined by the nature of the factors that caused it:

• Violent – mechanical damage, asphyxia, exposure to extreme temperatures and electric current.
• Sudden – diseases of the respiratory system, cardiovascular system, gastrointestinal tract, infectious lesions, diseases of the central nervous system and other organs and systems.

Particular attention is paid to the cause of death. This may be a disease or underlying injury that caused cardiac arrest. In the case of violent death, these are injuries caused by gross trauma to the body, blood loss, concussion and contusion of the brain and heart, shock of 3-4 degrees, embolism, reflex cardiac arrest.

Declaration of biological death

Biological death is determined after the brain dies. The determination is based on the presence of cadaveric changes, i.e. early and late signs. It is diagnosed in healthcare institutions that have all the conditions for such determination. Let's consider the main signs that allow us to determine death:

• Absence of consciousness.
• Lack of motor reactions and movements to painful stimuli.
• Absence of pupillary response to light and corneal reflex on both sides.
• Absence of oculocephalic and oculovestibular reflexes.
• Absence of pharyngeal and cough reflexes.

In addition, a spontaneous breathing test may be used. It is performed only after receiving complete data confirming brain death.

There are instrumental studies used to confirm the non-viability of the brain. For this purpose, cerebral angiography, electroencephalography, transcranial Doppler ultrasonography or nuclear magnetic resonance angiography are used.

Diagnosis of clinical and biological death

The diagnostics of clinical and biological death is based on the signs of dying. The fear of making a mistake in determining death pushes doctors to constantly improve and develop methods of life tests. Thus, more than 100 years ago in Munich there was a special burial vault in which a cord with a bell was tied to the hand of the deceased, hoping that they made a mistake in determining death. The bell rang once, but when the doctors came to help the patient who had woken up from a lethargic sleep, it turned out that it was the resolution of rigor mortis. But in medical practice there are known cases of erroneous diagnosis of cardiac arrest.

Biological death is determined by a complex of signs that are associated with the “vital tripod”: cardiac activity, functions of the central nervous system and respiration.

• To date, there are no reliable symptoms that would confirm the preservation of breathing. Depending on the environmental conditions, a cold mirror, auscultation of breathing, or the Winslow test (a vessel with water is placed on the dying person's chest, the vibrations of which are used to judge the respiratory movements of the sternum) are used.
• To check the activity of the cardiovascular system, palpation of the pulse on the peripheral and central vessels and auscultation are used. These methods are recommended to be carried out at short intervals of no more than 1 minute.
• To detect blood circulation, the Magnus test (tight constriction of the finger) is used. The lumen of the earlobe can also provide certain information. If there is blood circulation, the ear has a reddish-pink color, while in a corpse it is gray-white.
• The most important indicator of life is the preservation of the function of the central nervous system. The performance of the nervous system is checked by the absence or presence of consciousness, muscle relaxation, passive body position and reaction to external stimuli (pain, ammonia). Particular attention is paid to the reaction of the pupils to light and the corneal reflex.

In the last century, cruel methods were used to check the functioning of the nervous system. For example, during the Jose test, a person's skin folds were pinched with special pincers, causing painful sensations. During the Degrange test, boiling oil was injected into the nipple, and the Raze test involved cauterizing the heels and other parts of the body with a hot iron. Such peculiar and cruel methods show the lengths to which doctors went to determine death.

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Clinical and biological death

There are such concepts as clinical and biological death, each of which has certain signs. This is due to the fact that a living organism does not die simultaneously with the cessation of cardiac activity and respiratory arrest. It continues to live for some time, which depends on the ability of the brain to survive without oxygen, as a rule, it is 4-6 minutes. During this period, the fading vital processes of the organism are reversible. This is called clinical death. It can occur due to profuse bleeding, acute poisoning, drowning, electrical injuries or reflex cardiac arrest.

