Evaluating the definition of brain dead


By Dr. Tim Millea
Catholic Health Care Today Column

Dr. Millea

What is the definition of “death?” The answer seems straightforward. According to the Merriam-Webster Dictionary, death is “a permanent cessation of all vital functions,” a definition that is easily understandable and acceptable.  However, in the medical community, the determination that someone is dead is a debate that began decades ago.

In 1968, an ad hoc committee of the Harvard Medical School published an article to “examine the definition of brain death.” The committee’s focus was on the “characteristics of irreversible coma.” Since then, this topic has generated significant and increasing debate and criticism. The core issue relates to a basic yet perplexing question: If there is no indication of brain activity but the heart is still beating, is that person dead?

A presidential commission, appointed in 1981, attempted to clarify the answer. The commission’s work produced the Uniform Determination of Death Act (UDDA). From then until now, the legal standard in the United States has made brain death equivalent to “circulatory-respiratory cessation,” which is absence of heart and lung function. That equivalency continues to be at the center of this debate. With the monitoring and assessment available, it is clear when the heart stops functioning. In contrast, how can the cessation of brain function be determined with certainty?


Electroencephalography (EEG) is a test that identifies brain waves, similar to the use of an EKG to detect electrical activity in the heart. However, an EEG is not a comprehensive test for complete brain activity. It does not detect activity in all areas of the brain and does so only in limited areas. In 1987, a short six years after introduction of the UDDA, a study at Loyola Medical Center found 11 patients with persistent EEG activity up to a week after being declared “brain dead.” Thereafter, the use of EEG for assessment of brain death was no longer required due to its lack of accuracy.

Another criterion for brain death is the absence of brainstem reflexes, such as the pupils’ reaction to light, gag reflexes and responses to painful stimulation. However, as with EEG, concerns about the accuracy of these examinations persist. A growing number of cases are documented of individuals with absent brainstem reflexes who were declared brain dead and subsequently regained consciousness and even significant recovery.

Equally troubling is the use of an “apnea test” to determine brain death. Apnea, in medical terms, is the absence of breathing. Patients who “qualify” as brain dead usually require a ventilator. The ability to breathe is controlled by part of the brainstem, thus the premise is that without the ventilator, a brain-dead patient would not breathe on their own. To test this, the ventilator is disconnected from the patient for eight to 10 minutes.  If there is no evidence of breathing efforts, the patient is determined to be brain dead. Therein lies a significant concern.

What if the patient’s brain is still functioning but no reliable methods exist to confirm that?  What happens if an apnea test is carried out?  Asked differently, what happens to a functioning brain when it is deprived of oxygen for eight to 10 minutes? According to the National Institutes of Health, after five minutes, the brain stops functioning. This is a troubling concern in current debates regarding the UDDA. In essence, a test that is intended to determine brain death may well be causing brain death.

The UDDA is being evaluated for possible revisions by the Uniform Law Commission (ULC), a national group of attorneys that works to develop legislation, rules and procedures that will be helpful to the states.  Section 1 of the current UDDA defines a determination of death as “either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem.” The first criterion is indisputable. If the heart and lungs no longer function, the person is dead. The second criterion has led to increasing debate and hesitation among physicians, bioethicists and attorneys. Is a determination of brain death valid if the ability is lacking to confirm, accurately and consistently, “cessation of all functions of the entire brain”? On a moral level, are individuals with a functioning brain being declared “dead” simply because that function can’t be determined medically?

Critics of the current UDDA are pressing the ULC to eliminate the use of “brain death” as a criterion and limit it to circulatory and respiratory function cessation. If that is not accomplished, the UDDA should revise the document to include “opt outs” for the patient’s family to refuse evaluations such as the apnea test.  A defense of the current document often involves the need for organs for transplant. Indeed, the lack of donated organs is true.  However, if the patient’s heart is still beating and even a portion of the brain is still functioning, our Church teaches that the body-soul unity is still intact.  As Christians, we hold respect for the dignity of every life — from conception to natural death.  That does not include a “death” determined by inaccurate means.

(Dr. Tim Millea is president of the St. Thomas Aquinas Medical Guild and a member of St. Paul the Apostle Parish in Davenport.)

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