Diagnosis of Death

Diagnosis of death John Oram MB ChB FRCA DICM (UK) Paul Murphy MA (Cantab) FRCA Matrix reference 2C06, 3C00 The diagnosis, confirmation, and certification Two sets of criteria for the diagnosis of Key points of death are core skills for medical practitioners brain death have been of particular influence. Death consists of the loss in the UK.1 Although the confirmation of death The landmark Harvard code of practice sets the of capacity for remains relatively straightforward in the standard for ‘whole brain’ death that dominates consciousness and the loss majority of circumstances, developments in opinion in North America and beyond, and of the ability to breathe. advanced resuscitation techniques together with which underpins the requirement for ancillary Brainstem death occurs the continuing recognition of the medical testing that sometimes accompanies contempor- after neurological injury benefits of cadaveric organ donation present the ary criteria.3 In contrast, the original UK cri- when the brainstem has clinician working in critical care with specific teria were based upon a conviction that the key been irreversibly damaged but the heart is still beating challenges. Although these can largely be over- elements of brain death—namely irreversible and the body is kept alive come, to do so requires a thorough understand- loss of the capacity to breathe combined with by a ventilator. ing of the pathophysiological events that the irreversible loss of the capacity for con- surround death within the broader societal sciousness—could be satisfied through loss of Two appropriately qualified clinicians are required to context of what are considered the essential dis- brainstem function alone and that such a state diagnose brainstem death tinctions between what is alive and what is could usually be diagnosed on clinical 4 after exclusion of reversible dead. grounds. Regardless of the details, acceptance causes of unconsciousness, of the concept of brain death had two conse- confirmation of the absence Historical perspective quences. First, there emerged an understandable of brainstem reflexes, and belief that there were now different kinds of completion of apnoea testing. The historical record is littered with countless death—brain death and cardiorespiratory or Cardiorespiratory death can examples of failures to distinguish deep coma somatic death. Secondly, because transplan- be diagnosed after 5 min of from death, and accounts of the obsession with tation outcomes from organs retrieved from observed asystole, long premature burial and the use of phrases such as heartbeating brain dead donors were superior to enough for irreversible ‘saved by the bell’ and the ‘graveyard shift’. those from asystolic donors, brain death has damage to the brainstem to Although the scientific foundations of modern become inextricably linked with organ have occurred. medical practice have largely allowed these donation. Recently updated guidelines issues to be resolved, they have been replaced from the Academy of Medical by even more challenging circumstances that Royal Colleges provide Fundamental concepts are primarily the result of techniques of of death guidance on the procedures advanced resuscitation. For example, the dem- governing the diagnosis of onstration of the effectiveness of cardiopulmon- As noted above, aspects of modern critical care death. ary resuscitation in maintaining cerebral have placed new demands upon the diagnostic perfusion has challenged the axiom that cardiac criteria for death and even challenged our very John Oram MB ChB FRCA DICM (UK) arrest is inevitably associated with death (at understanding of it. Declaration of death in a Consultant in Anaesthesia and Critical least temporarily). Similarly, interventions in corpse in an advanced stage of decay and Care Department of Anaesthesia patients with terminal respiratory arrest second- decomposition requires little in the way of The General Infirmary at Leeds ary to an intracranial catastrophe has led to the diagnostic acumen. However, the possibility of Great George Street emergence of a state of profound and irrevers- successful resuscitation in a patient who has Leeds LS1 3EX, UK Tel: þ44 113 3926345 ible apnoeic coma in patients whose heart con- recently suffered a cardiac arrest, together with Fax: þ44 113 3922645 tinues to beat for as long as mechanical the maintained circulation and somatic physi- E-mail: [email protected] ventilation is continued. This second group of ology in an individual who is brainstem dead, (for correspondence) patients, originally described as being in a state highlights the inadequacy of using cardiore- Paul Murphy MA (Cantab) FRCA beyond coma (le coma de´passe´),2 has proved spiratory criteria alone in the diagnosis of Consultant in Anaesthesia and Critical Care particularly challenging for both the medical death. Furthermore, some philosophers and Department of Anaesthesia The General Infirmary at Leeds profession and society as a whole, although ethicists speculate that the loss of capacity for Great George Street eventually led to the emergence of widely thought, reason, and feeling may indicate a Leeds LS1 3EX, UK accepted criteria for brain death. state of death of the person that could be doi:10.1093/bjaceaccp/mkr008 Advance Access publication 15 March, 2011 77 Continuing Education in Anaesthesia, Critical Care & Pain | Volume 11 Number 3 2011 & The Author [2011]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. Downloaded from https://academic.oup.com/bjaed/article-abstract/11/3/77/257231 by guest All rights reserved. For Permissions, please email: [email protected] on 12 November 2017 Diagnosis of death distinguished from the biological death of the organism as a whole. However, there remains a professional and indeed societal conviction that death occurs as a single phenomenon that marks the end of the biological existence of the organism and that its timing can be identified with a reasonable degree of accuracy. Recent statements from both the UK and the USA give professional credibility to these convictions. For instance, guidance from the Academy of Medical Royal Colleges (AoMRC) in the UK5 states that: Death entails the irreversible loss of those essential character- istics which are necessary to the existence of a living human person and, thus, the definition of death should be regarded as the irreversible loss of the capacity for consciousness, com- Fig 1 The relationship between the various criteria for the diagnosis and confirmation of death. bined with irreversible loss of the capacity to breathe. The President’s Council on Bioethics in the USA has expanded on Diagnosis of death by neurological criteria these ideas,6 proposing that in order for an organism to be con- The UK Code for the diagnosis of brainstem death, more recently sidered to be living an animal must be a whole, describing whole- referred to diagnosis of death by neurological criteria, has three ness as follows: essential components: Determining whether an organism remains a whole depends (i) fulfilment of essential preconditions; upon recognizing the persistence or cessation of the funda- (ii) exclusion of potentially reversible contributions to a state of mental vital work of a living organism—the work of self- apnoeic coma; preservation, achieved through the organism’s need-driven (iii) the formal demonstration of coma, apnoea, and the absence commerce with the surrounding world. When there is good of brainstem reflex activity. reason to believe that an injury has irreversibly destroyed an organism’s ability to perform its fundamental vital work, then The new guidance from the AoMRC builds on the original Codes the conclusion that the organism as a whole has died is of Practice and provides greater clarity over various elements of warranted. both patient assessment and the performance of the tests them- selves. Clinical interrogation of the brainstem serves to demon- The statement of the Presidential Council goes on to define the strate the absence or otherwise of brainstem functions, but it is the essential elements of an organism’s vital work of commerce with initial phases of assessment that indicate their irreversibility. its surroundings: The tests should be carried out by two qualified doctors who are (i) openness or receptivity to the signals and stimuli that emanate competent with the procedure, one of these should be a consultant from the environment—consciousness; and both should have been fully registered with the General Medical (ii) the ability of an organism to interact with the environment to Council for at least 5 yr. The tests must be undertaken by the two selectively obtain what it needs for survival, and an innate doctors together and completed successfully on two occasions. drive that compels an organism to do what it must to complete this interaction—for example, through spontaneous respiration Preconditions engage in the exchange of carbon dioxide for oxygen. (i) The patient should be deeply unconscious, apnoeic, and Thus, the key elements of a biological standard for death are con- mechanically ventilated. sidered to be the simultaneous and irreversible loss of both the (ii) There should be no doubt that the patient has suffered irreversible capacity for consciousness and the capacity to breathe. The criteria brain damage of known aetiology, common causes of brainstem required to confirm such a state will vary according to the precise death including spontaneous intracranial haemorrhage,

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