Not brain-dead, but ripe for transplant
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Not brain-dead, but ripe for transplant
04 August 2006
Exclusive from New Scientist Print Edition. Subscribe and get 4 free issues.
Rachel Nowak
Linda Geddes
The crisis in organ donation
On a cold Canadian night, Janet, a 20-year-old aspiring athlete, rolled her car. Her seat belt slipped up around her neck, adding to a plethora of injuries, including brain damage so severe that she had to be kept permanently anaesthetised, and spinal damage that would likely lead to quadriplegia.
For 25 days Janet (not her real name) lay in intensive care. One specialist declared her case hopeless, and recommended switching off life support. Had that happened, first her heart would have stopped, and several minutes later her brain activity would have ceased. Yet although Janet was a card-carrying organ donor, in many countries her organs wouldn't be used. This is because doctors would normally wait to confirm that she was brain-dead (see "Redefining death"). In the time it takes to do that her organs would have been irreparably damaged.
For this reason, organs for transplant usually come from patients with brain injuries so severe that brain death is determined before the life support that keeps their hearts and lungs functioning is removed, enabling their organs to be kept in good condition until the moment they are harvested. Such organs are in critically short supply.
Now, however, this situation is changing. In June, Ottawa Hospital in Canada announced its first organ transplant in recent history from a patient who hadn't been classified as brain-dead, but whose heart had stopped - so-called "donation after cardiac death" (DCD). By switching to this definition of death for transplant purposes, doctors hope to increase the number of healthy organs available and the number of potential donors from which they can be harvested.
For example, the Australian Health Ethics Committee (AHEC) is considering recommending legislation to enable more DCDs, as part of a drive to turnaround Australia's flagging organ donation rates. A similar shift is taking place in the US, where a limited number of DCDs already take place. There, the number of DCD kidney transplants has increased fivefold since 1995 to over 500 in 2004, and numbers are expected to increase sharply over the next decade.
The driving force behind this change is the worldwide shortage of organs (see "The crisis in organ donation"). Last week, doctors at the World Transplant Congress in Boston, Massachusetts, heard how the pool of available organs in the US could increase by up to 20 per cent if DCD was adopted more widely - enough to treat many of the estimated 6000 people in the US who die each year while on organ waiting lists. In the UK, strong government support has helped swell numbers of DCDs more than sixfold in the last 15 years, to 120 in 2005.
“The pool of available organs in the US could increase by 20 per cent if donation after cardiac death was widely adopted”
In light of this, it is all the more surprising to discover that the medical community is divided about the ethics of DCD. What's more, donor-card holders, far from consenting to the new practices, are blissfully unaware of the seismic shift in organ collection procedures.
"Doctors are very pragmatic," says Christopher Doig, a critical care specialist at Canada's Foothills Hospital in Calgary, Alberta. "But there is something inherently bothersome about changing the way we are going to determine death so that we can increase the numbers of organs for donation."
For many doctors, harvesting organs only after brain death draws a clear line in the sand, removing any conflict between patient care and the interests of organ recipients. Often too, the decision to withdraw life support is a subjective one. In the case of Janet, a second specialist advised against ending life support, and after almost a year in hospital, she is now wheelchair-bound but happy to be alive. One concern is that if DCD becomes routine, doctors caring for critically ill people may have their judgement swayed by the needs of those on transplant waiting lists.
Michael Nicholson, a transplant surgeon at Leicester General Hospital, a leading centre for DCD in the UK, thinks the potential for conflict is overplayed. "Intensive care doctors have to inevitably withdraw treatment from some people, irrespective of whether the transplant team exists. When that happens the least they can do is have the family talk with a transplant coordinator," he says.
However, some critical-care doctors believe the problems go even deeper. They argue cessation of heartbeat and breathing are not necessarily irreversible, and point to cases where patients whose hearts didn't respond to cardiac resuscitation later came back to life - in one case a full 7 minutes later. By contrast, this so-called "Lazarus phenomenon" has never been documented in brain-dead patients.
Transplant surgeons who perform DCD point to a key safeguard in their protocols - a waiting period between cessation of heartbeat and allowing the transplant team to get to work. However, even this may be being eroded by the need to retrieve organs before they become too damaged. Originally, a 10-minute waiting period was chosen because after this time the patient would likely be brain-dead too. In many transplant centres this has now dropped to 5 minutes, while three US transplant centres use a 2-minute interval - before loss of brain function is total and when the heart could start beating again, albeit only rarely.
The most controversial aspect of DCD is the practice of giving patients drugs such as anticoagulants to preserve organs before, or just as, life support is removed. This is banned in the UK because it is deemed not to be in the interest of the patient, but it is routine in many centres in the US, despite concerns that it may hasten the death of the patient.
In Australia, where the ethics of DCD are still being considered, "the consensus is that it's reasonable [to use drugs] but only if it does not harm the donor and there has been prior consent," says Peter Joseph, chair of AHEC's working party on the ethics of organ donation. "We want the current consent form changed so that you tick a box to specifically consent to such interventions if you are on life support and your death is imminent."
This is a step in the right direction, says Doig, but much more needs to be done before DCDs become widespread. "Like any other major healthcare issue, be it euthanasia or abortion, what's important is that society debates the issue and comes up with a position," he says. "Then, and only then, individual practitioners can decide whether they want to partake."
From issue 2563 of New Scientist magazine, 04 August 2006, page 6-7
04 August 2006
Exclusive from New Scientist Print Edition. Subscribe and get 4 free issues.
