The permanent vegetative state: ethical crux, medical fiction?

• Author: Borthwick, Christian J.

In 1994 a Multi-Society Task Force made up of representatives of the American Academy of Neurology, the Child Neurology Society, the American Neurological Association, the American Association of Neurological Surgeons, and the American Academy of Pediatrics produced a Consensus Statement on the Medical Aspects of the Persistent Vegetative State (PVS).(1)

The vegetative state can be diagnosed according to the following

criteria: (1) no evidence of awareness of self or environment and an

inability to interact with others; (2) no evidence of sustained,

reproducible, purposeful, or voluntary behavioural responses to visual,

auditory, tactile, or noxious stimuli; (3) no evidence of language

comprehension or expression; (4) intermittent wakefulness manifested

by the presence of sleep-wake cycles; (5) sufficiently preserved

hypothalamic and brain-stem autonomic function to permit survival

with medical and nursing care; (6) bowel and bladder incontinence;

and (7) variably preserved cranial-nerve reflexes (pupillary, oculocephalic,

corneal, vestibulo-ocular, and gag), and spinal reflexes.... A

wakeful unconscious state that lasts longer than a few weeks is referred

to as a persistent vegetative state.(2)

This consensus statement built on the 1990 work of the American Medical Association's Council on Scientific Affairs and Council on Ethical and Judicial Affairs and presents the appearance of virtual unanimity among the governing elements of American medicine on a linked series of beliefs on the diagnosis, treatment, and ethical status of post-coma patients. These medical conventions are generally accepted unquestioningly as constituting a factual foundation for ethical debate in this area; ethicists like Ronald Dworkin and Peter Singer can thus use PVS as the basis for structures of ethical reasoning--limiting cases that eliminate confounding variables by providing practical examples of humanness combined with insentience.

The courts have also for some decades been prepared to take judicial cognizance of the condition in such cases as Gannon v. Albany Memorial Hospital.(3) In that case Carrie Coons, an eighty-six-year-old woman, was hospitalized after a massive stroke. Initially able to speak single words, her condition deteriorated until she was completely unresponsive. She was unable to eat or drink independently, was maintained by a gastrostomy tube, and the hospital physicians agreed that she was a PVS patient. Ms. Coons's sister maintained that Ms. Coons would not want to be kept alive in that condition, and the court accepted this. The court noted that PVS was an irreversible condition, that PVS patients were incapable of consciously experiencing or appreciating life, and that the prevailing medical view, as evidenced by the positions of professional societies, supported the withdrawal of artificial feeding from such patients. The court permitted her caregivers to withdraw the feeding tube.(4)

The name persistent vegetative state was originally proposed by Jennett and Plum in 1972 to describe patients with brain damage in a state that was no longer coma but was not recovery--that showed "wakefulness without awareness." "In our view the essential component of this syndrome is the absence of any adaptive response to the external environment, the absence of any evidence of a functioning mind which is either receiving or projecting information, in a patient who has long periods of wakefulness."(5) Karen Ann Quinlan is generally taken to be the prototypical PVS patient, and her lack of consciousness is generally taken as being axiomatic. "Karen Ann Quinlan ... has not been aware of the extra years of life she has had, and thus has had no benefit from them."(6) All diagnoses are intended to compress information--to carry in a name an etiology, or a treatment, or a course. A diagnosis of PVS carries no information about etiology and arises only after the failure of treatment; it does, however, incorporate a large element of prognosis. A typical recent article on the ethics of withdrawal of life support describes PVS as a condition where patients "are considered to have permanently lost the function of their cerebral cortex.... All voluntary reactions or behavioral responses reflecting consciousness, volition or emotion at the cerebral cortical level are absent.... [T]here is no observable experience of pain or suffering.... They remain permanently unaware."(7)

Two of the basic practical issues with any post-coma patients are "Will they recover?" and "Do they feel pain?" As far as possible, Jennett and Plum's definition removed both questions from the realm of argument by building the qualities of irreversibility and lack of consciousness into the attributes of the condition, and, as the quotation shows, most doctors and virtually all ethicists have from the outset accepted these attributed characteristics without question.

