What is brain death

The human brain is composed of six parts: medulla oblongata, pons, midbrain, cerebellum, mesencephalon and telencephalon, with the medulla oblongata, pons and midbrain collectively known as the brainstem. The respiratory center of the human body is located in the brainstem, so damage to the brainstem function will directly lead to respiratory function stop. Unlike some parts of the human body where cells can regenerate after injury, nerve cells cannot regenerate once they are necrotic. Therefore, when a person's brainstem suffers irreversible damage, the brainstem becomes permanently and completely dysfunctional, resulting in an irreversible loss of respiratory function. Subsequently, other organs and tissues of the body will also gradually lose their function because they are not supplied with oxygen.

Brain death is the irreversible loss of brain function, including the brainstem. Brain death is different from "vegetable", "vegetable" brain stem function exists, coma is only due to severe damage to the cerebral cortex or in a state of sudden inhibition, the patient can have voluntary breathing, heartbeat and brain stem response, while brain death is no voluntary breathing, is permanent, irreversible.

A lot of people are not aware of this.

Many countries in the past have taken "cardiac arrest" and "loss of respiration" as the criteria for death. But with advances in medical technology, patients' vital signs such as heartbeat, respiration and blood pressure can be reversed or maintained over time with a range of drugs and advanced equipment. However, if structural damage occurs in the brainstem, no medical treatment can save the patient. Thus, brain death appears to be a more scientific and reliable standard than cardiac death.

Since 1968, when the Special Committee on the Review of the Definition of Death at Harvard University put forward the indicators for judging brain death, more than 80 countries and regions in the world have successively established the criteria for brain death, and some countries have formulated corresponding laws on brain death, but there are also some countries that have adopted the coexistence of the criteria for brain death and cardiac death.

Since the artificial respirator can continue to maintain cardiopulmonary function for a long period of time when other organs of the patient's body have failed, it has led to the widespread acceptance of the viewpoint that the sign of the patient's death is the cessation of all brain functions, especially the brainstem function, which plays an integrated role in the patient's death. In order for a doctor to declare a patient brain dead, there must be evidence of a structural or metabolic cause of brain damage, and all causes of reversible coma must be excluded, such as acute intoxication (carbon monoxide poisoning, sedative sleeping pills, anesthetics, psychotropic drugs, muscle relaxants, etc.), hypothermia (anogenital temperature of 32 degrees Celsius), severe disorders of electrolyte and acid-base balance, metabolic and endocrine disorders (such as hepatic encephalopathy, uremic encephalopathy, non-ketoacidotic encephalopathy, and other diseases), and the presence of a brainstem, uremic encephalopathy, non-ketotic hyperglycemic encephalopathy) and shock.

Brain death is divided into primary brain death and secondary brain death, primary brain death is caused by primary brain diseases or injuries; secondary brain death is caused by primary diseases or injuries to organs outside the brain, such as the heart and lungs, resulting in cerebral hypoxia or metabolic disorders. The basic causes of brain death are: severe injury to brain tissue, hemorrhage, inflammation, tumors, cerebral edema, cerebral compression, cerebral herniation, or secondary to cardiopulmonary dysfunction

Significance

0?2?0?2?0?2?0?2?0?2?2.0.0.0.2 ①For the patient who has been confirmed to be brain dead and has been maintained in circulation for a certain period of time with the aid of an artificial respirator, there is no doubt that it is a good source for the mention of the arch transplantation of organs. Source. In Austria, Switzerland, Poland and other countries, the law provides that once a patient has been diagnosed as brain dead, his or her organs can be taken for transplantation.

0?2?0.2.0.2.0.2.0.2.0.2.0.2.2 ② For some patients with cardiac arrest, if the brain is not dead yet, it should be actively resuscitated, and make every effort to rescue. And it is ethically and scientifically reasonable to suspend resuscitation for those who have been judged to be brain dead.

