Cadaveric donation: brain stem death

Oluwafunmilayo Ololade JAWONIYI, Helen NOBLE and Kevin GORMLEY.

Queens University Belfast.

The brain stem is situated at the base of the brain. It regulates most of the automatic functioning systems within the human body upon which life is contingent. These include breathing, maintenance of blood pressure, heartbeat, swallowing, conveying information to and from the brain to the rest of the body, and other vital functions. Brain death or brain stem death, therefore, refers to complete, irrevocable or irreversible loss of brain stem functions. This might happen when blood and oxygen supply to the brain ceases, for example, as a result of cardiac arrest, heart attack, stroke and blood clot. Brain stem death could also be caused by brain tumour, viral brain infections (e.g. encephalitis), severe head injury and brain haemorrhage.

Brain stem death is not the same as, and should not be confused with coma and persistent vegetative state in which a sufferer might display a level of consciousness; breathe unaided; and, possibly recover if the brain stem’s core functions are not affected: See NHS Choices, 2014 http://www.nhs.uk/conditions/Organ-donation/Pages/Introduction.aspx. Brain death or brain stem death not only leaves victims with devastating neurological and brainstem injury, but also confines them to intensive care unit where their cardio-respiratory system is continuously maintained on mechanical ventilators.

Brain stem death is diagnosed by performing, on two separate occasions, five simple tests which verify that: (1) the pupils are fixed and dilated and do not react to light; (2) there is no eye movement; (3) there is no ear reflex; (4) there is no pain response; and, (5) there is no gag reflex. Globally, brain death is clinically adjudged as the death of an individual. It is a clinical declaration of death whereby an individual’s life is clinically considered to have ended, irreversibly, following which, under the dead donor rule, viable vital organs could be harvested and subsequently transplanted.

Donation after brain death (DBD), also called heart beating donation (HBD), therefore, refers to organ donation by and procurement from heart beating donors, for transplantation purposes, in well-controlled circumstances, following a diagnosis and confirmation of death using neurological criteria. The deployment of brain stem death as one of the criteria for organ donation is not uncontroversial. There are people (healthcare professionals, academics, and the general public) on both sides of the controversy. On one hand, some entertain fear about the reliability of brain death diagnosis, maintaining that such diagnosis could be flawed on account of cases where some patients who meet the criteria for brain death but do not have irreversible cessation of all functions of their entire brain because some of the brain stem’s homeostatic functions remain. This might include temperature control for example. On the other hand, some maintain that not all function of the brain needs to be absent for a patient to be dead, only those that are critical to maintaining integration of the body functions. It is also argued that whilst the loss of those critical functions, over time, ultimately culminates in cardiac arrest, even when aided with mechanical ventilators some who meet all the criteria for brain death potentially could survive many years with all their bodily functions, excepting consciousness and brain stem reflexes, still intact. This has led to calls for a review of brain death as a criterion for ODT and its replacement with loss of personhood as a rationale or basis for neurological determination of death.

Some people inextricably link the concept of brain death to ODT with a view to ensuring that the former serves the purposes of the latter. Conversely, others maintain that this medical concept evolved independently of ODT. In spite of the controversies surrounding the deployment of brain death as one of the criteria for organ donation, and despite the contributions of donation after brain death (DBD) toward increasing the number of donors, organs harvested from brain death donors remain insufficient to adequately meet demands. Moreover, improvements in care and management of patients with brain injuries have lowered incidents of brain deaths. Similarly, health and safety promotions or advertisements as well as road safety legislations and campaigns have helped to reduce tragic accidents that often caused brain injuries.

