Don d'organes, du nouveau ...

 Jeudi 10 mai 2012

Avant de donner vos organes, lisez ceci

"Saviez-vous que, pour pouvoir prélever des organes, le « mort » doit souvent être… anesthésié ???
Hé oui, c’est une réalité qui est rarement révélée aux donneurs, et à leur famille. Cela ne veut pas dire qu’il ne faut pas faire de don d’organes, au contraire. Mais il est important de ne pas le faire aveuglément.
Pour pouvoir être transplantés, les organes doivent être frais. Le cœur d’une personne morte depuis ne serait-ce que cinq minutes est inutilisable : il ne se remettra jamais à battre, y compris avec un pacemaker (un appareil qui donne des chocs électriques pour stimuler les pulsations). Il en va de même des autres organes vitaux (reins, foie, pancréas, poumons…)
Pour que les organes soient bien frais, donc, il faut qu’ils soient encore en train de fonctionner au moment où ils sont prélevés. Ils ne peuvent donc pas être prélevés sur un « mort » réellement mort, mais sur une personne en état de « mort cérébrale », ce qui, nous allons le voir… est très différent.

Revenu du séjour des morts

Le journal anglais Daily Mail publie l’histoire d’un jeune britannique qui a eu la vie sauvée par son père qui s’était opposé à ce que ses organes soient prélevés pour servir à des transplantations. (1)
L’affaire s’est produite à l’hôpital universitaire de Coventry, dans le nord de l’Angleterre :
Stephen Thorpe, 17 ans, avait été gravement blessé à la tête lors d’un accident de voiture au cours duquel était mort son ami Matthieu, 18 ans, qui conduisait le véhicule.
Les médecins le mirent sous coma artificiel et, deux jours plus tard, le déclarèrent en état de « mort cérébrale ». La « mort cérébrale » permet l’ouverture de la procédure de prélèvement d’organes. Mais les parents de Stephen, qui étaient auprès de lui, affirmèrent qu’ils « sentaient que leur fils était encore là » et qu’il réagissait à certaines paroles.
Alors que quatre médecins de l’hôpital confirment la « mort cérébrale » et souhaitent que commence le prélèvement d’organes, les parents de Stephen font appel au Docteur Julia Piper, praticienne de médecines traditionnelles et alternatives. Celle-ci obtient l’autorisation de faire examiner Stephen par un neurochirurgien de confiance, qu’elle connaît.
Celui-ci conclut que le jeune garçon n’est absolument pas « mort cérébralement ». Il demande qu’il soit au plus vite sorti de son coma artificiel. Et en effet, cinq semaines plus tard, Stephen rentre chez lui, entièrement remis.
Aujourd’hui, Steven a 21 ans et étudie la comptabilité à l’université de Leicester. « Mon impression est que l’hôpital n’était pas très favorable à ce que mon père demande une contre-expertise médicale » a-t-il déclaré au Daily Mail.

Ne pas confondre « mort » et « mort cérébrale »

Le concept de « mort cérébrale » a été inventé en 1968. Jusque-là, on ne connaissait que deux états : vivant ou mort.
Une personne était vivante tant que son corps restait chaud, que son cœur continuait à battre, qu’elle respirait et que son sang continuait à circuler.
La mort, au contraire, était déclarée lorsque la vie avait quitté le corps. Un corps mort, au sens traditionnel du terme, devient froid, rigide. Il ne répond plus à aucun stimulus. Le cœur ne bat plus, la tension artérielle disparaît. Le patient arrête de respirer. La peau, les ongles et les muqueuses prennent une couleur bleutée. Mettre le cadavre sous respiration artificielle ne relance pas l’oxygénation du corps. Stimuler le cœur par une impulsion électrique (pacemaker) ne le fait pas recommencer à battre.
Une personne morte ne peut tout simplement plus guérir. Ses organes vitaux, le cœur, le foie, les poumons, les reins et le pancréas ne fonctionnent plus. On ne peut plus les transplanter sur une personne vivante, car ils commencent à se décomposer aussitôt que l’oxygénation et la circulation sanguine s’arrêtent. Cinq minutes plus tard, ils sont inutilisables.
Pour pouvoir prélever des organes encore vivants, et donc capables d’être transplantés sur une nouvelle personne, les médecins créèrent en 1968 le concept de « mort cérébrale ». Une personne dont le cœur fonctionne, le sang circule, et la respiration est régulière peut donc aujourd’hui être déclarée en état de « mort cérébrale ». On sait pourtant que, dans ce cas, la plupart des fonctions vitales continuent, dont la digestion, l’excrétion (évacuation des déchets), et l’équilibre des fluides.
S’il a des blessures, on constatera que le « mort cérébral » cicatrise, et si c’est un enfant, qu’il continue à grandir. Il peut même traverser la puberté. Une femme enceinte en état de « mort cérébrale » peut continuer à porter son enfant : la plus longue période enregistrée est de 107 jours jusqu’à l’accouchement.
En revanche, une fois que ses organes vitaux sont retirés pour être transplantés sur une autre personne, le « donneur » d’organe décède pour de bon.

Pour prélever des organes, le « mort » doit d’abord être anesthésié

Très souvent, la personne en état de « mort cérébrale » est sensible aux opérations chirurgicales. C’est ce que les médecins appellent l’effet Lazare, du nom de l’homme qui, dans les Evangiles, ressortit de son tombeau.
Pour pouvoir prélever les organes vitaux, les médecins doivent donc pratiquer l’anesthésie, ou injecter des substances paralysantes pour éviter les spasmes musculaires, ou les changements brutaux de pression sanguine, de rythme cardiaque, et d’autres réflexes protecteurs.
Dans la pratique médicale normale, de telles réactions de la personne opérée indiquent à l’anesthésiste que l’anesthésie est trop légère, et que le patient souffre.
Ces informations, que n’importe quel médecin pourra vous confirmer, sont malheureusement mal connues du grand public. Il semble également que les familles à qui l’on demande d’autoriser un prélèvement d’organe ne soient malheureusement pas toujours informées objectivement.

