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Hibernation: What is it? Types of Human Hibernation and Hibernation in the Medical Field of I.Randi

Introduction

The meaning of hibernation can vary depending on the area in which the term is used.

In fact, we talk about hibernation both in the field of human medicine and in the zoological field. In addition to this, the concept of hibernation is also used in the industrial field.

Normally, the word "hibernation" triggers the imagination and makes us think of science fiction scenarios in which people freeze to wake up in a distant future, however, the current concept of human hibernation is very different and does not allow (for the moment ) the achievement of similar goals.

In medicine, in fact, we talk about artificial hibernation to indicate a particular procedure thanks to which it is possible to lower the patient's body temperature by a few degrees, slowing down vital functions for therapeutic purposes. At the same time, however, there is a type of human hibernation that is practiced post-mortem for those who request it; in these cases, however, it would be more correct to speak of human cryopreservation .

Hibernation in Medicine

Artificial hibernation in the medical field or controlled therapeutic hypothermia

In medicine the term "artificial hibernation" has long been used to indicate a procedure consisting in lowering body temperature below 35 ° C. Today, however, this term is considered obsolete and the procedure is referred to as therapeutic hypothermia, controlled hypothermia, induced therapeutic hypothermia (ITI) or targeted temperature management .

How does it work

Human hibernation used in the medical field involves lowering the central body temperature below 35 ° C, in order to preserve the cells from damage and death. In detail, body temperature is brought to around 32-34 ° C through the use of special cooling catheters or through the use of cooling blankets .

This particular type of hibernation is practiced in patients where there is a need to safeguard cells from damage resulting from a hypoxic condition . Not surprisingly, therapeutic hypothermia is typically used in the following cases:

  • In resuscitated patients after a cardiac arrest ;
  • In the presence of head trauma ;
  • In the case of neonatal hypoxic-ischemic encephalopathy ;
  • In the presence of perinatal asphyxia .

In such conditions, in fact, it is believed that a lowering of body temperature is able to reduce the need for oxygen and other cellular nutrient substrates, facilitating the repair and healing processes .

Please note

Therapeutic hypothermia is not a front-line strategy, but is put into practice, if possible, when traditional medical-surgical approaches have not led to satisfactory results.

Depending on the case, the cooling can have a variable duration ranging from 12-24 hours up to a maximum of 48-72 hours . At the end of this period, the patient is gradually warmed up until the normal body temperature values ​​are reached. However, it is important to point out that, in order to avoid damage, heating must take place in a not excessively fast manner.

As you can easily guess, this is an extremely delicate and complex procedure that requires continuous monitoring of the patient and his vital functions. For this reason, this particular form of hibernation must be performed only in specialized and authorized centers and only by competent doctors in this area.

Please note

Therapeutic hypothermia does not lead to a decrease in mortality, but patients who survive the above conditions and have undergone this form of hibernation seem to have a better prognosis and a better quality of life than surviving patients who did not receive the therapeutic hypothermia. In detail, it appears that, over a period of 3-6 months, patients subjected to this type of hibernation present a greater cognitive and functional improvement than patients not subjected to the procedure.

Side effects

Although useful, therapeutic hypothermia can still give rise to important side effects, such as:

  • Increased risk of infections;
  • Cardiac rhythm disorders and abnormalities of heart contractility;
  • Respiratory disorders (respiratory exchange disorders);
  • Blood clotting disorders and increased bleeding risk;
  • Electrolytic anomalies;
  • hypovolemia;
  • Changes in blood glucose levels.

As you can see, the side effects that can occur in patients subjected to this form of hibernation are quite important and sometimes very serious, for this reason, it is essential that the patient is kept under close observation with a continuous monitoring of his vital functions, in order to guarantee a timely intervention should one or more of the aforementioned side effects occur.

Post-Mortem Human Hibernation

Post-Mortem Human Hibernation and Cryopreservation of Human Bodies

Post-mortem human hibernation is practiced to preserve the human body after death, in the hope that in the future technologies will be devised that will allow the thawing of the body and medical-scientific technologies that are able to bring back to life the thawed people.

