Alexander Capron, a noted expert in medical policy and ethics, opened his 2001 article concerning brain death with an infamous quote: “If one subject in health law and bioethics can be said to be at once well settled and persistently unresolved, it is how to determine that death has occurred.”
Prominent medical and philosophical literature, several legal cases questioning a hospital’s or physician’s diagnosis, and the national headlines these cases captured have created doubts about the validity of brain death. The ambiguous nature of some criteria and considerations only makes clinical practice that much more uncertain, says Michael Rubin, M.D., M.A., Associate Professor of Neurology and Neurosurgery and Director of Clinical Ethics at UT Southwestern through the Peter O’Donnell Jr. Brain Institute.
"It doesn't take many of these cases to put a very concerning light on the situation. Then families that are suffering Google it and find a case of 'brain death reversal' that may have never actually been appropriately declared. The most important thing we can do is make sure we get the diagnosis right," Dr. Rubin says.
As an author of the American Academy of Neurology’s updated guidelines for diagnosing brain death in adults and children, Dr. Rubin has worked with medical professionals across the country to bring clarity to the debate.
“I think the most interesting aspect of the new guidelines is it really shows the intersection of medical practice, public policy, philosophy, ethics, and law,” Dr. Rubin says. “As much as we try to focus on the clinical elements of it, what we've seen with developments over the last few years is clearly there is more than just the physician opinion that impacts how we actually practice.”
Well Settled – The Origins of Defining Brain Death
For all its modern-day complexities, the academic history of brain death dates back less than a century. Pierre Mollaret and Goulon were among the first to formally describe the concept in their 1959 paper, “Le Coma de Dépassé,” where they explored the idea of coma patients who were beyond recovery, despite cardiorespiratory activity.
Henry K. Beecher and colleagues took it a step further in 1968, when they sought to classify an irreversible coma as a benchmark to declare death, provided specific criteria were met. As medical technology advanced, they argued, hospitals would fill with comatose patients who would never wake up, creating excess burden on their loved ones, medical facilities, and other patients needing hospital beds and organ transplants.
The discourse among medical, legal, and government experts culminated in 1980, when the American Medical Association (AMA), the American Bar Association (ABA), and the Uniform Law Commission (ULC) convened to determine once and for all the base definition of death in the United States. There, they drafted three brief bullet points that constitute the entirety of the Uniform Determination of Death Act (UDDA):
- An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death must be made in accordance with accepted medical standards.
- This Act shall be applied and construed to effectuate its general purpose to make uniform the law with respect to the subject of this Act among states enacting it.
- This Act may be cited as the Uniform Determination of Death Act.
This marked a firm turning point for physicians nationwide, but naturally, this one piece of legislation did not end the brain death debate in the United States. Several states would go on to enact variations of the UDDA with alternate definitions for declaring death, omitting one or more of the main requirements it outlined. Multiple physician groups have advocated for revising the UDDA in the intervening years but have not made much headway.
Persistently Unresolved – Central Disagreements Around Brain Death
In the decades since the UDDA was first written, physicians have continued to grapple with emerging issues brought up by medical advances and legal disputes. Experts in neurology and pediatric neurology would further publish and revise guidelines for determining brain death in adults in 2010, followed by guidelines regarding brain death determination in infants and children in 2011. Updating universal standards for medical practitioners, however, has largely been hampered by ongoing debates among medical organizations, lawmakers, and the public.
Many of the arguments relate to a handful of nebulous questions:
Is it really death?
The core question here is if a loss of neurological function is morally equivalent to a loss of respiratory/circulatory function.
Although brain death has generally been accepted as true death in most of the Western world, a number of cases involving patients who continued to be supported through artificial means after a brain death diagnosis have called this acceptance into question. For this reason, some physicians, such as Robert Troug, M.D., have argued brain death should be regarded as a “social construct” and treated the same as any biological death. Others, such as D. Alan Shewmon, M.D., have argued the brain plays more of a modulatory role in the human body but is not required for most life-sustaining systems.
What is the ideal brain criterion of death?
Even if medical consensus says brain death is a valid reason to declare a patient death, that just leads to an even larger debate over the specific criteria required. The time between cardiac arrest and resuscitation, which areas of the brain were deprived of blood flow, and other underlying conditions are just a few factors that can affect a patient’s survivability, as well as their neurologic function. Further studies have concluded that the brain may be more capable of restoration than previously thought. In experiments, an extracorporeal pulsatile-perfusion system has restored some functions in pig brains four hours after blood flow ceased, including synaptic activity.
