Tags

, ,

Greetings, people, and a special welcome to those of you recently signed up to this blog on the medical history behind current events. Lovely to have you, and such a delight to have people other than those I am related to and who are, therefore, genetically obliged to read this. (Hi Mom!) It was also especially great to have your comments on the last post – I appreciate them, so thank you.

Today, I have something from the bizarre files of strange-but-true medical history for you. Here’s what made me think of it: this week, doctors at a conference in Barcelona for anesthesiologists called for more guidance on how to tell when a person is dead. Here’s the link.

I know, I know! What type of first dates are these people going on??? Kidding. Kidding. But, funnies aside, there is a very serious issue here, and one with a history.

When is a person dead? Historically, the answer to that question was always: “When their heart stops beating and they stop breathing.” Partly, this heart/lung definition of death related to an old idea, dating back to ancient Greek medicine, that the heart was the seat of life. It was, according to Aristotle, the first part of the body formed in utero, the source of the body’s heat and seat of the soul, directing and controlling the bodily economy. (None of which is the case. Sounds nice, though.) And partly it reflected the physiological fact that, without blood being pumped around the body carrying oxygen and glucose to the cells, all the organs would indeed fail and the person would definitely be dead.

Patent sketch (1882) for a "device for indicating life in buried persons".

Patent sketch (1882) for a “device for indicating life in buried persons”.

Under the heart/lung definition of death, the test for whether a person was dead or not was to feel for a pulse, and check with, say, a mirror for condensation from breathing. These tests were (and are) however not a fail-safe. People who are very cold or heavily drugged might seem not to have a pulse or be breathing. There are ghoulish accounts of corpses reanimating in mortuaries and exhumed skeletons found to have clawed the lids of their coffins. For this reason, laws were passed in the nineteenth century requiring a delay before burying a body after death had been certified by a doctor. Just in case. Enterprising inventors of the Victorian era offered coffins equipped with speaking tubes or bells, just in case you came to six feet down and needed to contact the surface to be dug out.

But let’s fast forward to the 1960s when the heart/lung view of when to call it quits came into question. Two developments made this an issue.

Development One was technological. Life support systems—artificial respirators which could take over breathing for a patient whose brain was not prompting this function—had made it possible to keep severely brain-damaged patients alive. (And antibiotics helped stave off infection which is a big risk for patients in a coma.) Electro-encephalograph machines (EEGs) allowed physicians to detect and measure the electrical activity of patient’s brains. EEGs showed that there were some patients in comas whose hearts were still beating (machines couldn’t take over that function), but their brains were so damaged that the neurons were no longer firing and sending out electrical signals. The brain was dead; the rest of the body was not. Barring rare accounts of miracles, for most such patients there was no hope of recovery. Instead they faced a continued existence—life would be too active a word—with machines invasively taking over their bodily functions until heart attack or infection killed them.

Christiaan Barnard (1922-2001)

Christiaan Barnard (1922-2001)

Development Two which really brought things to a head was this: in December 1967 South African surgeon Christiaan Barnard announced that he had successfully performed what Time magazine called “the ultimate surgery”. He had transplanted a donor heart into his patient, Louis Washkansky, a 54-year-old grocer dying of heart disease. Washkansky lived for 18 days after the surgery—not a long time, but long enough to show that the new heart had worked. The heart had come from Denise Darvall, a young woman who had been hit by a car the day before and was on life support. Her brain was no longer functioning and she was in a coma, on life support.

Successful kidney transplants from so-called “beating-heart cadavers” had been performed since 1953, but Barnard’s feat suggested the world was on the brink of a new era in medicine—an era of transplants. But only if donor organs could be found.

Under the older heart/lung criteria for whether a person was dead, patients like Denise Darvall in irreversible comas whose hearts were still beating were “alive”. Barnard for years kept secret the fact that Denise Darvall’s heart had not stopped of its own accord before he removed it from her body. He had induced a heart attack by injecting her heart with potassium. According to the law at that time (but not later), Christiaan Barnard had killed Denise Darvall when he stopped her heart to use it for transplantation. Even though patients in such irreversible comas weren’t breathing for themselves, their hearts were still beating and therefore, by the heart criteria they were still alive. They would have to stay in intensive care units until their hearts stopped—and this would probably mean that their organs were no longer viable for transplant.

So in 1968, Harvard Medical School convened a committee to redefine death. The Ad-Hoc Committee of Harvard Medical School to Examine the Definition of Brain Death (as it was called) was composed of neurologists, physiologists, public health clinicians, biochemists, transplant surgeons, a medical historian (shout out for the medical historian!) and an ethicist. Together, the committee met to develop criteria by which “irreversible coma” would become “the new criteria for death”. An irreversible coma was characterized by “a permanently nonfunctioning brain”.

In its report, published in the Journal of the American Medical Association, the committee set out diagnostic tests that would identify when a person in a coma had a “permanently nonfunctioning brain”: they would not respond to stimuli such as noise or pain; they couldn’t move or breathe for themselves; their EEG was flat (no electrical activity in the brain); and none of their reflexes worked (such as the pupil no longer contracting in response to bright light; tapping muscles with a reflex hammer producing no movement.) Brain death, argued the committee, not a non-beating heart, should be what signified that a person was not coming back.

