Reversible brain death after cardiopulmonary arrest and induced hypothermia

Controversies in defining and determining death in critical care

Circulatory-respiratory or brain tests are widely accepted for definition and determination of death, but have several controversial issues. Both determinations have been stimulated by organ donation, but must be valid independently of this process. Current controversies in brain death include whether the definition is conceptually coherent, whether the whole-brain or brainstem criterion is correct, whether one neurological examination or two should be required, and when to conduct the examination following therapeutic hypothermia. Controversies about the circulatory determination of death include the minimum duration of asystole that is sufficient for death to be declared, and whether the distinction between permanent and irreversible cessation of circulatory functioning is important. In addition, the goal of organ donation raises issues such as the optimal way to time and conduct the request conversation with family members of the patient, and whether the Dead Donor Rule should be abandoned.

Ethical issues in organ transplantation

We discuss ethical issues of organ transplantation including the stewardship tension between physicians' duty to do everything possible for their patients and their duty to serve society by encouraging organ donation. We emphasize consideration of the role of the principles of justice, utility and equity in the just distribution of transplantable organ as scarce resources. We then consider ethical issues of determining death of the organ donor including the remaining controversies in brain death determination and the new controversies raised by circulatory death determination. We need uniformity in standards of death determination, agreement on the duration of asystole before death is declared, and consensus on the allowable circulatory interventions on the newly declared organ donor that are intended to improve organ function. We discuss the importance of maintaining the dead donor rule, despite the argument of some scholars to abandon it.

Continuous evaluation of neurological prognosis after cardiac arrest

Post-resuscitation care has changed in the last decade, and outcome after cardiac arrest has improved, thanks to several combined measures. Induced hypothermia has shown a treatment benefit in two randomized trials, but some doubts remain. General care has improved, including the use of emergency coronary intervention. Assessment of neurological function and prognosis in comatose cardiac arrest patient is challenging, especially when treated with hypothermia. In this review, we evaluate the recent literature and discuss the available evidence for prognostication after cardiac arrest in the era of temperature management. Relevant literature was identified searching PubMed and reading published papers in the field, but no standardized search strategy was used. The complexity of predicting outcome after cardiac arrest and induced hypothermia is recognized in the literature, and no single test can predict a poor prognosis with absolute certainty. A clinical neurological examination is still the gold standard, but the results need careful interpretation because many patients are affected by sedatives and by hypothermia. Common adjuncts include neurophysiology, brain imaging and biomarkers, and a multimodal strategy is generally recommended. Current guidelines for prediction of outcome after cardiac arrest and induced hypothermia are not sufficient. Based on our expert opinion, we suggest a multimodal approach with a continuous evaluation of prognosis based on repeated neurological examinations and electroencephalography. Somatosensory-evoked potential is an established method to help determine a poor outcome and is recommended, whereas biomarkers and magnetic resonance imaging are promising adjuncts. We recommend that a decisive evaluation of prognosis is performed at 72 h after normothermia or later in a patient free of sedative and analgetic drugs.

Brain death dilemmas and the use of ancillary testing

The Uniform Determination of Death Act indicates that "an individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead," with brain death being determined based on "accepted medical standards." The AAN has published practice guidelines providing medical standards for the determination of brain death. The most recent AAN guideline update notes that "because of the deficiencies in the evidence base, clinicians must exercise considerable judgment when applying the criteria in specific circumstances" and that "ancillary tests can be used when uncertainty exists about the reliability of parts of the neurologic examination or when the apnea test cannot be performed. This article presents two cases commonly encountered in clinical practice in which the findings of the guideline-specified clinical neurologic assessment may be difficult to interpret, hampering the clinical determination of brain death. In these circumstances, ancillary testing specifically assessing for cerebral circulatory arrest may be helpful.

Mass media campaigns and organ donation: managing conflicting messages and interests

Mass media campaigns are widely and successfully used to change health decisions and behaviors for better or for worse in society. In the United States, media campaigns have been launched at local offices of the states' department of motor vehicles to promote citizens' willingness to organ donation and donor registration. We analyze interventional studies of multimedia communication campaigns to encourage organ-donor registration at local offices of states' department of motor vehicles. The media campaigns include the use of multifaceted communication tools and provide training to desk clerks in the use of scripted messages for the purpose of optimizing enrollment in organ-donor registries. Scripted messages are communicated to customers through mass audiovisual entertainment media, print materials and interpersonal interaction at the offices of departments of motor vehicles. These campaigns give rise to three serious concerns: (1) bias in communicating information with scripted messages without verification of the scientific accuracy of information, (2) the provision of misinformation to future donors that may result in them suffering unintended consequences from consenting to medical procedures before death (e.g, organ preservation and suitability for transplantation), and (3) the unmanaged conflict of interests for organizations charged with implementing these campaigns, (i.e, dual advocacy for transplant recipients and donors). We conclude the following: (1) media campaigns about healthcare should communicate accurate information to the general public and disclose factual materials with the least amount of bias; (2) conflicting interests in media campaigns should be managed with full public transparency; (3) media campaigns should disclose the practical implications of procurement as well as acknowledge the medical, legal, and religious controversies of determining death in organ donation; (4) organ-donor registration must satisfy the criteria of informed consent; (5) media campaigns should serve as a means of public education about organ donation and should not be a form of propaganda.

Neurologic determination of death

Death determined by neurologic criteria or brain death is better understood as brain arrest or the final clinical expression of complete and irreversible neurologic failure. Despite widespread national, international, and legal acceptance of the concept, substantial variation exists in the standards and their application, and there remains a need to clarify and standardize terminology (eg, ancillary and supplementary testing, brain death, or neurologic determination of death). The aim of this article is to review the specific criteria and requirements of brain death, paying special attention to areas of controversy and practice inconsistency.