Le cas de Stephen n’est pas isolé

Il existe des dizaines de cas similaires à celui de Stephen, dans lesquels une personne comateuse ou inconsciente est déclarée en état de « mort cérébrale » ou « sans espoir de guérison ». Bien souvent, les familles subissent alors des pressions pour autoriser les prélèvements d’organes.
En 2011, l’Hôpital Sainte-Croix de Drummondville (au Québec), a demandé l’autorisation d’extraire les yeux d’une patiente qui s’était étranglée pendant son repas à l’hôpital en l’absence de personnel soignant, affirmant qu’elle était en état de « mort cérébrale ». Après que la famille eut demandé des preuves au médecin, elle se réveilla et retrouva l’essentiel de ses facultés. (2)
En 2008, un Français de 45 ans s’est réveillé sur la table d’opération, tandis que les médecins s’apprêtaient à lui prélever ses organes, suite à un arrêt cardiaque. Lors de l’enquête menée par le « comité d’éthique », plusieurs médecins reconnurent que ce type de cas, bien que rare, leur était parfaitement connu. (3)
La même année, Sack Dunlap, un Américain de 21 ans, « mort cérébralement », était sur le point de se faire retirer ses organes vitaux lorsque ses deux sœurs, toutes les deux infirmières, décidèrent de vérifier qu’il était en effet « mort cérébralement ». Discrètement, elles enfoncèrent une pointe sous son ongle de pied, ce qui provoqua une forte réaction de Dunlap, prouvant qu’il était conscient. Il se remit complètement et déclara plus tard qu’il était conscient et entendait les médecins autour de lui discuter des organes qu’ils allaient lui prélever !
Alors, dans ce domaine comme dans tous les autres, cher lecteur, rappelez-vous qu’il s’agit de votre vie, votre santé, et jamais de celle ni des médecins, ni des personnes qui vous conseillent, même lorsque celles-ci sont de la meilleure volonté.
Bien à vous,"

Sources de cet article :
1. The Daily Mail, le 24 avril 2012 : http://www.dailymail.co.uk/health/article-2134346/Steven-Thorpe-Teenager-declared-brain-dead-FOUR-doctors-makes-miracle-recovery.html?printingPage=true
2. http://www.journalexpress.ca/Société/Santé/2011-06-30/article-2624757/Un-mal-de-dent-qui-a-failli-virer-en-don-dorganes/1
3. Article publié dans le journal Le Monde, disponible ici : http://actuagencebiomed.blogspot.fr/2008/06/le-donneur-dorganes-ntait-pas-mort.html

http://www.santenatureinnovation.fr/chirurgie/avant-de-donner-vos-organes-lisez-ceci?utm_source=Newsletter-gratuite&utm_medium=emailing&utm_campaign=201205D-avant-de-donner-vos-organes-lisez-ceci

A Drug That Wakes the Near Dead

http://www.nytimes.com/2011/12/04/magazine/can-ambien-wake-minimally-conscious.html?_r=2&pagewanted=all

Dead-donor’ rule dangerously misleading, experts say

Dr. Fraser Rubens works alongside nurse Elizabeth Knapp as he pours litres of warmed-up saline solution into the chest cavity after a new heart has been placed in Jack Quinte. Copyright: Julie Oliver / Postmedia News files.

"Doctors should abandon the 'dangerously misleading' policy of having to declare donors dead before their organs can be extracted for transplant, and adopt a more honest policy that acknowledges some patients may still be technically alive, Canadian and Spanish experts suggest in a provocative new commentary.

They advocate replacing the current 'dead-donor rule' with a policy that educates the public about the true nature of patients used in transplant, obtains informed consent — and ensures the donor does not suffer during the organ harvesting.

The authors, including Dr. Neil Lazar, director of the medical-surgical intensive care unit at Toronto General Hospital, say the focus should be on the well-being of donors rather than whether they are legally dead. That could mean giving anesthetics during organ harvesting.

'Because there is a general assumption that dead individuals cannot be harmed, veneration of the dead-donor rule is dangerously misleading,' they wrote. 'Ultimately, what is important for the protection and respect of potential donors is not to have a death certificate signed, but rather to be certain they are beyond suffering and to guarantee that their autonomy is respected.'
The suggestions, made at a major U.S. bioethics conference last week and in a recent paper in the American Journal of Bioethics, are coming under strenuous criticism by the transplant community, however. Some experts call the proposal a theoretical argument that has little foundation in reality, but that could seriously hurt the ongoing struggle to recruit potential organ donors.
'In the overwhelming majority of cases, the concept of death is easy, obvious and not really subject to any complex interpretation. It’s very clear,' said Dr. Andrew Baker, medical director of the Trillium Gift of Life Network, which oversees Ontario’s transplant system. 'They’re dead, you can see it, there is no return of anything.'
Dr. Baker, head of trauma and neurosurgery at Toronto’s St. Michael’s Hosptial, said he sees daily the medical 'marvel' of organ transplantation, the lives it saves and the consolation it gives to the relatives of dead patients. It would be tragic if donation rates were undermined by unfounded concerns, he said.
'If you said ‘No’ [to donation] for the totally wrong reason, because the National Post wrote that some good doctor said you might feel something [during organ harvesting], that would just be too much.'
Dr. Sam Shemi, a prominent Montreal intensive-care physician, echoed his concerns. Determining death in organ donation cases 'is more professional, rigorous and performed according to a higher standard than in any other situation,' he said.
In questioning death declaration, the bioethics paper focuses largely on a recent trend in transplantation.
Most transplant organs are taken from patients declared brain dead. Those people account for only about 10% of hospital deaths, however, leaving a shortage of donors and hundreds of gravely ill Canadians languishing and dying on transplant waiting lists.
In response, the medical community has recently embraced a new protocol, where organs are removed after the heart has stopped — in Canada, five minutes after it has halted — but when the patient is not necessarily brain dead. Approved at a 2006 conference of experts, the procedure has been used hundreds of times since across the country, helping increase the total number of donors by more than 25% in Ontario alone.
While the medical community generally supports 'donation after cardiac death [DCD],' there has been some controversy. The paper by Dr. Lazar and colleagues notes that in most DCD cases, doctors have made a decision not to continue life-support measures that keep the patient breathing and their heart beating. That does not necessarily mean the heart could not be started again, artificially at least, they argue.
It is also possible that when cardiac death is declared, there may still be some brain activity, raising at least the possibility the donor could feel pain during the harvesting of organs, the paper argues. The process of inserting catheters that pump blood through the transplant organs before removal could also start blood circulation in the brain, triggering some limited activity there, the article says.
Dr. Baker said there is no evidence, however, that cardiac death is anything but the complete lack of life. When someone is removed from a ventilator, first they stop breathing, then their heart stops. That means that the brain stem, which regulates those activities and is considered the last part of the brain to die, would have lost all function.
And perfusion is done here in a way that there is no blood flow through the brain, he said.
James DuBois, a health ethics professor at Saint Louis University, also argued that determination of death is well-founded in transplant cases, and worried about the impact of removing the dead-donor rule.
It could 'have negative consequences: decreasing organ donation rates, upsetting donor family members and creating distress among health care workers,' he wrote in a response published by the bioethics journal."

