Achievements of modern intensive care allow people to be returned literally from the other world within a few hours after cardiac arrest, just when they should be declared dead by all the formal criteria.
“Until now, it was customary to record the death of a person after cardiac arrest and respiratory arrest,” says Dr. Sam Parnia of the State University of New York, USA. "And there was nothing to be done about it."
By observing the cells of a dying organism, scientists have found that death does not occur overnight, but is a sequential process. In other words, after the cessation of pulse and respiration, the cells of the body begin their own process of extinction.
This process can take hours and could possibly be reversed, according to Sam Parnius. The professor also argues that the generally accepted opinion that as soon as the heart stops pumping blood through the body, a person has only a few minutes before irreversible brain damage appears, is outdated. According to him, cardiac arrest only precedes the process of extinction in general.
The brain damage caused by the lack of oxygen occurs in stages. During the first seconds, brain activity begins to slow down, and only after a few minutes, the glucose-deprived cells begin, stage by stage, to carry out the death program.
“There are a number of signals that the dying organism transmits to the brain cells and thus gives them the command that it is time to die. So, we have the opportunity to slightly change this program, to tell them “stop, you need to wait,” says Dr. Lance Becker, professor of resuscitation at the University of Pennsylvania, USA.
Suggestions on how to stop the extinction process came from the observation of people who were brought back to life after little or no brain damage within hours of cardiac arrest and brain activity.
The reason for such successful "returns", in addition to correctly applied measures of intensive care and resuscitation, is hypothermia, that is, a condition in which the main body temperature drops several degrees below normal.
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The researchers found that hypothermia appears to help protect brain cells from destruction by reducing their oxygen demand and interrupting early stages of dying. Despite the fact that the body cooling technique has already helped to resuscitate many patients with cardiac arrest, there is a so-called point of no return, when the damage is too severe and "return" becomes impossible.
Brain before and after death
In addition, it was observed that the success of resuscitation actions depends on the methods used to start the heart after its arrest and the method of rewarming the body after hypothermia. “What we learn is contrary to common sense, because we were all taught that when oxygen levels are low, oxygen should be given, and if blood pressure is low, then you need to raise it,” says Lance Becker.
Rapid blood flow and too much oxygen to the brain during resuscitation can actually worsen neurological conditions. Conversely, moderate oxygen delivery to the brain can be critical to successful resuscitation.
The idea of cooling the body after cardiac arrest has been in the minds of the scientific community for several decades, but until now no one was completely sure that it could bring real benefits to patients. It is only in recent years that scientists have been able to provide evidence that hypothermia improves patients' chances of survival, and professional associations now recommend considering hypothermia as a way to restore a patient's circulation.
Medical institutions say they are aware of the method proposed by the association, but have not yet used it. It is also noted that the ideal option for applying the above measures is to replace people with devices and machines capable of performing resuscitation procedures, releasing the correct volumes of oxygen and blood for delivery to the brain. After all, it is the timely cooling and the verified reduction of oxygen volumes after the heart starts up - these are the factors that should increase the chances of returning without brain damage, scientists emphasize.
In accordance with the prevailing opinion in medical practice, there is no point in resuscitating a patient who has suffered significant brain damage, who will continue to exist only in a state of eternal coma. However, according to scientists, our knowledge of brain damage and extinction is incomplete and it is not always clear what damage the patient has already suffered, and whether they are reversible.
“We managed to find out for sure that these concepts of the irreversibility of brain damage are absolutely wrong,” the experts emphasize. "If you follow these conclusions right away, without going all the way, you can simply write off people without doing anything."
According to Lance Becker, doctors should use all available methods, if they already undertook to resuscitate a patient. "If we are going to do something to save a person, why are we doing less than is available?" - the scientist asks.
