PVS; ETHICAL CRUX, MEDICAL FICTION?

THE PERMANENT VEGETATIVE STATE; ETHICAL CRUX, MEDICAL FICTION?

By Chris Borthwick

Abstract

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). This Statement presents a picture of the degree of diagnostic certainty achievable in this area that is in many respects misleading. Its attempt to propose a condition called Permanent Vegetative State, which would be based on a high degree of medical certainty either that there is no further hope for recovery of consciousness or that, if consciousness were recovered, the patient would be left severely disabled, confuses two different issues.

 


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).

    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, oculophalic, 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. (1)

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; liberal 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. (2)

In that case Carrie Coons, an 86-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 Coon'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, noted that PVS patients were incapable of consciously experiencing or appreciating life, and noted also 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 carers to withdraw the feeding tube.

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. (3)

Karen Anne 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. (4)

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 on 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. ...there is no observable experience of pain or suffering. ... They remain permanently unaware... (5)

Two of the basic practical issues with any post-coma patient 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. (6)

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'.

The MPDLR reporter's comment in that case was "It is clear that Ms. Coons was not in a persistent vegetative state."(7) 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

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).(8) The number of people diagnosed as having the condition has therefore increased, and the Consensus Statement guesses that there are between 10,000 to 25,000 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 robust. 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 3,500 and 10,000.

A previous survey of care costs for PVS patients (9) 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. The Consensus Statement refers to a single case study to reach an estimate of cost of care of the PVS patient at in a nursing facility as costing from $126,000 to $180,000 per year, on average two and a half times the previous estimate. 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. (10)

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, have still a reasonable (11) chance of recovery, 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

    The Multi-Society Task Force set among its criteria for PVS

    1) no evidence of awareness of self or environment...

    2) no evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to... stimuli;

    3) no evidence of language comprehension or expression. (12)

The fundamental problem with this formulation has been obvious from the beginning. Whether Carrie Coons is speaking or silent, how do you determine whether she is thinking?

    ....there is a group of patients who never show evidence of a working mind. This concept may be criticized on the grounds that observation of behavior is insufficient evidence on which to base a judgment of mental activity... (13)

The concept is indeed vulnerable to just this criticism. Behavior is observable, consciousness (or unconsciousness) is a deduction. Behavior may not in all cases be a reliable guide. Brain damage frequently takes out many of the physical capacities that normally support volitional actions; in the 'locked-in syndrome'

    consciouness and cognition are retained but movement and communication are impossible because of severe paralysis of the voluntary motor system... Patients with this syndrome can usually establish limited communication through eye-movement signals. (14)

It can thus in observational terms consist essentially of PVS with the addition of purposive eye movements.

There are many forms of brain damage that can affect the control of eye movements. The Task Force is uneasily aware of the possibility of such errors.

    By definition, patients in a persistent vegetative state are unaware of themselves or their environment. They are noncognitive, nonsentient, and incapable of conscious experience. There is, however, a biological limitation to the certainty of this definition, since we can only infer the presence or absence of consciousness in another person. ...an error might occur if a patient in a locked-in state ... was wrongly judged to be unaware. Thus, it is theoretically possible that a patient who appears to be in a persistent vegetative state retains awareness but shows no evidence of it. In the practice of neurology, this possibility is sufficiently rare that it does not interfere with a clinical diagnosis carefully established by experts. (15)

Any statement that a physiological state of events is true 'by definition' should arouse query, and there are a number of questions to be asked here. Some are practical - how reliable is the diagnosis of PVS? how often is it in fact made by experts? A more basic question, however, is how is it possible know whether the possibility is rare or not?

Later in the Consensus Statement the possibility of undiagnosable locked-in syndrome appears to move slightly further away from the theoretical to the possible.

    In rare cases, it may be difficult to distinguish a persistent vegetative state from a severe locked-in state. Under such unusual circumstances, a patient may not be able to express behavioral responses to painful stimuli or the responses may be extremely difficult to detect; the absence of a response cannot be taken as proof of the absence of consciousness. (16)

If the absence of a response cannot in cases of severe locked-in syndrome be taken as proof of the absence of consciousness, and if severe locked-in syndrome is virtually indistinguishable from PVS, then the absence of a response cannot in any individual case of PVS be taken as proof of the absence of consciousness. For the Consensus Statement to say that the possibility may be disregarded because it is rare is to assume as a given exactly what the Statement is trying to establish. In the face of this possibility, how can one conceivably prove, in any single case, or in any number of cases, that the subject(s) is/are not sentient? If one cannot prove it, what is the justification for assuming it?

