1
|
Mahon S. Variation and convergence in the morpho-functional properties of the mammalian neocortex. Front Syst Neurosci 2024; 18:1413780. [PMID: 38966330 PMCID: PMC11222651 DOI: 10.3389/fnsys.2024.1413780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Accepted: 06/03/2024] [Indexed: 07/06/2024] Open
Abstract
Man's natural inclination to classify and hierarchize the living world has prompted neurophysiologists to explore possible differences in brain organisation between mammals, with the aim of understanding the diversity of their behavioural repertoires. But what really distinguishes the human brain from that of a platypus, an opossum or a rodent? In this review, we compare the structural and electrical properties of neocortical neurons in the main mammalian radiations and examine their impact on the functioning of the networks they form. We discuss variations in overall brain size, number of neurons, length of their dendritic trees and density of spines, acknowledging their increase in humans as in most large-brained species. Our comparative analysis also highlights a remarkable consistency, particularly pronounced in marsupial and placental mammals, in the cell typology, intrinsic and synaptic electrical properties of pyramidal neuron subtypes, and in their organisation into functional circuits. These shared cellular and network characteristics contribute to the emergence of strikingly similar large-scale physiological and pathological brain dynamics across a wide range of species. These findings support the existence of a core set of neural principles and processes conserved throughout mammalian evolution, from which a number of species-specific adaptations appear, likely allowing distinct functional needs to be met in a variety of environmental contexts.
Collapse
Affiliation(s)
- Séverine Mahon
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, Paris, France
| |
Collapse
|
2
|
Parent B, Thiessen C, Wall A, Levan M, Gordon EJ. A Clarified Interpretation of Permanence Justifies Death Determination in NRP Protocols. THE AMERICAN JOURNAL OF BIOETHICS : AJOB 2024; 24:46-48. [PMID: 38829585 DOI: 10.1080/15265161.2024.2337402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
|
3
|
Bernat JL, Khush KK, Shemie SD, Hartwig MG, Reese PP, Dalle Ave A, Parent B, Glazier AK, Capron AM, Craig M, Gofton T, Gordon EJ, Healey A, Homan ME, Ladin K, Messer S, Murphy N, Nakagawa TA, Parker WF, Pentz RD, Rodríguez-Arias D, Schwartz B, Sulmasy DP, Truog RD, Wall AE, Wall SP, Wolpe PR, Fenton KN. Knowledge gaps in heart and lung donation after the circulatory determination of death: Report of a workshop of the National Heart, Lung, and Blood Institute. J Heart Lung Transplant 2024; 43:1021-1029. [PMID: 38432523 PMCID: PMC11132427 DOI: 10.1016/j.healun.2024.02.1455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 03/05/2024] Open
Abstract
In a workshop sponsored by the U.S. National Heart, Lung, and Blood Institute, experts identified current knowledge gaps and research opportunities in the scientific, conceptual, and ethical understanding of organ donation after the circulatory determination of death and its technologies. To minimize organ injury from warm ischemia and produce better recipient outcomes, innovative techniques to perfuse and oxygenate organs postmortem in situ, such as thoracoabdominal normothermic regional perfusion, are being implemented in several medical centers in the US and elsewhere. These technologies have improved organ outcomes but have raised ethical and legal questions. Re-establishing donor circulation postmortem can be viewed as invalidating the condition of permanent cessation of circulation on which the earlier death determination was made and clamping arch vessels to exclude brain circulation can be viewed as inducing brain death. Alternatively, TA-NRP can be viewed as localized in-situ organ perfusion, not whole-body resuscitation, that does not invalidate death determination. Further scientific, conceptual, and ethical studies, such as those identified in this workshop, can inform and help resolve controversies raised by this practice.
