Brain Death

Brain death is a legal definition of death that emerged in the 1960’s as a response to the ability to resuscitate individuals and mechanically keep the heart and lungs working. In simple terms, brain death is the irreversible end of all brain activity. It should not be confused with a persistent vegetative state.

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When a person does not respond to external stimuli because of brain damage, the condition is known as a coma. In some cases, damage may affect the whole brain, including the brainstem. This part of the brain controls many of the bod’s vital automatic functions, such as heart rate and breathing. If the brainstem is severely damaged, such as after a head injury, these vital automatic functions, such as heart rate and breathing. If the brainstem is severely damaged, such as after a head injury, these vital functions may be affected. if brain damage is irreversible and the brain ceases to function, the person may be certified as brain dead. A person who is brain dead will be completely unable to respond to any stimuli and unable to breathe independently. Without a life-support machine, death occurs within a few minutes.

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Legal history of brain death
Traditionally, both the legal and medical community determined death through the end of certain bodily functions, especially respiration and heartbeat. With the increasing ability of the medical community to resuscitate people with no heart beat, respiration or other visible signs of life, the need for a better definition of death became obvious. This need gained greater urgency with the widespread use of life support equipment, which can maintain body functions indefinitely, as well as rising capabilities and demand for organ transplantation

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In the U.S., an ad hoc committee at Harvard Medical School published a pivotal 1968 report to define irreversible coma. The Harvard criteria gradually gained consensus toward what is now known as brain death. In the wake of the 1976 Karen Ann Quinlan controversy, state legislatures moved to accept brain death as an acceptable indication of death. Finally, a presidential commission issued a landmark 1981 report — Defin­ing Death: Medical. Legal, and Ethical Issues in the Determination of Death. — that rejected the “higher brain” approach to death in favor of a “whole brain” definition.

Today, both the legal and medical communities use “brain death” as a legal definition of death. Using brain-death criteria, the medical community can declare a person legally dead even if life support equipment keeps the body’s metabolic processes working. The first nation to adopt brain death as a legal definition death was Finland in 1971. In the United States, Kansas enacted a similar law earlier.

Religion and brain death
There has been but limited opposition to the shift from traditional indicia of death, based on breathing and heartbeat, to the brain death criteria. However, traditionalist Orthodox Jews have staunchly defended the traditional conception of death in the U.S. and Israel (See Time of Death by J. David Bleich.) Conversely, some modern Orthodox rabbis and Israel’s Chief Rabbinate have adopted determinations of death based on brain function. (See Moshe Tendler’s elucidation of Rabbi Moshe Feinstein‘s responsa.) As a result, Orthodox Jewish ethics has been sharply divided over key death-related policies. Tactically, Orthodox Jewish opponents to brain death have requested waivers from state law, as a matter of religious freedom, so as to continue relying on traditional indicia.[2] Meanwhile, proponents have been active in advocating organ donations and transplants.

Similarly, Islamic views on brain death are mixed. (“Views of Muslim scholars on organ donation and brain death” Transplantation Proceedings, Volume 29, Issue 8, December 1997, Page 3217. Faroque A. Khan, The Definition of Death in Islam: Can Brain Death Be Used as A Criteria of Death in Islam? Farhat Moazam, Bioethics and Organ Transplantation in a Muslim Society: A Study in Culture, Ethnography, and Religion, Indiana University Press, 2006, p.32ff.)

The 1981 federal report, Defin­ing Death, found that Catholic and Protestant theologies did not object to brain death criteria. Indeed, Dennis Horan, president of the pro-life group American Citizens United for Life, stated:

Legislation limiting the concept of brain death to the irreversible cessation of total function of the brain, including the brain stem, is beneficial and does not undermine any of the values we seek to support.

In Catholic medical ethics, brain death was accepted as early as 1957 in the statement of Pope Pius XII that death is determined by medical experts and it “does not fall within the competence of the Church.” (See, “The Prolongation of Life” in The Pope Speaks 4:4 1958) More recently, the Pontifical Academy of Science has upheld Catholic doctrine. (“The determination of brain death and its relationship to human death.” Working Group, 10-14 December 1989, pp. xxvii-210 ) Nevertheless, there was some Catholic dissent on neurological criteria for death. Some pro-life activists oppose or question the current medical criteria for brain death.

Medical criteria for determining brain death
A brain-dead individual has no electrical activity in the brain and no clinical evidence of brain function upon physical examination. This includes no response to pain and no cranial nerve reflexes. Reflexes include pupillary response (fixed pupils), oculocephalic reflex, corneal reflex, no response to the caloric reflex test and no spontaneous respirations.

It is important to distinguish between brain death and states that mimic brain death (e.g., barbiturate intoxication, alcohol intoxication, sedative overdose, hypothermia, hypoglycemia, coma or chronic vegetative states). Some comatose patients can recover, and some patients with severe irreversible neurologic dysfunction will nonetheless retain some lower brain functions such as spontaneous respiration, despite the losses of both cortex and brainstem functionality. Thus, anencephaly, in which there is no higher brain present, is generally not considered brain death, though it is certainly an irreversible condition in which it may be appropriate to withdraw life support.

Note that brain electrical activity can stop completely, or drop to such a low level as to be undetectable with most equipment. This includes a flat EEG during deep anaesthesia or cardiac arrest. To preclude these states being defined as brain death, the term refers only to the permanent cessation of electrical activity.

The diagnosis of brain death needs to be rigorous to determine whether the condition is irreversible. Legal criteria vary, but it generally requires neurological exams by two independent physicians. The exams must show complete absence of brain function, and may include two isoelectric (flat-line) EEGs 24 hours apart. The proposed Uniform Determination Of Death Act in the United States attempts to standardize criteria. The patient should have a normal temperature and be free of drugs that can suppress brain activity if the diagnosis is to be made on EEG criteria.

Alternatively, a radionuclide cerebral blood flow scan that shows complete absence of intracranial blood flow can be used to confirm the diagnosis without performing EEGs.

Brain death and consciousness
It is presumed that a permanent cessation of electrical activity indicates the end of consciousness. Those who view the neo-cortex of the brain as solely responsible for consciousness, however, argue that electrical activity there should be the only consideration when defining death. In many cases, especially when elevated intracranial pressure prevents blood flow into the brain, the entire brain is nonfunctional; however, some injuries may affect only the neo-cortex.

Brain death and organ donation
Most organ donation for organ transplantation is done in the setting of brain death. In some nations (for instance, Belgium, Brazil, Poland, Portugal and France) everyone is automatically an organ donor, although some jurisdictions (such as Singapore) allow opting out of the system. Elsewhere, consent from family members or next-of-kin is required for organ donation. The non-living donor is kept on ventilator support until the organs have been surgically removed. If a brain-dead individual is not an organ donor, ventilator and drug support is discontinued and cardiac death is allowed to occur.
Depending on the age and previous health of the person and the cause of death, relatives may be asked about their wishes regarding organ donation.

What might be done?
If doctors believe that brain death has occurred, a series of tests is carried out by two experienced medical consultants to confirm the diagnosis. these tests check the person’s response to stimuli and the functions that are controlled by the brainstem. They include testing the ability to breathe independently without a life-support machine.

A diagnosis of brain death is made only if doctors confirm that brain and brainstems functions have been lost and that the cause has been identified but cannot be reversed, despite everything possible having been done.

Someone with brain death will not survive for more than a few days, even with care in the critical care unit. full medical support, including mechanical ventilation, will go on while relatives are given counseling. Doctors will discuss the situation fully with the family, and family members will be involved in the decision on when to switch off the life-support machine.


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