The fundamental issue is not 'Can cases of locked-in syndrome be confused with cases of PVS?' but 'Is it possible that PVS is the same thing as locked-in syndrome, but without purposive eye movement?'

Patents with PVS do give responses that under other circumstances or with other diagnoses might suggest awareness.

    Patients in a vegetative state are usually not immobile. They may move the trunk and limbs in meaningless ways. They may occasionally smile, and a few may even shed tears; some utter grunts or, on rare occasions, moan or scream. ... (17)

However, these behaviors are not in these cases treated as significant.

    Such activities are inconsistent [and] nonpurposeful... These motor activities may misleadingly suggest purposeful movements, yet these responses have been observed in patients in whom careful study has disclosed no evidence of psychological awareness or the capacity to engage in learned behavior. (18)

The term 'purposeful' relates to intentionality, and is inherently unobservable; the term 'inconsistent' presents itself as observational. Even then, however, questions would arise as to how often a behavior would have to be evoked appropriately to free it from this taint. In Karen Anne Quinlan's case, for example, the court judgment notes that

    ...nurses indicate that [on one occasion] she blinked her eyes two times when asked to and appeared responsive by moving her eyes when talked to but there is no further evidence of this type reaction thereafter. (19)

How many repetitions of this action would be required to establish consistency sufficiently to meet the requirements of reversing the definition? The situation is complicated by the uncontested existence of a number of factors - medication cycles, fatigue, differing levels of arousal, muscle wasting - that might induce inconsistency of response in conscious patients.

It is also true that in that last quotation the term 'careful study' is professionally loaded. These signs must be interpreted, and the question is in practical terms whose interpretation is to prevail, relatives or professionals. The question of purposefulness is exactly the point where there is likely to be dispute between professionals and family members. One study of children diagnosed as PVS (20) found that in 12 out of 13 cases (92%) parents felt that the children could recognize voices, and that in 8 (62%) of cases parents felt that the children could make their likes and dislikes known; that is to say, in 92% of cases the parents did not accept the diagnosis of unawareness. Another study (21) found that of thirty-three permanently unconscious patients

... more than half were visited daily by family members... A large majority of those family members also thought that the PVS patient was aware of light and dark, of pain, of conversation, and of their presence.. (22)

The very existence of the diagnosis of PVS arose in part out of the need to impress upon families the meaninglessness of these observations.

A significant grasp reflex often appears, and this may be provoked by chance touch of the bedclothes; to the inexperienced observer or hopeful family the resulting movement may look as though it was initiated by the patient and may even be regarded as purposeful or voluntary. (23)

    The family, then, is in daily contact for hours at a time, the physician drops by several times a week for ten minutes; his observations require some theoretical reinforcement if they are to override those of the family. PVS is in one of its aspects the apotheosis of the privileging of the professional gaze. (24)

More generally, this approach does place the onus on the person to demonstrate his or her awareness rather than on the diagnosing doctor to establish its absence. It is easy to suggest behaviors that would constitute evidence of psychological awareness; it is less easy to demonstrate that absence of these behaviors can be accounted for in no other way than by absence of psychological awareness, and this remains true even in 'patients in whom careful study has disclosed no evidence of psychological awareness'. The attempted proof is circular; patients who give no evidence of consistent response are regarded as being without consciousness only because their presentation is similar to that of other patients who give no evidence of consistent response. It would be possible to address the issue directly, asking people who have emerged from PVS whether or not they felt pain; while a negative answer might simply mean that they did not remember, a positive answer would be decisive. One small study of patients who emerged from coma suggested that they did remember life in coma. (25) Such a study has not been done with ex-PVS patients, and does not appear to have been contemplated.

It is important to remember that the question of awareness is a directly practical issue. Because PVS patients are insentient by definition, it is often recommended that their pain - or at least their pain behavior - is to go untreated.

    ...they do not "feel" (experience) pain in the sense of conscious discomfort that physicians would be obligated to treat... (26)

Any physician who does not treat pain, or even 'pain behavior', in these situation - any physician prepared to ignore the recorded recovery rate and the recorded misdiagnosis rate, and physician prepared to overlook the possibility of undiagnosed locked-in syndrome - should be struck off the register. Any such outcome is, of course, unlikely. It is not at all unlikely that hundreds of patients across the USA are suffering untreated pain because their physicians have relied on the Multi-Society Task Force Consensus Statement.

