LIFE AND DEATH: NEGOTIATING THE TWILIGHT ZONE

Stuart J. Youngner, MD

Department of Medicine, University Hospitals, Cleveland,

USA

The transition between living human being and corpse has been a topic of fascination for centuries. Modern technology has enabled us to stretch out this transition, postponing the inevitable for hours, days, or longer. In doing so we have created "twilight" states, conditions in which persons have characteristics of both the living and the dead. Twilight states have been the subject of human fantasy and fears throughout recorded history. Now they are a reality, forcing us to make difficult judgments about quality of life, treatment limitation, and the proper respect owed to semi-corpses. It has raised questions about the very definition of death, tempting us to manipulate that definition in order to solve important moral and social problems. These developments have led some persons to suggest that we decouple the determination of death from important social behaviors most often associated with it-for example, the removal of organs for transplantation. As neuroscientists and philosophers debate arcane academic points about the definition of death, the general public is, necessarily, left out. Nonetheless, people of all types remain profoundly concerned about the transition from life to death and want to trust their physicians and health care systems to either save them from death or treat them respectfully as death embraces them.

CEREBRAL RESUSCITATION AT 2000 A.D.

Peter Safar, M.D., Dr.h.c., FCCM, FCCP

SCRR, University of Pittsburgh

USA

Research and clinical trials of cerebral resuscitation potentials for severe traumatic brain injury (TBI) began in the 1950s. It culminated by 2000 A.D. in a systematic sequence of measures for the control of lethal intracranial pressure (ICP) rise; and various physical and pharmacologic strategies to minimize the deleterious aspects of inflammatory responses to brain contusion which kill neurons distant from the impact. The main therapeutic breakthrough for use after TBI has been mild to moderate cerebral hypothermia. This talk will be primarily on cerebral resuscitation from the temporary complete global brain ischemia (GBI) of prolonged cardiac arrest (CA). This has been researched by us and others since 1970. Only very long GBI is followed by brain death. Normothermic arrest times of 5-20 min no-flow and standard resuscitation are followed by varying degrees of permanent brain damage. The encephalopathy "matures" over several days. Selectively vulnerable neurons in selectively vulnerable regions ultimately develop apoptosis and necrosis. One prerequisite for the recovery of cerebral neurons after GBI of > 5 min is overcoming the no-reflow phenomenon. This can be achieved with brief spontaneous or induced arterial hypertension. The other prerequisite is mitigation of the delayed protracted cerebral hypoperfusion with hypermetabolism. This can be achieved with hypertensive hemodilution, normocapnia and metabolic depression by barbiturate with or without hypothermia. Even with normalized CBF, vulnerable cells are triggered into dying by complex chemical cascades which during ischemia set the stage for postischemic reoxygenation injury. Brain saving potentials explored for initiation during ischemia (preservation) and/or during and after reperfusion (resuscitation) have aimed at delaying loss of energy; preventing membrane depolarization; opposing calcium loading and excitotoxicity; mitigating protease activity, apoptosis, and reoxygenation damage; and preventing the late damage of mitochondria which can lead to DNA damage. For all the above, few old or new drugs have given statistical benefit, none a clinical breakthrough. In contrast, the discovery of mild postarrest hypothermia has become a potential clinical breakthrough. The year 2000 witnesses the fruition of clinical trials of mild hypothermia after CA; and of animal outcome studies which develop, for temporarily unresuscitable conditions, "suspended animation for delayed resuscitation" with pharmacologic and profound hypothermic strategies.

CONSCIOUSNESS AS THE MAIN FUNCTION OF THE ORGANISM: A STRONG SUPPORT FOR A BRAIN-ORIENTED CONCEPT OF DEATH

Calixto Machado

Institute of Neurology and Neurosurgery

Havana, Cuba

Any full account of death should include three distinct elements: a definition of death, its anatomical substratum, and the tests required to diagnose death as defined. The -three main brain-oriented formulations of death are the 'whole brain', the 'brainstem' and the 'higher brain' standards. I will outline and criticize these accounts, proposing a new standard of human death. based on the physiological mechanisms of consciousness generation. Consciousness has two physiological components: arousal and awareness. As brainstem-diencephalic and cortical structures interact to generate consciousness, any rigid distinction between their functions, in terms of arousal and awareness, would be misleading. Substantial interconnections among the brainstem, subcortical structures and the neocortex serve both components of human consciousness. Therefore, consciousness generation is based on anatomy and physiology throughout the brain. None of the three current brain-oriented formulations is wholly satisfactory. I propose a standard of human death which identifies consciousness as the key human attribute: it is both the source of human individuality and integrates a wide range of bodily functions.

TOO FAR BEYOND THE VEGETATIVE STATE? MEDICINE, ETHICS, LAW & THE MINIMALLY CONSCIOUS STATE

Ronald Cranford, M.D. & Lawrence J. Nelson, Ph.D, J.D.

Hennepin County Medical Center & Santa Clara University,

USA

The clear majority view in American law and bioethics holds that surrogate decision makers may legitimately refuse medical treatment, including medically provided nutrition and hydration, for patients in the permanent vegetative state (PVS), i.e., patients who will virtually never recover any degree of consciousness. However, the emerging trend in American judicial decisions is to deny surrogates the authority to refuse medical treatment on behalf of patients who are severely mentally incapacitated but demonstrate various signs of minimal consciousness and who thus are clinically outside of PVS. Patients like this are considered by some neurologists who have studied the phenomenon to be in the minimally conscious state (MCS), a condition of severely altered consciousness in which minimal but definite behavioral evidence of self or environmental awareness is demonstrated. To date, the medical, legal, and ethical response and evaluation of patients in MCS has been either incomplete, flawed, or confused. We offer several comments about this situation. First, medicine needs to determine whether MCS is a distinct clinical entity or syndrome and, if it is, to define and identify the clinical indicia of this syndrome with reasonable precision. Medicine needs to address the questions involving the relationship of MCS to PVS and the diagnostic and prognostic usefulness of identifying these and other states of seriously altered consciousness as well. Second, the legal reasoning beneath the trend of strongly distinguishing patients in PVS and MCS for purposes of surrogate decision making and termination of treatment needs to be examined and critiqued. In particular, the use of the clear and convincing evidence standard by several courts for determining the MCS patients own wishes about cessation of treatment as the sole method for deciding the fate of such a patient should be rejected. Finally, the core ethical issues surrounding the permissibility of treatment cessation, the sanctity of human life, the danger of the slippery slope as it pertains to allowing persons with any degree of consciousness to die by forgoing medical treatment, the moral significance of consciousness, and the moral propriety of surrogate decision making for the mentally impaired must be clearly analyzed and specifically applied to the non-PVS patient.

PERSISTENT VEGETATIVE STATE VERSUS APALLIC SYNDROME, A COMPARISON OF TWO ENTITIES

F. Gerstenbrand, H. Binder, G. Birbamer, Ch.A. Stepan

Vienna, Austria; Staffelstein,

Germany

The first case with symptoms of an apallic syndrome was reported by Rosenblath in 1899. The original description of apallic syndrome based on the history of two patients including remission was published by E. Kretschmer in 1940. Gerstenbrand analyzed 74 patients with apallic syndrome in 1967, of whom 38 showed a remission, in 13 cases a resocialization was observed. Apart from the clinical course, and neuropathological findings, pathophysiology and therapy were published 1977 in a monnography based on the „ Verona Symposion " on apallic syndrome (G. Dalle Ore, F. Gerstenbrand, C.H. Luecking, G. Peters, U.H. Peters). All later pulications confirmed the original concept, that the apallic syndrome is a functional failure of the cerebral functions while brain stemm functions are maintained. Only in a few cases with apallic synrdrome a severe morphological lesion of the brain is found, these suffer from chronic apallic syndrome/persistent vegetative state. In 1972 Jennett and Plum wrote a paper on persistent vegetative state, which the called „a syndrome, in search of a name". The authors did not focus on the dicription of the clinical course, but on the disinhibition of the vegetative functions wihout chances of remission. After having observed several patients a revision was nessesary. Therefore the term "persistent" had to be deleted. There are two differnt ways in wich the apallic syndrome as well as the vegetative state may develop depending on whether the origin is an acute incidence (traumatic, hypoxic, encephalitic, etc.) or a progressive condition (Creutzfeldt–Jacob disease, Huntington`s chorea, AIDS, etc.). Patients who fell into the apallic syndrome/vegetative state after an acute incidence may undergo remission, 35% of them can be resocialized, 20% remain permanent (chronic apallic syndrome/persistent vegetative state). All patients with an apallic syndrome/vegetative state need consistent modern treatment as everyone of these could expect full remission.

AUDITORY PATHWAY DYNAMICS DURING BRAIN DEATH

A Starr

University California Irvine,

USA

The first and second components of auditory brain stem potentials are generated by the distal and central portions of the VIII cranial nerve, respectively. The exact generators are not known but likely include spiral ganglion neurons for Wave I and proximal VIII nerve fibers for Wave II. Spiral ganglion cells are truly bipolar with the axon and dendrite at polar opposite sides of the cell body. The axons and dendrites are myelinated. The fibers have a diameter of approximately 7-10 micra. The ABR waves I and II persist for some time during the dying of the brain when the other components have disappeared. Wave I in particular shows dramatic fluctuations in amplitude during the evolution of the dying of the brain. We propose that these amplitude changes of Wave I are examples of the effects anoxia on ganglion cell excitability rather than on changes in synaptic function between inner hair cells and VIII nerve dendrites or changes in efferent olivocochlear bundle modulation of outer hair cells. Studies of the dynamics of auditory nerve excitability may provide objective measures of central neuronal function during anoxic brain disorders and the effects of therapies directed at correcting the defects at the neuronal level.