0?2?0?2?0?2?0?2?0?2?0?2 ③ Doctors are thus able to accurately determine when death has occurred. This is also helpful in resolving legal issues that may be involved (e.g., insurance, inheritance, etc.). ?0?2

History of Development

The concept of brain death has a history of more than 40 years, and it is a scientific phenomenon that has been recognized and revealed by the in-depth development of medical science, and is not the whim of an expert or someone else, but is in line with the general understanding of scientific concepts, and has stood the test of history.

The emergence of the concept

The concept of "brain death" first arose in France. In 1959, French scholars P. Mollaret and M. Goulon first proposed the concept of "Le Coma Dépassé" (coma overload) at the 23rd International Neurological Society, and at the same time reported the existence of this pathological state of 23 cases, and began to use the term The term "brain death" was introduced. Their report suggested that the likelihood of reviving a patient diagnosed with "coma overload" was virtually nil. The medical community accepted and recognized the term. This realization began.

Since then, research on this "coma overload" has focused on determining the diagnostic criteria for brain death and ruling out a "brain death-like state," while suggesting that deep hypothermia and drug overdose must be ruled out before a diagnosis of brain death can be made. Since 1966, "brain death" has been recognized as a marker of death in France.

The world's first criteria for brain death

In 1966, the United States proposed brain death as a sign of clinical death. In 1968, at the 22nd World Medical Congress, the Special Committee on the Review of the Definition of Brain Death at Harvard Medical School proposed "irreversible loss of brain function" as the new death criterion and formulated the world's first diagnostic criteria for brain death:

1. Irreversible deep coma;

2. Spontaneous respiratory arrest;

3. Loss of brainstem reflexes;

4. Loss of brainwaves (flat).

Death is pronounced when the above criteria are met and the test is repeated several times within 24 or 72 hours with no change in the results. However, it is necessary to exclude both hypothermia (<32.2°C) or the recent administration of barbiturates and other central nervous system depressants.

Criteria established by the World Health Organization

In the same year, the International Committee for the Scientific Organization of Medicine (ICOM), established by the World Health Organization (WHO), stipulated the criteria for death as follows:

1. Respiratory and cardiac arrest;

2. Irreversible deep coma;

3. Disappearance of neural reflexes of the brainstem (e.g., pupil-to-light and corneal reflexes, cough reflexes, and swallowing reflexes are lost);

4.

The essential elements are the Harvard criteria.

In 1971, the concept that brain stem death is brain death was introduced in the United States.

The Royal Society of Medicine (RSA) formulated the British Criteria for Brain Death in 1976, proposing that brain stem death is brain death, a step forward from irreversible coma.

In 1979, it was explicitly stated that a patient could be declared dead once brain death had occurred.

The Royal Society of Medicine (RSA) formulated the Criteria for Brain Stem Death in 1995.

In 1980, Li Dexiang, a Chinese scholar, proposed that brain death should be whole-brain death, thus overcoming the defects of cerebral death (irreversible coma), brain stem death and other partial brain death equivalent to brain death, and this viewpoint has been recognized by Chinese scholars ****.

Diagnostic criteria for brain death in China

Brain death is an irreversible state of loss of skills of the whole brain, including the brain stem.

Prerequisites include a clear cause of coma and exclusion of reversible coma of all causes.

Diagnostic criteria: deep coma, total loss of brainstem reflexes, and absence of spontaneous breathing. All of the above must be present.

Confirmation test, flat electroencephalogram, transcranial brain Doppler ultrasound showing brain death pattern, somatosensory evoked potentials p fourteen or more waveforms disappeared. One of these three must be positive.

Brain death observation time: after the first confirmation of the diagnosis, the observation of 12 hours without change, can be confirmed as brain death.

Diagnostic criteria for brain death in children

The diagnosis of brain death in children should be more careful, and the following can be referred to:

(1) Coma and respiratory arrest exist at the same time.

(2) Total loss of brainstem reflexes, dilated and fixed pupils, fixed eyes, and complete cessation of respiratory activity.

(3) Constant and unchanged results of the above tests.