Brain Reading

The claim of lack of awareness is supported by references to studies of brain function.

    At present, three lines of evidence based on careful clinical and laboratory studies support the conclusion that patients in a vegetative state are unaware of themselves or their environment. (27)

All the studies referred to in support of the hypothesis of unconsciousness suffer from a number of defects. There are only a few such studies ('a small number of laboratory tests'). They refer to small numbers of people. They are not completely consistent. They assume, above all, that we have the knowledge to be able to interpret the readings correctly, and they assume that the damaged brain has no alternative modes of functioning.

The first line of evidence is that

    motor or eye movements and facial expressions in response to various stimuli occur in stereotyped patterns that indicate reflexive responses integrated at deep subcortical levels rather than learned voluntary acts. The presence of these responses is consistent with complete unawareness. (28)

No studies are cited to support this argument. It can nonetheless be seen, however, that the argument is severely limited. A large number of situations - lying on a bed with your eyes shut, for example - are consistent with complete unawareness. The question is whether any such situation is inconsistent with other possible hypotheses. The presence of stereotyped motor movements would seem to be consistent with locked-in syndrome - at least, the presence or absence of such movements is nowhere suggested as a diagnostic differentiator between the two conditions. If such movements are consistent with locked-in syndrome, then they are consistent with awareness.

The second point suggested is that is that

    positron-emission tomographic studies of regional cerebral glucose metabolism show levels far lower than those in patients who are aware or in a locked-in state (29)

The Levy study on differences in cerebral blood flow and glucose utilisation cited by the Multi-Society Task Force on this point ( 'No overlap in metabolic impairment was noted when these patients were compared with three patients who had the locked-in syndrome' (30)), in fact shows that

    at least two of the patients described... had significant cognitive recovery ... (31)

Other disconfirming evidence exists- some cited in the Statement, some not (32) - that shows

    normal cerebral blood flow in patients in a persistent vegetative state. (33)

The cerebral blood flow data is thus inconsistent.

The third line of evidence is that

    all available neuropathological examinations of the brains of patients with a clinical diagnosis of a persistent vegetative state show lesions so severe and diffuse that awareness would have been highly improbable... (34)

Both these comparisons - between the brain indicators of PVS and locked-in patients, and between the brains of PVS patients and average brains - are logically defective. On the most straightforward level, any study that compares PVS readings on any scale only with normal readings (Hansotia, 1985 , (35) for example) can prove nothing. The question is not whether there is brain damage, or the nature of the brain damage; rather, it is whether such damage is such as to exclude sensation. Even the slightly more sophisticated comparison (Levy et al, 1987 (36)) between

People with PVS /People with locked-in syndrome

cannot establish that any difference in brain states or brain function is inconsistent with sensation (or recovery). The comparison that counts is

People with PVS /People recovered from or misdiagnosed as PVS /People with locked-in syndrome

No other indices provide meaningful assistance. EEG data, for example, is unhelpful in providing reliable physiological markers for the condition.

    Evoked-response testing is useful statistically, but not always clinically... ...there are no established correlations between the results of neuroimaging studies and... the potential for recovery... (37)

Other indices are similarly unproven;

    Questions have been raised about the validity of cerebral metabolic studies to determine whether patients in a vegetative state are conscious or can experience pain or suffering. These questions remain unanswered... (38)

In summary, the range of neurodiagnostic tests that have been said to offer

    strong evidence that such bodies can no longer either think or experience pain and suffering (39)

are insufficient to support that judgment.

If the capacity for pain is in fact extinguished in some patients, furthermore, there can be no certainty that this feature persists. "Nothing is more constant about the nervous system than its ability to change." (40) There is some peripheral evidence that pain, in particular, can relocate its functions, or at least that neurones can establish new synapses that are involved in 'pain behavior'.(41)

Here, as elsewhere, problems may arise from setting a baseline that fails to take regard for even normal variation, still less the range of deviance. No researcher has been concerned with assessing the maximum span of these measures within consciousness, and so there is no estimate of the minimum score recorded in readings from an aware patient. There is precedent for highly deviant readings on some other brain function measures being consistent with consciousness.