METHODS AND LIMITS OF BRAIN-DEATH DIAGNOSIS IN 1999

J.M.Guérit

Clinique Saint-Luc - Université Catholique de Louvain, Brussels,

Belgium

The diagnosis of brain death (BD) is still a matter of philosophical and methodological debate. Philosophically, the whole-brain formulation requires destruction of the entire encephalon, while the higher-brain formulation only requires destruction of the neocortex. Although the latter probably more closely approaches the concept of human death, it raises the problem of definitely proving that the neocortex has been totally destroyed so that, even if one adopts the higher-brain formulation, brain-stem destruction should still be required as an indirect proof of neocortical destruction. However, this does not apply for anencephalic neonates. Although most authors agree about which clinical tests should be performed for BD diagnosis, there is still discussion about the optimal way to conduct the apnea test. Among the confirmatory tests, the reliability of the EEG is questioned, the value of evoked potentials is stressed, and transcranial Doppler is considered to be a safe bedside technique for the direct assessment of intracranial circulation.

EVOLUTION OF ANCILLARY TESTS IN THE DIAGNOSIS OF BRAIN DEATH: FROM EEG AND ANGIOGRAPHY TO EVOKED POTENTIALS AND SPECT.

E.Facco, M. Munari, F. Baratto, A.U. Behr.

Neuro Intensive Care Unit - Dept. of Pharmacology and Anesthesiology, University of Padua,

Italy

The EEG, introduced in 1968 by the Harvard Criteria, was the first ancillary test for the confirmation of brain death (BD), but its limitations (low sensitivity and specificity) have been widely emphasized during the past three decades. Four-vessel angiography was introduced in the seventies to confirm BD in patients with reversible factors of coma (e.g., sedation, intoxications, metabolic disorders), but its main limitation was the invasivity, yielding possible harmful complications: since then, the use of cerebral blood flow tests has been increasingly advocated to achieve the absolute certainty of the diagnosis. In general, the criteria for the diagnosis of brain death (BD) spring from the adopted concept of death, and closely depend on it, giving raise to differences and even discrepancies in the diagnostic criteria adopted by different countries: in this regard, the EEG can be relevant only when the death of the cortex is included in the definition of BD (and, essentially, in patients with primary brain stem damage), while the kernel of the diagnosis remains the death of the brain stem in all cases, whatever the accepted concept of BD. Auditory brainstem responses (ABRs) and short latency somatosensory evoked potentials (SEPs), are to be considered as an extension of the clinical examination, allowing to explore brain stem and hemispheric structures, which cannot be clinically explored in coma: furthermore, they retain all their value even in patients with reversible factors of coma. Among cerebral blood flow tests, Doppler ultrasonography and contrast or radionuclide angiography detect the blood flow in main cerebral vessels, but can tell almost nothing about tissue perfusion, viability or function and are not free from false positivity; on the other hand, contrast angiography may cause complications, such as vasospasm and thrombosis. Single Photon Emission Tomography (SPECT) allows obtaining non invasive, three-dimensional pictures of brain perfusion, including posterior fossa, thus standing for the gold standard in the diagnosis of BD. When properly recorded and analyzed, ABRs and SEPs allow to confirm the diagnosis in most, if not all, cases: in our experience on over 130 cases, they were able to confirm BD in about 95% of cases and to exclude it in the remaining cases, despite they met all clinical and EEG criteria. SPECT clearly confirms BD with an outstanding picture of "empty skull", while a preserved brain perfusion is always present in pre-terminal patients. The main concern is the possible persistence of a weak, isolated perfusion of the basal ganglia and/or thalamus in brain dead small children or adults submitted to craniectomy: it shows the high sensitivity of SPECT even in terminal patients, but prevents the diagnosis of BD according to the concept of "whole brain death". It is worth emphasizing that this is not a limit of SPECT, but, on the contrary, is a matter of redefinition of BD and cerebral viability. In conclusion, ABRs, SEPs and SPECT allow for a reliable confirmation of BD and seldom may detect a residual life in the brain stem even in patients with clinical and EEG picture of BD (despite the absence of any reversible cause of coma). Since they improve the certainty of he diagnosis, they should be included in brain death criteria: it is no longer time to recommend EEG and angiography, and not even mention evoked potentials and SPECT.

DEVELOPMENT OF BRAIN DEATH - A PROSPECTIVE CLINICAL AND NEUROPHYSIOLOGICAL STUDY IN PATIENTS WITH SEVERE BRAIN DAMAGE

Pohlmann-Eden, Bernd⁽¹⁾, Dingethal, Kai⁽¹⁾, Quintel, Michael⁽²⁾

(1)Dept. of Neurology and ⁽²⁾ Anaesthesiology , Klinikum Mannheim, University of Heidelberg,

Germany

Objective: To assess the value of non-invasive neurophysiological and neuroradiological data for a reliable diagnosis for brain death (BD). Background: Brain death is a common complication of severe brain damage (SBD). A reliable diagnosis and early prediction are essential for the individual affected, counselling the relatives and because of socioeconomic reasons. Material / methods: We prospectively investigated 42 comatose patients with SBD (29m/13f), mean age 39.6 years, mean initial GCS 6.6 by means of brainstem auditory (BAEP), somatosensory evoked potentials (SEP), EEG and CT-Scores. BAEPs, SEPs and GCS were serially documented on day 1, 3 to 4, and day 8 to 10. Results: 22 patients of the entire study group developed BD. Initial SEP Scores turned out to be the most reliable predictor for both favourable and unfavourable outcome (p < 0.001, Spearman´s correlation) and were superior to still significant BAEPs and non-significant CT-Scores. The initial bilateral loss of cortical responses (BLCR) was documented in all but 2 patients (93%). When BD had occurred, 86% of the patients showed a total loss of all BAEP-components; only 3 presented with either persisting wave I or wave II (uni-or bilateral). 4 BD patients with primarily supratentorial lesions meeting the clinical criteria of BD and showing loss of cortical SEP and brainstem Eps still had rudimentary subtle circumscribed EEG-activity. Discussion: The above described preserved focal EEG-activity in BD is most likely due to leptomeningeal collateralization via externa carotid artery and irrelevant for life-supporting metabolism. This finding does not conflict with a safe diagnosis of BD. SEPs when applied serially and used in the context of documented supratentorial SBD are the most reliable tools to predict bad outcome and brain death.

THE "CRITICAL ORGAN" FOR THE "ORGANISM AS A WHOLE": LESSONS FROM THE LOWLY SPINAL CORD

D. Alan Shewmon

Pediatric Neurology, UCLA Medical School, Los Angeles, CA.

USA

BRAIN DEATH – UPDATING A VALID CONCEPT FOR 2000

J. Korein, C. Machado and J. L. Bernat

Various investigators have presented criticisms about the concept of brain death. ^. We propose that for medical purposes the fundamental biological neurocentric definition of death of the human being is valid based on the irreversible cessation of operation of the critical system of the brain. This concept of death itself requires a paradigm shift and modification dictated by our current understanding of living systems, new observations, and further experience in applications of the diagnosis of death. However, the criterion and tests previously used to diagnose death as essentially brain death are for practical purposes unchanged. The relationships among "life", "death", "brain death", and irreversible intrinsic cessation of function of the "critical system of the brain" during the human life cycle will be detailed. The significance of the many aspects of consciousness will be stressed, and applied to the problems of persistent vegetative states and anecephaly.

CONSIDERACIONES ETICAS DE LA MUERTE ENCEFALICA

Dr. René Zamora Marín

H. Hermanos Ameijeiras

CUBA

Se realiza una pequeña revisión de la historia y evolución del concepto de la llamada "Muerte Encefálica" abordando las consideraciones éticas que la sustentan y la experiencia seguida en nuestro servicio de Terapia expresando al final que existen en la actualidad suficientes elementos que permiten considerarla como Muerte real de la persona humana. Se enfoca la muerte como la obtención de órganos para trasplantes.

DILEMAS EN LA MUERTE Y EL MORIR

Sofia Sordo, Enma Cuspineda, Bárbara Zas. María Elena Rodríguez

Cuba

La problemática de los dilemas éticos ha sido desarrollada en el mundo, en relación con los dilemas que se presentan en el ámbito médico como consecuencia del progreso de la ciencias biomédicas. Esto ha convocado a estudiosos de las más diversas ramas del saber a incursionar en el complejo mundo de los valores y los hechos en cuestiones de marcada trascendencia humana. Hasta hace poco tiempo las reflexiones e investigaciones en torno al tema han abordado el fenómeno fundamentalmente desde una interpretación teórica filosófica o como discurso ontológico de la esencia humana. A través del desarrollo de esta mesa mostraremos el interés en nuestro país a tomado este tema, en el que en poco tiempo se han realizado estudios que abordan esta problemática no solo a nivel teórico, sino a nivel práctico ya que son situaciones que el profesional tiene que enfrentar y a las que de una manera u otra tiene que responder, de ahí la necesidad de investigaciones empíricas en este campo y la caracterización del dilema como un problema subjetivo, es decir se impone la interpretación de la problemática de los dilemas éticos en la práctica profesional concreta y en su especificidad e integridad, sus repercuciones en el desempeño profesional y en la subjetividad de los entes implicados en ella y su repercución en la calidad de las decisiones que se tomen y en su salud psíquica. El grupo multidisciplinario de ética clínica del Hospital Hermanos Ameijeiras constituido desde dic. 1993 responde con su programa de desarrollo a esta necesidad en la que tiene en cuenta no sólo la investigación, sino la formación y la conducción de los dilemas éticos en el actual profesional.