Controversy

While the concept of "brain death" was first proposed by a few medical professionals in the West, a number of "miracles" in recent years seem to indicate that brain death is not enough to prove that a person is truly dead, or that this kind of miracle of regaining spontaneous breathing or even consciousness after brain death is not enough to prove that a person is truly dead. There is a probability that such a miracle of regaining spontaneous breathing and even consciousness after brain death exists. Perhaps it is also possible that brain death is not being determined with sufficient rigor; after all, humans know very little about the brain. For this reason, most countries that recognize brain death as the basis for death still retain the traditional criteria of "cessation of spontaneous respiration, cardiac arrest, dilated pupils, zero blood pressure, etc." as the criterion for determining death, and brain death is only an auxiliary determination.

Examples

According to U.S. media reports on the 26th, a U.S. woman, Wilma Thomas, recently suffered a heart attack that left her without any brainwave activity for 17 hours, and her heart stopped beating three times, and she was finally officially declared "dead" by her doctor and removed from the life-support system. But surprisingly, as her family was tearfully preparing for her funeral, Wilma, whose body had begun to stiffen, suddenly regained her heartbeat and woke up 10 minutes later, miraculously "coming back from the dead"!

According to reports, the 59-year-old Wilma Thomas is a native of Charleston, West Virginia, U.S. Early in the morning of May 23, Wilma had a heart attack at home and called her son. Paramedics responded to the call and arrived at her apartment to break down the door and found her on the floor with no pulse, so they immediately rushed her to a local West Virginia hospital. Doctors scrambled to revive Wilma. But during the resuscitation, Wilma's heart stopped beating three times in a row. Doctors had to shock her chest several times with an electric defibrillator to try to get her heart to beat again.

What's even more frightening is that for 17 hours, even Wilma's brain activity stopped almost completely, with no detectable brain waves being generated! Although doctors tried everything they could to save Wilma's life, even using "cryotherapy" - lowering her body temperature with ice to stimulate her brain to revive - Wilma showed no signs of survival. "At that point, there was no sign that Wilma was still neurologically functional," said Kevin Eggleston, the internist in charge of her rescue.

With Wilma's life on the line, all of her family rushed to the hospital to pray for her safety. But all signs pointed to the fact that Wilma was dying. I was praying in my heart, 'God, bring mom back to life,'" said son Tim Thomas. But there was no longer the slightest sign of life in her body; her skin had begun to harden and her hands and toes were curled."

When Wilma's heart stopped beating for the last time at 1:30 a.m. on May 24, doctors finally had to officially declare Wilma dead. Learning the terrible news, the family had only one difficult decision to make - to agree with the paramedics to turn off the switch on the ventilator and other instruments and equipment that were keeping Wilma alive. We prayed and prayed, but in the end we were forced to accept the fact that mom was not going to make it because she had no heartbeat," said son Tim Thomas. It broke our hearts to make that decision." The family then bid Wilma a tearful goodbye before leaving the hospital and beginning preparations for Wilma's funeral.

Wilma was reportedly an organ donor who had decided to donate her organs to others after her death, and for that reason, doctors did not send her to the morgue after declaring her "dead," but instead sent her to an air-conditioned, temperature-controlled operating room where they were about to remove all of her available organs. But at this critical moment, a miracle happened - 10 minutes after Wilma's life support was removed, she suddenly and miraculously regained her heartbeat and woke up! She moved her arms and legs, then started coughing and opened her eyes!

Wilma's "return from the dead" stunned all the doctors and nurses present. She suddenly moved her arms, which we thought was just a reflex of the dead," recalled Dr. Eggleston. But then she made more movements, and the electrocardiograph showed that she had regained her heartbeat!" Even more unbelievably, the awakened Wilma even began to speak to the doctor and asked him, "Where is my son?"

A nurse rushed to call Wilma's son, Tim, who was already five miles away from the hospital. He, too, nearly dropped his jaw when he learned that his "dead" mother was moving again and had a heartbeat. Tim recalled, "By the time I got back to the hospital, my mother was able to talk to me and asked me in confusion, 'Where have you been? Apparently, she had no memory of anything that had happened since she went into a coma on May 23, as if nothing had ever happened."