National Post
Article by Thomas Blackwell
tblackwell@nationalpost.com

Alarm at proposal to scrap dead donor rule

"Let's scrap the fiction that most patients are dead when their organs are removed and allow doctors to take them from people who are still living. This is the provocative proposal by doctors from Canada and Spain which is creating a stir in bioethics circles.Speaking at the American Society of Bioethics and Humanities annual conference in Minneapolis earlier this month, Dr Neil Lazar, of Toronto General Hospital, Maxwell J. Smith, of the University of Toronto, and David Rodriguez-Arias, of the Basque University, argued that it is more important to know whether the patients are comfortable and 'beyond harm' than whether they are alive.
Like conservative critics of organ transplants, they stress the ambiguity determining death no matter which the two criteria for death are used. 'Cardiac death' (DCD) could be reversible and 'brain death' is not always verifiable. They realise that scrapping the 'dead donor rule' (DDR) will seem ghoulish to the public. For this reason, they call for an extensive public education campaign so that people will continue to donate their organs.
Their ideas were published earlier, in the August issue of the American Journal of Bioethics. They wrote:
'Rigorous informed consent, protection from harm, and transparency toward the public could constitute a threefold pillar on which organ procurement of vital organs could operate in an ethically acceptable and socially responsible way.'
However, other doctors disagreed strongly. Mohamed Y. Rady and Joseph L. Verheijde, of Arizona State University, said that abandoning the dead donor rule is impossible unless society legalises physician-assisted suicide. Two doctors from National Taiwan University Hospital observed that 'DCD without respecting the DDR will inevitably discourage DCD, and thus will shrink the supply of organs.'
A philosopher, Stephen Napier, of Villanova University thinks that the proposal is illogical: 'How could not knowing that the DDR is satisfied entail abandoning it?' Another bioethicist, James Dubois, of St Louis University, suggested that it was unethical to publish a proposal which could damage public confidence in organ donation.
The proposal rattled transplant surgeons. 'In the overwhelming majority of cases, the concept of death is easy, obvious and not really subject to any complex interpretation. It's very clear,' said Dr. Andrew Baker, a surgeon in Ontario, told the National Post. 'They're dead, you can see it, there is no return of anything.'"

http://www.bioedge.org/index.php/bioethics/bioethics_article/9823

The dead more alive than the "vegetative"?

by Jared Yee | Sep 02, 2011        
"It has been easy to tell between the living and the dead. However, modern medicine has created a new option: persistent vegetative state (PVS). People in such a state have suffered serious brain damage as a result of accident or stroke. This often means they have no hope of regaining consciousness. However, because parts of their brains that run activities such as breathing are intact, their vital functions can be prolonged indefinitely.
It is always a traumatic decision whether to let people in such a state to die. It depends in part, however, on how the fully alive perceive the mental capacities of the vegetative - an area that has not been explored much. Kurt Gray of the University of Maryland and Annie Knickman and Dan Wegner of Harvard University, conducted an experiment designed to find exactly how people perceived those in PVS, results of which were published in the journal Cognition.
In interviews with researchers about hypothetical car-accident victims, study participants attributed less "mind" to those left in a PVS than to those who had "passed away" or lay in a coffin in a cemetery. As the title of the study puts it, people in a PVS are "more dead than dead." People trapped in this state are not actually dead, of course. According to the National Institute of Neurological Disorders and Stroke, these people are "alive but unable to move or respond to his or her environment." Further:
"Individuals in such a state have lost their thinking abilities and awareness of their surroundings, but retain non-cognitive function and normal sleep patterns. Even though those in a persistent vegetative state lose their higher brain functions, other key functions such as breathing and circulation remain relatively intact. Spontaneous movements may occur, and the eyes may open in response to external stimuli. Individuals may even occasionally grimace, cry, or laugh. Although individuals in a persistent vegetative state may appear somewhat normal, they do not speak and they are unable to respond to commands."
The most famous example of a person in a PVS is Terri Schiavo, the Florida woman who spent 15 years in a PVS before her husband, Michael Schiavo, was able to have her feeding tube removed. She died of dehydration in 2005." ~ Economist, Aug 20; Los Angeles Times, Aug 20

Source:
http://www.bioedge.org/index.php/bioethics/bioethics_article/9722

La "règle du donneur mort" pour le don d'organes largement battue en brèche

Mais chuuut ! Le grand public ignore tout à ce sujet ... Le donneur d'organes est mort et bien mort. Voici un résumé de tous ces articles :

LES ORGANES D'UN MORT NE SOIGNENT PERSONNE

Source : http://www.bioethics.net/journal/

"Can the Dead Donor Rule be Resuscitated?"

by Simone Lucia Vernez, David Magnus

AJOB 2011; 11(8):1

FULL TEXT

"Donation After Circulatory Death: Burying the Dead Donor Rule"

by David Rodríguez-Arias, Neil Lazar, Maxwell Smith

AJOB 2011; 11(8):36-43

ABSTRACT

"It's All About the Brain"

by D. Micah Hester, Jerril Green

AJOB 2011; 11(8):44

FULL TEXT

"Dead Tired of Repititious Debates About Death Criteria"

by James M DuBois

AJOB 2011; 11(8):45

FULL TEXT

"Donation, Death and Harm"

by Walter Glannon

AJOB 2011; 11(8):48

FULL TEXT

"Justice Is Not Merely Semantics: Recasting the Significance of the Dead Donor Rule"

by Miriam Bentwich

AJOB 2011; 11(8):50

FULL TEXT

"Justifying Physician-Assisted Death in Organ Donation"

by Joseph L. Verheijde, Mohamed Y. Rady

AJOB 2011; 11(8):52

FULL TEXT

"Donation after Cardiac Death: An Alternative Solution to Burying the Dead Donor Rule"

by Sandra Woien

AJOB 2011; 11(8):54

FULL TEXT

"Take My Organs, Please": A Section of my Living Will

by Thomas Cochrane, Matt Bianchi

AJOB 2011; 11(8):56

FULL TEXT

"Further Deliberating Burying the Dead Donor Rule in Donation After Circulatory Death"

by Yen-Yuan Chen, Wen-Je Ko

AJOB 2011; 11(8):58

FULL TEXT

"Out of the Frying Pan and Into the Fire"

by Stephen Napier

AJOB 2011; 11(8):60

FULL TEXT

Pr. Louis Puybasset, "Enjeux éthiques en réanimation". Paris, Ed. Springer-Verlag France, 2010