Rachel Nowak
Linda Geddes
The crisis in organ donation
On a cold Canadian night, Janet, a 20-year-old aspiring athlete, rolled her car. Her seat belt slipped up around her neck, adding to a plethora of injuries, including brain damage so severe that she had to be kept permanently anaesthetised, and spinal damage that would likely lead to quadriplegia.
For 25 days Janet (not her real name) lay in intensive care. One specialist declared her case hopeless, and recommended switching off life support. Had that happened, first her heart would have stopped, and several minutes later her brain activity would have ceased. Yet although Janet was a card-carrying organ donor, in many countries her organs wouldn't be used. This is because doctors would normally wait to confirm that she was brain-dead (see "Redefining death"). In the time it takes to do that her organs would have been irreparably damaged.
For this reason, organs for transplant usually come from patients with brain injuries so severe that brain death is determined before the life support that keeps their hearts and lungs functioning is removed, enabling their organs to be kept in good condition until the moment they are harvested. Such organs are in critically short supply.
Now, however, this situation is changing. In June, Ottawa Hospital in Canada announced its first organ transplant in recent history from a patient who hadn't been classified as brain-dead, but whose heart had stopped - so-called "donation after cardiac death" (DCD). By switching to this definition of death for transplant purposes, doctors hope to increase the number of healthy organs available and the number of potential donors from which they can be harvested.
For example, the Australian Health Ethics Committee (AHEC) is considering recommending legislation to enable more DCDs, as part of a drive to turnaround Australia's flagging organ donation rates. A similar shift is taking place in the US, where a limited number of DCDs already take place. There, the number of DCD kidney transplants has increased fivefold since 1995 to over 500 in 2004, and numbers are expected to increase sharply over the next decade.
The driving force behind this change is the worldwide shortage of organs (see "The crisis in organ donation"). Last week, doctors at the World Transplant Congress in Boston, Massachusetts, heard how the pool of available organs in the US could increase by up to 20 per cent if DCD was adopted more widely - enough to treat many of the estimated 6000 people in the US who die each year while on organ waiting lists. In the UK, strong government support has helped swell numbers of DCDs more than sixfold in the last 15 years, to 120 in 2005.
“The pool of available organs in the US could increase by 20 per cent if donation after cardiac death was widely adopted”
In light of this, it is all the more surprising to discover that the medical community is divided about the ethics of DCD. What's more, donor-card holders, far from consenting to the new practices, are blissfully unaware of the seismic shift in organ collection procedures.
"Doctors are very pragmatic," says Christopher Doig, a critical care specialist at Canada's Foothills Hospital in Calgary, Alberta. "But there is something inherently bothersome about changing the way we are going to determine death so that we can increase the numbers of organs for donation."
For many doctors, harvesting organs only after brain death draws a clear line in the sand, removing any conflict between patient care and the interests of organ recipients. Often too, the decision to withdraw life support is a subjective one. In the case of Janet, a second specialist advised against ending life support, and after almost a year in hospital, she is now wheelchair-bound but happy to be alive. One concern is that if DCD becomes routine, doctors caring for critically ill people may have their judgement swayed by the needs of those on transplant waiting lists.
Michael Nicholson, a transplant surgeon at Leicester General Hospital, a leading centre for DCD in the UK, thinks the potential for conflict is overplayed. "Intensive care doctors have to inevitably withdraw treatment from some people, irrespective of whether the transplant team exists. When that happens the least they can do is have the family talk with a transplant coordinator," he says.
However, some critical-care doctors believe the problems go even deeper. They argue cessation of heartbeat and breathing are not necessarily irreversible, and point to cases where patients whose hearts didn't respond to cardiac resuscitation later came back to life - in one case a full 7 minutes later. By contrast, this so-called "Lazarus phenomenon" has never been documented in brain-dead patients.
Transplant surgeons who perform DCD point to a key safeguard in their protocols - a waiting period between cessation of heartbeat and allowing the transplant team to get to work. However, even this may be being eroded by the need to retrieve organs before they become too damaged. Originally, a 10-minute waiting period was chosen because after this time the patient would likely be brain-dead too. In many transplant centres this has now dropped to 5 minutes, while three US transplant centres use a 2-minute interval - before loss of brain function is total and when the heart could start beating again, albeit only rarely.
The most controversial aspect of DCD is the practice of giving patients drugs such as anticoagulants to preserve organs before, or just as, life support is removed. This is banned in the UK because it is deemed not to be in the interest of the patient, but it is routine in many centres in the US, despite concerns that it may hasten the death of the patient.
In Australia, where the ethics of DCD are still being considered, "the consensus is that it's reasonable [to use drugs] but only if it does not harm the donor and there has been prior consent," says Peter Joseph, chair of AHEC's working party on the ethics of organ donation. "We want the current consent form changed so that you tick a box to specifically consent to such interventions if you are on life support and your death is imminent."
This is a step in the right direction, says Doig, but much more needs to be done before DCDs become widespread. "Like any other major healthcare issue, be it euthanasia or abortion, what's important is that society debates the issue and comes up with a position," he says. "Then, and only then, individual practitioners can decide whether they want to partake."
From issue 2563 of New Scientist magazine, 04 August 2006, page 6-7
"Where there is sacrifice there is someone collecting the sacrificial offerings."-- Ayn Rand
"Some of my friends sit around every evening and they worry about the times ahead,
But everybody else is overwhelmed by indifference and the promise of an early bed..."-- Elvis Costello
"Some of my friends sit around every evening and they worry about the times ahead,
But everybody else is overwhelmed by indifference and the promise of an early bed..."-- Elvis Costello
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