Wilma's "miraculous resurrection" has left doctors in disbelief, according to Dr. Eggleston: "It's a miracle. There are some things that doctors can't explain, and I think this is a classic case. Wilma doesn't seem to have been affected by this incident in any way, she is now acting completely normal and we are all very surprised and happy." Wilma is reportedly expected to make a full recovery. on the 25th she said, "I feel so good right now, much better than I did the other day!"

Fuzhou, Nov. 7 (Xinhua) -- Yesterday, Peng, a Chongqing worker who came to Quan, crossed the line between life and death, and also broke through the medical practice that death can be confirmed after 12 hours of brain death.

It is understood that the patient Peng is more than 30 years old this year, Chongqing people, to work in Quanzhou more than 2 months. October 31 night was injured and sent to Quanzhou Success Hospital for treatment. Quanzhou Success Hospital vice president Prof. Li Changde said that on the morning of the 2nd, he and surgeon Xu Mingyao to treat the patient Peng, when Peng was unconscious, according to his brother Peng Dajiang said he had been unconscious for 10 hours.

After resuscitation, by 10 p.m. on Nov. 3, although there was still a weak heartbeat, Peng's symptoms already met the medical community's criteria for brain death: deep coma, total loss of brainstem reflexes, and no spontaneous respiration.

Thirty-four hours later at 8:30 a.m. on the morning of Nov. 5, Prof. Li asked the family for their opinion: the patient was already brain-dead, should he still receive treatment?

On Nov. 5, Peng's mother rushed to Quanzhou from Chongqing. It was during the two days that the mother rushed over that the miracle happened.

These days, Peng's body is cold, the doctor several times to measure the body temperature can not be measured. Yesterday morning, Peng Dajiang suddenly felt his brother's body warm, 6 a.m., the nurse measured the temperature, actually reached 35 degrees Celsius. At 10 a.m., dozing at the bedside of Peng Dajiang was woken up by Professor Li's exclamation: "It's a miracle!" Originally, Peng at this time has regained independent breathing, "with breathing that he has been out of the shadow of brain death."

According to Professor Li, the prevailing medical death criteria are brain death and cardiac death, but China's legislation only recognizes the cardiac death criterion: that is, the heart stops beating for the end of life. However, the heart is an independently contracting organ, and even in the absence of cerebral innervation, the heart can maintain beating for a long time. That's why many medical doctors believe that the brain death criterion is more scientific and has more significance for organ transplants, and a brain death law is already in the works in China.

Latest criteria

It is understood that the latest criteria of the Ministry of Health's brain death law drafting group are: deep coma, all brainstem reflexes disappeared, no independent breathing (maintained by respiratory machine, apnea test positive). After the first diagnosis, the observation of 12 hours without change, can be confirmed brain death

The structure of the human brain

The human brain is composed of the medulla oblongata, the bridge of the brain, the midbrain, the cerebellum, the mesencephalon and the telencephalon and other six parts, the medulla oblongata, the bridge of the brain and the midbrain is known as the brain stem. The respiratory center of the human body is located in the brainstem, so damage to the brainstem function will directly lead to the cessation of respiratory function. Unlike some parts of the human body where cells can regenerate after injury, nerve cells cannot regenerate once they are necrotic. Therefore, when a person's brainstem suffers irreversible damage, the brainstem becomes permanently and completely dysfunctional, resulting in an irreversible loss of respiratory function. Subsequently, other organs and tissues of the body will also gradually lose their function because they are not supplied with oxygen.

Firm

0?2?0.2.0.2.0.2.0.2.0.2.0.2 Clinically, brain death refers to the irreversible loss of function of the entire brain, including the brainstem. Brain death is different from "vegetable", "vegetable" brain stem function exists, coma is only due to severe damage to the cerebral cortex or in a state of sudden inhibition, the patient can have voluntary respiration, heartbeat and brain stem response, while brain death is no voluntary respiration, is permanent and irreversible.