Collapse
Affiliation(s)
- James L Bernat
- Department of Neurology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire.
| | - Kiran K Khush
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Sam D Shemie
- Division of Critical Care Medicine, Montreal Children's Hospital, McGill University, Montreal, PQ, Canada
| | - Matthew G Hartwig
- Division of Thoracic Surgery, Department of Surgery, Duke University Health System, Durham, North Carolina
| | - Peter P Reese
- Center for Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anne Dalle Ave
- Kennedy Institute of Ethics, Georgetown University, Washington, District of Columbia
| | - Brendan Parent
- Division of Medical Ethics and Department of Surgery, NYU Grossman School of Medicine, New York, New York
| | - Alexandra K Glazier
- Brown University, School of Public Health, Providence, Rhode Island; New England Donor Services, Waltham, Massachusetts
| | - Alexander M Capron
- Gould School of Law and Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Matt Craig
- Lung Biology and Disease Branch, National Heart, Lung and Blood Institute, Bethesda, Maryland
| | - Teneille Gofton
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Elisa J Gordon
- Department of Surgery, Center for Biomedical Ethics and Society, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Andrew Healey
- Department of Medicine McMaster University and William Osler Health System, Hamilton, Ontario, Canada
| | | | - Keren Ladin
- Research on Ethics, Aging, and Community Health (REACH Lab); Departments of Occupational Therapy and Community Health, Tufts University, Medford, Massachusetts
| | - Simon Messer
- Department of Transplant, Golden Jubilee National Hospital, Clydebank, Scotland UK
| | - Nick Murphy
- Departments of Medicine and Philosophy, Western University, London, Ontario, Canada
| | - Thomas A Nakagawa
- University of Florida College of Medicine-Jacksonville, Department of Pediatrics, Division of Pediatric Critical Care Medicine, Jacksonville, Florida
| | - William F Parker
- Department of Medicine and Public Health Sciences, University of Chicago, Chicago, Illinois
| | - Rebecca D Pentz
- Winship Cancer Institute, Emory University, Atlanta, Georgia
| | | | - Bryanna Schwartz
- Division of Cardiovascular Sciences, National Heart, Lung and Blood Institute, Bethesda, Maryland; Department of Cardiology, Children's National Medical Center, Washington, District of Columbia
| | - Daniel P Sulmasy
- The Kennedy Institute of Ethics and the Departments of Medicine and Philosophy, Georgetown University, Washington, District of Columbia
| | - Robert D Truog
- Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital; Center for Bioethics, Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
| | - Anji E Wall
- Department of Surgery, Baylor University Medical Center, Dallas, Texas
| | - Stephen P Wall
- Ronald O. Perelman Department of Emergency Medicine; NYU Grossman School of Medicine and Department of Population Health, NYU, New York, New York
| | - Paul R Wolpe
- Center for Ethics, Department of Medicine, Emory University, Atlanta, Georgia
| | - Kathleen N Fenton
- Advanced Technologies and Surgery Branch, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, and Department of Bioethics, Clinical Center, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
4
|
Murphy NB, Shemie SD, Capron A, Truog RD, Nakagawa T, Healey A, Gofton T, Bernat JL, Fenton K, Khush KK, Schwartz B, Wall SP. Advancing the Scientific Basis for Determining Death in Controlled Organ Donation After Circulatory Determination of Death. Transplantation 2024:00007890-990000000-00733. [PMID: 38637919 DOI: 10.1097/tp.0000000000005002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
In controlled organ donation after circulatory determination of death (cDCDD), accurate and timely death determination is critical, yet knowledge gaps persist. Further research to improve the science of defining and determining death by circulatory criteria is therefore warranted. In a workshop sponsored by the National Heart, Lung, and Blood Institute, experts identified research opportunities pertaining to scientific, conceptual, and ethical understandings of DCDD and associated technologies. This article identifies a research strategy to inform the biomedical definition of death, the criteria for its determination, and circulatory death determination in cDCDD. Highlighting knowledge gaps, we propose that further research is needed to inform the observation period following cessation of circulation in pediatric and neonatal populations, the temporal relationship between the cessation of brain and circulatory function after the withdrawal of life-sustaining measures in all patient populations, and the minimal pulse pressures that sustain brain blood flow, perfusion, activity, and function. Additionally, accurate predictive tools to estimate time to asystole following the withdrawal of treatment and alternative monitoring modalities to establish the cessation of circulatory, brainstem, and brain function are needed. The physiologic and conceptual implications of postmortem interventions that resume circulation in cDCDD donors likewise demand attention to inform organ recovery practices. Finally, because jurisdictionally variable definitions of death and the criteria for its determination may impede collaborative research efforts, further work is required to achieve consensus on the physiologic and conceptual rationale for defining and determining death after circulatory arrest.
