When a person’s heart stops beating, brain cells begin to die within minutes. However, sometimes it is still possible to return from the “world of the dead.”
It is true that most of the time, death is permanent. When someone’s heart stops, he rarely beats again. However, at certain times, it is possible bring a person back to life, even after the heart has stopped.
But, after all, what is the longest period someone was clinically dead and returned to life?
In general, remaining more than 30 minutes “dead” and returning without significant brain damage is very rare. However, in specific circumstances, people have happened to be revived after several hours and have completely recovered.
To understand how this is possible -writes to -first it is important to accurately define what death is.
“Most of the time, when doctors say ‘clinically dead’refer to heart death-and that means that the heart is no longer beating, ”he explained to this magazine, Daniel Mark Rolstondoctor at Northwell Health in New York.
When a person’s heart stops beating, all body cells – And, more importantly, those of the brain – Stop receiving blood fresh and oxygenated.
After about five minutes without oxygen, the cells begin to diein an irreversible process.
The other type of clinical death is the cerebral deathwhich occurs when the brain is so damaged that can no longer control basic vital functionslike breathing and heartbeat.
Importance of RCR
A cardiorespiratory resuscitation (RCR) It serves to keep the blood fresh to circulate through the body and keep the brain cells alive after a cardiac stop. By manually compressing the chest and providing rescue insufflation, it is possible to keep the cells oxygenated for a short time, even when the heart is not beating by itself.
In most cases, RCR cannot restart the heart, but it can allow gain time to apply other techniques that can do it.
For the heart to beat again, then resorts to a technique called defibrillationwhich applies an electric current external to the heart, imitating the natural electrical signs that make the heart muscle contract. In some cases, these electrical impulses can even “restart” the heart and make it beat again.
According to the American Red Cross, which Live Science cites, the survival rate after RCR in a hospital environment is about 20%. Outside the hospital, this rate goes down to about 10%, because people are not trained and response times are longer.
Rolston states that successful resuscitation after more than half an hour are extremely rare, even with continuous RCR: “If anyone is not revived after 30 minutes, the likelihood of survival is very small.”
Hypothermia can work
Hypothermia occurs when central body temperature goes down below 35 ° C, and, by itself, can be very dangerous, leading to the bankruptcy of the heart and lungs, and eventually to death.
But if the heart has already stopped, hypothermia can, paradoxically, have beneficial effects.
O cold soften body metabolism, protecting brain cells delicate to die after running out of oxygen.
“If you cool quickly, the body can protect yourself for a long time”,
explained to Live Science, Samuel Tishermanas well University of Maryland School of Medicinewhich studies the therapeutic use of hypothermia in cases of cardiac stop caused by trauma.
“There are numerous reports of people who drowned in very cold water, submerged for almost an hour and survived“, account.
Eight hours and 42 minutes
Second Live Science, the longest known case of successful resuscitation after a cardiac arrest and accidental hypothermia is that of a 31-year-old man who was “Risen” after eight hours and 42 minutes.
Its body temperature had fallen to about 26 ° C. Was made RCR over three and a half hours. When he arrived at the hospital, he was placed in a vital support system that kept the blood flow for five hours.
The man was gradually heated and successfully resumed. Three months later, according to the medical report, he had fully recovered, without permanent neurological damage.
Impossible to reverse brain death
And, on the one hand, cardiac death can, in certain situations, have reversal; with the Brain death is not so. When a patient is declared with brain death, the brain can no longer send signs to the body to control vital functions.
The definition of brain death implies that the brain regions that support life are irreversibly destroyed, so there is no possibility of recovery.
