Multi-Society Task Force on PVS. Medical aspects of the persistent vegetative state (1)

Regional cerebral blood flow changes related to affective speech presentation in persistent vegetative state

A story told by his mother was presented on tape to a trauma patient in persistent vegetative state (PVS). During auditory presentation, measurements of regional cerebral blood flow (rCBF) were performed by means of positron emission tomography (PET). Changes in rCBF related to this stimulus condition, as compared to presenting non-word sound, were evaluated by means of statistical parametric mapping (SPM). This analysis indicated activation of rostral anterior cingulate, right middle temporal and right premotor cortices, which may reflect appropriate cortical involvement in processing emotional attributes of sound or speech.

[Ethics in intensive medicine]

In more than 30 years of development of intensive care medicine (ICM), our specialty has acquired moral and ethical standpoints, although not without public pressure and discussions. Special commissions dealing, e.g., with brain death, terminal care, ethics of foregoing life-sustaining treatment in the critically ill, withholding or withdrawing mechanical ventilation, and other issues have been formed in a number of medical societies. International consensus conferences have helped to clarify some of the issues. With increasing experience, a multitude of ethical problems have arisen in ICM that have to be dealt with, such as the issue of quality of life. What is an unworthy life? Are we allowed to make judgments for our patients? What is cost-effectiveness in ICM? Other restrictions include bed and equipment shortages in the intensive care unit (ICU), the necessity for triage--undisputed in catastrophe medicine--and how one should proceed in managing elective patients? In situations of limited ICU bed availability, sicker patients will be admitted, sparing out patients who are less ill for observation and those with poor quality of life and poor prognosis. For the future, it will likely be necessary to define the patients who should be admitted to an ICU more than those who should not be admitted. An ICU treatment entitlement index would be directly proportional to the probability of successful outcome and the quality of the remaining life, and would be inversely related to costs for achieving success. The ICU outcome with survival, hospital mortality, and follow-up of ICU patients is considered. DNR (do not resuscitate), the dying patient, terminal care, terminal weaning--DNT (do not treat)--active and passive euthanasia, living wills, quality of life, and cost-effectiveness for ICU patients are defined. Their application in the ICU will be discussed and problems pointed out. Outcome predictions using scores (APACHE III, SAPS II, MPM) have been developed based on previous experience, but should only be applied to patient groups and for quality assurance in ICUs. The most frequent and difficult problem in the ICUs is the vegetative state, which requires an exact diagnosis. The differential diagnosis from other comatose states such as coma, brain death, and locked-in-syndrome is depicted. The ethics of interrupting life-sustaining treatment in critically ill patients have been worked out by a Task Force on Ethics of the Society of Critical Care Medicine (1990). A consensus was found that the patient may judge to forego therapy; ethically it is then appropriate to withhold or withdraw therapy. According to the consensus, withdrawing an already initiated treatment should not necessarily be regarded as more problematic than a decision not to initiate treatment. In my mind, however, there is a great difference between withdrawing or withholding, e.g., ventilation. A dissentive opinion by some members of the Task Force stated that hydration and nutrition other than high-technology or parenteral nutrition are key components of patient care, and should not be equated with medical intervention. The ethical problems associated with active euthanasia (physician-assisted suicide or death) as practised in the Netherlands are also discussed. In most countries this practice seems unacceptable. From 30 years experience in ICM, there are many more ethical questions and case reports without clear solutions. Care decisions for single patients in unacceptable situations should be made after medical evaluation by the intensivist with the medical team and, if possible, by the patient and/or his or her surrogate. Legislation and solutions cannot be expected for single patients, but ethics committees could be helpful in decision-making.

Ethically justified, clinically comprehensive guidelines for percutaneous endoscopic gastrostomy tube placement

Guidelines for the placement of percutaneous endoscopic gastrostomy (PEG) tubes are not available. We developed a decision-making algorithm by integrating the medical and ethical dimensions of the decision. According to our algorithm, physicians should not offer PEG tubes to patients with anorexia-cachexia syndromes. For patients with permanent vegetative states, physicians should offer and recommend against the procedure. For patients who have dysphagia without other deficits in quality of life, physicians should offer and recommend the procedure. For the the remaining patients who have dysphagia with other deficits in quality of life, the physician's role is to provide non-directive counselling regarding the short and long-term consequences of a trial of PEG tube feeding.