Collapse
Affiliation(s)
- Nicholas B Murphy
- Departments of Medicine and Philosophy, Western University, London, ON, Canada
| | - Sam D Shemie
- Division of Critical Care Medicine, Montreal Children's Hospital, McGill University, Montreal, QC, Canada
- System Development, Canadian Blood Services, Ottawa, ON, Canada
| | - Alex Capron
- Gould School of Law and Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Robert D Truog
- Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, MA
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA
| | - Thomas Nakagawa
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Florida College of Medicine-Jacksonville, Jacksonville, FL
| | - Andrew Healey
- Ontario Health (Trillium Gift of Life Network), Toronto, ON, Canada
- Divisions of Emergency and Critical Care Medicine, Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Teneille Gofton
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - James L Bernat
- Department of Neurology, Dartmouth Geisel School of Medicine, Hanover, NH
| | - Kathleen Fenton
- Advanced Technologies and Surgery Branch, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Department of Bioethics, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Kiran K Khush
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA
| | - Bryanna Schwartz
- Heart Development and Structural Diseases Branch, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
- Division of Cardiology, Children's National Hospital, Washington, DC
| | - Stephen P Wall
- Ronald O. Perelman Department of Emergency Medicine, NYU Grossman School of Medicine, New York, NY
- Department of Population Health, NYU Grossman School of Medicine, New York, NY
| |
Collapse
|
5
|
Hermann B, Candia‐Rivera D, Sharshar T, Gavaret M, Diehl J, Cariou A, Benghanem S. Aberrant brain-heart coupling is associated with the severity of post cardiac arrest brain injury. Ann Clin Transl Neurol 2024; 11:866-882. [PMID: 38243640 PMCID: PMC11021613 DOI: 10.1002/acn3.52000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 12/24/2023] [Indexed: 01/21/2024] Open
Abstract
OBJECTIVE To investigate autonomic nervous system activity measured by brain-heart interactions in comatose patients after cardiac arrest in relation to the severity and prognosis of hypoxic-ischemic brain injury. METHODS Strength and complexity of bidirectional interactions between EEG frequency bands (delta, theta, and alpha) and ECG heart rate variability frequency bands (low frequency, LF and high frequency, HF) were computed using a synthetic data generation model. Primary outcome was the severity of brain injury, assessed by (i) standardized qualitative EEG classification, (ii) somatosensory evoked potentials (N20), and (iii) neuron-specific enolase levels. Secondary outcome was the 3-month neurological status, assessed by the Cerebral Performance Category score [good (1-2) vs. poor outcome (3-4-5)]. RESULTS Between January 2007 and July 2021, 181 patients were admitted to ICU for a resuscitated cardiac arrest. Poor neurological outcome was observed in 134 patients (74%). Qualitative EEG patterns suggesting high severity were associated with decreased LF/HF. Severity of EEG changes were proportional to higher absolute values of brain-to-heart coupling strength (p < 0.02 for all brain-to-heart frequencies) and lower values of alpha-to-HF complexity (p = 0.049). Brain-to-heart coupling strength was significantly higher in patients with bilateral absent N20 and correlated with neuron-specific enolase levels at Day 3. This aberrant brain-to-heart coupling (increased strength and decreased complexity) was also associated with 3-month poor neurological outcome. INTERPRETATION Our results suggest that autonomic dysfunctions may well represent hypoxic-ischemic brain injury post cardiac arrest pathophysiology. These results open avenues for integrative monitoring of autonomic functioning in critical care patients.
