In the US, doctors during the experiment for the first time introduced a person into a state of suspended animation, writes New Scientist.
The need for this, in this case, is because many people who have received life-threatening injuries die before surgeons could have time to help them.
Samuel Tisherman of the University of Maryland Graduate school of medicine in Baltimore said that he and his colleagues managed to put at least one patient into a state of suspended animation. He did not want to reveal how many patients survived the procedure.
The new technique was included as an experiment in a complex of resuscitation measures, which can count on patients delivered to the University medical center with life-threatening injuries — for example, with gunshot or knife wounds. Such victims have heart failure, lose more than half their blood — and doctors usually have only a few minutes to help them, with a survival rate of less than five percent.
According to the developers, they quickly cool the human body to about 10-15 degrees Celsius by replacing all blood with saline cooled to near zero temperature. In this case, the brain activity is almost completely stopped, and the patient, “who otherwise could be pronounced dead,” is disconnected from the cooling system and placed on the operating table.
After that, the team of surgeons has two hours for surgery, designed to eliminate the cause of acute blood loss. Then the patient is restored to normal temperature and tries to start the heart.
As part of the study, the results of the treatment of ten people using this technique will be compared with the results of the treatment of the same number of people who were in a similar situation but did not receive similar assistance. Administration of the USA on sanitary inspection behind quality of foodstuff and medicines has approved the experiment. The patient’s consent is not required for this test, as it is a condition that is directly life threatening.
Tisherman said he hopes to be able to announce the test results in full by the end of 2020.
At normal body temperature, which is about 37 degrees Celsius, the cells of the human body constantly need oxygen to produce energy. When the heart stops beating, the blood no longer carries oxygen to the cells, and without it, the brain can only live for about five minutes, after which irreversible damage will occur. However, a decrease in body and brain temperature leads to a slowdown or suspension of all chemical reactions in cells, which thus need less oxygen.
Animal studies have shown that pigs with a life-threatening injury can be induced to cool for up to three hours and in this mode, surgical treatment of the injuries can be performed, after which they can be resuscitated.
At the same time, according to Tisherman, the maximum possible period for which it is thus possible to enter safely into a state of suspended animation is still unknown. When cells reheat, they can get specific damage due to some chemical reactions, and the longer the cells are without oxygen, the more damage occurs. Probably, to solve this problem, it is possible to introduce a mixture of certain substances into the tissues and thus increase the period of suspended animation, but now the causes of such cellular damage are insufficiently studied.