DETERMINACION Y CERTIFICACION DE LA MUERTE EN CUBA

Calixto Machado, Sofia Sordo, Leonardo Peéez, Nelson Gómez, Nicolás Montoto

La Habana, Cuba

El fenómeno de la muerte no escapa al Derecho. No se trata tan sólo de sus efectos en las distintas ramas del ordenamiento jurídico sino de la necesidad de un diagnóstico y certificación, y así dar respuesta a la formulación consagrada en el artículo 26 del Código Civil vigente en Cuba. Para ello se proponen los principios o bases de una futura legislación en este orden, partiendo de los distintos criterios diagnósticos con especial referencia al neurológico, personal facultativo, certificación legal de la muerte, coincidencia necesaria en el personal que diagnostica y el que certifica e indepencia del diagnóstico de muerte encefálica de la ablación de órganos. Atendiendo a estos aspectos los invitamos a reflexionar y dar respuesta a través de la presentación de esta mesa a los cuestionamientos que esta temática genera y para la cual se requiere de un abordaje multidisciplinario y multicéntrico.

WHEN PERSONS LINGER IN BRAIN-DEAD BODIES: ICU DISCOURSE ABOUT DONATION IN JAPAN AND NORTH AMERICA

Margaret Lock

Canada

The Organ Transplant Law was passed in Japan in the fall of 1997 making it possible for organs for transplant to be legally procured from brain dead bodies provided that a donor card has been signed by both the individual and a family member. Brain dead patients who have not signed donor cards are not legally dead and continue to be given life support until the family agrees that it can be stopped. Two years after passage of the law only four procurements have taken place. This paper will review the reasons why organ procurement remains uncommon in Japan. A comparative perspective on the attitudes and practices of ICU specialists in Japan and North America suggests that the different rates of donation in these two locations can be explained largely on the basis of what takes place between practitioners and patient families in the ICU. Required request is not practiced in Japan, and the default position is that donation will not take place. The implications of these findings for patients waiting for organs in Japan will be discussed.

BRAIN DEATH IS NOT THE DEATH OF MAN.

Wolfgang Goetze-Clarén, M.D. Hon.D.LL.

Forum Medizinische Ethik, Universität München, LMU,

Germany

The paper will contain the following trends of thought and topics: Briefing on the developments of the brain death Disputes in the western countries. Religious views and anthropological preoccupation and legal stalemates are to be levelled off in respectful recognition. We favour the living patient but inform the prospective donor by indisputable and realistic demonstration of the current physiology on the scientific knowledge of coma diluere in contrast to coma depassé. We recognize the turning point of life to irreversible death underlining the status for organ explantation, provided the donor himself has signed his advanced will. Discussion of the countries which legalise organ explantation from non heart beating patients unless revocation had been expressed by the next of kin. In summary this evaluation on the problematics and unpleasantness of the indemonstrable neurophysiology during the pathway to death obliges the medical profession to observe another waiting time. We have reason to believe that brain death will become history. Discussing various research models but remaining on the Harvard statute for the time being. We must, however, be aware of the fact that the brain death criterium is nothing but a biologic theory, serviceable, and yet a falciforme concept which is inconruent with the death of the human.

BRAIN DEATH IS NOT ACTUAL DEATH: PHILOSOPHICAL ARGUMENTS

Josef Seifert

International Academy of Philosophy,

Principal of Liechtenstein.

According to the (1) biophilosophical argument, the irreversible brain stem or whole brain-infarction destroys the integrated unity of the human body and thereby is death of the human organism, reducing the body to a big organ-bank. Against this argument the following arguments will be advanced: (a) the integrating function of the brain for the life-processes in the rest of the body can be suspended in conscious patients; human consciousness presupposes necessarily human life. Therefore bd is not death. Moreover, the concept of integrated unity is vague and besides can certainly be applied to the remaining levels of integration in brain dead patients. Therefore the functioning of brain stem and its integrating role can neither be identical with human life nor a necessary condition for it. (b). Human life is more than integrated wholeness of vital processes differing essentially from mere vegetative life: it depends on the presence of man's philosophically demonstrable simple, indivisible and spiritual soul and its union with the body. Against an (2) anthropological-medical argument is unsound because being based on a probably true thesis and on some false premises: that actual personal conscious life requires cerebral brain activity as condition is a probable fact (although recent studies, Shewmon 1997, have shown that also the brain stem can assume certain functions in this regard), but the personalistic line argument" has, as second premise, at least one of the following three false assumptions: (1) a materialistic notion of personhood or (2) an actualism that reduces the being of the person to his doings qua person, or (3) the thesis that only the brain is real body on which the incarnated life of the human person depends all three of these positions are argued to be false in the paper. The first premise alone is insufficient to ground the identification of brain death with actual death if all possible supportive second premises collapse. Finally, even if the possibility of brain death being actual death is admitted, the moral certainty necessary to perform life-destroying explantations of vital organs is missing. Based on these reasons, the paper argues that the identification of brain death with actual death is a primarily philosophical aberration of medical practice and theory and ought to be abandoned; potential and ethical consequences ought to be drawn.

POTENTIALITY, IRREVERSIBILITY, AND DEATH

John P. Lizza, Ph.D.

Department of Philosophy, Kutztownlkjlkj University

USA

This paper examines how the concepts of potentiality and irreversibility have been used in discussion of the definition of death and non-heart-beating organ donation. Initially, I focus on D. Alan Shewmon's rejection of neurological criteria for death on grounds that the human organism retains the potential for the specifically human functions of intellect and will, even though it may satisfy the tests for loss of all brain function. I argue that Shewmon relies on a problematic and unrealistic concept of potentiality, and that a better, more realistic concept of potentiality is consistent with accepting neurological criteria for death. I then show how participants in the discussion of non-heart-beating organ donation (Cole, Bartlett, Tomlinson) have invoked problematic and unrealistic concepts of irreversibility. Finally, I propose an alternative, more realistic account of irreversibilty that can be used in the definition and criteria of death.

HUMAN BRAIN DEATH IN PERSPECTIVE: COMMENTS ON THE SPINAL DOG AND DECAPITATE FROG.

Arthur C. Grant, M.D., Ph.D.

Department of Neurology; UCI Medical Center,

USA

At the close of the millennium the significance of brain death to death of the person remains controversial. The issue is approached from many views incorporating practical, moral, religious, legal and philosophical principles. Despite their differences these arguments often spring from a common dilemma, namely whether a functional human brain is necessary for human life. Contemporary perspectives on human brain death also share a limiting anthrocentrism, ignoring a century of provocative work in animal physiology. Sherrington's classic work on the spinal dog, and the author's experience with the decapitate frog will be reviewed. These examples clearly illustrate that a brain is not necessary for complex, coordinated, and even plastic reflex "behavior". Nor is it required for sentience, a quality closely tied to notions of life and individuality. In the frog there is an eerie similarity between behavior of the intact animal, and reflexive reactions seen in the decapitate body. It follows, at least conceptually, that if homeostasis and "sentience" reflect "life" then human life is possible without any brain at all. This disturbing idea implies that perhaps it is appropriate to separate brain death and death of the person from an ill-defined notion of sentience, and from loss of homeostasis.

Implications of ischemic penumbra for the diagnosis of brain death

Cicero Coimbra, M.D., Ph.D.

Laboratory for Experimental Neurology, Department of Neurology and Neurosurgery, Federal University of São Paulo,

Brazil

Literature data support the possibility that a global reduction of blood supply to the whole brain or solely to the infratentorial structures down to the range of ischemic penumbra for several hours or a few days may lead to misdiagnosis of irreversible brain or brain stem damage in a subset of deeply comatose patients with cephalic areflexia. The following proposals are advanced: (1) the lack of any set of clinically detectable brain functions does not provide safety to diagnosis of brain or brain-stem death; (2) by further reducing the intracranial perfusion pressure, apnea testing may induce irreversible brain damage and should be abandoned; (3) moderate hypothermia, antipyresis, prevention of arterial hypotension, and occasionally intra-arterial thrombolysis may contribute to good recovery of a possibly large subset of cases of brain injury currently regarded as irreversible; (4) confirmatory tests for brain death should not replace nor delay the administration of those potentially effective therapeutic measures; (5) in order to validate confirmatory tests, further research is needed to relate their results with specific levels of blood supply to the brain. The current criteria for the diagnosis of brain death should be revised. Acknowledgements: The author is indebted to the following funding sources: Brazilian Council for the Development of Science and Technology (CNPq), Foundation for Research Support in the State of São Paulo (FAPESP), Brazilian Program for Support of Centres of Excellence in Research (PRONEX).

THE SHIFTING BOUNDARY BETWEEN LIFE AND DEATH: COGNITIVE AND SOCIAL PROBLEMS

Nora Machado, Ph.D.