This is the first time that I have been in a coma, and I have been in a coma.

0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2 Brain death refers to the criteria for declaring death by reference to the permanent loss of function of the brainstem or the central nervous system above the brainstem. Brain death is different from "vegetative state", in which the brainstem functions normally, and coma is only due to severe damage to the cerebral cortex or a sudden state of inhibition, and the patient can have voluntary respiration, heartbeat, and brainstem response, whereas in brain death, there is no voluntary respiration, and the death is permanent and irreversible. permanent and irreversible. The first step in the process is to determine if the patient has a heart rate of 0.2%, 0.2% and 0.2%. In many countries, "cardiac arrest," "loss of respiration," and "zero blood pressure" used to be the criteria for death. However, with the development of medical science and technology, the patient's vital signs such as heartbeat, respiration and blood pressure can be reversed or maintained for a long period of time through a series of drugs and advanced equipment. However, if structural damage to the brain stem occurs and destroys it, it eventually develops into cardiac death regardless of medical treatment. Therefore, brain death appears to be a more scientific and reliable criterion than cardiac death. ?0?2

Diagnostic criteria for brain death in China

Brain death is an irreversible state of loss of skills of the whole brain, including the brainstem.

Prerequisites include a clear cause of coma and exclusion of reversible coma of all causes.

Diagnostic criteria: deep coma, total loss of brainstem reflexes, and absence of spontaneous breathing. All of the above must be present.

Confirmation test, flat electroencephalogram, transcranial brain Doppler ultrasound showing brain death pattern, somatosensory evoked potentials p fourteen or more waveforms disappeared. One of these three must be positive.

Brain death observation time: after the first confirmation of the diagnosis, the observation of 12 hours without change can be confirmed as brain death.

Diagnostic criteria for brain death in children

The diagnosis of brain death in children should be more careful, and the following can be referred to:

(1) Coma and respiratory arrest exist at the same time.

(2) Total loss of brainstem reflexes, dilated and fixed pupils, fixed eyes, and complete cessation of respiratory activity.

(3) Constant and unchanged results of the above tests.

Related Information

0?2?0?2?0?2?0?2?0?2?0?2?0?2?0?2?0?2?0?2 Since 1968, when the Special Committee for the Review of the Definition of Death at Harvard University in the U.S.A. put forward diagnostic indexes for brain death, there have been more than 80 countries and regions of the world which have successively established the death criteria, and some of the countries have formulated the corresponding laws of brain death, but there are also some countries that have used the brain death and respiratory death criteria coexist way.

The brain irreversibly stops moving. The EEG shows a straight line. Brain death is the definitive sign of death. Traditionally, death was not declared until respiration and circulation ceased. However, with the progress of medical science and technology, heart and lung function can be artificially maintained, and some primary brain damage has caused extensive necrosis of brain tissue, and the damage is irreversible. After the concept of brain death was put forward in 1957, with the development of organ transplantation, a lot of researches have been carried out on brain death from the aspects of clinical, electrophysiological, cerebral circulation, cerebral metabolism, and neuropathology, etc. The concept of brain death has been recognized by many countries. The concept of brain death has been recognized by the laws of many developed countries. Resuscitation can be stopped when brain death is determined, and the organs of brain-dead people are available for transplantation.

0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 2? 0? 0? 2 The diagnostic criteria for brain death include: ① the brain's response to the outside world is absent. ② Absence of automatic respiration (requiring an artificial respirator). (iii) Absence of spontaneous movements and induced movements (passive flexion of the limbs after receiving a nociceptive stimulus). Brainstem reflexes are absent, including pupillary light reflex, corneal reflex, head-eye reflex, and vestibular reflex. ⑤ Electroencephalogram is electrically resting. Brainstem evoked potentials are absent. (7) Transcranial Doppler ultrasound does not detect blood flow. (8) The above manifestations last for at least 24 hours. ⑨ Need to exclude drug intoxication or hypothermia-induced coma.