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In reply: Comment on: Canadian clinical practice guideline on brain death
PurposeCurrently, there is little empirical data on family understanding about brain death and death determination. The purpose of this study was to describe family members’ (FMs’) understanding of brain death and the process of determining death in the context of organ donation in Canadian intensive care units (ICUs).Methods
We conducted a qualitative study using semistructured, in-depth interviews with FMs who were asked to make an organ donation decision on behalf of adult or pediatric patients with death determination by neurologic criteria (DNC) in Canadian ICUs.ResultsFrom interviews with 179 FMs, six main themes emerged: 1) state of mind, 2) communication, 3) DNC may be counterintuitive, 4) preparation for the DNC clinical assessment, 5) DNC clinical assessment, and 6) time of death. Recommendations on how clinicians can help FMs to understand and accept DNC through communication at key moments were described including preparing FMs for death determination, allowing FMs to be present, and explaining the legal time of death, combined with multimodal strategies. For many FMs, understanding of DNC unfolded over time, facilitated with repeated encounters and explanation, rather than during a single meeting.Conclusion
Family members’ understanding of brain death and death determination represented a journey that they reported in sequential meeting with health care providers, most notably physicians. Modifiable factors to improve communication and bereavement outcomes during DNC include attention to the state of mind of the family, pacing and repeating discussions according to families’ expressed understanding, and preparing and inviting families to be present for the clinical determination including apnea testing. We have provided family-generated recommendations that are pragmatic and can be easily implemented.
In this paper, we discuss situations in which disagreement or conflict arises in the critical care setting in relation to the determination of death by neurologic criteria, including the removal of ventilation and other somatic support. Given the significance of declaring a person dead for all involved, an overarching goal is to resolve disagreement or conflict in ways that are respectful and, if possible, relationship preserving. We describe four different categories of reasons for these disagreements or conflicts: 1) grief, unexpected events, and needing time to process these events; 2) misunderstanding; 3) loss of trust; and 4) religious, spiritual, or philosophical differences. Relevant aspects of the critical care setting are also identified and discussed. We propose several strategies for navigating these situations, appreciating that these may be tailored for a given care context and that multiple strategies may be helpfully used. We recommend that health institutions develop policies that outline the process and steps involved in addressing situations where there is ongoing or escalating conflict. These policies should include input from a broad range of stakeholders, including patients and families, as part of their development and review.
To the Editor,
Shemie et al. constructed the ‘‘2023 Clinical Practice
Guideline on a brain-based definition of death and criteria for
its determination after arrest of circulation or neurologic
function in Canada,’’ providing a biomedical definition of
death.1 This Guideline remarked, ‘‘Death is defined as the
permanent cessation of brain function (i.e., brain function is
lost, will not resume spontaneously, and will not be restored
through intervention) and is characterized by the complete
absence of any form of consciousness (wakefulness and
awareness) and the absence of brainstem reflexes, including
the ability to breathe independently.’’1
The World Brain Death Project (WBDP) similarily
defined brain death/death by neurologic criteria (BD/DNC)
as ‘‘the complete and permanent loss of brain function as
defined by an unresponsive coma with loss of capacity for
consciousness, brainstem reflexes, and the ability to
breathe independently.’’2
I proposed that death is the ‘‘irreversible loss of both
components of consciousness–arousal and awareness–
which provides the key human attributes and the highest
level of control in the hierarchy of integrating functions
within the human organism.’’ The critical attribute of life is
consciousness. Korein and Machado discussed that the brain
provides the highest level of control within the organism.3
Pallis used ‘‘capacity of consciousness,’’ referring to
‘‘arousal,’’ one component of consciousness.4 Therefore, I
propose to rephrase the WBDP definition ‘‘the complete
and permanent loss of brain function as defined by an
unresponsive coma’’ with ‘‘loss of both components of
consciousness—arousal and awareness—and the ability
to breathe.’’3
The Guideline also proposed that ‘‘residual brain cell
activity that is not associated with the presence of
consciousness or brainstem function does not preclude
death determination (e.g., posterior pituitary antidiuretic
hormone release, temperature control, or cellular-level
neuronal activity).’’1
The hypothalamus plays a key role in the central
control of the autonomic nervous system (ANS). The
hypothalamus contains neurons that send axons to the
preganglionic neurons for both the sympathetic and
parasympathetic nervous systems, regulating the
autonomic outflow. If there is a residual hypothalamic
function in patients with brain death, finding a remaining
autonomic function is possible. I reported on a patient
who showed remaining heart rate variability (HRV) in
very low-frequency waves after completing a BD/DNC
clinical diagnosis. All HRV bands were preserved in Jahi
McMath and showed autonomic reactivity to ‘‘Mother
Talks’’ stimulation, suggesting enduring awareness.
