Brain Stem Death - Evolution of Diagnostic Criteria

Evolution of Diagnostic Criteria

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 brain stem and a specified challenge to the brain stem 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, "brain stem 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 brain stem function will produce this state and “therefore brain stem death is equivalent to the death of the individual”.