    EEG on a post-encephalitic patient... shows the most profound (delta) slowing, as is usually seen only in the deepest sleep or coma, even though the patient was perfectly conscious and alert throughout the EEG recording. (42)

However greatly we improved our measurements, however, the philosophical problem would remain. All that comparisons between one set of readings and another can show is that there is a difference. Even if it could be shown that patients with PVS invariably produced readings on a relevant scale that were 50%, say, or 30%, or 1% of normal levels, or even 1% of the lowest reading ever recorded in a patient able to testify to his or her own awareness, this would not establish that a reading of 0.5% or 0.3% or 0.01% was inconsistent with awareness. Whatever the lowest recorded level of expressed consciousness, it still cannot be proved (and should not necessarily be assumed) that less active brains are in fact unconscious to the extent of not feeling pain. The gap must be filled by a leap of faith - faith in the medical profession, and faith in 'common sense'.

Reliability and Permanence

In fact few PVS patients will ever have brain readings taken. Most are diagnosed on simple clinical examination. The reliability of a diagnosis of PVS is, on the extraordinarily small amount of available evidence, poor. One study of patients in nursing homes who had been identified by nursing home personnel (nurses and physicians) to be in a PVS discarded 11 out of 62 subjects (17%) on the grounds that they

    were considered by us to have some awareness of their environment, with some of the patients demonstrating volitional movement. (43)

A 17% error rate is not encouraging, but it is considerably less than the 37% error rate found in the only study addressing the question directly (44), where 18 out of 49 people were found to be inaccurately diagnosed. An error rate of 37% should really be sufficient to dismiss PVS to join hysteria and green sickness in the limbo of dead diagnoses. Perhaps for this reason, that figure appears nowhere in the Consensus Statement. The study in which it occurs is described thus;

    An accurate diagnosis is critical. Errors in diagnosis have occurred because of confusion about the terminology used to describe patients in this condition, the inexperience of the examiner, or an insufficient period of observation. (45)

Errors in diagnosis have occurred? This hardly counts as full disclosure. Remember, the Statement suggests that 10,000 to 25,000 adults in the USA have been diagnosed as having PVS. At a 17% error rate that would represent 1,700 to 4,250 false positives, at 37% 3,700 to 9,250. However inflated the original estimates were, there are unquestionably hundreds of people in the USA who now are being treated as if they are in PVS when they are not, and any discussion of treatment that omits discussion of this possibility is not being honest with its audience.

In most conditions it is possible to make meaningful distinctions between misdiagnosis and recovery. PVS does not have any independent characteristics powerful enough to make such a distinction. This complicates discussion of recovery rates. Historically, Jennet and Plum wanted "to identify an irrecoverable state"; irrecoverable and thus permanent. They named the syndrome 'persistent vegetative state' because they didn't have the data to make 'permanent vegetative state' stick.

    ... the criteria needed to establish that prediction [of irrecoverability] reliably have still to be confirmed. Until then 'persistent' is safer than 'permanent' or 'irreversible' ... (46)

The Multi-Society Task Force consider data on 434 head injury patients and note that

    Three months after injury, 33 percent of the patients had recovered consciousness; 67 percent had died or remained in a vegetative state. Recovery had occurred in 46 percent of patients at 6 months and in 52 percent at 12 months. Recovery after 12 months was reported in only 7 of the 434 patients. (Multi-Society Task Force, 1994)

Only 7, or 1.6 % of the total, does not sound very many. To many ethicists these chances are insignificant - faint, theoretical, a bare mathematical possibility;

    ... the common view that even the faintest theoretical chance of a recovery justifies keeping human vegetables alive indefinitely presupposes... that staying alive indefinitely cannot itself be against the patient's interests. If we accept the possibility that it may be, then we can no longer rely on a bare mathematical possibility of recovery as an excuse for not doing what the patient himself probably wanted. (47)

We should, however, note that the Consensus Statement is putting the worst complexion on the figures. The relevant figure is not the number who recover in any period as a percentage of the whole but that figure as a percentage of the ones available to recover - those who had not died or recovered already. Taking that calculation, at the end of the first year 52% of patients had recovered consciousness, 33% had died, and only 15%, or 65, were still in PVS; and 7 out of 65 is 10.6% - not wonderful, but rather more than theoretical. Again, when the Consensus Statement notes that only one patient (0.23% of the total) is recorded as recovering consciousness after 30 months, the question is one out of how many survivors; at a minimum it is 1/57, or 1.8%, and if the death rate is assumed to have continued at 33% per year it would be 1/32, or 3.2%. The boundaries of certainty in PVS from non-traumatic causes are set sooner, at 3 months, and only 4% of patients are said to recover after that time; however, that still represents 5.5% of the 72% remaining in PVS.