Collapse
Affiliation(s)
- Bertrand Hermann
- Faculté de MédecineUniversité Paris CitéParisFrance
- Medical Intensive Care UnitHEGP Hospital, Assistance Publique ‐ Hôpitaux de Paris‐Centre (APHP.Centre)ParisFrance
- INSERM UMR 1266, Institut de Psychiatrie et Neurosciences de Paris (IPNP)Université Paris CitéParisFrance
| | - Diego Candia‐Rivera
- Sorbonne Université, Paris Brain Institute (ICM), INRIA, CNRS UMR 722, INSERM U1127, AP‐HP Hôpital Pitié‐SalpêtrièreParisFrance
| | - Tarek Sharshar
- Faculté de MédecineUniversité Paris CitéParisFrance
- INSERM UMR 1266, Institut de Psychiatrie et Neurosciences de Paris (IPNP)Université Paris CitéParisFrance
- GHU Paris Psychiatrie Neurosciences, Service hospitalo‐universitaire de Neuro‐anesthésie réanimationParisFrance
| | - Martine Gavaret
- Faculté de MédecineUniversité Paris CitéParisFrance
- INSERM UMR 1266, Institut de Psychiatrie et Neurosciences de Paris (IPNP)Université Paris CitéParisFrance
- Neurophysiology and Epileptology DepartmentGHU Paris Psychiatrie et NeurosciencesParisFrance
| | - Jean‐Luc Diehl
- Faculté de MédecineUniversité Paris CitéParisFrance
- Medical Intensive Care UnitHEGP Hospital, Assistance Publique ‐ Hôpitaux de Paris‐Centre (APHP.Centre)ParisFrance
- Université Paris Cité, INSERM, Innovative Therapies in HaemostasisParisFrance
- Biosurgical Research Lab (Carpentier Foundation)ParisFrance
| | - Alain Cariou
- Faculté de MédecineUniversité Paris CitéParisFrance
- Medical Intensive Care UnitCochin Hospital, Assistance Publique ‐ Hôpitaux de Paris‐Centre (APHP‐Centre)ParisFrance
- Paris‐Cardiovascular‐Research‐CenterINSERM U970ParisFrance
| | - Sarah Benghanem
- Faculté de MédecineUniversité Paris CitéParisFrance
- INSERM UMR 1266, Institut de Psychiatrie et Neurosciences de Paris (IPNP)Université Paris CitéParisFrance
- Medical Intensive Care UnitCochin Hospital, Assistance Publique ‐ Hôpitaux de Paris‐Centre (APHP‐Centre)ParisFrance
| |
Collapse
|
6
|
Candia-Rivera D, Machado C. Reduced Heartbeat-Evoked Responses in a Near-Death Case Report. J Clin Neurol 2023; 19:581-588. [PMID: 37455508 PMCID: PMC10622722 DOI: 10.3988/jcn.2022.0415] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/30/2022] [Accepted: 01/25/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND AND PURPOSE Whether brain-heart communication continues under ventricular fibrillation (VF) remains to be determined. There is weak evidence of physiological changes in cortical activity under VF. Moreover, brain-heart communication has not previously been studied in this condition. We aimed to measure parallel changes in heart-rate variability (HRV), cortical activity, and brain-heart interactions in a patient who experienced VF. METHODS The EEG and EKG signals for the case report were acquired for approximately 20 h. We selected different 1-min-long segments based on the changes in the EKG waveform. We present the changes in heartbeat-evoked responses (HERs), HRV, and EEG power for each selected segment. RESULTS The overall physiological activity appeared to deteriorate as VF proceeded. Brain-heart interactions measured using HERs disappeared, with a few aberrant amplitudes appearing occasionally. The parallel changes in EEG and HRV were not pronounced, suggesting the absence of bidirectional neural control. CONCLUSIONS Our measurements of brain-heart interactions suggested that the evolving VF impairs communication between the central and autonomic nervous systems. These results may support that reduced brain-heart interactions reflect loss of consciousness and deterioration in the overall health state.
