Different philosophies and religions present us with different ideas about death and its spiritual and personal dimensions. In our modern age, while doctors now have precise criteria to determine when death has occurred, there is still debate among medical scientists about exactly what it means to die.
The dividing line between life and death would seem to be clear. When someone dies, it means they are no longer an active physical and mental presence. But in reality, the boundary does not seem to be quite so sharp, either in medical terms or in terms of our personal experience.
Most familiarly, perhaps, an individual’s identity does not cease to exist when they are no longer around to interact with us. Physical absence often makes little difference to our consciousness of a person. Anyone who has lived through the death of someone they are close to knows that the person’s identity lives on vividly in the minds of everyone who knew them. We retain an image of the person as they existed most characteristically in their relations to us. If the person was debilitated by illness or old age, this process of constructing them in memory may begin long before death, as well as extend after it. We prefer to think of the person when they were closer to their prime, rather than in pain and reduced by illness. After the person’s death or departure from active life, we are still able to perceive how they would have felt and reacted in certain situations, imagine their thoughts, hold conversations with them in our minds, and experience them strongly as a continued presence in our lives.
This is not just something that happens when someone dies. We all at times find ourselves imagining how our best friend, a close relative, or a partner would characteristically respond in a given situation when they are not currently with us. We carry their existence in our consciousness, whether they are alive or dead. Thus, we live on in the consciousness of others, as we live in theirs and they in ours in normal life. This is the one sense in which we all can experience a kind of immortality – as a force influencing and affecting those we know in life.
Medical and legal death
The boundary between life and death in medical and legal terms is also not as clear as one might at first think. Historically, medical science had little difficulty defining death – it was the absence of breathing and heart; when these vital systems closed down irreversibly, so did all the other functions of the body. The patient was dead, with the predictable consequence of physical disintegration to follow.
Today, these old certainties have been obscured by advances in medical technology. Doctors can now keep somebody’s systems functioning long after others have ceased. Bypass machines and respirators can carry out the functions of the heart and lungs in patients who have suffered devastating neurological damage and who will never recover consciousness. In effect, the body can be kept biologically alive – growing, developing, and repairing its worn-out cells – although it is capable of existing only at a vegetative level. The rapid development of intensive care medicine over the past few decades has triggered a complex debate about the nature of death. Not surprisingly, this has been led by the medical and legal professions, which demand a definition of death consistent with modern practice and workable criteria by which to pronounce the end of life. This has legal implications, for example, in determining whether an assault becomes homicide.
Defining death
The move toward drawing up a new definition of death came in 1968 when a committee of distinguished US physicians, theologians, lawyers and philosophers assembled at Havard Medical School. They concluded that death should be redefined as the irreversible loss of function of the whole brain. A person was to be regarded as legally dead when his or her brain was no longer alive and could not be brought back to life. The medical and legal establishments quickly adopted the so called Harvard criteria based on this definition, and nvm appears on the statutes of all states in the USA and in more or less similar forms around the world. The widespread acceptance of the new definition of death owes much to one very practical pressure – the development of transplant medicine. Kidneys were the first organs to be successfully transplanted from one individual to another, but today, heart, liver, pancreas, and lung transplants are performed routinely. Transplant surgery requires the organs to be in good condition, which means that they should be ‘ harvested’ as soon as possible after death. If brain death has been diagnosed, there is no obstacle to the removal of organs while the heart is still beating. Much of today’s transplant surgery – and its ability to prolong and improve the lives of thousands of patients – would not be possible without the brain death standard.
Between life and death
One of the purposes of the Harvard criteria is to distance doctors from the ethical minefield that now surrounds a diagnosis of death. But there are two conditions – coma and persistent vegetative state (PVS) – that still cloud the issue for clinicians. A coma is a profound state of unconsciousness. It may be caused by a head injury or a period of oxygen deprivation caused by, for example, a heart attack, smoke inhalation, or near-drowning. The affected person is alive but cannot be roused from an apparent ‘sleep-like’ state and is unable to respond to external stimuli. Recovered patients often report that they were able to see, hear, and understand while in a state of coma, which suggests a level of consciousness. However, they had no way of communicating this awareness to other people.
PVS, which sometimes follows a coma, is a condition in which the patient loses function of the cerebral cortex – the part of the brain that controls the ‘ higher’ brain activities, including perception and conscious thought. However, the brainstem continues to function, maintaining activities such as breathing and heartbeat. The patient may laugh, cry out, or make spots of our movements, and the eyes may even be able to track a moving object.
With intensive physical therapy and medical care, most patients will come out of a coma within four weeks. Many make a full recovery, but some emerge with a range of physical or psychological difficulties. These depend on the severity of the damage to the patient’s brain tissue. The prognosis for PVS is far worse. A patient in PVS for more than one month is extremely unlikely ever to regain consciousness, and the few patients who have regained awareness have been severely mentally disabled, blind, deaf, or paralyzed.
The dilemma raised by PVS is this medical science makes it possible to maintain patients in PVS not just for weeks but for decades. The medical bill for one patient can run into hundreds of thousands of dollars, and today, there are an estimated 14,000 patients in the USA in PVS. Patients in PVS are clearly not dead by current definitions, and yet their prospects for recovery after a few months are negligible. In these cases, should the boundaries of death be widened to include irreversible P VS, and if so, what criteria should be used if we decide to stop feeding and treating patients in this condition?
The matter is still highly controversial, but what will follow is likely a further redefinition of death based on irreversible loss of consciousness – the single characteristic that is most specifically human.
Diagnosing Brain Death
The following criteria must all be met before a doctor can diagnose brain death:
- The patient is unable to take a single breath unaided.
- The pupils of the patient’s eyes are fixed open.
- The patient does not respond in any way to painful stimulation, such as a needle prick.
- There is no muscle tone in the arms and legs.
- There are no signs of activity in the brainstem, indicated by the following factors.
- The eyeballs are fixed in their sockets.
- There is no cough or gag reflex when the back of the throat is stimulated.
- There is no corneal reflex – that is, the patient does not move when the surface of the eyeball is stroked.
- There is no response when ice-cold water is poured into the ear (if the person is alive, the person’s eyes will move).
After these criteria have been checked, brain death will only be confirmed when the doctor is sure that the patient has not taken opiate or barbiturate drugs within the last 24 hours. In addition, scans must be carried out to confirm that no blood is penetrating the brain, or EEG measurements made to show no sign of detectable electrical activity in the brain.
Transplant surgery
Since Christian Barnard performed the first heart transplant operation in 1967, the diagnosis of brain death has become crucial. Organs for transplant can be taken from a body only when brain death has been diagnosed. They are then preserved by cooling and transported to the transplant site as quickly as possible.