And that is indeed what happened. The Harvard Committee’s recommendations today form the foundation of how death is defined for medical and legal purposes around the world. Death by committee. For those of us who have worked in bureaucracy, that is an all-too-familiar occurrence (he he) but I find it a startling episode in the history of medicine.

Medical historians and ethicists debate the various influences on the Harvard Committee’s decisions. The Committee itself said that it wanted to redefine death for two main reasons. One reason was to reduce the burden of brain-dead patients—the cruelty of continued massive medical intervention and the impact on relatives—as well as the burden on other patients needing hospital beds already occupied by comatose patients. The other reason the Committee gave was that, if transplant surgery was to become a reality, doctors needed legal certainty about when they could or could not take organs from someone. Putting it bluntly, the Committee wanted clear guidelines so that no one could accuse transplant surgeons of taking organs out of people while they were still “alive”.

Other commentators have said that the Committee wanted to ensure a supply of organs for transplantation. The reasons for this could either be altruistic—because surgeons wanted to be able to help people needing transplants—or for professional interest—because surgeons were enthused about this exciting new surgical opportunity and wanted to have a go at it.

One could see this episode in medical history as evidence of how the medical profession strives to weave an ethical pathway through the moral dilemmas thrown up by disease, technology, and the limits of medical attainment and try to work out the best way to help patients. Or, should you be so inclined, you could also interpret it as doctors trying to clear the way for them to indulge in exciting new opportunities for their skill. I think a fair reading of the evidence of the Harvard Committee’s deliberations and what they said for themselves suggests that there are elements of both of these factors. But I also think that delight in exercising skill as a doctor is perfectly compatible with caring for patients—people can both want to help people and take pleasure in their skill in doing so.

not-dead-yetSo why are the anesthesiologists at the conference this week wanting more guidance on when a person is dead? Why is determining death still an issue? Well, for one thing, death turns out to be extremely complicated. Like the joke in The Princess Bride, there’s “all dead” and then there’s a considerable range of “mostly dead.”

The criteria the Harvard Committee set out for determining death and which are used today with some variations and refinements are meant to determine when the “whole brain” has stopped functioning. But some people argue the criteria are too broad and so identify people as dead who are in fact not dead yet. And others say the criteria are too narrow and more people are dead than what the criteria would say. On the “too narrow” side there is evidence that in some people who pass the “whole brain” criteria some parts of their brains are still working—their bodily temperature is still being regulated, for example, or their neuro-hormones are still signaling. Something is still working in there, so clearly the “whole” brain is not dead.

And on the “too broad” side, some people say “whole brain” death is too much and what we really mean when we say a person is dead is that they are permanently unconscious and will never wake up again. That is, it is not the “whole brain” that matters but the “higher brain” dying that should be what “death” means. Under this definition, people in what is called a “persistent (or permanent) vegetative state” (PVS)—heart beating, breathing, but permanently unconscious—would be considered “dead” when under the “whole brain” criteria they are not.

And even setting these debates aside about how much dead is all dead, the criteria used to determine death vary between different countries. This is particularly the reason why the anesthesiologists meeting in Barcelona would like clarification. You might be dead in Italy, but in England, say, you’re still alive. (And I say that without casting any cultural aspersions.) Trying to find a ethical answer to the meaning of death when there are currently no perfect solutions is a difficult, fraught and important challenge. But surely, being dead should be a condition the same the world over, and so the World Health Organisation is working on developing an international standard. Presumably also by committee.

Interested? Want more?

* The Harvard Ad Hoc Committee’s report is:

Ad Hoc Committee of the Hard Medical School to Examine the Definition of Death. “A Definition of Irreversible Coma.” Journal of the American Medical Association 205, no. 6 (1968): 85-88.

* Later development of the Harvard criteria and review of the issues:

President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research. “Defining Death: Medical, Legal and Ethical Issues in Determination of Death.” Washington, D.C: US. Government Printing Office, 1981.

* Reviews of the Harvard Committee’s work, including debates about what factors influenced its decisions:

Giacomini, Mia. “A Change of Heart and a Change of Mind? Technology and the Redefinition of Death in 1968.” Social Science of Medicine 44, no. 10 (1997): 1465-82.

Pernick, M.S. “Brain Death in a Cultural Context: The Reconstruction of Death 1967-1981.” In The Definition of Death: Contemporary Controversies, edited by S.J. Youngner, R.M. Arnold and R. Schapiro, 3-33. Baltimore: Johns Hopkins University Press, 1999.

Wijdicks, Eelco F.M. “The Neurologist and Harvard Criteria for Death.” Neurology 61, no. October (2003): 970-76.

* On use of brain death criteria in different countries around the world:

Baron, Leonard, Sam D. Shemie, Jeannie Teitelbaum, and Christopher James Doig. “History, Concept and Controversies in the Neurological Determination of Death.” Canadian Journal of Anesthesiology 53, no. 6 (2006): 602-08.

* On the debate about the “whole brain” standard:

Truong, Robert. “Is It Time to Abandon Brain Death?” The Hastings Center Report 27, no. 1 (1997): 29-37.

Advertisements