Brain stem death

Brainstem death is a clinical syndrome defined by the absence of reflexes with pathways through the brainstem—the 'stalk' of the brain, which connects the spinal cord to the mid-brain, cerebellum and cerebral hemispheres—in a deeply comatose, ventilator-dependent patient.Identification of this state carries a very grave prognosis for survival; cessation of heartbeat often occurs within a few days although it may continue for weeks if intensive support is maintained. Brainstem death is a clinical syndrome defined by the absence of reflexes with pathways through the brainstem—the 'stalk' of the brain, which connects the spinal cord to the mid-brain, cerebellum and cerebral hemispheres—in a deeply comatose, ventilator-dependent patient.Identification of this state carries a very grave prognosis for survival; cessation of heartbeat often occurs within a few days although it may continue for weeks if intensive support is maintained. In the United Kingdom, the formal diagnosis of brainstem death by the procedure laid down in the official Code of Practice permits the diagnosis and certification of death on the premise that a person is dead when consciousness and the ability to breathe are permanently lost, regardless of continuing life in the body and parts of the brain, and that death of the brainstem alone is sufficient to produce this state. This concept of brainstem death is also accepted as grounds for pronouncing death for legal purposes in India and Trinidad & Tobago. Elsewhere in the world the concept upon which the certification of death on neurological grounds is based is that of permanent cessation of all function in all parts of the brain—whole brain death—with which the British concept should not be confused. The United States' President's Council on Bioethics made it clear, for example, in its White Paper of December 2008, that the British concept and clinical criteria are not considered sufficient for the diagnosis of death in the United States of America. The United Kingdom (UK) criteria were first published by the Conference of Medical Royal Colleges (with advice from the Transplant Advisory Panel) in 1976, as prognostic guidelines. They were drafted in response to a perceived need for guidance in the management of deeply comatose patients with severe brain damage who were being kept alive by mechanical ventilators but showing no signs of recovery. The Conference sought 'to establish diagnostic criteria of such rigour that on their fulfilment the mechanical ventilator can be switched off, in the secure knowledge that there is no possible chance of recovery'. The published criteria—negative responses to bedside tests of some reflexes with pathways through the brainstem and a specified challenge to the brainstem respiratory centre, with caveats about exclusion of endocrine influences, metabolic factors and drug effects—were held to be 'sufficient to distinguish between those patients who retain the functional capacity to have a chance of even partial recovery and those where no such possibility exists'. Recognition of that state required the withdrawal of fruitless further artificial support so that death might be allowed to occur, thus 'sparing relatives from the further emotional trauma of sterile hope'. In 1979, the Conference of Medical Royal Colleges promulgated its conclusion that identification of the state defined by those same criteria—then thought sufficient for a diagnosis of brain death—'means that the patient is dead'. Death certification on those criteria has continued in the United Kingdom (where there is no statutory legal definition of death) since that time, particularly for organ transplantation purposes, although the conceptual basis for that use has changed. In 1995, after a review by a Working Group of the Royal College of Physicians of London, the Conference of Medical Royal Colleges formally adopted the 'more correct' term for the syndrome, 'brainstem death'—championed by Pallis in a set of 1982 articles in the British Medical Journal—and advanced a new definition of human death as the basis for equating this syndrome with the death of the person. The suggested new definition of death was the 'irreversible loss of the capacity for consciousness, combined with irreversible loss of the capacity to breathe'. It was stated that the irreversible cessation of brainstem function will produce this state and 'therefore brainstem death is equivalent to the death of the individual'. In the UK, the formal rules for the diagnosis of brainstem death have undergone only minor modifications since they were first published in 1976. The most recent revision of the UK's Department of Health Code of Practice governing use of that procedure for the diagnosis of death reaffirms the preconditions for its consideration. These are: