Redefining death: A new ethical dilemma
■ To secure life-saving vital organs, some physicians are pushing the boundaries of what constitutes death. The ramifications for the transplant system could be profound.
A days-old infant sustained severe neurological injury after being asphyxiated during birth, but the dying baby's condition did not meet the criteria for brain death -- long the only circumstance under which vital organs were procured. The baby was transferred to Children's Hospital in Aurora, Colo., a suburb of Denver, where the family decided to withdraw life support. Family members also agreed to let surgeons there attempt to transplant the baby's heart into an infant born with complex congenital heart disease.
But to accomplish this, the potential donor heart had to stop working. The question: How long after cardiac functioning ceased should the retrieval team wait to ensure the baby's heart would not restart without intervention? The complicating factors: Odds of successful transplantation decrease as the wait after cessation of cardiocirculatory function increases. But acting too soon can make retrieval seem like death by organ donation.
The Denver team waited 75 seconds.
The infant who received that heart lived, as did two other babies who received hearts from donations retrieved shortly after cardiac death in transplants the Denver team performed between May 2004 and May 2007. The results were published in the Aug. 14, 2008, New England Journal of Medicine.
The clinical debate over whether 75 seconds without cardiac function after withdrawing life support is sufficient time to confidently declare death is unsettled, but the questions these cases raise go even deeper. Some bioethicists and physicians say the cases are merely the latest in the organ transplantation era to stretch the definition of death in ways that could potentially undermine Americans' trust in physicians and in the organ donation process.
A matter of minutes
Expanding the pool of potential pediatric heart donors beyond those who meet brain-death criteria can help meet a pressing need. About 100 infants younger than a year old receive life-saving heart transplants every year. But as many as 50 infants in need of heart transplants die each year while waiting on the United Network for Organ Sharing list, according to an NEJM editorial.
About a third of infants who die in pediatric hospitals do so after life support is withdrawn. These infants represent a valuable pool of life-saving organs. The Denver team said that at Children's Hospital, 12 potential infant donors died of cardiocirculatory causes during the three years of the study, accounting for a possible 70% increase in organ donation.
According to the "dead-donor rule" adopted as law in all 50 states, patients must be declared irreversibly dead before their vital organs can be retrieved for transplantation, provided there is consent from patients or surrogate decision-makers.
Securing organs from brain-dead patients has been deemed ethical since a Harvard Medical School committee formulated the criteria in 1968; every state recognizes brain death as legal death.
Over the last decade and a half, organ donation after cardiac death has become medically and legally acceptable, though the timing question has proved contentious. The so-called Pittsburgh protocol, published in 1993, called for a two-minute wait after cardiopulmonary arrest before declaring death and retrieving organs. The Institute of Medicine in 1997 said transplant teams should wait five minutes after cardiac functioning ceases before retrieving organs.
Then in 2000, the IOM said some data suggested a shorter interval of 60 seconds, though its report said "existing empirical data cannot confirm or disprove a specific interval at which the cessation of cardiopulmonary function becomes irreversible." The Society of Critical Care Medicine recommends a wait of at least two minutes but no longer than five minutes.
American Medical Association policy doesn't address the time issue, but says the practice is "ethically acceptable" as long as conflict-of-interest and palliative care protocols are followed.
In its first infant heart donor case, the Colorado team waited three minutes. But the Children's Hospital ethics committee determined, based on data it reviewed, that a 75-second wait would be sufficient and would reduce the risk of injury to the donor heart from blood loss.
This groundbreaking decision has received fierce criticism, including a series of editorials published in the NEJM. A member of the Children's Hospital ethics committee declined to speak with AMNews.
But the author of one editorial derided as "arbitrary" the 75-second protocol the Colorado team used. "We know that infants, compared to older people, tend to be more resilient," said James L. Bernat, MD, professor of medicine and neurology at the Dartmouth Medical School in New Hampshire. "We are always more conservative in our delineations with infants. It's especially troubling that they reached that conclusion."
The process of deciding how long to wait before declaring cardiac death "shouldn't be done ad hoc," he said. "It should be something done following guidelines. There are some guidelines out there; admittedly, there could be better ones. I understand why they wanted to shorten the wait, but I don't think it's a good idea."
Bioethicist Arthur L. Caplan, PhD, agreed. "I'm not against moving fast and saving other lives. But the big 'but' is you have to do that with a national consensus, not local groups saying when it comes to neonates 75 seconds is plenty of time to wait," said Caplan, director of the University of Pennsylvania Center for Bioethics.
Other critics said the concept of transplanting a heart after cardiac death isn't logical.
"If someone is pronounced dead on the basis of irreversible loss of heart function, after all, it would not be possible for heart function to be restored in another body," wrote Robert M. Veatch, PhD, a Georgetown University medical ethics professor, in an Aug. 14, 2008, NEJM essay. "One cannot say a heart is irreversibly stopped if, in fact, it will be restarted."
Veatch said the dead-donor rule should be changed to allow patients or their families to opt for a standard that takes a loss of functioning consciousness (short of brain death) as another kind of death. Physicians could then procure hearts "in the absence of irreversible heart stoppage."
Robert D. Truog, MD, said the Denver cases illustrate the underlying problem in how death is defined to facilitate organ donation and transplantation. He said it is time to reconsider the dead-donor rule.
"The existing paradigm, built around the dead-donor rule, has increasingly pushed us into more and more implausible definitions of death, until eventually we end up with such a tortured definition that nobody's going to believe it," said Dr. Truog, professor of medical ethics and anesthesia at Harvard Medical School in Massachusetts.
"When you get there, you run the risk of really undermining confidence in what this whole system is about," he said.
"We are seeing it play out in the Denver example," he added. "What made it problematic was that they were trying to fit what they did into our existing ethical norms. It's like trying to fit square pegs in round holes. It just doesn't fit."
Dr. Truog has long argued for what he admits is a "radical departure" from the current definition of norms for death. He disagrees that brain death is actual death, noting that major life functions continue. Brain-dead patients have given birth, for example.
Dr. Troug argues that vital organ donation does cause patients to die, and to say otherwise misleads patients and families. But dying patients on life support and their families have a right to consent to such donations, even if it causes death, he said.
While the debate over the timing of cardiac death is contentious, most experts disagree with Dr. Truog's opinion on the dead-donor rule.
"The dead-donor rule serves a great purpose," said John J. Paris, a Boston College bioethicist. "There is a great sentiment among people that [physicians] might try to do you in to take your organs. ... The protection is we only take organs from those who are dead and can't take organs to cause them to be dead, which is a substantial leap from where we are. And the slippery slope is very slippery in that case. If you don't have to be dead to get the organs, then from whom can we take them?"
Dr. Truog said no transplants should take place without consent from patients or their surrogates, and such donations should be limited to patients whose surrogates want to discontinue life support.
That standard is not good enough for Georgetown's Veatch.
He said Dr. Truog's proposal "amounts to an endorsement of active, intentional killing of the patient -- that is, active euthanasia. It would be euthanasia by vital organ removal."
The Denver heart transplant cases already have sparked a contentious debate over how soon is too soon to declare death. Whether physicians, bioethicists and lawmakers will be spurred to redefine death remains to be seen.
Franklin G. Miller, PhD, said it is unlikely. He has co-authored articles with Dr. Truog that call for doing away with the dead-donor rule.
He predicted that "we can just muddle through" with the current definitions of death.
Miller, a bioethicist at the National Institutes of Health, said "people will get bent out of shape" by critiques of the dead-donor rule. "But I think we need, in a way, to get bent out of shape to make sense out of what we're already doing."