Assistant Professor/ Research Fellow

University of Uppsala/ University of Amsterdam, Sweden,

The Netherlands

Life support technology in clinical settings such as intensive care units, while allowing for the recovery of and maintenance of patients in a critical state, pave the way for new problems and uncertainties. The development of the concept of brain-death and several types of coma involves shifts in perspective in areas of substantial moral and legal significance. A universal distinction in human affairs is that between "living" and "dead". It relates to a sense of order in matters that have profound social implications. Very different normative regimes are applied in the case of situations involving the "living" as opposed to those of "the dead." That is, many of the rules and practices associated with "appropriate" behavior toward (or treatment of) the "living" differ, of course, from those for "appropriate" behavior toward "the dead." Another distinction basic to the human conception of order and normality is that between the "natural" and the "social." If a process or phenomena is defined as "natural," for instance in the sense of a "natural" death, then human agents are not assumed to have moral or legal responsibility for the event. That is, they need not consider themselves as being moral agents, required (rather than possibly choosing, if they wish) to take responsibility and to try to deal with the event or process. On the other hand, if a process or phenomena is defined as "social," human agents, or particular human agents, are understood as morally or legally responsible and are required, therefore, to act and to be accountable for relevant events and developments. Ambiguities, misunderstandings, and controversies about these boundaries set the stage for a sense of disorder, dissonance, and potential conflict, which are profoundly troubling in the case they concern matters of death and life. This approach to cognitive and social order implies that what is "normal" in circumstances defined as natural differs from that which is understood as "normal" in circumstances defined or understood as social (and calling for moral accountability and regulation). Moreover, what has become more or less normal in a given context for some may be seen by others as abnormal (and potentially threatening). These differences arise in connection with, for instance, the development of modern, high-tech conceptions of death and coma. The paper discusses the importance of social understandings of "normality" in relation to death and several of the social mechanisms whereby normality is established or re-established (drawing on the work of the Sociologist Erving Goffman). There is an intricate and delicate web of assumptions, rules, and actor commitments and interests that maintain a particular conception of normality. But such conceptions are vulnerable to, for instance, radical technical change. Advances in life-support technology", by altering the boundary between institutionalized conceptions and practices relating to death, destabilize for many people the sense of normality and order. "Life-support" techniques have led to a fundamental alteration of what until a few years ago were regarded as fixed, natural parameters. They have engendered not only conceptual ambiguities regarding how "life" and "death" are to be defined, understood and treated, but also a number of difficult ethical dilemmas and controversies. These cognitive and normative developments contribute to undermining public confidence in stable, "natural" boundaries between life and death, and between what is understood as "natural" and that which is understood as "social" (and calling for moral accountability and regulation). The paper concludes by emphasizing the importance of a general consensus about matters with profound moral and social implications such as "life and death" and "natural" and "social", and the appropriate social rules for guiding human action in relation to these different circumstances with significant differences in normative responsibility and accountability. However, consensus is more and more difficult to achieve (or to legislate) in a differentiated modern world with multiple specialties, perspectives, and authorities. Bridging these gaps and establishing a common frame and a common discourse in legal and ethical terms is often a difficult (but nonetheless necessary) enterprise. The long, troubled history of legislating brain-death in Sweden provides an illustration of the problem and the importance of addressing the problem  deliberately and effectively.

IS A PERSON EVER IN A PERSISTENT VEGETATIVE STATE?

Wade L. Robison

Ezra A. Hale Professor in Applied Ethics Rochester Institute of Technology,

USA

The question is not empirical, but conceptual. We now say that a person cannot be brain dead. Once the brain is dead, the person is dead, and we have a corpse, not a person, to deal with. But at least one of the standard criteria for a person make it impossible for a person ever to be in a persistent vegetative state. Once in such a state, the inference would go, we are no longer dealing with a person, but with some other kind of being--still alive, no doubt, because at least some portions of the brain stem are functioning, but not a person. There are practical difficulties in being sure that we have a being who was a person that is now in a persistent vegetative state, and so the conceptual question may be answered either way without making, for now, any difference to our practices. But if the beings we are keeping alive as persons cannot be persons, then we have a very different set of questions to answer than we have if they are persons. Among other things, we need to determine whether we need to keep such beings alive, given that they are not persons but bear such a set of relations to a being who was a person. One of the standard criteria for someone's being a person is that the being be capable of consciousness. This is not a sufficient condition, but it is arguably a necessary condition. But if it is, then a being in a persistent vegetative state lacks a condition necessary for being a person. Such a being not only lacks consciousness, but lacks the capacity for consciousness. Making such a judgment has no impact on such other questions as whether or not abortion is unethical, for instance. Someone may argue that a fetus has the capacity for consciousness and so ought not to be aborted, but a being in a persistent vegetative state lacks even the capacity. What marks such a being out as of unique concern is its relation to what was a person: it is in the same body, and is to that extent the same as, the person who was in that body and capable of being conscious. The being has a history that includes in some way that of the person, and one of the questions that we must ask is whether the way in which it includes that history obligates us to keep it alive.

CLINICAL EVALUATION OF EMERGENT CONSCIOUSNESS AFTER A DEEP COMA DUE TO CEREBROVASCULAR DISEASES

José M. Domínguez-Roldán, M. Romero-López, J. M. Barrera-Chacón

Hospital Universitario "Virgen del Rocío", Sevilla,

Spain

The evaluation of the level of consciousness has been well studied in the acute phase of different clinical processes ( head trauma, etc). Several scales (Glasgow coma scale, Innsbruck scale, Edinburgh-2 scale, etc) have been used for prediction of outcome of the patients, and some of these scales have also showed usefulness in the management of patients in the acute phase, giving orientation of monitoring needs, and therapeutical strategies. However, few studies have been developed analysing the usefulness and accuracy of clinical scales in the clinical monitoring of recovering of consciousness. The main purpose of this study has been to establish the utility of different scales in the evaluation of the awakening of patients after a deep coma due to cerebrovascular processes. We have also investigated the timing of appearance of the different clinical signs accompanying the awakening and the relationship between some scales used in the acute phase of haemorrhagic stroke (Glasgow coma scales, World Federation of Neurosurgeons scale, Hunt-Hess scale, etc.) and the recovering of the consciousness scales. The study group was constituted by 32 patients admitted to our ICU after an acute cerebrovascular disease ( 17 intracerebral haemorrhage, 15 subarachnoid haemorrhage). All the patients developed a deep coma during the stay in the ICU. After withdrawal neurodepressor drugs, and every day, 3 independent observers carried out the clinical examination of the patients using different scales (Coma/Near semicoma scale, NAIR, Neurobehavioral Assessment Scale, Rancho de Los Amigos Scale, and Disability Rating Scale). The preliminary results of this study show the neuro-ophtalmologic and facial activity (ocular tracking, movements of the mouth etc.) as the early recovered signs of presence of consciousness. Functional scales and deepen-coma scales are less useful than Coma/near-coma scale in the demonstration of recovering of consciousness.

MANAGEMENT AND PROGNOSIS OF PATIENTS WITH FIXED AND DILATED PUPILS

Carlo Schaller; Hans Clusmann

Department of Neurosurgery, University of Bonn, Born,

Germany

Introduction: Due to sedation and ventilation many neurosurgical patients are not fully neurologically assessable. Dilated and fixed pupils (FDP) in the comatose on the other hand are related with poor prognosis of the affected patient. We have evaluated the causes and the impact of this finding on the outcome of a prospective patient series. Patients/methods: Onehundred patients (51f, 49m) from 3 months to 87 (mean:48.4) years, who presented with or who developed uni- or bilateral FDP are included in the study. They were splitted into three groups according to their history: Group 1 (trauma) comprised N=46 patients, group 2 (subarachnoid or intracerebral hemorrhage) N=41 patients and group three (previous intracranial surgery) N=13 patients. All patients had neurosurgical intensive care according to internal standards and surgery was performed on the basis of staff-decisions. Results: Fifty patients (50%) underwent removal of an intracranial hematoma - N=35 with ipsilaterally FDP, N=15 with bilaterally FDP. Of these N=27 (54%) died, N=15 made a poor recovery (Glasgow outcome score [GOS] II/III), and N=8 (16%) were GOS IV/V with no statistically significant difference between the 3 groups. Conservative treatment was initiated in N=20 patients with ipsilaterally FDP and in N=30 patients presenting with bilaterally FDP. Of these 46 (92%) died, N=2 were GOS II, and 2 GOS IV. The timeframe of FDP-detection did not differ between the surgical/conservative group. No patient in whom previous FDP did not become reactive immediately after decompressive surgery survived. No patient with bilaterally FDP on admission survived with conservative treatment. Conclusion: The prognosis for patients with persistent FDP immediately upon intiation of neurosurgical treatment - surgical or conservative - remains grave. Surgery improves the prognosis only if performed early and for clear indications such as epidural hematomas. FDP upon previous elective surgery were not detected earlier and the prognosis for these patients did not differ from the others.

LONG-TERM OUTCOME FOLLOWING MEDICAL REVERSAL OF TRANSTENTORIAL HERNIATION IN PATIENTS WITH SUPRATENTORIAL MASS LESIONS.

Adnan I. Qureshi MD; Romergryko G. Geocadin MD; Jose I. Suarez MD; John A. Ulatowski MD, PhD.

Division of Neurosciences Critical Care, The Johns Hopkins Medical Institutions, Baltimore, Maryland,

USA

Objective: To determine the short and long-term outcome following successful reversal of transtentorial herniation by medical treatment. Although it has been recognized that aggressive medical management can reverse transtentorial herniation, it is believed that overall outcome in such patients is poor. Methods and Patients: A prospective cohort study was performed in the setting of a dedicated Neurocritical Care Unit of a university hospital. Twenty eight consecutive patients were followed who underwent an episode of transtentorial herniation (defined as decrease in level of consciousness accompanied by pupillary dilatation) secondary to a supratentorial mass lesion followed by successful reversal. Herniation was reversed using a combination of hyperventilation, mannitol and hypertonic saline guided by but not mandated by a protocol. A small number of patients also had decompressive surgery. Measurements and main results: The following outcomes were analyzed: risk of second herniation, radiological evidence of structural damage or vascular compromise related to herniation on post herniation computed tomographic (CT) scan, in hospital mortality and long-term functional outcome using Rankin score and Barthel index. A total of 32 episodes of transtentorial herniation were reversed in 28 patients over a 14 month period (total number of herniation patients unknown). The most common precipitating cause were edema (n=23) or new/expanding intracerebral hematoma (n=5). Following first reversal of transtentorial herniation in 28 patients, second herniation episode was observed in 16 patients after a mean interval of 88.2 hours (range 23-432 hours); four were successfully reversed. On follow-up CT scan, hypodense lesion in midbrain (n=6), temporal lobe contusion (n=2), posterior cerebral artery (n=3) and middle cerebral artery (n=1) infarction were visualized. In-hospital mortality was 60% (n=15) with brain death being the cause of death in 13 patients (care was withdrawn in 8 patients). Second episode of herniation (p=0.002) and midbrain involvement during herniation (p=0.02) were associated with in-hospital mortality. Over a mean follow-up period of 11.4± 4.2 months, two patients died of cerebral neoplasm and HIV-related sepsis, respectively. Of the 11 survivors, 7 were functionally independent (Rankin score less than 3 and Barthel index greater than 60). Patients that required surgery had poor survival. Conclusions: Although mortality following transtentorial herniation is high, we found a surprising potential for meaningful recovery with aggressive medical reversal of transtentorial herniation. Our study implies that timely medical intervention for reversing transtentorial herniation can result in preservation of neurological function. A further study to better characterize recovery from transtentorial herniation in all comers is planned.