All these figures, of course, represent the outcomes of a meta-analysis; that is, they do not contain any weighting for best practice.

    ...there have been no formal studies of the effect of the level of care on the life expectancy of patients in a persistent vegetative state. (Multi-Society Task Force , 1994, p. 1576)

Nor have there been any studies of the effect of the level of care on the recovery rate. There have been no comparative studies of recovery rates in different hospitals, no attempt to identify the recovery rate in best practice conditions (or to compare recovery rates in hospitals with differing policies on resuscitation). In the larger studies percentages of post twelve-month recovery in non-traumatic PVS range from 0% (48) to over 5% (49) ; if it was assumed that the highest figure was attainable across the board, and might even be improved upon if more resources were devoted to research in this area, the graph could be redrawn differently. Similarly, there have been no comparative studies on the incidence of locked-in syndrome in different regions - indeed, there have been no estimates at all of the incidence of locked-in syndrome. Rates of locked-in syndrome might be expected to vary with, among other things, the amount of trouble the facility took to check for communication. If one were to take the expected recovery rates from best practice facilities along with the highest recorded rates of locked-in syndrome then it is probable that the 'high degree of clinical certainty' would be even more significantly diminished.

These percentages are significant because the Multi-Society Task Force has now proposed to take up the challenge set by Jennet and Plum in 1972 and define the 'permanent vegetative state'.

    A wakeful unconscious state that lasts longer than a few weeks is referred to as a persistently vegetative state. ... A permanent vegetative state, on the other hand, means an irreversible state, which like all clinical diagnoses in medicine, is based on probabilities, not absolutes. A patient in a persistent vegetative state becomes permanently vegetative when the diagnosis of irreversibility can be established with a high degree of clinical certainty - that is, when the chance that the patient will regain consciousness is exceedingly small. We believe that there are sufficient data on the prognosis for neurologic recovery to allow us to distinguish between persistent and permanent vegetative states. (50)

This boundary is to be set at the twelve-month level for traumatic and the three-month level for non-traumatic PVS patients.

    On the basis of these probabilities, a persistent vegetative state can be judged to be permanent 12 months after a traumatic injury in adults and children; recovery after this time is exceedingly rare and almost always involves a severe disability. In adults and children with non-traumatic injuries, a persistent vegetative state can be considered to be permanent after three months; recovery does occur, but it is rare and at best associated with moderate or severe disability. (51)

The words 'extremely rare' have, in context, an unfortunate ring of frequency about them. Leaving the question of disability to one side for the moment, and ignoring the issue of misdiagnosis, it appears that at least 10.6% of post-traumatic Permanent Vegetative State and 5.5% of non-traumatic Permanent Vegetative State patients will recover consciousness if given continuing care.

The effect of a diagnosis of Permanent Vegetative State will often be to ensure that they will not be given continuing care.

    Several medical societies and interdisciplinary bodies have asserted that surrogate decision makers and patients acting through advance directives have the right to terminate all forms of life-sustaining medical treatment, including hydration and nutrition, in adult patients in a persistent vegetative state. These organizations include the President's Commission for the Study of Ethical Problems in Medicine and Behavioral and Biomedical Research (1983), the Hastings Center (1987), the American Academy of Neurology (1989), the American Medical Association (1990), and the United Kingdom Institute of Medical Ethics Working Party on the Ethics of Prolonging Life and Assisting Death (1991). (52)

At the lowest level, a hospital may be influenced by considerations of cost-benefit analysis to give less intense care to a Permanent Vegetative State patient. More directly, a hospital that has on the basis of a diagnosis of Permanent Vegetative State received the permission of the family to withdraw nutrition and hydration can have a considerable degree of confidence that the patient will not recover; Carrie Coons found a narrow window of opportunity.

The Crucial Redefinition

The Multi-Society Task Force is able to tolerate what would be, under pre-existing criteria, significant probable error rates because it has redefined the notion of irreversibility. All previous discussion of PVS has used the original Jennett & Plum criteria

    - the absence of any adaptive response to the external environment, the absence of any evidence of a functioning mind (53)

The Multi-Society Task Force begins with this definition.