Collapse
Affiliation(s)
| | - Calixto Machado
- Department of Clinical Neurophysiology, Institute of Neurology and Neurosurgery, Havana, Cuba
| |
Collapse
|
7
|
Kreitmair KV. On the ethical permissibility of in situ reperfusion in cardiac transplantation after the declaration of circulatory death. JOURNAL OF MEDICAL ETHICS 2023:jme-2022-108819. [PMID: 37541783 DOI: 10.1136/jme-2022-108819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 07/15/2023] [Indexed: 08/06/2023]
Abstract
Transplant surgeons in the USA have begun performing a novel organ procurement protocol in the setting of circulatory death. Unlike traditional donation after circulatory death (DCD) protocols, in situ normothermic perfusion DCD involves reperfusing organs, including the heart, while still contained in the donor body. Some commentators, including the American College of Physicians, have claimed that in situ reperfusion after circulatory death violates the widely accepted Dead Donor Rule (DDR) and conclude that in situ reperfusion is ethically impermissible. In this paper I argue that, in terms of respecting the DDR, in situ reperfusion cardiac transplantation does not differ from traditional DCD cardiac transplantation. I do this by introducing and defending a refined conception of circulatory death, namely vegetative state function permanentism I also argue against the controversial brain occlusion feature of the in situ reperfusion DCD protocol, on the basis that it is ethically unnecessary and generates the problematic appearance of ethical dubiousness.
Collapse
Affiliation(s)
- Karola Veronika Kreitmair
- Medical History and Bioethics, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin, USA
| |
Collapse
|
8
|
Charpier S. Between life and death: the brain twilight zones. Front Neurosci 2023; 17:1156368. [PMID: 37260843 PMCID: PMC10227869 DOI: 10.3389/fnins.2023.1156368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/24/2023] [Indexed: 06/02/2023] Open
Abstract
Clinically, and legally, death is considered a well-defined state of the organism characterized, at least, by a complete and irreversible cessation of brain activities and functions. According to this pragmatic approach, the moment of death is implicitly represented by a discrete event from which all cerebral processes abruptly cease. However, a growing body of experimental and clinical evidence has demonstrated that cardiorespiratory failure, the leading cause of death, causes complex time-dependent changes in neuronal activity that can lead to death but also be reversed with successful resuscitation. This review synthesizes our current knowledge of the succeeding alterations in brain activities that accompany the dying and resuscitation processes. The anoxia-dependent brain defects that usher in a process of potential death successively include: (1) a set of changes in electroencephalographic (EEG) and neuronal activities, (2) a cessation of brain spontaneous electrical activity (isoelectric state), (3) a loss of consciousness whose timing in relation to EEG changes remains unclear, (4) an increase in brain resistivity, caused by neuronal swelling, concomitant with the occurrence of an EEG deviation reflecting the neuronal anoxic insult (the so-called "wave of death," or "terminal spreading depolarization"), followed by, (5) a terminal isoelectric brain state leading to death. However, a timely restoration of brain oxygen supply-or cerebral blood flow-can initiate a mirrored sequence of events: a repolarization of neurons followed by a re-emergence of neuronal, synaptic, and EEG activities from the electrocerebral silence. Accordingly, a recent study has revealed a new death-related brain wave: the "wave of resuscitation," which is a marker of the collective recovery of electrical properties of neurons at the beginning of the brain's reoxygenation phase. The slow process of dying still represents a terra incognita, during which neurons and neural networks evolve in uncertain states that remain to be fully understood. As current event-based models of death have become neurophysiologically inadequate, I propose a new mixed (event-process) model of death and resuscitation. It is based on a detailed description of the different phases that succeed each other in a dying brain, which are generally described separately and without mechanistic linkage, in order to integrate them into a continuum of declining brain activity. The model incorporates cerebral twilight zones (with still unknown neuronal and synaptic processes) punctuated by two characteristic cortical waves providing real-time biomarkers of death- and resuscitation.
Collapse
Affiliation(s)
- Stéphane Charpier
- Sorbonne Université, Institut du Cerveau – Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié-Salpêtriére, Paris, France
- Sorbonne University, UPMC Université Paris, Paris, France
| |
Collapse
|
9
|
Shlobin NA, Aru J, Vicente R, Zemmar A. What happens in the brain when we die? Deciphering the neurophysiology of the final moments in life. Front Aging Neurosci 2023; 15:1143848. [PMID: 37228251 PMCID: PMC10203241 DOI: 10.3389/fnagi.2023.1143848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/12/2023] [Indexed: 05/27/2023] Open
Abstract
When do we die and what happens in the brain when we die? The mystery around these questions has engaged mankind for centuries. Despite the challenges to obtain recordings of the dying brain, recent studies have contributed to better understand the processes occurring during the last moments of life. In this review, we summarize the literature on neurophysiological changes around the time of death. Perhaps the only subjective description of death stems from survivors of near-death experiences (NDEs). Hallmarks of NDEs include memory recall, out-of-body experiences, dreaming, and meditative states. We survey the evidence investigating neurophysiological changes of these experiences in healthy subjects and attempt to incorporate this knowledge into the existing literature investigating the dying brain to provide valuations for the neurophysiological footprint and timeline of death. We aim to identify reasons explaining the variations of data between studies investigating this field and provide suggestions to standardize research and reduce data variability.