Hence, I described a new state of disorder of
consciousness.5
This 2023 Clinical Practice Guideline provides the biomedical definition of death based on permanent cessation of brain function that applies to all persons, as well as recommendations for death determination by circulatory criteria for potential organ donors and death determination by neurologic criteria for all mechanically ventilated patients regardless of organ donation potential. This Guideline is endorsed by the Canadian Critical Care Society, the Canadian Medical Association, the Canadian Association of Critical Care Nurses, Canadian Anesthesiologists’ Society, the Canadian Neurological Sciences Federation (representing the Canadian Neurological Society, Canadian Neurosurgical Society, Canadian Society of Clinical Neurophysiologists, Canadian Association of Child Neurology, Canadian Society of Neuroradiology, and Canadian Stroke Consortium), Canadian Blood Services, the Canadian Donation and Transplantation Research Program, the Canadian Association of Emergency Physicians, the Nurse Practitioners Association of Canada, and the Canadian Cardiovascular Critical Care Society.
Importance
There are inconsistencies in concept, criteria, practice, and documentation of brain death/death by neurologic criteria (BD/DNC) both internationally and within countries.
Objective
To formulate a consensus statement of recommendations on determination of BD/DNC based on review of the literature and expert opinion of a large multidisciplinary, international panel.
Process
Relevant international professional societies were recruited to develop recommendations regarding determination of BD/DNC. Literature searches of the Cochrane, Embase, and MEDLINE databases included January 1, 1992, through April 2020 identified pertinent articles for review. Because of the lack of high-quality data from randomized clinical trials or large observational studies, recommendations were formulated based on consensus of contributors and medical societies that represented relevant disciplines, including critical care, neurology, and neurosurgery.
Evidence Synthesis
Based on review of the literature and consensus from a large multidisciplinary, international panel, minimum clinical criteria needed to determine BD/DNC in various circumstances were developed.
Recommendations
Prior to evaluating a patient for BD/DNC, the patient should have an established neurologic diagnosis that can lead to the complete and irreversible loss of all brain function, and conditions that may confound the clinical examination and diseases that may mimic BD/DNC should be excluded. Determination of BD/DNC can be done with a clinical examination that demonstrates coma, brainstem areflexia, and apnea. This is seen when (1) there is no evidence of arousal or awareness to maximal external stimulation, including noxious visual, auditory, and tactile stimulation; (2) pupils are fixed in a midsize or dilated position and are nonreactive to light; (3) corneal, oculocephalic, and oculovestibular reflexes are absent; (4) there is no facial movement to noxious stimulation; (5) the gag reflex is absent to bilateral posterior pharyngeal stimulation; (6) the cough reflex is absent to deep tracheal suctioning; (7) there is no brain-mediated motor response to noxious stimulation of the limbs; and (8) spontaneous respirations are not observed when apnea test targets reach pH <7.30 and Paco2 ≥60 mm Hg. If the clinical examination cannot be completed, ancillary testing may be considered with blood flow studies or electrophysiologic testing. Special consideration is needed for children, for persons receiving extracorporeal membrane oxygenation, and for those receiving therapeutic hypothermia, as well as for factors such as religious, societal, and cultural perspectives; legal requirements; and resource availability.
Conclusions and Relevance
This report provides recommendations for the minimum clinical standards for determination of brain death/death by neurologic criteria in adults and children with clear guidance for various clinical circumstances. The recommendations have widespread international society endorsement and can serve to guide professional societies and countries in the revision or development of protocols and procedures for determination of brain death/death by neurologic criteria, leading to greater consistency within and between countries.
In this paper, I reviewed the case of Jahi McMath who was diagnosed as being in brain death (BD). Nonetheless, ancillary tests, performed 9 months after initial brain insult, showed conservation of intracranial structures, EEG activity, and autonomic reactivity to “Mother Talks” stimulus. She was clinically in a state of unarousable and unresponsiveness, without evidence of awareness of self or environment, but full absence of brainstem reflexes, and partial responsiveness rejected the possibility of being in coma. Jahi was not a UWS, because she was not in a wakefulness state, and showed partial responsiveness. LIS patients are wakeful and aware, and although these cases are quadriplegic, they fully or partially preserve brainstem reflexes, vertical eye movements, and/or blinking, and respire by their own, rejecting the possibility of classifying her as a LIS patient. She was not a MCS because she did not preserve arousal, and only partially preserved awareness. The CRS-R resulted in a very low score, not corresponding with MCS patients. MCS patients fully or partially preserve brainstem reflexes, and usually breathe by their own. MCS has been always described as a transitional state between coma, UWS, but MCS has never been reported in a patient who has all clinical BD findings. This case doesn’t contradict the concept of BD, but brings again to discussion the needs of using ancillary tests in BD. I concluded that Jahi represented a new state of disorder of consciousness, non-previously described, that I have termed: “responsive unawake syndrome” (RUS).
A brain-based definition of death and criteria for its determination after arrest of circulation or neurologic function in Canada: a 2023 clinical practice guideline
- S D Shemie
- L C Wilson
- L Hornby
- SD Shemie
Shemie SD, Wilson LC, Hornby L, et al. A brain-based definition of
death and criteria for its determination after arrest of circulation or
neurologic function in Canada: a 2023 clinical practice guideline.
Can J Anesth 2023; 70: 483-557. https://doi.org/10.1007/s12630-023-02431-42
Jahi McMath: a new state of disorder of consciousness
- C Machado