Ethical conflict resolution based on an ethics of relationships for brain injury rehabilitation

An ethics of relationships for brain injury (BI) rehabilitation is described based on three principles; (1) human relationships are important; (2) human relationships are as important as individual survival; (3) human relationships are important enough to extend throughout the family of humankind. Within the context of this ethics of relationships, ethical conflict resolution (ECR) is offered as a process to address disagreements among those involved in BI rehabilitation. ECR provides a means to arrive at moral decisions in situations in which people disagree about the appropriate course of action because of differing values. ECR recognizes that, although disagreements in BI rehabilitation settings can be associated with multiple other factors, including disturbed self-awareness, emotions, communication, and interpersonal dynamics, such disagreements may also be value-based, either in whole or part. ECR invites the professional team to identify the value-based portion of these disagreements and provides a rational and supportive process to address disagreements. In this discussion of ECR, common and potentially universal areas of ethical concern in BI rehabilitation are identified, as well as potential risks. Specific examples of the application of ECR in cases of vegetative state, coma stimulation, and cognitive rehabilitation are described.

Vegetative state and responses to sensory stimulation: an analysis of 24 cases

A meta-analysis was performed on data from 24 single-case experimental studies evaluating the immediate effects of sensory stimulation treatment on patients in vegetative state following traumatic brain injury. Response to treatment was evaluated by time sampling behaviour pre- and post-treatment, and examining for changes in behaviour that suggested increased arousal. In this analysis the relative effectiveness of different treatment protocols was examined. The effects of variables such as age, gender and time since injury on magnitude of behaviour change was examined; also whether there was a relationship between response to treatment and outcome in terms of whether patients emerged from vegetative state or not. Analyses showed that multimodal stimulation produced greater behavioural changes than unimodal stimulation, and the use of personally salient stimuli in multimodal stimulation the greatest changes of all. Age and gender both showed effects on the magnitude of the behaviour change, but time since injury did not. Patients who did not emerge from the vegetative state were no less likely that those who did to produce statistically significant changes in behaviour in response to treatment. The paper includes a discussion of general issues concerning vegetative state.

The Coma Exit Chart: assessing the patient in prolonged coma and the vegetative state

The patient who remains in prolonged coma or in the vegetative state presents major problems in medicine, ethics and resource economics. Diagnosis and decision making are often difficult. A Coma Exit Chart can be developed using the parameters of the Glasgow Coma Scale to measure the exiting of the patient from prolonged coma or the vegetative state.

Survey of British clinicians' views on management of patients in persistent vegetative state

BACKGROUND

The best care and management of patients in persistent vegetative state (PVS) has been the subject of sustained moral and legal debate for a number of years. However, the views of clinicians in the UK involved in caring for patients in PVS are largely unknown.

METHODS

A postal questionnaire was sent to 1882 consultant members of the British Association of Orthopaedic Surgeons, the Association of British Neurologists, the Society of British Neurosurgeons, and the British Society of Rehabilitation Medicine. Their views were sought on various aspects of the management and care of PVS, in particular the appropriateness of a decision not to treat and a decision to withdraw artificial nutrition and hydration (ANH).

FINDINGS

1027 doctors responded (55%) of whom 558 (54%) had experience of managing patients in PVS. Over 90% of responding doctors considered that it could be appropriate not to treat acute infections and other life-threatening conditions. 65% of doctors considered that withdrawal of ANH could be appropriate. About two-thirds of doctors who thought treatment-limiting decisions could be appropriate thought that such decisions could be considered with the first 12 months of the patient being in PVS. Despite recent case law, less than half the doctors responding to the survey thought that an advance directive made by the patient should have a decisive influence in determining treatment-limiting decisions. Most doctors would like decisions about withdrawing ANH to be made in conjunction with family members and in accordance with agreed guidelines but without the need to go to court.

INTERPRETATION

There is a broad consensus among doctors that treatment-limiting decisions are sometimes appropriate for patients in PVS, irrespective of whether they have experience of the condition or of the specialty to which they belong. However, two thirds of doctors said that such decisions can be considered at a time earlier than that recommended by the British Medical Association. It is not clear why some doctors thought a decision not to treat could be appropriate while a decision to withdraw ANH would not be.

Post-comatose cystomanometric peculiarities

This study was the result of team work by urologists and neurologists in managing patients who have been in coma. The aim of this study is to evaluate the urodynamic differences between the various clinical conditions which characterise the coming out from a coma state. The second aim is to assess any correlation between clinical parameters (age, noxa of coma, Glasgow Coma Scale (GCS), days since brain lesion, days of catheterisation) and urodynamic findings. A urodynamic study was carried out on 24 patients (20 males and 4 females) who had come out of a coma state and were in the Subintesive Care Unit for coma in the Neurological Rehabilitation Department of our hospital. The patients were divided according to neurological criteria into 3 groups: persistent vegetative state (PVS), evoluted vegetative state (EVS) and minimally responsive state (MRS). No correlation was found between clinical parameters and urodynamic findings except between age and voiding percentage volume (%VV). Patients in PVS show detrusorial hyperreflexia with substantial contractions, while bladder residual volume (RV) is lower and voiding percentage volume (% VV) is higher than in the other two groups (P<0.05). EVS patients show detrusorial hyperreflexia (less than in PVS patients, but the difference is not statistically significant). MRS patients have higher bladder capacity than PVS and EVS patients, but again the difference is not statistically significant. Patients in PVS and EVS have a better micturition reflex (with regard to RV and %VV) than the MRS patients.