"Rapidement après sa création, à la fin des années 1950, la réanimation a été le lieu d’une effervescence où se pensaient les aspects techniques et l’innovation de cette discipline médicale nouvelle. Mais là, surgit rapidement la question du sens de l’action menée aux plans humain et philosophique. Grâce aux moyens extraordinaires mis en œuvre et au savoir-faire des équipes médicales et soignantes, des succès inespérés furent obtenus, en particulier dans les domaines de l’insuffisance respiratoire, de l’insuffisance rénale, des détresses circulatoires, de la toxicologie et des comas. Mais il devenait également possible de faire survivre de façon prolongée des personnes pour lesquelles aucun espoir de guérison n’était permis et qui évolueraient vers des états de dépendance et de perte d’autonomie insupportables. Ces situations firent naître des controverses sur le bien fondé de certaines pratiques de la réanimation et, progressivement, cette spécialité médicale devint le fer de lance dans la réflexion sur l’obstination déraisonnable, la mort encéphalique, la transplantation d’organe, l’assistance respiratoire, les comas prolongés et la limitation ou l’arrêt thérapeutiques.
Pour apporter un éclairage nouveau et original sur les questions éthiques qui émaillent la pratique de la réanimation, l’ouvrage collectif dirigé par Louis Puybasset rassemble des textes d’auteurs choisis pour leur compétence et leur connaissance du terrain. Il leur donne la parole pour témoigner de certains aspects méconnus de l’éthique du soin, en levant parfois certains tabous. L’ouvrage est divisé en six grands chapitres. Le premier aborde les fondements philosophiques et juridiques sur lesquels s’appuie le discernement éthique en pratique clinique, et les suivants traitent successivement du patient et de ses proches en réanimation, des soignants, des questions spécifiques liées à la limitation et l’arrêt thérapeutique, du don d’organe et enfin des aspects médico-économiques de la réanimation.

Au fil du texte qui constitue cet ouvrage de 634 pages, la réflexion déclinée sous des angles et des points de vues variés et originaux, éclaire ce lieu étonnant où l’on ne ressuscite pas toujours, où l’on meurt souvent et où les normes sociales sont parfois bousculées. Ce livre, d’une grande force, est un outil précieux de réflexion sur les enjeux existentiels de ce monde clos et mystérieux pour celui qui un jour sera confronté à la réanimation, qu’il soit patient, soignant, médecin ou proche. Il offre un éclairage humaniste permettant à la pensée de ne pas être captive d'une vision purement technique."

Michel Hasselmann, Professeur des Universités, Praticien Hospitalier, Réanimation Médicale - Nouvel hôpital civil.

Source :
Lettre du CEERE, mars 2011

Organ donation and the ethics of muddling through

Klaus Hoeyer and Anja MB Jensen, Department of Public Health, Faculty of Health Sciences, University of Copenhagen, CSS, Øuster Farimagsgade 5, Room 10.0.09, DK-1014 Copenhagen, Denmark

Critical Care 2010, 15:109doi:10.1186/cc9379
Published: 24 January 2011

Abstract

"Organ donation offers opportunities for people in critical care units to help save the lives of other patients. It is not always easy, however, to handle the transition from treating a patient to preserving a potential donor, and organ donation consistently provokes ethical questions in critical care units. What do we expect ethics to deliver? In light of a recent ethics conference in Denmark, we suggest that by acknowledging that decisions made in the clinic rarely abide to rational decision trees with clear ethical priorities, we can better learn from each other's experiences. We suggest embracing an 'ethics of muddling through' to enhance relevant reflections and stimulate a productive dialogue among health professionals."

Death, brain death, and the limits of science: why the whole-brain concept of death is a flawed public policy

J Law Med Ethics. 2010 Sep;38(3):667-83. doi: 10.1111/j.1748-720X.2010.00520.x.

Death, brain death, and the limits of science: why the whole-brain concept of death is a flawed public policy. Nair-Collins M., Clinical Trials Support Division, Nathan Kline Institute for Psychiatric Research.

Abstract

Legally defining "death" in terms of brain death unacceptably obscures a value judgment that not all reasonable people would accept. This is disingenuous, and it results in serious moral flaws in the medical practices surrounding organ donation. Public policy that relies on the whole-brain concept of death is therefore morally flawed and in need of revision.

© 2010 American Society of Law, Medicine & Ethics, Inc.

Heated debate over Jewish organ transplants

"In the on-going debate over the ethics of removing organs from 'brain dead' patients, the conservative view has scored a goal. The chief rabbinical court of the UK has decreed that only 'cardiorespiratory death is definitive'. The Beth Din's conditions would mean that an observant Jew could donate kidneys, livers or corneas, for example, but not heart or lungs.

The result was consternation in the British Medical Association, as 66% of donations came from donors after brain death in 2010 and 34% from donors after cardiovascular death. The BMA called for an urgent meeting to clarify the situation.
The decision was greeted by fierce criticism across the Atlantic. Rabbi Moshe Tendler, a medical ethics professor at New York's Yeshiva University, declared: 'The Beth Din must realise they have sentenced to death anyone waiting for a vital organ transplant.' In his opinion brain stem death was 'the only accurate method to determine that a patient has died'.
The UK's Chief Rabbi, Lord Jonathan Sacks, tried to clarify the statement by admitting that there may be 'reasonable disagreement as to whether a patient is alive or dead'. However, the original wording of the Beth Din's statement was strong:
There is a view that brain stem death is an acceptable Halachic [Jewish law] criterion in the determination of death. This is the view of some Poskim (Halachic decisors) . However it is the considered opinion of the London Beth Din in line with most Poskim worldwide, that in Halacha cardiorespiratory death is definitive.
The Beth Din says that it wants the UK's National Organ Donor Registry to come up with a donation system which will be compatible with Jewish practice.
The issue is far from academic, as anger over a recent case in Israel shows. Avi Cohen, a 51-year-old soccer star who had played for Liverpool in his heyday, was brain-injured in a car smash in December. He had been a strong advocate for organ donation. After learning that he was 'brain dead', his relatives began to discuss arrangements for organ donation with the hospital. The Chief Rabbinate in Israel had ruled in 1986 that brain death was sufficient for donation in certain cases. And Sephardi Chief Rabbi told the Cohen family that the donation was a mitzvah [permissible]. However, other rabbis persuaded the family that only cardiac death was acceptable and the donations did not happen. An editorial in the Jerusalem Post called this 'meddling' 'morally despicable'."
http://www.bioedge.org/index.php/bioethics/bioethics_article/9361

Severely Brain-Injured Child Benefits From Cord Blood Cell Transplantation

Les donneurs d'organes sont des patients se trouvant dans un état irréversible, du fait de la destruction irréversible de leur cerveau (la "mort encéphalique" équivaut à un coma dépassé). Et si, grâce aux cellules souches contenues dans le sang du cordon ombilical, il était possible de rendre réversibles les lésions au cerveau conduisant à cet état de "mort encéphalique" qui permet le prélèvement d'organes ?

