There are clear signs of biological death, which indicate that there was a stopping of important processes in the body, leading to irreversible death of a person. But since modern methods allow the patient to be reanimated even when, by all indications, he is dead. At each stage of the development of medicine the symptoms of the approaching death are specified.
Causes of biological death
Biological or true death means irreversible physiological processes occurring in cells and tissues. It can be natural or premature (pathological, including instantaneous). The organism at a certain stage exhausts its forces in the struggle for life. This leads to the stopping of the heartbeat and respiration, biological death occurs. Its causes are primary and secondary, they can be such etiological factors as:
- acute, heavy blood loss;
- concussion or squeezing of organs (vital);
- asphyxia;
- shock state;
- incompatible with life damage;
- embolism ;
- intoxication;
- diseases of an infectious and non-infectious nature.
Stages of biological death
How does a person die? The process can be divided into several stages, each of which is characterized by a gradual suppression of the basic vital functions and their subsequent stopping. The following stages are called:
- Pre-conditioning state. Early symptoms of biological death - pallor of the skin, weak pulse (it is probed on the arteries of the carotid and femoral), loss of consciousness, a decrease in pressure. The condition worsens, oxygen starvation increases.
- Terminal pause. A special intermediate stage between life and death. The latter is inevitable, if not to spend urgent resuscitation measures.
- Agony. The final stage. The brain stops regulating all functions of the body and the most important processes of life. To revive the body as an integral system becomes impossible.
How does clinical death differ from biological death?
In connection with the fact that simultaneously the organism does not die with the cessation of cardiac and respiratory activity, two similar concepts are distinguished: clinical and biological death. Each has its own signs, for example, in the case of clinical death, there is a pre-state: there is no consciousness, pulse and breathing. But the brain is able to survive without oxygen for 4-6 minutes, the activity of the organs does not cease completely. This is the main difference between clinical death and biological: the process is reversible. A person can be revitalized by cardiopulmonary resuscitation.
Brain death
Not always the cessation of important body functions signifies a fatal outcome. Sometimes a pathological condition is diagnosed when there is brain necrosis (total) and the first cervical spinal segments, but gas exchange and cardiac activity are preserved by artificial ventilation. This condition is called brain, less often social death. In medicine, the diagnosis appeared with the development of resuscitation. Biological brain death is characterized by the presence of the following symptoms:
- Lack of consciousness (including coma ).
- Loss of reflexes.
- Atony of the muscles.
- Impossibility of independent breathing.
- No response to light pupils.
Signs of biological death in humans
The various signs of biological death confirm the death and are a reliable fact of death. But if the symptoms are noted with oppressive action of drugs or deep cooling of the body, they are not basic. The time of death of each organ is different. The tissues of the brain are affected more quickly than others, the heart remains viable for another 1-2 hours, and the liver and kidneys - more than 3 hours. Muscular tissues and skin retain viability even longer - up to 6 hours. Symptoms of biological death are divided into early and later ones.
Early signs of biological death
In the first 60 minutes after dying, the early symptoms of biological death appear. The main ones are the absence of three vitally important parameters: palpitation, consciousness, respiration. They indicate that resuscitation in this situation is meaningless. Early symptoms of biological death include:
- Drying of the cornea, blurred pupil. It is covered with a white film, and the iris loses its color.
- Lack of eye reaction to light stimulus.
- Cider, in which the pupil assumes an elongated shape. This is the so-called cat's eye, a sign of biological death, indicating that eye pressure is absent.
- Appearance on the body of the so-called Lärše spots - triangles of dried skin.
- Staining of the lips in a brown tint. They become dense, wrinkled.
Late signs of biological death
After the death within 24 hours there are additional - late - symptoms of the organism dying. It takes an average of 1.5-3 hours after cardiac arrest, and corpse stains of marble color appear on the body (usually in the lower part). In the first 24 hours, due to biochemical processes in the body, rigor mortis sets in and disappears after 2-3 hours. Signs of biological death include cadaveric cooling, when the body temperature drops to air temperature, dropping by an average of 1 degree in 60 minutes.
A reliable sign of biological death
Any of the symptoms listed above are signs of biological death, the evidence of which makes the resuscitation process meaningless. All these phenomena are irreversible and represent the physiological processes in the cells of tissues. A reliable sign of biological death is a combination of the following symptoms:
- maximum pupil dilated;
- rigor mortis;
- cadaveric stains;
- absence of more than 20-30 minutes of cardiac activity;
- cessation of breathing;
- posthumous hypostasis.
Biological death - what to do?
After the completion of all three processes of dying (pre-teaching, terminal pause and agony), a person's biological death occurs. It should be diagnosed by a doctor and confirmed by a lethal outcome. The most difficult thing is to determine brain death, which in many countries is equated with biological death. But after its confirmation, organs can be withdrawn for subsequent transplantation to recipients. To make a diagnosis, sometimes you need:
- the conclusion of such specialists as the resuscitator, neurologist , forensic expert;
- angiography of vessels, confirming the arrest of blood flow or its critically low level.
Biological death - help
With symptoms of clinical death (stopping breathing, stopping the pulse and so on), the doctor's actions are aimed at revitalizing the body. With the help of complex resuscitation measures, he tries to support the functions of blood circulation and respiration. But only when the positive result of resuscitation of the patient is confirmed is an obligatory condition. If signs of biological actual death are found, resuscitation is not carried out. Therefore the term has one more definition - the true death.
Statement of biological death
At different times, there were different ways to diagnose a person's death. The methods were both humane and inhumane, for example, the José and Razye trials implied pinching of the skin with forceps and the effect of red-hot iron on the limbs. Today, the statement of the biological death of a person is carried out by doctors and paramedics, employees of public health institutions, who have all the conditions for such a check. The main signs - early and late - that is, cadaveric changes allow us to conclude that the patient died.
There are methods of instrumental research confirming death, mainly of the brain:
- angiography cerebral;
- electroencephalography;
- magnetic resonance angiography;
- ultrasonography;
- test for spontaneous breathing, it is carried out only after obtaining complete data confirming the death of the brain.
Numerous signs of biological death allow doctors to ascertain the death of a person. In medical practice, there are cases of erroneous diagnosis , and not only lack of breathing, but also cardiac arrest. Because of the fear of making mistakes, the methods of life samples are constantly being improved, new ones are emerging. At the first signs of death, before the appearance of reliable symptoms of true death, doctors have a chance to return the patient to life.