Although donation after circulatory (cardiac) death (DCD) differs from traditionally and commonly accepted donor models of donation after brain death (DBD), DBD has proven to be relatively successful and efficient in comparison with DCD. This is especially so with regards to kidney donations and transplantations. Also, more evidence is emerging concerning successful transplantation of organs such as lungs, liver and pancreas harvested from DCD-donor. In spite of these contributions of DCD towards the supply of organs for transplantation, DBD remains the most common source of multiple organ donations. It is also the most reliable source for cardiac transplant recipients/patients. e brain stem is situated at the base of the brain. It regulates most of the automatic functioning systems within the human body upon which life is contingent. These include breathing, maintenance of blood pressure, heartbeat, swallowing, conveying information to and from the brain to the rest of the body, and other vital functions. Brain death or brain stem death, therefore, refers to complete, irrevocable or irreversible loss of brain stem functions. This might happen when blood and oxygen supply to the brain ceases, for example, as a result of cardiac arrest, heart attack, stroke and blood clot. Brain stem death could also be caused by brain tumour, viral brain infections (e.g. encephalitis), severe head injury and brain haemorrhage.

Brain stem death is not the same as, and should not be confused with coma and persistent vegetative state in which a sufferer might display a level of consciousness; breathe unaided; and, possibly recover if the brain stem’s core functions are not affected: See NHS Choices, 2014 http://www.nhs.uk/conditions/Organ-donation/Pages/Introduction.aspx. Brain death or brain stem death not only leaves victims with devastating neurological and brainstem injury, but also confines them to intensive care unit where their cardio-respiratory system is continuously maintained on mechanical ventilators. Brain stem death is diagnosed by performing, on two separate occasions, five simple tests which verify that: (1) the pupils are fixed and dilated and do not react to light; (2) there is no eye movement; (3) there is no ear reflex; (4) there is no pain response; and, (5) there is no gag reflex. Globally, brain death is clinically adjudged as the death of an individual. It is a clinical declaration of death whereby an individual’s life is clinically considered to have ended, irreversibly, following which, under the dead donor rule, viable vital organs could be harvested and subsequently transplanted. Donation after brain death (DBD), also called heart beating donation (HBD), therefore, refers to organ donation by and procurement from heart beating donors, for transplantation purposes, in well-controlled circumstances, following a diagnosis and confirmation of death using neurological criteria. The deployment of brain stem death as one of the criteria for organ donation is not uncontroversial. There are people (healthcare professionals, academics, and the general public) on both sides of the controversy. On one hand, some entertain fear about the reliability of brain death diagnosis, maintaining that such diagnosis could be flawed on account of cases where some patients who meet the criteria for brain death but do not have irreversible cessation of all functions of their entire brain because some of the brain stem’s homeostatic functions remain. This might include temperature control for example. On the other hand, some maintain that not all function of the brain needs to be absent for a patient to be dead, only those that are critical to maintaining integration of the body functions. It is also argued that whilst the loss of those critical functions, over time, ultimately culminates in cardiac arrest, even when aided with mechanical ventilators some who meet all the criteria for brain death potentially could survive many years with all their bodily functions, excepting consciousness and brain stem reflexes, still intact. This has led to calls for a review of brain death as a criterion for ODT and its replacement with loss of personhood as a rationale or basis for neurological determination of death.

Some people inextricably link the concept of brain death to ODT with a view to ensuring that the former serves the purposes of the latter. Conversely, others maintain that this medical concept evolved independently of ODT. In spite of the controversies surrounding the deployment of brain death as one of the criteria for organ donation, and despite the contributions of donation after brain death (DBD) toward increasing the number of donors, organs harvested from brain death donors remain insufficient to adequately meet demands. Moreover, improvements in care and management of patients with brain injuries have lowered incidents of brain deaths. Similarly, health and safety promotions or advertisements as well as road safety legislations and campaigns have helped to reduce tragic accidents that often caused brain injuries. Although donation after circulatory (cardiac) death (DCD) differs from traditionally and commonly accepted donor models of donation after brain death (DBD), DBD has proven to be relatively successful and efficient in comparison with DCD. This is especially so with regards to kidney donations and transplantations. Also, more evidence is emerging concerning successful transplantation of organs such as lungs, liver and pancreas harvested from DCD-donor. In spite of these contributions of DCD towards the supply of organs for transplantation, DBD remains the most common source of multiple organ donations. It is also the most reliable source for cardiac transplant recipients/patients.

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