COMATOSE PATIENTS WITH INTRACEREBRAL HAEMORRHAGE

Stolevski. V., Pangovski I., caparevski A., Boskovski K., Lozance K., Mitof Visurski Lj.

Institution Medical Faculty- Skopje

Republic of Macedonia

Introduction: The aim of the study was to provide a view to the the patients which have intracerebral haemorrhage (including all types) and devenloped coma. In addition we want to made connections between the stage of coma (the estimation was done according to he Glasgow coma scale, as well as H-H scale).and how long it lasts, vis a vis chances to outlife and recover. Methods: We have considered a large number of history files, from 10 years period. All of the patients files were complettely examined, including the medical procedures that have been done like angiography, CT scan, NMR image. Results: The results show that intracerebral haemorrhage have had 235 patients which have failed in coma. 160 of the patients were man which is approximately 75%, the rest were women. Great number of them 183 died. 108 of Them (45%)were exposed under surgical procedures. Increased blood preasure (TA) , as risk factor was present at 67 patients which is 25% of all. Unfortunately angiografy was done in only 13 patienst (less than 5%). Finally 36 of them have had SAH alone or combined with other types of haemorrages. Conclusion: In the and we can conclude that intracerebral haemathomas that compromise basal ganglia is definitly first place life threatening desease, after follows blood in ventricular system, SAH , and lastly subdural haematomas. Patients with high blood preasure that suffer any kind of haemorrhages have the highest mortality rate . The number of the patients with coma and intracerebral haemorrhage in Macedonia is closely related and simmilar to those in Europe and other neighbouring countries.The tretment of the patients is also the same so we achieve the level of the developed countries. According to our medical care the patiens have equal chances to pass through coma treatment, to recover and to be resocialised.

VITAMIN DEFICIENCY, STROKE, AND DEMENTIA

James F. Toole, M.D.

President, World Federation of Neurology, Department of Neurology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem,

USA

Vascular dementia and coma following infarction of strategic portions of the frontal lobes or upper brainstem are becoming increasingly important problems due to the reduction of death from other preventable diseases. With increased longevity, the impact of abnormal diet upon the microcirculation of the brain becomes evermore important. This includes, among other causes, hyperhomocysteinemia as a result of genetic abnormalities or deficiency in absorption and utilization of folic acid and/or dietary abnormalities which contribute to folic acid deficiency. Initial work on the interaction between folic acid/B₁₂/B₆ was done in Cuba in the 1940’s by Dr. Thomas Spies. Only half a century later has the full impact of dietary deficiencies in these essential substances been realized as a cause for stroke and dementia,and food fortification initiated for its prevention. There is both a genetic and a non-genetic enzymyopathy involving vitamins B₁₂, B₆, and folic acid, resulting in elevations of methylmalonic acid and/or homocysteine. The toxic effects of hyperhomocysteinemia are suspected to be increased production of hydrogen peroxide, oxidative stress, and endothelial dysfunction or increased oxidation of LDL and changes of LPA in hypercoagulability. Interventions to reduce homocysteine levels related to food fortification, dietary change, and other strategies will be discussed, as well as an update regarding a prospective randomized trial to determine whether intervention after initial non-disabling stroke can reduce the recurrence rate of secondary strokes.

VASOMOTOR REACTIVITY OF THE CEREBRAL CIRCULATION IN PATIENTS WITH CLINICAL DIAGNOSIS OF BRAIN DEATH.

J.I. Suarez, MD, O.O. Zaidat, MD.

Neurosciences Critical Care. University Hospitals of Cleveland, Case Western Reserve University. Cleveland, OH,

USA

CEREBRAL CIRCULATORY ARREST IN PATIENTS IN WHOLE BRAIN DEATH. A PROCESS THAT CAN BE MONITORED.

José M. Domínguez-Roldán, J.M. Barrera-Chacón, M.V-Rivera-Fernández, C.García-Alfaro

Hospital Universitario "Virgen del Rocío", Sevilla,

Spain

The cerebral circulatory arrest is a process that accompany the whole brain death. The relationship between intracranial pressure, kind of intracranial lesion and cerebral circulatory arrest was studied in a group of patients with hemorraghic cerebrovascular processes. We present our experience in the monitoring of cerebral circulation using transcranial Doppler sonography Different patterns of evolution till complete cerebral circulatory arrest were observed. Asymmetries in cerebral circulation between both cerebral hemispheres were detected in cases of hemispheric occupying space lesions. We also find, in cases of infratentorial lesions, data of cerebral circulatory arrest in cerebral arteries of the base of the skull associated to persistence of some clinical activity of the brainstem. All these hemodynamics and clinical situations will be presented and analysed.

DOPPLER TRANSCRANEAL COMO COADYUVANTE EN EL DIAGNÓSTICO DE MUERTE CEREBRAL.

González-Segura C; Pascual M; Quintana S*;Torras J; Tormos P.

Coordinación de Trasplantes del Hospital de Bellvitge y del *Hospital de Mútua de Terrassa. Barcelona

España

En España se exige el resultado de 2 electroencefalogramas isoeléctricos para completar el diagnóstico de muerte cerebral (MC). En presencia de drogas depresoras del sistema nervioso central (SNC) se puede confirmar la MC con otras pruebas no afectadas por la presencia de dichas drogas. Analizamos nuestra experiencia con el doppler transcraneal (DTC). Se divide la muestra en 2 grupos: donantes con DTC (grupo 1) y donantes sin DTC ( grupo 2) Las variables se expresan en porcentajes o media (DE). Desde el año 1991 ha habido 298 donantes de órganos. La edad de los donantes fue de 41 años (17), un tercio de los cuales fueron mujeres. En 62 donantes (21%) el DTC confirmó la MC, en 52 casos se realizó por presencia de drogas depresoras del SNC y en 10 por otros motivos. La estancia media y los órganos extraídos del grupo 1 fueron 3,84 y 3,16 versus 3,16 y 3,15 del grupo 2; sin diferencias significativas entre ambos grupos. Probablemente gracias a la realización del DTC en los donantes del grupo 1 se ha logrado obtener un número de órganos similar al del grupo 2. En otras series la presencia de drogas depresoras del SNC retrasa el diagnóstico de MC con la consiguiente disminución de calidad y número de órganos.

DOPPLER TRANSCRANEANO EN LA MUERTE ENCEFÁLICA

Corina Puppo, Elia Caragna, Horacio Panzardo, Alberto Biestro.

Centro de Tratamiento Intensivo y Departamento de Emergencia, Hospital de Clínicas, Unidad Neuroquirúrgica, Sanatorio IMPASA, Montevideo,

Uruguay

Se realizó una revisión retrospectiva de los estudios doppler transcraneanos (DTC) que se habían solicitado 1) como exámenes auxiliares en el diagnóstico de muerte encefálica (ME), o 2) realizados en pacientes con injuria encefálica grave en los que a pesar de existir mínimos signos de actividad neurológica clínica se encontró un patrón ultrasonográfico compatible con ME. Estos estudios se realizaron en 13 pacientes, de edades entre 11 y 71 años, media de 35, portadores de injuria encefálica aguda estructural: 5 traumática, 6 vascular, 2 infecciosa. Once pacientes presentaban coma arreactivo con arreflexia de tronco cerebral, dos pacientes GCS de 4 con mínima reactividad. Estos tampoco presentaban reflejos de tronco. Seis pacientes habían recibido tiopental en infusión i/v, razón que impedía completar el diagnóstico clínico de ME. Se estudió la velocidad circulatoria en las arterias cerebral media y anterior, a travás de la ventana temporal, y la carótida interna a nivel del sifón carotídeo a travás de la ventana orbitaria. Se dividieron los resultados en dos grupos: 1) Patrón de alta resistencia (tres pacientes), cuya Vm_ACM promedio fue de 33 cm/s (DE 13.32), y el IP promedio 2.07( DE 0.9.8). Este patrón es compatible con hipertensión endocraneana y baja presión de perfusión encefálica, pero no hace diagnóstico ultrasonográfico de ausencia de circulación cerebral. 2) Paro circulatorio cerebral (flujo oscilante, espigas sistólicas)(diez pacientes)con una Vm_ACM de 8 cm/seg(DE 3.13), y un IP de 6.36, (DE 2.07).Hacemos, aquí sí, diagnóstico de ausencia de flujo o circulación totalmente insuficiente. Todos los pacientes fallecieron en menos de 24 hs. de la realización del estudio. (ME ó PCR) Dos pacientes presentaban patrón de paro circulatorio cerebral, pero la clínica no era compatible con una ME, (GCS 4).Estos resultados podrían interpretarse como falsos positivos para el diagnóstico de ME,o lo que creemos más probable, ME inminente.