Collapse
Affiliation(s)
- Nathan A. Shlobin
- Department of Neurosurgery, Henan Provincial People’s Hospital, Henan University School of Medicine, Zhengzhou, China
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Jaan Aru
- Institute of Computer Science, University of Tartu, Tartu, Estonia
| | - Raul Vicente
- Institute of Computer Science, University of Tartu, Tartu, Estonia
| | - Ajmal Zemmar
- Department of Neurosurgery, Henan Provincial People’s Hospital, Henan University School of Medicine, Zhengzhou, China
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, KY, United States
| |
Collapse
|
10
|
Fernandez Hernandez S, Barlow B, Pertsovskaya V, Maciel CB. Temperature Control After Cardiac Arrest: A Narrative Review. Adv Ther 2023; 40:2097-2115. [PMID: 36964887 PMCID: PMC10129937 DOI: 10.1007/s12325-023-02494-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/08/2023] [Indexed: 03/26/2023]
Abstract
Cardiac arrest (CA) is a critical public health issue affecting more than half a million Americans annually. The main determinant of outcome post-CA is hypoxic-ischemic brain injury (HIBI), and temperature control is currently the only evidence-based, guideline-recommended intervention targeting secondary brain injury. Temperature control is a key component of a post-CA care bundle; however, conflicting evidence challenges its wide implementation across the vastly heterogeneous population of CA survivors. Here, we critically appraise the available literature on temperature control in HIBI, detail how the evidence has been integrated into clinical practice, and highlight the complications associated with its use and the timing of neuroprognostication after CA. Future clinical trials evaluating different temperature targets, rates of rewarming, duration of cooling, and identifying which patient phenotype benefits from different temperature control methods are needed to address these prevailing knowledge gaps.
Collapse
Affiliation(s)
| | - Brooke Barlow
- Department of Pharmacy, Memorial Hermann the Woodlands Medical Center, The Woodlands, TX, USA
| | - Vera Pertsovskaya
- The George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Carolina B Maciel
- Department of Neurology, University of Florida College of Medicine, Gainesville, FL, 32611, USA
- Department of Neurosurgery, University of Florida College of Medicine, Gainesville, FL, 32611, USA
- Comprehensive Epilepsy Center, Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, University of Utah, Salt Lake City, UT, 84132, USA
| |
Collapse
|
11
|
Lalgudi Ganesan S, Hornby L, Weiss M, Dawe K, Lanos C, Wollny K, Dhanani S, Gofton T. Brain-based arterial pulse pressure threshold for death determination: a systematic review. Can J Anaesth 2023; 70:685-698. [PMID: 37138154 PMCID: PMC10202984 DOI: 10.1007/s12630-023-02425-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 05/05/2023] Open
Abstract
PURPOSE There is lack of consensus regarding the minimum arterial pulse pressure required for confirming permanent cessation of circulation for death determination by circulatory criteria in organ donors. We assessed direct and indirect evidence supporting whether one should use an arterial pulse pressure of 0 mm Hg vs more than 0 (5, 10, 20, 40) mm Hg to confirm permanent cessation of circulation. SOURCE We conducted this systematic review as part of a larger project to develop a clinical practice guideline for death determination by circulatory or neurologic criteria. We systematically searched Ovid MEDLINE, Ovid Embase, Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Library, and Web of Science for articles published from inception until August 2021. We included all types of peer-reviewed original research publications related to arterial pulse pressure as monitored by an indwelling arterial pressure transducer around circulatory arrest or determination of death with either direct context-specific (organ donation) or indirect (outside of organ donation context) data. PRINCIPAL FINDINGS A total of 3,289 abstracts were identified and screened for eligibility. Fourteen studies were included; three from personal libraries. Five studies were of sufficient quality for inclusion in the evidence profile for the clinical practice guideline. One study measured cessation of cortical scalp electroencephalogram (EEG) activity after withdrawal of life-sustaining measures and showed that EEG activity fell below 2 μV when the pulse pressure reached 8 mm Hg. This indirect evidence suggests there is a possibility of persistent cerebral activity at arterial pulse pressures > 5 mm Hg. CONCLUSION Indirect evidence suggests that clinicians may incorrectly diagnose death by circulatory criteria if they apply any arterial pulse pressure threshold of greater than 5 mm Hg. Moreover, there is insufficient evidence to determine that any pulse pressure threshold greater than 0 and less than 5 can safely determine circulatory death. STUDY REGISTRATION PROSPERO (CRD42021275763); first submitted 28 August 2021.
