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The Waiting Game
Organ Transplant Controversy January 2, 1998 |
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Questions answered
in this forum:
Is one way to avoid the ethical mess is to have a "National" society of organ donations? What is the difference between heart and brain death? Is it necessary to use Regitine to preserve organs, and what are its dangers? What is the research/clinical status of alternatives such as artificial organs, animal organs, etc.? Is there something wrong with this constant prolonging of life? Online NewsHour asks: What is the difference between heart and brain death? Does it make a difference for procuring organs?
Dr. Michael DeVita responds:
The traditional criteria for death are three: absense of circulation (blood flow), absense of respiration (no breathing) and absense of neurologic activity (unresponsiveness). The vast majority of people are pronounced dead using these well accepted criteria. However, ever since doctors developed the capability to sustain life artificially through the use of heart and lung machines, there has been a group of patients who did not meet the traditional criteria for death. These patients were kept alive by machines, without hope of recovery and without possibility of recovering consciousness. In the late 1960's and early 1970's, there was a national debate to determine whether such patients could and should be pronounced dead, and if so, what criteria to use. In 1981, a President's Commission recommended that it is appropriate to pronounce death using only neurologic criteria even if the heart and lungs were still working. Patients satisfying these criteria are termed "brain dead." The commission specifically stated that the new neurologic criteria were intended to complement and not replace the traditional criteria. And that is what happened. There are two complementary criteria for determining death. An analogy might be using either DNA analysis or fingerprint analysis to determine identity: they are each reasonable and sufficient to determine identity. One need not do both.
Before "non-heartbeating" organ donation occurs, doctors determine death using the traditional criteria, while in "heartbeating" organ donation, the neurologic criteria are used because the heart is still beating. In both situations the patient is legally dead before procurement occurs. Some reports have questioned whether the non-heartbeating patients are really dead because their brains might still be functioning. This is definitely not the case. Most brains cease to function BEFORE the heart stops, usually when the blood pressure gets very low, about 50 or so (normal is usually about 120 or so). In addition, when circulation stops, brain function always stops within 12 seconds except in a very few specific situations which are impossible during non-heartbeating organ donation. The University of Pittsburgh protocol requires that after the heart has stopped, we wait an additional two minutes to make sure the heart really has stopped, and then we pronounce death. Several minutes later, after the family can say their farewells, the organ procurement can proceed.
Ms. Renee Fox responds:
Death may be a unitary phenomenon, as the report on Defining Death issued in 1981 by the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research declared: and it is certainly a universal and ultimately inevitable happening. However, at this historical juncture in the United States, there are two sets of medically and legally legitimate criteria for determining and pronounced death. (1) An individual may be diagnosed and pronounced dead on the basis of the cessation of heartbeat and breathing – of circulatory and respiratory functions. These are long-standing, traditional indicators that the medical profession has used as definitive signs of the occurrence of death. (2) A person may be "defined" as dead on the basis of the irreversible cessation of all functions of the brain, including the brain steam (the "whole brain."). These are the newer criteria for determining death – ones that were given both substantive and symbolic impetus by the publication in 1968 of the report of an ad hoc committee of Harvard Medical School that set forth the characteristic of a permanently non-functioning brain, a condition it refers to as "irreversible coma." "Brain death" has not supplanted heart-lung-based death. The two co-exist ecumenically. Furthermore, regardless of which criteria are used, the precise standards for determining death vary in different protocols, and in different states as well (since this is a matter of state law.)
The incentive to develop and apply the concept of brain death was given powerful impetus by at least two major medical technological advances: the development of intensive care, mechanical support systems that can artificially maintain respiration and circulation in patients whose brains have irretrievably ceased functioning: and the advent of organ transplantation for which viable and intact organs are needed. The suitability of organs for transplantation diminishes rapidly once the donor's respiration and circulation stop. The most ideal organ donors are otherwise healthy individuals who have died following traumatic brain injuries – who have been declared "brain dead" – and whose breathing and blood flow are being artificially maintained. However, even with the best intensive care, the organs of these potential donor patients, then, a clear understanding of the criteria of brain death and their implementation is crucial in order to ensure that such patients are dead.
During the 1990's, in response to the widening gap between the "demand" for organs for transplantation and their "supply," and increasing consternation among transplanters over the life-and-death implications of this "organ shortage" for the thousands of patients with end-stage diseases on long waiting-lists for transplants, a number of U.S. medical centers have developed protocols or proposals for recovering organs from what are termed "non-heart-beating donors" whose deaths are determined by the cessation of heart and respiratory function, rather than whole brain function. These are gravely ill or severely injured patients on life support who, with proper consent, are removed from the mechanical assist technology that is artificially maintaining their heart beat breathing, or patients who have suffered unexpected cardiac arrest who cannot be resuscitated. There is considerable concern in the media as well as in certain medical circles about whether the need to remove organs from such patient-donors as soon as possible after circulation and respiration cease subjects from and their families to an indecent death, and even more worrisome, about whether these patients are really "dead-dead," as some nurses put it, when the organs are excised from their bodies.
Dr. William Ritchie responds:
The medically accepted standard criteria for the determination of death is found in the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research, 1981. Defining Death: Medical, Legal, and Ethical Issues in the Determination of Death. Washington, D.C.: U.S. Government Printing Office.An individual who has sustained irreversible cessation of circulatory and respiratory functions meets the criteria for heart death. An individual who sustains irreversible cessation of all functions of the entire brain, including the brain stem meets the criteria for brain death. A variety of medical test are used by licensed physicians to confirm that death has occurred.
Three important principles provide the moral frame work for organ procurement in the U.S. First, the dead donor rule mandates that persons must be dead before their organs are taken. Second, the prohibition against active euthanasia (homicide), although patients may be allowed to die under certain circumstances. Finally, the primacy of consent: patient or family consent must precede organ retrieval.
When brain death is declared, the transplantable organs can remain viable for an extended period via the use of a ventilator, continuing the process of providing nutrients. After the declaration of death, family can be given time to accept the occurrence of death before being approached for organ donation, a process call decoupling. It also provides time for families to consider the donation option.
When heart death occurs, all circulation of nutrients cease causing damage to the organs. Transplantable organs can remain viable for only a short period of time, unless organ preservation techniques are initiated. Normally families only have a few minutes after the pronouncement of death to consider the donation option. At Washington Hospital Center, we can extend this period by initiating in situ preservation of the kidneys in potential non-heart beating donors. This allows families additional time to consider donation. This process involves flushing the kidneys with a cooling solution containing preservatives while they are still inside the body after death occurs. The kidneys are removed only after consent has been obtained from the family. In the District of Columbia, a law exist that allows hospitals to began in situ preservation if the family is not readily available in order to provide time to locate them and give them the option to consider donation.
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