ALTERACIONES DE LA HEMODINÁMICA CEREBRAL EN LA FASE AGUDA DEL TCE Y MUERTE CEREBRAL

Francisco Murillo Cabezas

Jefe de Servicio de Cuidados Críticos y Urgencias, Hospital Universitario "Virgen del Rocío", Sevilla,

España

Los clásicos trabajos de Overgaard y Tweed, en la década de los setenta, enseñaron que el traumatismo craneoencefálico (TCE) grave induce modificaciones en el flujo sanguíneo cerebral (FSC) y su regulación, y que éstas se relacionan con el estado clínico de los pacientes y su ulterior resultado. Asimismo, los estudios anatomopatológicos de Graham y Adams de la escuela de Glasgow mostraron la alta incidencia de lesiones cerebrales isquémicas en los fallecidos por TCE, las cuales podían atribuirse a un déficit neto de FSC o desacoplamiento entre FSC y los requerimientos celulares. Previamente los estudios de Gobiet y más adelante los trabajos del grupo de Obrist, al inicio de la década de los ochenta, insistieron en investigaciones sobre la relación entre el FSC y el estado neurológico y pronóstico del TCE, así como sobre la dependencia recíproca entre los cambios del FSC y la presión intracraneal. Sin embargo, ha sido la difusión de la medida de la saturación de oxígeno de la sangre venosa extraída en el bulbo de la vena yugular interna (SJO₂), como estimación indirecta del FSC, así como la de otros parámetros derivados o relacionados con ella como la D(a-vj)O₂ y el índice Lactato/Oxígeno (LOI) divulgados a partir de la mitad de los ochenta, entre otros por Cruz y Robertson, lo que ha facilitado el estudio de la hemodinamia y metabolismo cerebral en la fase aguda del TCE. Anteriormente el propio Obrist y, posteriormente, entre otros, Bouma, Becker, etc., investigaron los cambios temporales del metabolismo y FSC en la fase aguda del TCE, caracterizando distintos patrones metabólicos y hemodinámicos en los pacientes y observando la predominancia de algunos de estos patrones en distintas fases del TCE. Los recientes avances en el conocimiento de la fisiopatología del TCE, y sobre todo la incorporación de diversos sistemas de neuromonitorización que estudian distintos aspectos de la hemodinamia y metabolismo cerebral a pie de cama, como los anteriormente citados, más algunos de reciente incorporación como el Doppler transcraneal, la saturación regional transcutánea de oxígeno mediante espectrometria cercana al infrarrojo (SRO₂), la presión tisular de oxígeno (PtiO₂), la microdiálisis cerebral, junto a sistemas más sofisticados y que requieren laboratorios fuera de las unidades de cuidados intensivos como la tomografía por emisión de positrones (PET) o de fotones simples (SPECT) han refinado los conocimientos sobre los perfiles hemodinámicos de la fase aguda del TCE grave.

ADVANCES IN THE MANAGEMENT OF INCREASED INTRACRANIAL PRESSURE

Karen March RN, MN, CCRN, CNRN

Neuroscience Clinical Nurse Specialist, Harborview Medical Center

USA

The consequences of increased intracranial pressure and secondary brain injury leave the patient with long term disabilities. It is our responsibility as health care providers to understand the complex pathophysiologic changes that occur following a brain injury and to optimize the patient's outcome by preventing secondary injury. The purpose of this session is review the integration of techniques that are used to assess the effects of brain injury and increased intracranial pressure and to discuss the current trends in the management of increased intracranial pressure. The techniques that will be discussed are the analysis of intracranial pressure waveform analysis, the transcranial doppler, and the retrograde jugular catheter. The management of increased intracranial pressure will be discussed using an algorithm to approach the decision making process that should be used to determine the most appropriate treatment modality or modalities for the patient. Current research about treatments will be discussed to support the use of each recommended treatment.

INTRACRANIAL PRESSURE MONITORING AS A COMPLEMENTARY DIAGNOSIS OF BRAIN DEATH : PRELIMINARY OBSERVATIONS.

Svetlana Agapejev, Rodrigo P. Ignácio, Benedito D. Amorim F^o, Carlos C.M. Freitas

Department of Neurology and Psychiatry - School of Medicine, University of the State of São Paulo (UNESP),

Brazil

The clinical evolution of 6 patients, with continuous intracranial pressure (ICP) monitoring, admitted to the Intensive Care Unit of Neurology of the Hospital of Clinics – UNESP of Botucatu, and followed until irreversible cardiac failure (ICF), was studied retrospectively. The evolution of ICP showed that it reached a maximum 1 to 12 hours before a decrease in wave amplitude occurred – this was observed approximately 47 to 60 hours before ICF. The tracing became linear approximately 30 hours before ICF in all patients, with or without sedatives. The clinical diagnosis of brain death was obtained 3 to 28 hours after the tracing had become linear. The authors suggest that the diagnosis of brain death may be made early with the use of ICP monitoring, even before the clinical diagnosis. They also emphasize the need for more observations in a large number of patients with and without sedatives.

ACTUALIZACIONES EN LA FISIOPATOLOGÍA DEL TRAUMATISMO CRANEOENCEFÁLICO GRAVE

J.Sahuquillo

Servicio de Neurocirugía, Hospitales Universitarios Vall d’Hebron, Barcelona,

España

Los traumatismos craneoencefálicos representan la primera causa de muerte en la población por debajo de los 45 años de edad. En la última década se han producido avances significativos tanto en el conocimiento de los mecanismos básicos de los traumatismos como en su fisiopatología. Aunque una parte considerable de las lesiones se producen de forma inmediata al impacto (lesiones primarias), muchas de ellas aparecen un periodo variable de tiempo después del traumatismo (lesiones secundarias). La isquemia cerebral, causada por hipertensión intracraneal, por una reducción en la presión de perfusión cerebral o secundaria a insultos sistémicos en la fase prehospitalaria (hipoxia, hipotensión o anemia) es la lesión secundaria de mayor prevalencia en los traumatismos craneoencefálicos graves . El hecho de que las lesiones secundarias originan a su vez, importantes cascadas metabólicas, que son la causa más importante de alteraciones celulares y de lesiones estructurales irreversibles (lesiones terciarias), ha sido el avance fisiopatológico más significativo en el conocimiento de los TCE. Este mejor conocimiento de su fisiopatología ha permitido mejorar la monitorización y mejorar de forma significativa la asistencia ofrecida a estos pacientes. En esta ponencia, revisamos los conceptos fundamentales en los mecanismos etiopatogénicos implicados en los traumatismos cráneoencefálicos graves, los avances en su fisiopatología y en las cascadas metabólicas implicadas.

TREATMENT OF SPONTANEUS HYPERTENSIVE INTRACEREBRAL HAEMATOMAS IN COMATOSE PATIENTS

Caparoski A., Pangovski I., Stolevski V., Lj. Visurski

Institution Neurosurgical department, Medical faculty – Skopje,

Republic of Macedonia

Arterial hypertension associated and caused by generalisated arteriosclerosis, inflamative degeneration (vasculitis) of the blood vessels, age of the patients and other risk factors is one of the most common source for spontaneus intracerebral hematoma. During the last eight years, since 1990 till 1998, we observed and surgicaly treated a group of 124 comatose patients with spontaneus hypertensive intracerebral hematoma.(SHIH). 68 of the the patents were threated surgicaly and remaining 56 patients with conservative treatment. There were 66 females and 58 males with an range of 38-79 ( mean 58 years). Diagnosis was based on clinical examinations and CT. The localisation of haematoma in 93% was supratentorial, and 7 % of the patients with infratentorial localisation. In 52 % of patients the haematoma was located in basal gangia. The mortality was 66% in the group of patients treated surgicaly and 68 % in the group of patient with conservative treatment. The results indicate that spontaneus hypertensive intracerebral haematomas (SHIH) localisated in haemispherical white matter and cerebellum performing exspansive intracranial lesion are subject of choice for operative treatment, while SHIH located deep in midline and basal ganglia are with out significant diference in prognosis, between surgical and conservative treatment. Determining parameters for the cure outcome of SHIH in this location, are age of the patient, the stage of consciousness neurological deficit, and the volume and localisation of the haematoma.

PROBLEMS PRESENTED BY THE BIRTH OF INFANTS OF 23-26 WEEKS OF GESTATION AND / OR WEIGHT BELOW 1000 GMS

Dr. Sanford J. Matthews

Piedmont Hospital, Atlanta, Georgia

USA

The dilemma of expending resources on infants who promise little in the way of normal motor and cognitive development because of their vulnerability to cerebral hemorrhage and bronchial disease inherent in the management techniques to control respiratory distress syndrome (surfactant lack). In this time of escalating sophistication in the technology of neonatal care, with resources strained to the limit of economic tolerance, neonatalogists are confronted with escalating stresses and anguishing choices as to the limits of intervention in cases involving immaturity and organ failure. All of these choices are compounded by the desires and hopes of the parents of these infants, not to mention the concerns, hopes and ambitions of the caregivers, whose training and orientation invariably lean to supporting life, rather than modifying the effort to sustain it. The idea that the caregiver should make a decision with regard to life support in an infant whose future is bleak flies in the face of all that the profession has espoused. These dilemmas have become a part of everyday pediatrics. The solutions to these problems seem more problematic as our ability to support life in these tiny infants become more sophisticated with time. A discussion of philosophical, technical and sociological aspects of these trying challenges will illustrate individual problems. The limited medical resources of many countries will serve as a departure as we discuss the allocation of these resources in the light of economics, allocation of talent and institutional opportunity to be expended as solution to these troublesome challenges.

ALGUNAS CONSIDERACIONES EN RELACIÓN AL DIAGNÓSTICO DE LA MUERTE ENCEFÁLICA EN LOS NIÑOS

Desiderio Pozo Lauzán; Albia J. Pozo Alonso

Hospital Pediátrico Universitario "William Soler", Ciudad de La Habana,

Cuba

La muerte encefálica se define como el cese irreversible de todas las funciones cerebrales, incluyendo el tallo cerebral;no siempre resulta fácil confirmar la misma, principalmente en los niños, siendo más complejo en los neonatos y lactantes. El objetivo fundamental de este trabajo es la revisión de los criterios clínicos de muerte encefálica para su posible aplicación en los niños con un grado aceptable de confiabilidad. Se analizan también los diferentes métodos auxiliares de diagnóstico que pudieran constituir una herramienta útil como complemento de los criterios clínicos, enfatizándose en la necesidad de realizar la validación de los mismos, particularmente en menores de un año.