    A patient in a persistent vegetative state becomes permanently vegetative when the diagnosis of irreversibility can be established with a high degree of clinical certainty - that is, when the chance that the patient will regain consciousness is exceedingly small. (54)

By the end of the page, however, the definitional criteria have been expanded immensely.

    These data... can be used by a physician to determine when a persistent vegetative state becomes permanent - that is, when a physician can tell the patient's family or surrogate with a high degree of medical certainty that there is no further hope for recovery of consciousness or that, if consciousness were recovered, the patient would be left severely disabled. (55)

One of the members of the Multi-Society Task Force was the same Dr. Plum who named the condition and who called in 1972 for research to establish the criteria needed to establish reliably a prediction of irrecoverability. Twenty-two years of research having failed to achieve this reliability, he now says that it was unnecessary. Lack of consciousness is and has always been the conceptual core of the definition of persistent vegetative state. The Task Force has now redefined it as an irrelevancy. Plum et al have created a new diagnosis named Permanent Vegetative State that does not necessarily involve either permanence or vegetativeness. Patients have Permanent Vegetative State if they will (probably) be either unconscious or disabled . (56) Unconsciousness and disability are thus to be regarded as equivalent. Will courts and families be advised of this caveat? This development surely constitutes bad faith. If a study of the accuracy of the American judicial system were to come to the conclusion that the situation was satisfactory because 98% of people in jail were either guilty or black we would, I hope, conclude that they had confused the issues. This Consensus Statement would seem to present a close analogy.

It is still difficult for me to believe that the learned academies concerned have actually read the precise terms of the Consensus Statement to which they have committed themselves. At the very least, if it is the intention 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 to redefine the prospect of severe disability as a medical indication justifying the withdrawal of nutrition and hydration we can reasonably ask that they present the issue for further public discussion.

The Real Imperatives

If we do not accept the substitution of disability for lack of consciousness then the evidence is indisputable that Permanent Vegetative State is not necessarily permanent and not unquestionably insentient.

If an assemblage of professional bodies such as the Task Force accept propositions that are unsupported by the evidence, one conclusion that may be drawn is that their acceptance rests in part on other unexpressed and perhaps unformulated propositions with a stronger connection to their basic values and interests. . Cynics, or ethicists, might suggest that one focus of interest might be the possible value that these people with disability might contribute to we normal people, either as organ donors or (as they feel no pain) as subjects of medical experimentation. Such direct explanations are unlikely, or at least quite insufficient. There are other, more general, motivations. Some are cultural, or social, or psychological; others are practical or economic.

    · The use of the diagnosis of PVS does contribute to the institutionalization of life and death authority in the medical profession.

    · Some ethicists believe, like Dworkin, that people who are alive and human but not sentient establish a theoretical point that can then be used in other ethical contexts - abortion, say, or animal rights.

    · Many people passionately believe, like Jennett, that patients in PVS place a strain on limited resources and that physicians who care for them

      sound... a death knoll (57) for those who are denied the benefits of appropriate care by [this] spendthrift attitude. (58)

    · Some ethicists believe, like Dworkin, that it is in the best interests of people with such severe disabilities to have 'the right to die' invoked on their behalf.

    · We would all be happier if we could be sure that people in unendurable situations were unaware.

All these opinions may be valid. It is certainly possible to argue that we would all be better off (or at least that all of us who have not been diagnosed as having PVS would be better off) if we were relieved of our anxieties, or if physicians were able to end life without so much argument, or if more money was available for other areas of medical care, or if abortion was shown to be objectively rational. It is possible to argue that people who have been diagnosed as having PVS might indeed be better off dead. The difficulty is that the Multi-Society Task Force is not willing to admit to the public - are perhaps not prepared to admit to themselves - that these benefits may have attached costs. They would seem to believe, perhaps rightly, that if they concede any considerable degree of uncertainty in the situation of PVS patients they will not be permitted to bring these benefits about. This means that any such gains - the reassurance of families, the status of physicians, the arguments of ethicists, the reform of hospital budgeting - are effective only because they are founded on lies. The truth is that none of these benefits can be obtained without taking a high risk that some people who are or will become conscious and aware will be treated as if they were irretrevably insentient.

