The resuscitation method to change the boundary between life and death so far is to "lower the temperature of the human body"
The boundary between life and death is not as obvious as it is thought. Today due to the development of resuscitation science, if the heart stops and the doctor so far "deathIt seems that it has become possible to resurrect human beings several hours from the stage that they would have judged it without being damaged to the brain.
Life After Death? New Techniques Halt Dying Process
"So far, when the patient's heart stopped breathing, I judged it as" dead "State University of New York Stony BrookDr. Sam Parnia who is an associate professor of intensive care medicine at. There has been no way to change this concept of death, but by elucidating the mystery of death on a cell-by-cell basis, scientists such as Sam Parnia can say "death" at the same time I know that it is not something to visit.
From the current human "definition of death", that is, when the heart stops and breathing stops, cells constituting the human body start their respective death processes. This process requires different time for each cell, and it takes about several hours as a whole.
◆ The process of death
After the heart stops and blood can not circulate in the body, brain cells are short of oxygen and nutrients. It was thought that the brain that lacked oxygen would suffer serious damage in only a few minutes. However, the scientists say this is an outdated way of thinking.
Damage to the brain due to lack of oxygen progresses slowly, but in a few seconds the brain activity will be affected. "When someone is in an oxygen deficiency state, there are signs of death in the whole body, if you know this, you can relax the process of cell death," said Dr. Lance Becker, a professor of emergency medicine at the University of Pennsylvania .
ByJean-Etienne Minh-Duy Poirrier
How will we stop the process of death? This answer can be drawn from case reports of patients who have had little or no brain damage after several hours have elapsed since the brain and heart stopped.
Experts say that those who survived safely were hypothermia in addition to appropriate treatment. Hypothermia is a state in which the body's core temperature is several degrees lower than the standard body temperature of 37 degrees Celsius. Studies have shown that hypothermia can relieve cell death by reducing brain oxygen demand. "The technique to cool the body has recovered a lot of patients after cardiac arrest, but there are too many injuries or it may take too long to recover," as this expert says, this method There are limits to some extent. Furthermore, how the patient is treated after the heart starts moving, and how to warm the hypothermia state body, which are important points for safely restoring cardiac arrest patients It seems to be also.
"What we have learned is contrary to this fact: if there are people in an oxygen deficient state, oxygen should be supplied, and if the blood pressure is decreasing the blood pressure should be raised I have learned so far, "says Becker. If the patient's heart is starting to move earlier in the procedure, the brain may suffer severe damage to the nerve due to elevated blood pressure and excessive oxygen. In other words, it is a very important point in resuscitation to adjust the amount of oxygen delivered to the brain using hypothermia well.
◆ What is the state-of-the-art resuscitation method
The idea of making the body hypothermia after cardiac arrest has existed for decades. However, it seems that scientists at the time were unconvinced whether this was really a beneficial treatment for patients. However, recent evidence suggests that hypothermia helps maintain and restore the patient's life by recent research. furtherAmerican Heart AssociationSpecialized organizations like the recommendation to lower the temperature of the patient's body after the patient's blood circulation has recovered.
The way to cool down the body and reduce the oxygen requirement after the heart starts to move is a groundbreaking resuscitation method that gives patients with cardiac arrest the opportunity to resuscitate without damage to the brain Have a secret.
◆ Concept of new death and ethical problems
As a general concept at the scene of medicine, there are things that do not resuscitate patients who are suffering from massive brain injury or who have fallen into a long coma. Resuscitation of patients who have been several hours after cardiac arrest could seriously damage the brain, which seems to be an ethical problem before this treatment. However, Dr. Mayer says, "Our knowledge of brain injury or death is incomplete and it is not clear how much damage is progressing, whether it is reversible, but all hands If you make a decision early without doing anything, you may miss a person who may actually be saved. "
By this method, it is said that about 10% of Americans will get the opportunity to take down their lives, but at what stage the patients are given treatment,Where to define "death" fromThe problem is likely to be even more complicated.
in Science, Posted by logu_ii