PITUITARY FUNCTION IN COMA AND BRAIN DEATH

R. Firsching, M. Engelhardt

Germany

The pituitary function during coma and brain death is not well known, there are reports on partly preserved functions after the onset of brain death. We investigated hormone levels in comatose patients and compared the pituitary function of survivors with fatal courses and levels after the onset of brain death. patients and methods: In 43 comatose patients with intracranial haemorrhage or after headinjury the blood levels of cortisone, follicle stimulating hormone (FSH), insulin like growth factor (IGF-1), luteinizing hormone (LH), estroge, prolactin, thyroid and thyroid stimulating hormone (TSH) and testosterone were evaluated and the levels of FSH, LH, PRL and TSH after stimulation were measured. Thirteen patients in coma survived, in 18 patients with a fatal course the levels were determined prior to an apnea test after the onset of fixed pupils and in 12 patients hormone levels were determined after the onset of apnea. Results: Most hormones proved to be lower after apnea than in comatose patients, who survived. After the onset of apnea there were normal levels of PRL and Cortisone in some patients, most hormone levels, however, were lower than normal. Only IGF-1 was normal in all patients after onset of apnea. Conclusion: There is a number of instances with normal pituitary function after the onset of brain death. Mostly hormone levels decrease with deaper coma grades.

IS THERE A BENEFIT FROM SUBSTITUTING VASPRESSIN DURING HEMODYNAMIC STABILISATION OF BRAIN DEAD ORGAN DONORS?

Link J, Gramm H-J, Schäfer M, Wamprecht R

Klinik fuer Anaesthesiologie und operative Intensivmedizin, Klinikum Benjamin Franklin, Freie Universitaet Berlin. D-12200 Berlin,

Germany

ESTADO VEGETATIVO PERSISTENTE/PERMANENTE: PRESENTACIÓN DE 17 CASOS (Parte I)

Ignacio Casas Parera, *Julio Ravioli, Eugenio Demarchi, ? Luis Barreiro de Madariaga, Santiago Bestoso Hugo Laborde

Instituto de Investigaciones Médicas Dr. Lanari; *Cátedra de Medicina Legal y Deontología Médica; Facultad de Medicina UBA; Hospital Central de Formosa; Universidad del Litoral; Htal. de Clínicas; UBA,

Argentina

Objetivo: mostrar los resultados del análisis clínico/estadístico de una serie de pacientes en estado vegetativo persistente/permanente. Pacientes y método: durante 1997 se incorporaron 17 pacientes en EVP/P, 9 mujeres y 8 hombres, con edades comprendidas entre los 21 y 80 años (36,23 ± 17,6). Los datos fueron analizados mediante regresión lineal y test de student para comparación de medias. Se aceptó un alfa de 0,05. Resultado: El tiempo en asistencia respiratoria mecánica fue de 15,9; 10,9 (rango 0-45 días) y el tiempo en coma fue de 19,9; 16,3 (rango 1-70 días). En los casos 1 a 16 la sobrevida fue de 143,9; 93,2 días (excluyendo el caso N°17: 7 años de sobrevida); los fallecidos tuvieron un tiempo de (107) 62,6 días y para el resto 156,2; 98,3. El 23,5% de los pacientes fallecieron durante el seguimiento en el año 1997. De los sobrevivientes (13 casos), el 38,5 % quedó en Grado 2 y el 61,5% en Grado 3 del Outcome Glasgow Scale (OGS). No hubo correlación entre el tiempo en coma y la sobrevida. El análisis estadístico comparando los grupos en grado 2 y 3 del OGS, con las variables tiempo en ARM y tiempo en coma, no hubo significancia, aunque se encontró una tendencia de menor N° de días en ARM y en coma a favor del Grupo 3 del OGS. Conclusión: 1) Predominan los pacientes adultos jóvenes. 2) Existe una tendencia a una mejor evolución clínica ( Grado en el OGS) en pacientes con menor número de días en ARM y en coma (mayor N° de casos aclararían este punto). 3) Llama la atención el reducido número de casos identificados como EVP/P.

BRAIN DEATH - THE EUROPEAN POSITION

F. Gerstenbrand, H. Baumgartner, H. Binder, Ch.A. Stepan,Vienna, Innsbruck,

Austria

Brain death is the irreversible break down of all brain functions, including brain stem functions with isoelecrtical EEG and facultative proofed circulatory arrest. Clinically special attention should be paid to the possible occurence of spinal reflexes and spinal automatisms. A clear differenciation must be established to locked-in syndrome and to apallic syndrome. This diagnostic basis is accepted in the whole of Europe, in the UK the term „brain stem death" officially is used. The waiting periode, the time between establishing the diagnosis and the withdrawal of supportive measures, extends in Europe from two to six hours, in special cases no waiting period is requested. The European consensus paper concerning brain death diagnostic directions is influenced by ethnical and religious differences. The Christian Orthodox community, being of great influence in Eastern Europe, demands to follow religious rules in details. In the Islamic idiology decisions taken by physicians are not generally accepted. Buddhism principally does not allow to live with an organ of another human being, or to donate an organ for implantation. Besides the religious differences rules of ethnic groups have to be considered. Another problem for European guidelines is the increasing wave to euthanasia and to the „end of life discussion" in some Western European countries. In Europe there are different basic rules regarding the organ donor. In Austria there is the principle rule that everybody is a potential donor unless he has a written statement (refusal) with him. The European consensus paper on brain death will be used as a basis for guidelines of the World Federation of Neurology.

GUIDELINES FOR EVALUATION OF BRAIN STEM DEATH AT THE HOSPITAL DAS CLÍNICAS OF THE UNIVERSITY OF SÃO PAULO MEDICAL SCHOOL.

Raul Marino Jr., MD

Professor and Chairman, Division of Neurosurgery, University of S. Paulo Medical School

Almir Ferreira de Andrade, MD

Director Emergency Service, Division of Neurosurgery, Hospital das Clínicas, University of S. Paulo Medical School

André Guelman Gomes Machado, MD.

Resident Physician, Division of Neurosurgery, Hospital das Clínica, University of S. Paulo Medical School

Brazil

Whenever a patient is diagnosed with Glasgow=3 points of known ethiology, the Organ Search Team (OST) begins the initial evaluation and stabilization of the patient. A first neurological evaluation is made if the patient is stable and doesn’t present any exclusion criteria. If the result is confirmatory of brain death, the OST consults the family about organ donation. After that, a subsidiary test is performed, usually the transcranial doppler. A second neurological examination is made after 6 to 12 hours, depending on the patient’s age. At this point, the diagnosis of brain death can be made. Two assistant physicians have to sign the declaration of death, one of them necessarily being a neurologist or neurosurgeon. All neurological examinations follow the same protocol for evaluation of brain stem function. The apnea test is made for 10 minutes, after 10 minutes of 100% oxygenation, on a monitored patient. The duration of the apnea test should be further discussed, since it may complicate the donor’s condition.

NEW DEATH DEFINITION IN FINLAND, THE COUNTRY THAT FIRST ADOPTED BRAIN DEATH

Kimmo Sainio

Department of Child Neurology, University of Helsinki,

Finland

The first brain death definition was established in Finland August 12^th 1970 and second with minor modifications May 23^rd 1971. In 1996 some experts were asked if there was a need for revision and National Authority for Medicolegal Affairs set up a committee in 1997 to propose a new definition. The main principles in the proposition were that death is a unique phenomenon with only one definition and that the death criteria are independent of the events that will take place after death like organ donation. The definition for death is: a man is dead when all his brain functions have permanently ceased. There are two sets of criteria. A. Defining death after cardiac arrest: 1) Secondary signs of death (like rigor mortis etc.). 2) Cessation of respiration and circulation in cases of unsuccessful resuscitation. 3) Cessation of respiration and circulation in cases where resuscitation is withheld. B Defining death with cardiac activity: 1) The reason for cessation of brain functions is established. 2) All brain responses are missing. The proposition includes recommendations for diagnostic measures, examinations of brain functions and resuscitation. Essential is that there is one definition of death, but two sets of criteria and that a definite diagnosis is not demanded, e.g. a verified lethal increase of intracranial pressure for unknown reason is enough for death diagnosis during cardiac activity.

DIAGNOSIS AND CONFIRMATION OF BRAIN DEATH

Stulin I.D., Musin R., Mnushkin A., Tardov M., Shibalev A., Sechkin A.

Moscow State Medico - Stomatological University, Moscow,

Russia

In experimental part of our study - applying of acute conditions to 15 dogs - we managed to show clear correlations between the level of intracranial hypertension, echopulsation amplitude, fluctuations of blood flow direction and velocity in extra- and intra-cerebral arteries and veins, progressive hypothermia of cortex and subcortical regions and fall of cerebral oxygen saturation. Another part of the study includes observations and monitoring of brain functions in 327 patients with progressing cerebral coma as a result of head trauma or hemorrhagic stroke, that have been treated in neurologic ICUs. All the results have been obtained throughout the work of our new subdivision - the Mobile Neurodiagnostic Unit. According to clinical and paraclinical data 38 of those atonic patients were considered brain dead. Owing to careful monitoring for many hours (6-74) of brain bioelectric activity (EEG, EP); extra- and intracerebral blood flow, cerebrospinal fluid circulation (Duplex, TCD, Echo-EG), brain oxygen saturation (transcranial cerebral oxymetry); to thermotoposcaning of cortical and subcortical structures-millimeter and decemeter thermography and to apnea oxygenation test we succeeded to create confirmation algorithm of brain function and intracerebral blood flow cessation, that really means brain death. Our unique practical experience in this field gives hope for insertion of such relatively cheap, non invasive, safe, and informative diagnostic complex into official protocol of brain death confirmation. We can try to suppose as well, that application of such a complex of paraclinical methods, each of them characterizing the different pathogenetic side of progressing cerebral coma, enables to limit or even to abolish the necessity for cerebral angiography and for apnea oxygenation test, which is not always indifferent to the patient. The paraclinic complex described helps to make brain death confirmation more precise and opportune, so it can be put into practice of mobile neurodiagnostic units.