"In three monthly injections, researchers transplanted neurally-committed, autologous cord blood derived cells tagged with iron oxide nanoparticles (SPIO) into the lateral cerebral ventricle of a 16-month old child with severe global hypoxic ischemic brain injury. The study, published in the current issue of Cell Medicine 1(2) and now freely available online here found through MRI tracking that the primary injected and tagged cells persisted in that brain hemisphere for more than four months. By six months, the severely impaired child showed some slight improvement over a former vegetative state.

'Hypoxic-ischemic encephalopathy remains one of the most devastating conditions in children, resulting in brain atrophy and persistent functional neurological impairment,' said Dr. Krystyna Domanska-Janik, corresponding author.

According to Dr. Domanska-Janik, they transplanted cord blood neural cells by repeated injection into lateral cerebral ventricle as the method appeared to be superior to intravascular injections because there would be a more 'local modulating outcome.'

'The capacity of cells to home to damaged sites in the central nervous system is crucial,' said Dr. Domanska-Janik. 'Our study found that transplantation of patient self-donor (autologous), neurally-committed cord blood cells is feasible, well tolerated, and safe.'

Once more, the transplanted cells were easily assessed by MRI for four months.

'Despite signs of neurological improvement noticed by the parents and neurologists after cell transplantation, this one case does not allow us to predict the true efficacy of such a treatment and further studies are needed,' she added.

The research team did suggest that six months post-transplantation, the child's diagnosis of a 'vegetative state' was no longer justified as the boy began responding to his mother's voice by smiling and a 50 percent reduction in his rate of seizures was achieved.

According to Dr. Paul Sanberg, executive director of the Center of Excellence for Aging and Brain Repair at the University of South Florida, and executive editor of Cell Medicine, this case report is potentially important.

'This first step in the use of autologous stem cells as a treatment for neonatal ischemic brain repair in the clinic provides a guardedly optimistic report for future studies,' said Dr. Sanberg. 'Of course, further and more comprehensive studies, with a larger patient population, are required to confirm its potential efficacy.'"

Notes:

Prof. Krystyna Domanska-Janik, Neuro Repair Dept. Mossakowski Medical Research Centre, 5 Pawinskiego str, 02-106 Warsaw, Poland.

Citation: Jozwiak, S.; Habich, A.; Kotulska, K.; Sarnowska, A.; Kropiwnicki, T.; Janowski, M.; Jurkiewicz, E.; Lukomska, B.; Kmiec, T.; Walecki, J.; Roszkowski, M.; Litwin, M.; Oldak, T.; Boruczkowski, D.; Domanska-Janik, K. Intracerebroventricular Transplantation of Cord Blood-Derived Neural Progenitors in a Child With Severe Global Brain Ischemic Injury. Cell Medicine 1(2):71-80; 2010.

Source:

David Eve

Cell Transplantation Center of Excellence for Aging and Brain Repair
January 3, 2011


Author: www.drugrehab.in
http://www.drugrehab.in/2011/01/severely-braininjured-child-benefits-from-cord-blood-cell-transplantation/

Douleur et mort encéphalique

http://www.cathinfo.com/index.php/Brain-dead-organ-donors-feel-pain

Ceci m'a bien sûr été confirmé par des spécialistes français (plusieurs), certains risquant leur carrière ...

"Hydrocortisone supplementation enhances hemodynamic stability in brain-dead patients"

Anesthesiology. 2010 May;112(5):1204-10.
Authors:  Nicolas-Robin A, Barouk JD, Amour J, Coriat P, Riou B, Langeron O.

Department of Anesthesiology and Critical Care, Groupe Hospitalier Pitié-Salpêtrière, Paris, France. armelle.nicolas-robin@psl.aphp.fr

Abstract

BACKGROUND:

"Hemodynamic instability is frequent in brain-dead patients and may result, in part, from absolute or relative adrenal insufficiency. Corticosteroid supplementation is widely used to restore hemodynamic stability in septic shock and to reduce the time of shock resolution. The authors verified that supplementation with hydrocortisone may enhance hemodynamic stability in brain-dead patients. METHODS: All consecutive brain-dead patients with hypotension requiring vasopressor agents were included in this single-center noninterventional clinical observation study. Assessment of baseline and adrenocorticotropic hormone (ACTH)-stimulated plasma cortisol concentrations was performed. Immediately after, patients were systematically treated with a single intravenous injection of hydrocortisone (50 mg), and norepinephrine administration was adjusted every 15 min to maintain mean arterial pressure between 65 and 90 mmHg. Adrenal insufficiency was defined as baseline plasma cortisol concentration less than 15 microg/dl and/or delta plasma cortisol concentration less than 9 microg/dl. Patients were considered as ACTH responders when delta cortisol concentration was more than 9 microg/dl 30 min after ACTH injection. RESULTS: Among the 31 patients included, the incidence of adrenal insufficiency was 87% [95% CI, 70-96%]. A significant (> or =30%) decrease in norepinephrine dose was obtained 180 min after hydrocortisone injection in 18 (59%) patients, from 0.31 [0.16-0.44] microg . kg(-1) . min(-1) to 0.18 [0.10-0.24] microg . kg(-1) . min(-1) (P < 0.01). The incidence of hemodynamic response was greater in ACTH nonresponders than in ACTH responders: 86% versus 50%, respectively, P < 0.05. CONCLUSIONS: Adrenal insufficiency with hemodynamic instability is frequent in brain-dead patients. After ACTH stimulation testing and hydrocortisone infusion, hemodynamic stability is enhanced especially in patients with true adrenal nonfunction."

Source:
http://www.ncbi.nlm.nih.gov/pubmed/20395825

"The circulatory-respiratory determination of death in organ donation."

De nouveaux standards pour les prélèvements "à coeur arrêté" aux USA. La grande question que l'on se pose pour un potentiel donneur d'organes (reins,foie) dans cette situation, c'est : "Est-ce que le cerveau est détruit ?" Les auteurs de cet article scientifique proposent de nouveaux standards pour s'assurer de la destruction du cerveau au préalable du prélèvement. Mais ces nouveaux standards requièrent des gestes techniques invasifs sur le patient, qui ne peuvent être effectués sans avoir recueilli un consentement de proche au préalable. Notons qu'en France, les mesures invasives sont mises en place avant de recueillir le consentement des proches, dans une situation de prélèvement ou d'éventuel prélèvement "à coeur arrêté" ("Donation under Cardiac Death" est le terme américain équivalent). "Les exigences spécifiques de prélèvement d’organes avec donneur à 'cœur arrêté' font émerger des questions devant faire l’objet de développements et d’approfondissement :

• Comment réfléchir l’accompagnement et le recueil du témoignage des proches de la personne décédée, quand le temps imparti à cette démarche est considérablement restreint par la nécessité de mettre en place des moyens de conservation des organes ?
• Quelles sont les conditions de respect du corps de la personne juste après son décès lorsqu’on pratique sur lui des gestes techniques invasifs ?
• Comment envisager une pédagogie spécifique du grand public que suppose la notion de consentement présumé au don d’organes ? …
Une réflexion éthique sur les pratiques qui entourent le prélèvement, et les modalités de mise en œuvre cohérente et respectueuse des principes affirmés par notre société semble aujourd’hui indispensable." (Dr. Marc Guerrier, Espace Ethique de l'AP-HP)



Crit Care Med. 2010 Mar;38(3):963-70.

