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Updated: 1 hour 42 min ago

Transplants: are the donors really, truly dead?

Mon, 2018-03-05 16:06

Organ donation has hit the headlines this week following a debate in Parliament. The Mirror claimed much of the glory with its headline: ‘’We did it!’ Organ transplant Bill to save up to 500 lives a year in England passes crucial Commons hurdle’

However, I have read nothing on the medical aspects of it, on the definitions of death and on the transplant procedure itself.

Dying patients may be seen as ‘organ resources’ by some clinicians desperate to acquire scarce organs for transplantation. One of the reasons given by people for not carrying a donor card is the fear that organs might be removed before death.  Another stated concern is that staff may over-readily apply a DNAR (do not attempt resuscitation) order in such circumstances, to provide organs for donation. Such fears need not be well-founded to have an effect.

The fear that organs might be removed from a person before they were clinically truly dead was cited among reasons given for the abolition of the presumed consent law in Brazil. Hovering in the public consciousness is the thought of a brain-dead body being kept artificially ventilated and perfused, warm and pink and apparently ‘alive’ whilst their family is asked urgently for permission to whisk the body away to theatre for organ retrieval.

When people are asked under what circumstances their organs should be taken the answer is of course: ‘when I am dead’. But the truth would probably surprise most people, because no one wants dead organs from a dead body. Organs have to be removed when still functional and as close to their living state as possible. Most people do not appreciate that generally organs are removed when on ventilatory life support. The BMA says: ‘once the patient’s heart has stopped beating the organs are no longer suitable for donation…’ so ‘…In order to obtain organs in good condition, the organs need to be ‘harvested’ as soon as possible after death.’

If it was simply a matter of taking organs from dead bodies there would be no shortage of organs. The problem is finding a potential donor who is clinically defined as brain dead and is on life support. If brain death is agreed, then surgeons can remove organs while the heart is still beating and the organs are still perfused with oxygenated blood.

So, the definition of death is clearly central to this. It may come as a surprise to many to learn that today there is no statutory definition of death in the UK. A definition by Academy of Medical Royal Colleges (AoMRC) is widely accepted however some have argued that there is still a degree of general public disquiet, alleged medical duplicity and continuing academic dissent surrounding the concept of death, as noted in this CMF File.  .

Death has been redefined variously since 1968, corresponding with the advent of organ transplantation and consequent need for ‘fresh’ organs. In the UK up to the 1970s, all organs for transplantation were donated after ‘circulatory death’ (a non-beating heart). Then the definition of ‘brain death’ was introduced, until 1995 when the terminology was changed again, to ‘brainstem death’, as residual activity in parts of the brain other than the brainstem had been demonstrated in patients considered to be ‘brain dead’.

The British Transplantation Society use a definition based on the AoMRC: ‘Death is irreversible and should be regarded as a state in which a patient has permanently lost the capacity for consciousness and brain stem function.

It also says that death occurs: ‘where cardio-respiratory criteria apply, death can be confirmed following five minutes of continuous cardio-respiratory arrest providing there is no subsequent restoration of artificial cerebral circulation.’.

Waiting five minutes after circulatory death, along with using other test criteria, to confirm death is somewhat reassuring, compared to other countries that wait even less time, but nonetheless as our knowledge of conscious awareness around the time of death develops, can we be sure that five minutes is a sufficient time period after pulse and respirations cease for the donor truly to die?  Many patients have been successfully resuscitated after much longer periods of cardiac arrest.

A BMA report on organ donation from 2000 acknowledges this possibility: ‘Death confirmed by brain stem tests should therefore be seen as the clearest indication of what is commonly understood as “death”, more so than the stopping of the heart, or of breathing, both of which can, in some circumstances, be reversed.

But despite this possibility, the same BMA report also says that: ‘It is possible for some organs and tissue to be removed for transplantation from non-heartbeating donors for a short period after death.’  ie after cardiac arrest.

Are there other reasons for concern about these widely accepted definitions of death?

One is that a brain dead body, or ‘cadaver’, can react to incisions for organ removal with an increase in heart rate and blood pressure. This a standard, and common, spinal reflex (marked spinal reflexes have been observed in the brain dead with liquefied cortex). The beating-heart ‘cadaver’ often has to be anaesthetised, or paralysed, to prevent it reacting to the operation, otherwise blood pressure can rise dramatically when an incision is made. The use of muscle relaxants and even general anaesthesia of donor ‘cadavers’ does not appear to square with the assertion that all integrative function of the body is lost in brain stem death. There may also sometimes be residual hormonal function and there still remain cases of patients declared brain dead who are maintained on ITU support for months or even years. See here too.

Does this continued functioning or responsiveness of the body as a whole suggest it is truly dead? Could it mean that sometimes a dying person might be misdiagnosed as already dead? Of course, such uncertainty is by no means the case for all, or even the majority of, deaths. Nevertheless, it seems to me (and some others) that there are still some unanswered questions.

Categories: Discussion