This particular form of hibernation is also known as " cryopreservation " since the body is brought to extremely low temperatures, defined, precisely, as cryogenic temperatures (usually below -130 ° C).

Post-mortem hibernation can only be practiced after death - which must be declared legally - when the heart stops beating but before brain death is declared.

Curiosity

An individual subjected to post-mortem cryopreservation - although declared legally dead - is regarded as a cryopreserved patient and not as a deceased patient.

Once the death of the individual has been legally declared - before the declaration of brain death - we are witnessing the intervention of technicians who mechanically restore breathing and the flow of blood to the brain in the body. After that, the body is immersed in icy water and transported to the center where cryopreservation will take place.

Once it reaches the selected cryogenesis center, a particular solution is injected intravenously into the body, whose task is to prevent the formation of ice crystals inside the cells following the freezing of the water contained in them. This step is essential to prevent the formation of ice crystals from causing damage and / or causing the cells to break. To make a somewhat simplistic comparison, this solution performs a function similar to that of the anti-freeze solutions used in engines or at industrial level.

At the end of this operation, the body is immersed in liquid nitrogen and brought to a temperature of -125 ° C; after a time of about three hours, the temperature is further lowered to the final value of -196 ° C.

Cryopreservation of Tissues and Cells

The cryopreservation, or cryopreservation, of tissues and cells, as it were, has been taking place for several years. The most widely known cell cryopreservation is, without doubt, that of sperm and human oocytes, but other types of cells and tissues can also be preserved at cryogenic temperatures. Indeed, another example of hibernation of this type is represented by the cryopreservation of bone marrow.

Post-Mortem Human Hibernation in Italy

In Italy, there is no center that offers the opportunity to take advantage of post-mortem hibernation. In fact, there are only three cryogenic centers around the world that offer a similar service: two in the United States and one in Russia. However, even if there are no such centers on Italian soil, no Italian law prevents post-mortem human hibernation. In this regard, it should be noted that all three cryogenic centers currently present offer special transport services - including intercontinental ones - of which, among other things, some Italian citizens have already benefited.

Please note

Currently, there is NO technology that allows people to be defrosted and brought back to life in post-mortem hibernation, just as there is no scientific evidence to show that - even if such technology were discovered and implemented - hibernating individuals they can retain their own functions, both physical and cognitive, even after waking up. For this reason, post-mortem hibernation is considered by the most skeptical as pure science fiction; while for those who decide to undergo it once they die, it is a hope.

Animal Hibernation

Hibernation in Zoology

In the field of zoology, we speak of hibernation to indicate the particular property possessed by different animals - both vertebrates and invertebrates - of entering a sort of latent vital state in order to survive the winter .

This state is characterized by a slowing down of vital functions that allows the animal to survive the unfavorable conditions typical of the cold season; in detail, we see:

  • Lowering body temperature;
  • Lowering of metabolism;
  • Slow heart rate;
  • Lower respiratory rate;
  • Muscle relaxation.

There are many species that are able to hibernate during the winter. Among the animals with this ability, we remember: hedgehogs, squirrels, marmots, dormice, bears, turtles, bats, frogs, toads, snakes, hornets, etc.

In mammals, the hibernation condition is more commonly known as " lethargy ".

Did you know that ...

Some animal species capable of going into hibernation have a particular gland, called " hibernation gland " or " hibernating gland ". It is a large gland located in the abdomen or chest of the animal; it is devoid of endocrine function but rich in adipose tissue that has a reserve function throughout the hibernation period, allowing the survival of the animal.

Hibernation in the Industry

Hibernation in the Ceramics Industry

As mentioned, the term "hibernation" is also used in the industrial field and, more in detail, in the field of the brick and ceramics industry . In this case, when we talk about hibernation we want to indicate a particular process to which the newly extracted clay is subjected. In detail, this material is left exposed to the action of atmospheric agents throughout the winter period, until the time of thawing. The purpose of this procedure is to remove impurities from the clay mass, at the same time increasing the degree of plasticity and the degree of fineness .