No matter how slight, if it’s possible to restore some brain function in select cases, that just leads to the next issue.
Is it “irreversible” or “permanent”?
In legal definitions, the use of the word “irreversible” versus “permanent” to describe a loss of functions has led to a semantic debate. “Irreversible” implies attempts have been made to restore brain function, while "permanent” does not. Since the UDDA’s verbiage relies on “irreversible,” this leaves the door open for arguments over whether restoration attempts should be made and to what extent. In some cases, this could extend the dying process, even when medical consensus says that sustaining a patient’s life this way will not make a difference.
Must hypothalamic neurosecretory function cease?
Even when patients meet the criteria for brain death, they could still show some brain activity, particularly neuroendocrine functions. As the UDDA delineates “all functions of the brain,” the persistence of these functions could mistakenly raise questions about whether recovery is possible or if testing standards should be refined further.
Should the apnea test require informed consent?
The apnea test is one of the most definitive tests for diagnosing brain death and can carry risk if not done properly, as it involves temporarily removing artificial ventilation. This has caused some discourse about when the test should be performed and whether it should require informed consent from the patient’s family.
Is it necessary to consider religious or philosophical accommodations?
Probably the issue most discussed by the general population is whether a patient’s beliefs should factor into a brain death diagnosis and to what extent. Various religious faiths have their own approaches to the subject, and states’ laws offer some guidance to physicians, but these vary so much on a case-by-case basis that a consensus may be unattainable.
How To Determine That Death Has Occurred – New Guidelines, Better Diagnosis
The latest efforts to revise the UDDA were paused in 2020 during the COVID-19 pandemic, and there have been no clear plans to resume since. Currently, with so many stakeholders involved having conflicting approaches to revisions, even the ULC committee formed for this task does not see a way to move forward.
In the meantime, a panel of neurological experts across multiple medical societies, covering pediatric and adult specialties, assembled to bring some direction to the situation. Using a modified Delphi process to reach a consensus, their efforts produced the AAN’s 2023 Pediatric and Adult Brain Death/Death by Neurologic Criteria Consensus Guideline.
In contrast to the UDDA’s three bullet points, the 21-page document extensively covers 85 recommendations for determining brain death, all with the main goal of more reliable and consistent diagnoses. Each recommendation provides direction related to most key issues, accompanied by the panel’s rationale behind it. The emphasis is on properly determining the cause for a brain injury, supported by thorough imaging, and not attempting to diagnose brain death in a patient unless it’s clear they would meet the criteria. Overall, the guidelines include methods to avoid misdiagnosis due to underlying factors, procedures for apnea testing, appropriate ancillary tests, and when to declare time of death.
From a patient standpoint, a direct, comprehensive set of standards may seem blunt, but credited author and neuroethicist Dr. Rubin sees them as more merciful than morbid for a patient’s loved ones:
"In an odd way, it can be very fulfilling to bring a family a definitive diagnosis that says, 'You don't have to make any decisions. It's over.' To take that suffering off of them because their loved one meets the legal criteria of death, as morbid as it is, really prevents a tumultuous time of asking, ‘Do we continue support? How long? What does this mean? What are we choosing for them?’”
Besides giving hospitals and physicians clearer guidance for their practice, the ultimate goal of more defined recommendations is to assuage doubts raised by the public and build a better relationship between families and their caregivers. The guidelines also recommend allowing families to be present during testing and keeping them informed to hopefully enhance the public’s trust. No matter what guidelines, policies, or other tools physicians have at their disposal, it ultimately comes down to the trust of the patient’s loved ones.
“A family comes into the room and sees their loved one supported on artificial equipment; they see a monitor with a heart rhythm and oxygen saturation. And at some point, we're going to come in and do an exam, review imaging and other data, and have to tell them that the person is no longer alive,” says Dr. Rubin. “That takes a gigantic leap of trust. While we may have complete confidence in the diagnosis, they have to be willing to accept that what we are telling them is as it is. It really shows the importance of the patient-physician relationship. Establishing that understanding early really leads to greater acceptance.”