Collapse
Affiliation(s)
- Saptharishi Lalgudi Ganesan
- Department of Paediatrics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
- Paediatric Critical Care Medicine, Children's Hospital - London Health Sciences Center, London, ON, Canada.
| | | | - Matthew Weiss
- Transplant Québec, Montreal, QC, Canada
- CHU de Québec, Université Laval Research Centre, Population Health and Optimal Health Practices Research Unit, Trauma-Emergency-Critical Care Medicine, Université Laval, Quebec City, QC, Canada
| | - Kirk Dawe
- Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
- Critical Care Program, Eastern Health, St. John's, NL, Canada
| | - Chelsea Lanos
- County of Renfrew Paramedic Service, Pembroke, ON, Canada
| | - Krista Wollny
- Faculty of Nursing, University of Calgary, Calgary, AB, Canada
| | - Sonny Dhanani
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
| | - Teneille Gofton
- Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| |
Collapse
|
12
|
Klowak JA, Nguyen ALV, Malik A, Hornby L, Doig CJ, Kawchuk J, Sekhon M, Dhanani S. Diagnostic test accuracy for cessation of circulation during death determination: a systematic review. Can J Anaesth 2023; 70:671-684. [PMID: 37138156 PMCID: PMC10202983 DOI: 10.1007/s12630-023-02424-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 12/16/2022] [Accepted: 12/16/2022] [Indexed: 05/05/2023] Open
Abstract
PURPOSE To synthesize the available evidence comparing noninvasive methods of measuring the cessation of circulation in patients who are potential organ donors undergoing death determination by circulatory criteria (DCC) with the current accepted standard of invasive arterial blood pressure (IAP) monitoring. SOURCE We searched (from inception until 27 April 2021) MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We screened citations and manuscripts independently and in duplicate for eligible studies that compared noninvasive methodologies assessing circulation in patients who were monitored around a period of cessation of circulation. We performed risk of bias assessment, data abstraction, and quality assessment using Grading of Recommendations, Assessment, Development, and Evaluation in duplicate and independently. We presented findings narratively. PRINCIPAL FINDINGS We included 21 eligible studies (N = 1,177 patients). Meta-analysis was not possible because of study heterogeneity. We identified low quality evidence from four indirect studies (n = 89) showing pulse palpation is less sensitive and specific than IAP (reported sensitivity range, 0.76-0.90; specificity, 0.41-0.79). Isoelectric electrocardiogram (ECG) had excellent specificity for death (two studies; 0% [0/510]), but likely increases the average time to death determination (moderate quality evidence). We are uncertain whether point-of-care ultrasound (POCUS) pulse check, cerebral near-infrared spectroscopy (NIRS), or POCUS cardiac motion assessment are accurate tests for the determination of circulatory cessation (very low-quality evidence). CONCLUSION There is insufficient evidence that ECG, POCUS pulse check, cerebral NIRS, or POCUS cardiac motion assessment are superior or equivalent to IAP for DCC in the setting of organ donation. Isoelectric ECG is specific but can increase the time needed to determine death. Point-of-care ultrasound techniques are emerging therapies with promising initial data but are limited by indirectness and imprecision. STUDY REGISTRATION PROSPERO (CRD42021258936); first submitted 16 June 2021.