Authors: Bernat JL, Capron AM, Bleck TP, Blosser S, Bratton SL, Childress JF, DeVita MA, Fulda GJ, Gries CJ, Mathur M, Nakagawa TA, Rushton CH, Shemie SD, White DB. Neurology Department, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA. bernat@dartmouth.edu

Comment in:

Crit Care Med. 2010 Mar;38(3):1011-2.

Abstract
OBJECTIVE:
"Death statutes permit physicians to declare death on the basis of irreversible cessation of circulatory-respiratory or brain functions. The growing practice of organ donation after circulatory determination of death now requires physicians to exercise greater specificity in circulatory-respiratory death determination. We studied circulatory-respiratory death determination to clarify its concept, practice, and application to innovative circulatory determination of death protocols."

RESULTS:
"It is ethically and legally appropriate to procure organs when permanent cessation (will not return) of circulation and respiration has occurred but before irreversible cessation (cannot return) has occurred because permanent cessation:
1) is an established medical practice standard for determining death;
2) is the meaning of "irreversible" in the Uniform Determination of Death Act; and 3) does not violate the 'Dead Donor Rule.'

CONCLUSIONS:
"The use of unmodified extracorporeal membrane oxygenation in the circulatory determination of death donor after death is declared should be abandoned because, by restoring brain circulation, it retroactively negates the previous death determination. Modifications of extracorporeal membrane oxygenation that avoid this problem by excluding brain circulation are contrived, invasive, and, if used, should require consent of surrogates. Heart donation in circulatory determination of death is acceptable if proper standards are followed to declare donor death after establishing the permanent cessation of circulation. Pending additional data on 'auto-resuscitation,' we recommend that all circulatory determination of death programs should utilize the prevailing standard of 2 to 5 mins of demonstrated mechanical asystole before declaring death."

http://www.ncbi.nlm.nih.gov

"Imminent brain death: point of departure for potential heart-beating organ donor recognition."

Encore patient, déjà potentiel donneur d'organes ? Jusqu'où peut-on aller pour anticiper un diagnostic de mort encéphalique, afin de recenser le plus grand nombre possible de potentiels donneurs d'organes en mort encéphalique ? Un patient qui n'est pas encore en mort encéphalique est déjà un donneur d'organes. Voilà ce que dit cet article du 16/03/2010, paru dans la revue scientifique "Intensive Care Medicine".

Authors: de Groot YJ, Jansen NE, Bakker J, Kuiper MA, Aerdts S, Maas AI, Wijdicks EF, van Leiden HA, Hoitsma AJ, Kremer BH, Kompanje EJ.

Department of Intensive Care, Erasmus MC University Medical Center Rotterdam, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands.

Abstract
PURPOSE:
"There is, in European countries that conduct medical chart review of intensive care unit (ICU) deaths, no consensus on uniform criteria for defining a potential organ donor. Although the term is increasingly being used in recent literature, it is seldom defined in detail. We searched for criteria for determination of imminent brain death, which can be seen as a precursor for organ donation."

METHODS:
"We organized meetings with representatives from the field of clinical neurology, neurotraumatology, intensive care medicine, transplantation medicine, clinical intensive care ethics, and organ procurement management. During these meetings, all possible criteria were discussed to identify a patient with a reasonable probability to become brain dead (imminent brain death). We focused on the practical usefulness of two validated coma scales (Glasgow Coma Scale and the FOUR Score), brain stem reflexes and respiration to define imminent brain death. Further we discussed criteria to determine irreversibility and futility in acute neurological conditions."

RESULTS:
"A patient who fulfills the definition of imminent brain death is a mechanically ventilated deeply comatose patient, admitted to an ICU, with irreversible catastrophic brain damage of known origin. A condition of imminent brain death requires either a Glasgow Coma Score of 3 and the progressive absence of at least three out of six brain stem reflexes or a FOUR score of E(0)M(0)B(0)R(0)."

CONCLUSION:
"The definition of imminent brain death can be used as a point of departure for potential heart-beating organ donor recognition on the intensive care unit or retrospective medical chart analysis."

Intensive Care Med. 2010 Mar 16
http://www.ncbi.nlm.nih.gov/pubmed/20232039

Canada : "Faits saillants - Nouvel espoir pour les patients souffrant d'insuffisance cardiaque"

Ottawa, Ontario - "Une nouvelle étude scientifique pourrait aider à réduire la pénurie générale de donneurs d'organes pour les patients en attente d'une greffe de cœur. Ce projet conjoint entre le CNRC, le Royaume-Uni et les États-Unis vise à montrer que des cœurs ayant cessé de battre, qui ne sont à l'heure actuelle pas utilisés pour une greffe du cœur, pourraient être de bons organes donneurs s'ils étaient prélevés rapidement et de manière appropriée."

"Le Dr Ganghong Tian dirige les efforts déployés par le CNRC pour trouver d’autres sources de donneurs pour les greffes de cœur.
'La transplantation cardiaque est le seul moyen efficace de traiter une insuffisance cardiaque congestive', explique le Dr Ganghong Tian, chercheur à l'Institut du biodiagnostic du CNRC (IBD-CNRC) à Winnipeg. 'Chaque année, environ 100 greffes de cœur sont réalisées au Canada, mais plusieurs centaines de patients sont sur une liste d'attente, ce qui signifie que près des deux tiers des patients n'ont pas la chance de recevoir le traitement dont ils ont besoin.'

Une grande partie de cette demande non satisfaite s'explique par le manque de donneurs adéquats pour des greffes de cœur. 'La majorité des donneurs pour une greffe de cœur sont des victimes d'accident de la route dont le cerveau a subi un dommage important, poursuit le Dr Tian. Les médecins traitants les ont déclarés cliniquement morts en se basant sur des lésions importantes et irréversibles au cerveau, même si leur cœur bat encore normalement.' Ces donneurs en état de mort cérébrale sont transportés à l'hôpital où leur cœur est prélevé pour être greffé sur un autre patient.

