Why Is Brain Death Death? A Thought Experiment

This guest post is part of The Bioethics Program’s Online Symposium on the Munoz and McMath cases. To see all symposium contributions, in reverse chronological order, click here.

by James Zisfein, M.D.
Chief, Division of Neurology, and Chair, Ethics Committee, Lincoln Medical Center

The Munoz case in Texas demonstrates that, with aggressive medical treatment, vital functions in some brain-dead patients can be maintained for weeks or months. Shewmon documented similar cases and coined the term “chronic brain death”. Is it still reasonable to continue using the brain death standard as a criterion of death if the rest of the body can maintain somatic integrative functions, including cardiovascular homeostasis, for a prolonged period without the brain? Some commentators question whether the “enduring utilitarian legal fiction of whole brain death as death has passed its sell by date.”

Notwithstanding those concerns, I must remind the reader that, as a practical matter, the brain death standard usually works well. Families understand the finality of death. The brain death standard allows for unilateral removal of medical support in what many of us feel is an extreme example of futility. It also provides the major source of vital organs for transplant, of which I will have more to say later. I’m happy with justifying brain death on utilitarian grounds alone.

But if we insist on philosophical underpinnings, it’s time for a thought experiment. In this experiment, I will dismember Michelle (virtually, of course, and with her permission). Let’s start by removing relatively unimportant parts, say the appendix, some lymph nodes, maybe the spleen. After doing that, we can agree (I hope) that Michelle is still Michelle.

Then we go for more important stuff. Arms and legs? No problem. Kidneys? We can substitute for their function with dialysis or a transplant. Michelle is still 100% Michelle. The removed parts are therefore irrelevant to Michelle’s personhood.

We’re not finished yet. Michelle’s heart can be removed and replaced with a donor heart, or a mechanical pump. (So much for the cardiac definition of death.)

You know where I’m going with this. The only body part that can’t be removed or replaced without changing its owner is the brain.

If we could remove Michelle’s brain and replace it (horrors!) with my brain, the resultant person would be me, with body parts that used to belong to Michelle. If we replaced Michelle’s brain with a computer, we would have a robot (albeit a rather fleshy and bloody one). In either case, Michelle would be gone.

It’s a short leap from this thought experiment to the realization that the irreversible loss of the brain, or its functions, is the irreversible loss (i.e., death) of the brain’s owner.

A less grisly argument, also based on personhood, would begin with a stipulation that all human beings are mortal. We are not allowed — by definition or otherwise — to convey immortality. That means we must always have some way of determining death.

With improving medical technology, that could become impossible. Absent a brain death standard, we could — at least in theory — keep someone alive indefinitely by continuing to change parts as they fail. Everything (other than the brain) that is vital could be substituted for, including the heart. Dr. Jarvik (of the Utah/Humana artificial heart project) boasted that his artificial heart could keep working for 300 years. After that? Put in another one, presumably an improved model. Voila, immortality. Not acceptable. The risk of “chronic brain death” that Shewmon cited, is, paradoxically, a good reason for having a brain death standard.

And we must consider the utilitarian importance of brain death for organ donation. Whistling past the graveyard: that’s how I would characterize ending the brain death standard of determining death, without (1) prior abolition of the “dead donor rule” (which states that vital organs can be taken only post-mortem) and (2) seeing how many pre-mortem donors that yields. I believe there would be strong resistance to ending the dead donor rule anywhere, let alone all 50 states, and that the number of pre-mortem vital organ donations would be small even if it were permitted.

Removal of the brain death standard, in the absence of legal and widely practiced pre-mortem organ donation, would likely cause thousands, perhaps tens of thousands of deaths on the organ waiting list. Allowing that calamity for the sake of ethical purity would place one’s ethics on a par with the Khmer Rouge.

For now, and for the foreseeable future, brain death is a criterion of death. It’s up to those of us who work in health care, ethics, and law to speak with clarity when communicating on this topic to the media, to courts, to bereaved families, and to our colleagues.


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