Collapse
Affiliation(s)
- Jennifer A Klowak
- Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital of Eastern Ontario (CHEO), 401 Smyth Rd, Ottawa, ON, K1H 8L1, Canada
| | | | - Abdullah Malik
- Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | | | - Christopher J Doig
- Department of Critical Care Medicine, Cumming School of Medicine, Calgary, AB, Canada
| | - Joann Kawchuk
- Department of Anesthesia, University of Saskatchewan, Saskatoon, SK, Canada
| | - Mypinder Sekhon
- Division of Critical Care Medicine, Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Sonny Dhanani
- Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital of Eastern Ontario (CHEO), 401 Smyth Rd, Ottawa, ON, K1H 8L1, Canada.
| |
Collapse
|
13
|
Gofton TE, Norton L, Laforge G, Gibson R, Debicki D, Althenayan E, Scales N, Beinum AV, Hornby L, Shemie S, Dhanani S, Slessarev M. Cerebral cortical activity after withdrawal of life-sustaining measures in critically ill patients. Am J Transplant 2022; 22:3120-3129. [PMID: 35822321 DOI: 10.1111/ajt.17146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/09/2022] [Accepted: 07/04/2022] [Indexed: 01/25/2023]
Abstract
Establishing when cerebral cortical activity stops relative to circulatory arrest during the dying process will enhance trust in donation after circulatory determination of death. We used continuous electroencephalography and arterial blood pressure monitoring prior to withdrawal of life sustaining measures and for 30 min following circulatory arrest to explore the temporal relationship between cessation of cerebral cortical activity and circulatory arrest. Qualitative and quantitative EEG analyses were completed. Among 140 screened patients, 52 were eligible, 15 were enrolled, 11 completed the full study, and 8 (3 female, median age 68 years) were included in the analysis. Across participants, EEG activity stopped at a median of 78 (Q1 = -387, Q3 = 111) seconds before circulatory arrest. Following withdrawal of life sustaining measures there was a progressive reduction in electroencephalographic amplitude (p = .002), spectral power (p = .008), and coherence (p = .003). Prospective recording of cerebral cortical activity in imminently dying patients is feasible. Our results from this small cohort suggest that cerebral cortical activity does not persist after circulatory arrest. Confirmation of these findings in a larger multicenter study are needed to help promote stakeholder trust in donation after circulatory determination of death.
Collapse
Affiliation(s)
- Teneille E Gofton
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Western Institute for Neuroscience, Western University, London, Ontario, Canada
| | - Loretta Norton
- Department of Psychology, King's University College at Western University, London, Ontario, Canada
| | - Geoffrey Laforge
- Western Institute for Neuroscience, Western University, London, Ontario, Canada
| | - Raechelle Gibson
- Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada
| | - Derek Debicki
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Western Institute for Neuroscience, Western University, London, Ontario, Canada
| | - Eyad Althenayan
- Department of Medicine/Critical Care, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Nathan Scales
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | | | - Laura Hornby
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Canadian Blood Services, Ottawa, Ontario, Canada
| | - Sam Shemie
- Canadian Blood Services, Ottawa, Ontario, Canada.,Pediatric Intensive Care, McGill University Health Centre & Research Institute, Montreal, Quebec, Canada
| | - Sonny Dhanani
- Pediatric Critical Care, Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Marat Slessarev
- Department of Psychology, King's University College at Western University, London, Ontario, Canada.,Department of Medicine/Critical Care, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| |
Collapse
|
14
|
Greyson B, van Lommel P, Fenwick P. Commentary: Enhanced Interplay of Neuronal Coherence and Coupling in the Dying Human Brain. Front Aging Neurosci 2022; 14:899491. [PMID: 35663570 PMCID: PMC9157615 DOI: 10.3389/fnagi.2022.899491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 04/04/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Bruce Greyson
- Department of Psychiatry & Neurobehavioral Sciences, University of Virginia School of Medicine, Charlottesville, VA, United States
- *Correspondence: Bruce Greyson
| | - Pim van Lommel
- Department of Cardiology, Rijnstate Hospital, Arnhem, Netherlands
| | - Peter Fenwick
- Department of Psychiatry, Emeritus Maudsley Hospital and Emeritus Kings College Institute of Psychiatry, London, England
| |
Collapse
|