'Comme nous n'avons pas assez de donneurs en état de mort cérébrale dont le cœur bat toujours, nous devons explorer d'autres avenues possibles', ajoute le Dr Tian. Les donneurs potentiels peuvent inclure des patients en état de mort cérébrale dont le cœur a cessé de battre avant d'être prélevé. Les patients branchés sur des appareils de maintien des fonctions vitales, qui ont des lésions graves au cerveau et n'offrent aucun espoir de rétablissement, pourraient aussi être des donneurs potentiels pour une greffe de cœur. À l'heure actuelle, les cœurs de ces deux groupes de patients ne sont pas prélevés en vue d'une greffe possible.

Comment le diagnostic de la mort cérébrale a-t-il changé les greffes cardiaques ?
Jusque dans les années 1970, les donneurs dont le cœur avait cessé de battre étaient la seule source pour toutes les opérations de greffe d'organes. Vers 1975, le milieu médical a introduit le concept de 'mort cérébrale' comme critère pour déclarer un patient cliniquement mort. Une fois que ce concept a été accepté, les chirurgiens ont cessé d'utiliser des organes prélevés sur des donneurs dont le cœur avait cessé de battre, parce qu'ils croyaient que les organes étaient endommagés dès que le sang cessait de circuler dans le corps du donneur. Toutefois, des reins, des foies et des poumons de donneurs dont le cœur a cessé de battre sont utilisés depuis 1980 pour des greffes d'organes. [En France, depuis 2007 seulement, Ndlr.]

'La raison sous-jacente est que si le cœur a cessé de battre, le sang ne circule plus pour fournir l'oxygène et les autres éléments nutritifs au cœur, et le muscle cardiaque devrait donc être endommagé de manière irréversible', explique le Dr Tian. Avec cette nouvelle étude, le Dr Tian et ses collaborateurs veulent déterminer s'ils peuvent récupérer en toute sécurité un cœur après qu'il a cessé de battre et que le patient a été déclaré cliniquement mort. Et si oui, quelle est la meilleure façon de s'assurer que le cœur peut faire l'objet d'une greffe?

Pour le savoir, des chercheurs de l'IBD-CNRC et du département de chirurgie cardiaque de l'Hôpital général Saint-Boniface à Winnipeg, de l'Université Cambridge au Royaume-Uni et de l'Université Stanford aux États-Unis procèdent à des greffes expérimentales sur des cœurs de porc. Cette étude a été amorcée par des chercheurs de Cambridge, qui ont invité l'IBD-CNRC à y participer en raison de son expérience dans le domaine de la recherche sur les gros animaux, de son équipement en imagerie et spectroscopie par résonance magnétique, ainsi que de son expertise dans la surveillance de la fonction cardiaque et de la viabilité des tissus. 'Jusqu'ici, nos résultats préliminaires sont très encourageants', déclare le Dr Tian.

Prochaines étapes

'Cela prendra encore beaucoup de temps pour trouver la meilleure façon de prélever ces cœurs, ajoute-t-il. Et il faudra du temps pour que les décideurs du milieu hospitalier acceptent d'utiliser des cœurs qui ont cessé de battre. Cette procédure doit faire ses preuves avant d'être utilisée sur des êtres humains. Mais nous avons bon espoir que la vie de nombreux patients souffrant d'insuffisance cardiaque pourra éventuellement être sauvée grâce à cette nouvelle source de donneurs d'organes.'

Évaluer la viabilité de cœurs qui ont cessé de battre

Pour déterminer si un cœur est encore viable après qu'il a cessé de battre, le Dr Tian et ses collègues utilisent la spectroscopie par résonance magnétique (RM), qui mesure le niveau d'énergie du muscle cardiaque et, plus précisément, ses niveaux d'adénosine triphosphate et de créatine phosphate. 'En termes plus simples, la spectroscopie RM permet de mesurer la quantité d'essence que vous avez dans votre réservoir à essence, explique le Dr Tian. Nous observons qu'après 15 minutes d'arrêt cardiaque, un cœur de porc est légèrement endommagé, mais que si nous le retirons et que nous le remplissons avec du sang oxygéné, nous pouvons remplir de nouveau le réservoir à essence et récupérer ce cœur.'"

Source :
http://www.nrc-cnrc.gc.ca/fra/actualites/cnrc/2009/11/05/patients-cardiaque.html

FOUR Score Coma Scale in Medical Intensive Care

This relatively new coma assessment scale performed well in predicting outcome in medical intensive care, but it needs further validation.

"For several decades, clinicians have struggled to find the most useful and reliable coma assessment scale. The Glasgow Coma Scale (GCS) is widely used and accepted but gives relatively limited information about brainstem function, eye opening and tracking, and respiratory patterns. Its usefulness is substantially limited for intubated patients, realistically the population to which coma scales are most appropriately applied. A group at the Mayo Clinic have developed and validated the FOUR (Full Outline of UnResponsiveness) score, a tool that provides significantly more information about brainstem function than the GCS and maintains usefulness for intubated patients. To date, the FOUR score has been used primarily by those trained in the neurosciences and applied primarily to patients in the neurocritical care unit.

Now, researchers have compared the predictive abilities of the FOUR score and the GCS as applied by nonneuroscience personnel to 100 patients in a nonneuroscience setting, the medical intensive care unit. The predictive power of the FOUR score for poor outcome had an area under the receiver operating characteristic curve of 0.75, compared with 0.76 for the GCS score. The mortality rate was higher in patients with the worst FOUR score (89 per cent) than in those with the worst GCS score (71 per cent). The FOUR score was performed reliably, consistently, and with excellent interrater reliability.

Comment: I am hopeful that this study will provide additional traction for the FOUR score to gain acceptance for common use for coma assessment in any intensive care unit. The main problem this score faces is that it has not been validated outside the Mayo Clinic, and thus its ability to supplant the GCS outside the Mayo Clinic remains hindered. However, given the ease of performance and high reliability of the FOUR score, and its vast superiority in giving more-detailed information about brainstem function, it is easy to imagine that it will be appropriately embraced by intensive care units in the future."

— David M. Greer, MD, MA

Dr. Greer is Assistant in Neurology, Massachusetts General Hospital, and Associate Professor of Neurology, Harvard Medical School, Boston.