The main signs of clinical dying:

• The absence of a pulse in the femoral or carotid artery is a sign of circulatory arrest.
• Absence of breathing - checked by visible movements of the chest during exhalation and inhalation. To hear the sound of breathing, you can put your ear to the chest, or bring a piece of glass or a mirror to your lips.
• Loss of consciousness – lack of response to pain and sound stimuli.
• Dilation of the pupils and their lack of reaction to light - the victim's upper eyelid is lifted to determine the pupil. As soon as the eyelid drops, it must be lifted again. If the pupil does not narrow, this indicates a lack of reaction to light.

If the first two of the above-described signs are present, then resuscitation must be carried out immediately. If irreversible processes have begun in the tissues of organs and the brain, resuscitation is ineffective and biological death occurs.

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The difference between clinical death and biological death

The difference between clinical death and biological death is that in the first case the brain has not yet died and timely resuscitation can revive all its functions and the functions of the body. Biological dying occurs gradually and has certain stages. There is a terminal state, that is, a period that is characterized by a sharp failure in the functioning of all organs and systems to a critical level. This period consists of stages by which biological death can be distinguished from clinical death.

• Pre-agony – at this stage, there is a sharp decrease in the vital activity of all organs and systems. The work of the heart muscles and the respiratory system is disrupted, the pressure drops to a critical level. The pupils still react to light.
• Agony – is considered the stage of the last burst of life. A weak pulse is observed, the person inhales air, the pupils' reaction to light slows down.
• Clinical death is an intermediate stage between death and life. It lasts no more than 5-6 minutes.

Complete shutdown of the circulatory and central nervous systems, respiratory arrest are signs that combine clinical and biological death. In the first case, resuscitation measures allow the victim to return to life with full restoration of the main functions of the body. If during resuscitation the patient's health improves, the complexion normalizes and there is a reaction of the pupils to light, then the person will live. If after emergency assistance there is no improvement, then this indicates a cessation of the functioning of the main life processes. Such losses are irreversible, so further resuscitation is useless.

First aid for biological death

First aid for biological death is a set of resuscitation measures that allow the restoration of the functioning of all organs and systems.

• Immediate cessation of exposure to damaging factors (electric current, low or high temperatures, compression of the body by weights) and unfavorable conditions (removal from water, release from a burning building, etc.).
• First medical and pre-hospital aid depending on the type and nature of injury, illness or accident.
• Transporting the victim to a medical facility.

Of particular importance is the rapid delivery of a person to the hospital. It is necessary to transport not only quickly, but also correctly, that is, in a safe position. For example, in an unconscious state or when vomiting, it is best to lie on the side.

When providing first aid, it is necessary to adhere to the following principles:

• All actions must be appropriate, quick, deliberate and calm.
• It is necessary to assess the surrounding environment and take measures to stop the impact of factors damaging the body.
• Correctly and quickly assess the person's condition. To do this, you should find out the circumstances under which the injury or illness occurred. This is especially important if the victim is unconscious.
• Determine what resources are needed to provide assistance and prepare the patient for transportation.

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What to do in case of biological death?

What to do in case of biological death and how to normalize the condition of the victim? The fact of death is established by a paramedic or doctor in the presence of reliable signs or by a combination of certain symptoms:

• Absence of cardiac activity for more than 25 minutes.
• Lack of spontaneous breathing.
• Maximum dilation of the pupils, no reaction to light and no corneal reflex.
• Postmortem hypostasis in sloping parts of the body.

Resuscitation measures are actions of doctors aimed at maintaining breathing, circulatory function and reviving the dying person's body. During resuscitation, cardiac massage is mandatory. The basic CPR complex includes 30 compressions and 2 breaths, regardless of the number of rescuers, after which the cycle is repeated. A mandatory condition for resuscitation is constant monitoring of effectiveness. If a positive effect of the actions is observed, they continue until the persistent disappearance of pre-death signs.

Biological death is considered the final stage of dying, which without timely assistance becomes irreversible. When the first symptoms of death appear, it is necessary to carry out emergency resuscitation, which can save a life.