Proton magnetic resonance spectroscopy in children with acute central nervous system injury

Single voxel proton magnetic resonance spectroscopy (1H-MRS) was used in 30 infants and children with acute central nervous system injuries to determine the value of changes in specific metabolite ratios in predicting outcome. The mean age of all patients was 38 +/- 52 months and the mean time of study after insult was 7 +/- 5 days. 1H-MRS was determined in the occipital gray and parietal white matter (8 cm3 volume, STEAM sequence with TE = 20 ms, TR = 3,000 ms). Data were expressed as ratios of different metabolite peak areas including N-acetylaspartate (NA), choline-containing compounds (Ch), creatine and phosphocreatine (Cr), and lactate (Lac). Statistically significant differences were observed when patients with good/moderate (G/M) outcomes (n = 17; mean age: 46 months) were compared to patients with bad outcomes (n = 10; mean age: 26 months). NA/Cr and NA/Ch were significantly lower in the bad outcome group (NA/Cr = 1.15 +/- 0.38; NA/Ch = 1.18 +/- 0.52) compared to the G/M group (NA/Cr = 1.41 +/- 0.28, P < .05; NA/Ch = 1.98 +/- 0.81, P < .01). Lactate was present in 80% of bad outcome patients and in none of the G/M group (P < .0001). Using a linear discriminant analysis and combining 4 clinical variables (Glasgow Coma Scale score, initial pH and glucose, number of days unconscious at time of 1H-MRS) allows classification of 94% of patients into their correct outcome group. Use of spectroscopy variables (NA/Cr, NA/Ch, Ch/Cr, presence of lactate) alone correctly classified 81% of patients. The combination of clinical and 1H-MRS variables correctly classified 100% of patients. Our findings suggest that 1H-MRS adds information which, in combination with clinical examination, may be useful in outcome assessment in children with serious acute central nervous system injury.

Recommendations for use of uniform nomenclature pertinent to patients with severe alterations in consciousness. American Congress of Rehabilitation Medicine

There continues to be considerable confusion and controversy on the use of diagnostic and clinical terms assigned to patients with severe alterations in consciousness. This confusion results largely from the lack of a uniform classification system that is based on behaviorally defined criteria. This position paper provides recommendations for defining coma, vegetative state (including persistent and permanent vegetative state), akinetic mutism, the minimally responsive state, and locked-in syndrome based on neurobehavioral and neuropathologic features. Current controversies surrounding use of these terms also are discussed.

Forgoing medically provided nutrition and hydration in pediatric patients

Discussion of the ethics of forgoing medically provided nutrition and hydration tends to focus on adults rather than infants and children. Many appellate court decisions address the legal propriety of forgoing medically provided nutritional support of adults, but only a few have ruled on pediatric cases that pose the same issue.

The cessation of nutritional support is implemented most commonly for patients in apermanent vegetative state(often referred to aspersistent vegetative state(hereinafter “PVS”)). An estimated 4,000 to 10,000 American children are in the permanent vegetative state, compared to 10,000 to 25,000 adults. Yet the dearth of literature, case reports, and court decisions suggests that physicians and families of pediatric patients stop medically provided nutrition or seek court orders much less frequently.

Neuropathological findings in the brain of Karen Ann Quinlan. The role of the thalamus in the persistent vegetative state

BACKGROUND

Karen Ann Quinlan had a cardiopulmonary arrest in 1975 and died 10 years later, having never regained consciousness. Her story prompted a national debate about the appropriateness of life-sustaining treatment in patients who are in a persistent vegetative state and led to the development of medicolegal guidelines for the care of such patients. This report describes the neuropathologic features of Quinlan's brain.

METHODS

The entire brain and spinal cord were systematically sampled for histologic examination. The brain stem and central cerebrum were embedded en bloc and serially sectioned. Three-dimensional computer reconstructions helped visualize the topographic features of the lesions.

RESULTS

Contrary to expectation, the most severe damage was not in the cerebral cortex but in the thalamus, and the brain stem was relatively intact. The neuropathological findings included extensive bilateral thalamic scarring, bilateral cortical scars primarily in the occipital pole and parasagittal parieto-occipital region, and bilateral damage to cerebellar and focal-basal-ganglia regions. The brain stem and basal forebrain and the hypothalamic components of the ascending arousal systems and brainstem regions critical to cardiac and respiratory control were undamaged. The lesions were consistent with hypoxia-ischemia after the cardiopulmonary arrest.

CONCLUSIONS

Although the neuropathological findings in the case of Karen Ann Quinlan were complex, the disproportionately severe damage in the thalamus as compared with the cerebral cortex supports the hypothesis that the thalamus is critical for cognition and awareness and may be less essential for arousal.