Published in Journal Watch Neurology October 20, 2009

My comment: this tool will help identify brain-dead potential organ donors in the medical intensive care unit, and hence extend the pool of potential organ donors ...
http://neurology.jwatch.org

"S100B and neuron-specific enolase as predictors of neurological outcome in patients after cardiac arrest and return of spontaneous circulation"

"S-100B and neuron-specific enolase as predictors of neurological outcome in patients after cardiac arrest and return of spontaneous circulation: a systematic review"

Abstract
Introduction
"Neurological prognostic factors after cardiopulmonary resuscitation (CPR) in patients with cardiac arrest (CA) as early and accurately as possible are urgently needed to determine therapeutic strategies after successful CPR. In particular, serum levels of protein neuron-specific enolase (NSE) and S-100B are considered promising candidates for neurological predictors, and many investigations on the clinical usefulness of these markers have been published. However, the design adopted varied from study to study, making a systematic literature review extremely difficult. The present review focuses on the following three respects for the study design: definitions of outcome, value of specificity and time points of blood sampling."

Methods
"A Medline search of literature published before August 2008 was performed using the following search terms: 'NSE vs CA or CPR', 'S100 vs CA or CPR'. Publications examining the clinical usefulness of NSE or S-100B as a prognostic predictor in two outcome groups were reviewed. All publications met with inclusion criteria were classified into three groups with respect to the definitions of outcome; 'dead or alive', 'regained consciousness or remained comatose', and 'return to independent daily life or not'. The significance of differences between two outcome groups, cutoff values and predictive accuracy on each time points of blood sampling were investigated."

Results
"A total of 54 papers were retrieved by the initial text search, and 24 were finally selected. In the three classified groups, most of the studies showed the significance of differences and concluded these biomarkers were useful for neurological predictor. However, in view of blood sampling points, the significance was not always detected. Nevertheless, only five studies involved uniform application of a blood sampling schedule with sampling intervals specified based on a set starting point. Specificity was not always set to 100 per cent, therefore it is difficult to indiscriminately assess the cut-off values and its predictive accuracy of these biomarkers in this meta analysis."

Conclusions
"In such circumstances, the findings of the present study should aid future investigators in examining the clinical usefulness of these markers and determination of cut-off values."

==> Full article online (read)

USA: "A 25-Year-Old Man with Coma after Cardiac Arrest"

NEJM, Volume 360:2118-2125 May 14, 2009, Number 20

"Case 15-2009 — A 25-Year-Old Man with Coma after Cardiac Arrest"

Authors: Camille N. Kotton, M.D., Nahel Elias, M.D., Francis L. Delmonico, M.D., and Richard L. Kradin, M.D.

Presentation of Case

Dr. Mathias Lichterfeld (Infectious Disease): "A 25-year-old man was admitted to this hospital because of coma after cardiac arrest."

"He had been well until 4 hours before admission, when he was seen to have had seizurelike movements and to have collapsed, without pulse or respirations. Emergency medical services was called and arrived approximately 7 minutes later. Examination disclosed ventricular fibrillation. Cardiopulmonary resuscitation, including the administration of epinephrine and atropine and electrical defibrillation followed by the administration of lidocaine, was performed; a junctional cardiac rhythm was established after 4 minutes. The patient remained hypotensive and unconscious." (...)

Source Information:

From the Infectious Disease Unit (C.N.K.) and the Departments of Transplant Surgery (N.E.) and Pathology (R.L.K.), Massachusetts General Hospital, Boston; New England Organ Bank, Newton, MA (F.L.D.); and the Departments of Medicine (C.N.K.) and Surgery (N.E., F.L.D.), Harvard Medical School, Boston.

NEJM, Volume 361:724-725 August 13, 2009 Number 7 - "Case 15-2009: A Man with Coma after Cardiac Arrest"

"To the Editor: Kotton et al. (May 14 issue) (...) present the case of a 25-year-old man with cardiac arrest. The initial rhythm was ventricular fibrillation. Despite successful resuscitation, brain death was declared and the heart was procured for transplantation. Although no structural abnormalities were identified on echocardiography or cardiac catheterization, primary ventricular fibrillation has many causes that are not readily diagnosed, (...) and when idiopathic it has a high rate of recurrence. (...) Therefore, the suitability of the donor's heart for transplantation needs to be determined by means of a thorough anatomical and electrophysiological assessment, which may be difficult to perform(...)"

Ventricular fibrillation : a condition that could make the donated heart unsuitable for transplantation needs ... And yet such hearts are procured and transplanted, putting the transplant patient at risk ...

UK: "Caution urged over fMRI for life or death decisions"

"Bioethicists funded by the Wellcome Trust have urged caution over the use of advanced neuroimaging techniques in making life or death decisions about patients in a vegetative state. Writing in the 'Journal of Medical Ethics', researchers from the Oxford Uehiro Centre for Practical Ethics at the University of Oxford and colleagues say that while functional magnetic resonance imaging (fMRI) offers new insights into the conscious state of vegetative state patients, we still do not know how to interpret these findings.

'It is very tempting to think that brain scans will provide clear cut, black and white answers, but it is unlikely that they will,' says Dr Dominic Wilkinson of the Oxford Uehiro Centre, one of the authors of the paper.

'Even if they do, there are lots of difficult ethical questions that go with these decisions. Neuroimaging will not provide a shortcut or make these easier.'

After a severe brain injury, some patients emerge from a coma in a vegetative state where they appear awake but are unaware of themselves or their environment.

Previous studies have used fMRI to examine vegetative state patients for evidence of cognitive function. One study found two patients that could apparently obey commands to imagine different activities (in this case playing tennis and walking around a house) that activate different parts of the brain. The researchers claimed at the time that this provided definitive proof that the patients were conscious.

Findings like this have led to calls for fMRI to be used as evidence when making life or death decisions involving patients in a vegetative state.

However, after reviewing the scientific evidence, the authors concluded that the evidence for consciousness from fMRI is still unclear.

'The problem is with interpretation,' says Dr Wilkinson, 'whether these patients really are conscious or if it is just a reflex.' Patients under anaesthesia, for example, can show signs of cognitive brain activity, including language processing, even when unconscious.

'There is brain activity, but is that the same as consciousness? And even if it is, this pattern of brain activity is unlikely to be found in most patients in a vegetative state. Moreover, it is not clear whether such findings make the patients any more likely to recover from their severely impaired state.'

Nevertheless, Dr Wilkinson says it is increasingly likely that fMRI data will be called on, particularly in contentious court decisions over the withdrawal of life support.

'People place a great deal on the diagnosis of consciousness in a vegetative state. But hard evidence for this is hard to come by.'

'It is not clear that the science is ready to be used in the courtroom. We should be very cautious to avoid overcalling the findings of these studies.'

'The ethics and the science are some way from a complete approach,' says Professor Julian Savulescu from the Oxford Uehiro Centre and lead author on the paper.

'What is critical is deciding what matters - for example, whether a person should autonomously decide to live or die, or which lives are worth living. This is an ethical question that science cannot answer.'"

Source