Again, it is arguable that this is an acceptable risk. It is possible to hold any number of opinions about what should be done with patients who are in post-coma states of disability, and their chances of recovery and their possibilities of awareness are not the only factors to be taken into account in decisionmaking. It is possible to decide that whether they recover or not the resources used on their care would still be better employed elsewhere. It is possible to hold the opinion - an ethicist has voiced it - that Carrie Coons' second thoughts on euthanasia were not objectively rational, and need not be heeded;

Her capacity for assessing evidence has been affected by her own bizarre experience...Courts should resist the temptation to oversimplify this job by treating a patient's utterances during brief periods of consciousness as determinative. (59)

I myself find this brisk dismissal of the patient's wishes somewhat reminiscent of the scene in Monty Python and the Holy Grail where John Cleese is attempting to load his resisting father on to the plague cart (60), but it does at least attempt to address the issue in the light of the observable facts. I do not for my own part believe that life should be preserved in all circumstances and in all cases. I am not, however, prepared to oversimplify the job of making decisions in these cases by accepting a diagnosis of PVS - a biased, partial, circular, and simplistic theoretical construct - as if it were determinative.

To behave as if the known statistics on recovery and misdiagnosis were somehow invisible, properly considered, to doctors and ethicists - to say, as the Consensus Statement says,

    By definition, patients in a persistent vegetative state are unaware of themselves or their environment. (61)

is to raise evasion to the level of a diagnosis and denial to the status of a philosophy.

 


Notes

1. Multi-Society Task Force on PVS, Medical Aspects of the Persistent Vegetative State: Second of two parts, New England Journal of Medicine, 330, 22, 1572-1579 (1994),.

2. 1501 NY Sup. Ct, April 3, 1989

3. Jennet, B., & Plum, F., 1972, Persistent Vegetative State After Brain Damage; A Syndrome in Search of a Name, Lancet, 734, 736 (1972)

4. Singer, P., The Future of Baby Doe, New York Review of Books, 31, 3, 17-23, 20 (1984)

5. Mitchell, K., Kerridge, I., & Lovat, T., Medical futility, treatment withdrawal, and the persistent vegetative state, Journal of Medical Ethics, 19, 71-76 (1993)

6. Dworkin, R., Life's Dominion: an argument about abortion, Knopf, New York, at 93

7. Haimowitz, S., Casenote; Right to die order vacated after patient awakens from persistent vegetative state, Mental & Physical Disabilities Law Reporter, 13, 5, 440-442

8. Walshe, T., & Leonard, C., 1985, Persistent Vegetative State; Extension of the Syndrome to Include Chronic Disorders, Archives of Neurology, 42, 1045-1047

9. Cranford, R., 1988, The Persistent Vegetative State: The Medical Reality, Hastings Centre Report, February/March

10. Multi-Society Task Force , 1994, at. 1576

11. 27% for traumatic injury and 7%, for nontraumatic injury.

12. Multi-Society Task Force , 1994, at. 1500

13. Jennet, B., & Plum, F., 1972, Persistent Vegetative State After Brain Damage; A Syndrome in Search of a Name, Lancet, 734,737

14. Multi-Society Task Force , 1994, at. 1502 As patients who do not establish such communication would be diagnosed as having not locked-in syndrome but PVS, it is not easy to conceive of a form of study that could support the use here of the word 'usually'.

15. Multi-Society Task Force , 1994, at. 1501

16. Multi-Society Task Force , 1994, at. 1577

17. Multi-Society Task Force , 1994, at. 1500

18. Multi-Society Task Force , 1994, at. 1500

19. In the Matter of Karen Quinlan, The complete briefs, court proceedings and decision in the Superior Court of New Jersey, University Publications of America, New York, p.545

20. Fields, A., Coble, D., Pollack, M., Cuerdon, T., & Kaufman, J., 1993, Outcomes of children in a persistent vegetative state, Critical Care Medicine, 21, 12, 1890-1894

21. Referred to but not referenced in Ross, J., The Puzzle of the Permanently Unconscious, Hastings Center Report, May-June, (1992)

22. Ibid.

23. See Jennett, B. & Plum, F., supra note 2, at 734

24. In many other cases, of course, relatives will wish to be reassured that the patient is feeling no pain, and here too a diagnosis of PVS makes the task of the physician easier.