BRAIN DEATH ASSESSMENT IN ITALY

L. Ridolfi ⁽¹⁾, N. Venturoli ⁽¹⁾, P. Mazzetti Gaito ⁽¹⁾, M.R. Pugliese ⁽¹⁾, D. Degli Esposti ⁽¹⁾, A. Nanni Costa ⁽²⁾, F. Petrini ⁽³⁾, G. Martinelli ⁽¹⁾

(1) Transplant Reference Center Emilia-Romagna Region, Italy

THE ROLE OF SENSORY EVOKED POTENTIALS IN PREDICTING OUTCOME IN POST-TRAUMATIC AND ANOXIC COMA

Ted L. Rothstein M.D.

USA

The early recognition of comatose patients with hopeless prognosis- regardless of how aggressively they are managed-is an urgent need. Somatosensory evoked potentials (SEP) have been evaluated as a prognostic guide in a variety of comatose states. This presentation will contrast the role of SEP in post-traumatic and anoxic coma. SEP has been most extensively evaluated in patients with severe head trauma which afflicts 400,000 Americans each year. Approximately 20 % of head injury is classified as severe with a mortality rate of 50%. SEP is useful in evaluating brain stem and hemispheric function and can assist in analyzing the site and severity of brain injury. SEP has been studied as a predictor of outcome in patients comatose after severe head injury. Its reliability in predicting unfavorable outcome remains controversial as some patients with absent cortical evoked potentials (CEP) have recovered. This suggests that wave form abnormalities can be reversed if the underlying condition is corrected. By contrast, the bilateral absence of CEP in anoxic coma following cardial arrest is the most discriminating predictor of unfavorable outcome. In our study of 50 patients in anoxic coma all 23 with absent CEP died without awakening. Neuropathologic findings in each of the 7 patients studied with absent CEP disclosed diffuse cortical laminar necrosis. A metaanalysis of 537 patients in anoxic coma identified 192 patients with bilateral absence of CEP and all died without awakening or entered persistent vegetative state (PVS). Greater utilization of SEP in anoxic coma would identify those patients with hopeless prognosis and avoid costly and dehumanizing care that is ultimately to no avail.

BIOCHEMISTRY DATA IN SEVERE ANOXIC COMA - WHAT IS THEIR ROLE FOR EARLY PREDICTION OF BAD OUTCOME?

Pohlmann-Eden, Bernd, Zingler, Vera, Faßbender, Klaus

Dept. of Neurology , Klinikum Mannheim, University of Heidelberg,

Germany

Objective: Early prediction of outcome of severe anoxic coma by means of serial biochemistry data, implemented in neurophysiological and clinical data. Background: Prediction of anoxic coma after sucessful cardiopulmonary resuscitation (CPR) by clinical data is most often unreliable and questionable in presence of normal looking imaging findings. The intraneuronal protein neuron-specific enolase (NSE) and the astroglial protein S-100 have shown in the past in both experimental and few clinical data that they are able to early reflect the extension of brain tissue damage. Material/methods: We prospectively investigated 32 comatose patients after CPR ( 17f, 15m), mean age 63.2 years, mean initial GCS 4.2 by means a multimodal approach using repeated clinical scores , standardized SEP-monitoring (day 2 and 7) and serum levels of S-100 and NSE taken on days 1, 2, 3, and 7 (analysis by immunolumionometric assay). 5 patients died because of extracerebral reasons and were excluded. Outcome was assesses by GOS-scale (Glasgow-outcome-Skala). Results: In the remaining group of 27 patients mean values of both S-100 and NSE were significantly increased in the bad outcome groups GOS 1+2 on all days in the given time frame compared to the good outcome groups. NSE had a maximum peak on day 3, S-100 already on day 1. The differences over time were significant up to p<0.001. The S-100 peak on day 1 was mainly the result of excessive values of these individuals who died already during the first 24 hours. In a retrospective analysis cut-off-values could be calculated reaching specificity of 100%. Discussion: Our preliminary data confirm the high predictive value for bad outcome assessment in anoxic coma of serially documented, elevated serum levels of both S-100 and NSE. It is challenging for the future to integrate these data in a multimodal approach and to develop a decision algorhythm with prospectively analyzed cut-off values.

VALOR PRONÓSTICO AL INGRESO DE LA EXPLORACIÓN NEUROLÓGICA Y ESTUDIOS NEUROFISIOLÓGICOS EN EL COMA

Zabalegui A, López MJ, Arroyo I*, Mercado A*, Martel C*, Fernández JA., Mº Jesús López Pueyo Arturo Zabalegui Pérez

Servicio de Medicina Intensiva y Neurofisiología*, UCI. Hospital General Yagüe, Burgos,

España

Objetivo: analizar el valor pronóstico al ingreso, de la exploración Neurológica [Motora (EM) y Troncular (ET)] y de los estudios Neurofisiológicos [Electroencefalograma (EEG) y Potenciales Evocados Auditivos (BAER) y Somatosensoriales (PESS)], en el coma. Pacientes y Métodos: estudio prospectivo durante los años 97-98, en pacientes ingresados en UCI en coma GCS<8. Los resultados de las exploraciones se dividieron en: a/ Maligno: EM con movimientos inapropiados o ausentes, ET sin respuesta, EEG "maligno" o isoeléctrico, BAER y PESS isoeléctricos. b/ Benigno: Resto de posibilidades. La variable pronóstica fue el GOS a los 6 meses, dividido en: a/ Buena evolución: GOS 1-3. b/ Mala evolución: GOS 4-5. Resultados: Se estudiaron 61 pacientes [edad media 46.09 (DS 19.80) años, SAPS II medio 46.36 (DS 12.88)]. La etiología del coma fue: Traumatismo craneoencefálico 28 pacientes, Accidente Cerebro Vascular 19, Encefalopatía hipóxica 7, Síndrome de Disfunción Multiorgánica 6 y Embolismo graso 1 paciente. Las exploraciones se realizaron como media a los 4.03 (DS 4.45) días del ingreso, estando en el momento de las distintas pruebas en tratamiento con Midazolam/Propofol en el 61.1% de los casos, Relajantes musculares en el 17.9% y Barbitúricos en el 14.0%. La Sensibilidad (S), Especificidad (E), Prevalencia (P), Valor Predictivo Positivo (VPP) de mala evolución de cada exploración y el nivel de significación (p) fueron:EM: E 26.7%; S 93.8%; P 68.1%; VPP 73.2%; p 0.010. ET: E 94.4%; S 38.7%; P 66.3%; VPP 92.3%; p 0.011. EEG:E 68.4%; S 72.7%; P 63.5%; VPP 80.0%; p 0.003. BAER: E 100%; S 38.7%; P 64.6%; VPP 100%; p 0.003. PESS: E 100%; S 44.4%; P 62.1%; VPP 100%; p 0.012. Conclusiones: En nuestro estudio, al ingreso, las pruebas que valoran el Tronco cerebral (ET, BAER, PESS), son las que presentan mejor E y VPP de mala evolución del coma. Ningún paciente con potenciales isoeléctricos, sobrevivió.

NEUROLOGIC AND ELECTROPHYSIOLOGIC EVALUATIONS FOR PREDICTION OF OUTCOME AFTER CARDIORESPIRATORY ARREST

Gregory C. Mathews; Peter W. Kaplan; Nisha Chandra and Robin A. Conwit

Presenting Author: Peter W. Kaplan, MB FRCP, Johns Hopkins Bayview Medical Center, Baltimore, MD,

USA

Neurologic examination, and more recently, EEG and SSEPs, have been used for prognosis in patients in coma after cardiorespiratory arrest (CRA). We retrospectively studied 43 patients to see how different methods of evaluation compared alone and in combination for prediction of outcome. Neurologic examinations (within 48 hours) and/or SSEPs and EEG (within 72 hours) were performed. Almost 90% (37/43) did not awaken before death or discharge. Absent pupillary responses (APR) occurred in 14/37 (38%), abnormal SSEPs in 23/37 (62%), abnormal EEG in 29/37 (78%) of those who never awoke. Of those who awoke, 1/6 (17%) had APR, 0/6 had abnormal SSEP, 3/6 (50%) had abnormal EEG. In terms of predictive value, APR predicted not awakening in 93% (14/15), abnormal SSEP in 100% (23/23) and abnormal EEG in 91% (29/32). Our data agree with published studies regarding the specificity of neurologic and electrophysiologic evaluation, but are striking in their lack of sensitivity for prognosticating which patients will not awaken. One reason for this was probably our early withdrawal of care, which occurred in 50% of patients who did not have any "negative" prognostic indicators. This trend appeared to arise from advance directives or caregiver bias that prognosis in coma after CRA is poor, rather than reliance on objective data. The factors that currently guide the decision making process for doctors and patient families need further study.

EVOKED POTENTIAL INVESTIGATION OF VISUAL DYSFUNCTION FOLLOWING METHANOL POISONING

Ph Hantson⁽¹⁾, Ph.D., M de Tourtchaninoff⁽²⁾, M.D., P Mahieu⁽¹⁾, M.D., JM Guérit⁽²⁾, Ph.D.