Some accidents and diseases leave their victims either in comas or in

what doctors call a persistent vegetative state. In either case they are

unconscious--though many patients in a persistent vegetative state

have open, moving eyes--and the higher centers of their brains have

been permanently damaged in a way that rules out any return to

consciousness. They are capable of no sensation and no thoughts.(8)

The Multi-Society Task Force is aware that these classifications are not always straightforward. So is Ms. Coons. In her case the court had permitted nutrition to be withdrawn; before the decision could be implemented, however, she woke up. She started eating and speaking. She was, not surprisingly, less positive than she had been before the stroke about her ethical views on termination of treatment. The court "ordered further neurological and psychiatric assessments."(9)

The MPDLR reporter's comment in that case was "It is clear that Ms. Coons was not in a persistent vegetative state."(10) Taken this way, the characteristics of the diagnosis are unusually immune to modification through observation. If you diagnose a number of people as having tuberculosis and all die, that outcome may for a time be accepted as a characteristic of the condition. If one eventually recovers, however, you will presumably modify your description of the disease to omit the words "invariably fatal"--will do so, at least, if you follow the usual pattern of medical development. If, contrariwise, you were to work on the rather more specialized PVS model of nosology, you would note that, while all patients with tuberculosis invariably died, there was another rarer, different, but observationally indistinguishable condition called pseudotuberculosis, whose patients invariably recovered. It is not clear that this is the most helpful approach to the problem.

The problem that Dworkin et al. do not address is that whether or not PVS is permanent, a diagnosis of PVS is not absolutely irreversible; some people with a diagnosis of PVS do recover, or at least recover sufficiently to demonstrate consciousness. Because some patients with a diagnosis of PVS do recover, it is not easy to prove that the condition of the brain in patients diagnosed as PVS, as a class, is such as to rule out the possibility of recovery or awareness in any given case. Ms. Coons may stand as a reminder that the fallibility of medical science cannot entirely be negated by self-confirming diagnostic criteria. The Consensus Statement of the Multi-Society Task Force is an attempt to extract from these uncertainties sufficient regularity to take the weight of clinical prescription. Their work requires close analysis.

Consequences of the Utilization of the PVS Diagnosis

While the general image of PVS is generally drawn from young trauma patients like Quinlan, the state is now increasingly being diagnosed in older people with post-stroke complications and older people with conditions such as dementia of the Alzeheimers type (DAT).(11) The number of people diagnosed as having the condition has therefore increased, and the consensus statement guesses that there are between ten thousand and twenty-five thousand adults in the USA in a persistent vegetative state. As these guesses are based on scaling up a small number of small studies a thousand times, these estimates are not particularly reliable. Even if they were correct, of course, it would not be the whole story; rough calculations based on the figures given in the statement suggest that approximately 50% of PVS patients have been in that state for less than six months, 70% for less than a year. The number of long-term PVS patients would thus on that assumption be somewhere between thirty-five hundred and ten thousand.

A previous survey of care costs for PVS patients that did at least refer to recorded costs in actual cases suggested a range from a low of $18,000 to a high of $120,000 with an average of around $60,000.(12) The consensus statement refers to a single case study to reach an estimate of cost of care of the PVS patient in a nursing facility as costing from $126,000 to $180,000 per year, on average two and a half times the previous estimate.(13) It suggests, based on this person, that "[a] rough approximation of the total annual costs in the United States for the care of adults and children in a persistent vegetative state is $1 billion to $7 billion."(14) Even if this sharply raised estimate was correct, it would still not be the relevant figure. As most patients have been in the state for less than six months, still have a reasonable chance of recovery,(15) and are still receiving treatment, their costs are not avoidable. Even with long-term patients, the question is not how much a patient who has progressed from, say, dementia to PVS costs in a nursing home, but rather how much more he or she costs as a PVS patient than as a dementia patient. The consensus statement figure is a negotiating tool, not an economic instrument.

Awareness and the Diagnosis of PVS

The Multi-Society Task Force...