25. Tosch, Patients' Recollections of their Posttraumatic Coma, J. Neuroscience Nursing, 20, 223,225 (1988)

26. Cranford, R., The Persistent Vegetative State; The Medical Reality (Getting the Facts Straight), Hastings Center Report, February March, 27-32, 1988

27. Multi-Society Task Force , 1994, at. 1501

28. Multi-Society Task Force , 1994, at. 1501

29. Multi-Society Task Force , 1994, at. 1501

30. Multi-Society Task Force , 1994, at. 1506

31. De Giorgio, C., & Lew, M., Consciousness, Coma, and the Vegetative State; Physical Basis and Definitional Character, Issues in Law & Medicine, 6, 4, 361-371 (1991) at 370

32. See De Giorgio, C., & Lew, M., supra note 31, at 368

33. Multi-Society Task Force , 1994, p. 1506

34. Multi-Society Task Force , 1994, at. 1501

35. Hansotia, P., Persistent Vegetative State; Review and Report of Electrodiagnostic Studies in Eight Cases, Archives of Neurology, 42, 1046-1052 (1985)

36. Levy, D., et al, 1987, Differences in Cerebral Blood Flow and Glucose Utilization in Vegetative Versus Locked-in Patients, Annals of Neurology, 22, 6, 673-682

37. Multi-Society Task Force , 1994, at. 1505

38. Multi-Society Task Force , 1994, at. 1504-5

39. See Levy, D., et al, supra, note 21, at 679

40. Barinaga, M., Watching the brain remake itself, Science, 266, 1475-1476 (1994)

41. Id. Sacks, O., Awakenings, Picador, London, p.331 (1990)

43. Tresch, D., Sims, F., Duthie, E., Goldstein, M., & Lane, P., Clinical Characteristics of Patients in the Persistent Vegetative State, Archives of Internal Medicine, 151, 930-932, p. 930 (1991)

44. Childs, N., Mercer, W., & Childs, H., Accuracy of Diagnosis of Persistent Vegetative State, Neurology, 43, 8, 1465-1467 (1993)

45. Multi-Society Task Force , 1994, p. 1502

46. See Jennett & Plum supra, note 2, at. 734

47. See Dworkin, supra, note 5, at 193

48. Sazbon, L, Zagreba, F., Ronen, J., Solzi, P., & Costeff, H., Course and outcome of patients in vegetative state of nontraumatic aetiology, Journal of Neurology, Neurosurgery, and Psychiatry, 56, 407-409 (1993)

49. Andrews, K, Recovery of patients after four months or more in the persistent vegetative state, BMJ, 306, 1597-1603 (1993)

50. Multi-Society Task Force , 1994, p. 1501

51. Multi-Society Task Force , 1994, p. 1575

52. Multi-Society Task Force , 1994, p.1577 All these bodies, of course, have relied on medical assurances of the irreversability and insentience of the condition.

53. Ibid.

54. Multi-Society Task Force , 1994, p. 1501

55. Multi-Society Task Force , 1994, p. 1501. Emphasis mine.

56. The diagnosis of Locked-In Syndrome, which Plum also named, has presumably now been swallowed up by its widened neighbour.

57. Sic.

58. Jennett, B., Resource Allocation for the Severely Brain Damaged, Arch Neurol 33, 595-597 (1976) I myself would have reservations about accepting without further argument the assumption that the funds freed up would be diverted to areas of higher medical need rather than being spent on, say, liposuction clinics.

59. Steinbock, B., Recovery From Persistent Vegetative State? The Case of Carrie Coons, Hastings Center Report, July/August (1989)

60. Carter. Hey, he's not dead.

Cleese. Yes he is.

Father. No I'm not!

Cleese. You're not fooling anybody but yourself, you know.

61. Multi-Society Task Force , 1994, p. 1501

62. Tresch, D., Sims, F., Duthie, E., Goldstein, M., & Lane, P., Clinical Characteristics of Patients in the Persistent Vegetative State, Archives of Internal Medicine, 151, 930-932, p. 930 (1991)

63. Childs, N., Mercer, W., & Childs, H., Accuracy of Diagnosis of Persistent Vegetative State, Neurology, 43, 8, 1465-1467 (1993)

64. Multi-Society Task Force , 1994, p. 1501 Multi-Society Task Force , 1994, p. 1501.

Republished with thanks from Issues in Law and Medicine, 1996

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