Criteria for brain death in Denmark.

In 1990, the Danish brain death legislation was adopted by the Danish Parliament. Each year, around 100 patients in Denmark fulfil criteria for brain death/death by neurological criteria (BD/DNC). In this review of current Danish criteria including the indication for ancillary investigation, which in Denmark is digital subtraction angiography (DSA), we conclude that the time has come to revise the national BD/DNC criteria. We propose that visible anoxic-ischaemic encephalopathy on brain CT after cardiac arrest does not require evaluation by ancillary testing, and that CT-angiography can be used instead of DSA.

The Unified Brain-Based Determination of Death Conceptually Justifies Death Determination in DCDD and NRP Protocols.

Organ donation after the circulatory determination of death requires the permanent cessation of circulation while organ donation after the brain determination of death requires the irreversible cessation of brain functions. The unified brain-based determination of death connects the brain and circulatory death criteria for circulatory death determination in organ donation as follows: permanent cessation of systemic circulation causes permanent cessation of brain circulation which causes permanent cessation of brain perfusion which causes permanent cessation of brain function. The relevant circulation that must cease in circulatory death determination is that to the brain. Eliminating brain circulation from the donor ECMO organ perfusion circuit in thoracoabdominal NRP protocols satisfies the unified brain-based determination of death but only if the complete cessation of brain circulation can be proved. Despite its medical and physiologic rationale, the unified brain-based determination of death remains inconsistent with the Uniform Determination of Death Act.

Orbital doppler ultrasound as an ancillary test for diagnosing brain death: A prospective, single blind comparative study.

OBJECTIVE: Transcranial Doppler ultrasound (TDUS), computed tomography angiography (CTA), and transcranial Doppler ultrasound to detect cerebral blood flow are among the adjunctive tests in diagnosing brain death. This study aimed to investigate the effectiveness of orbital doppler ultrasound (ODUS). METHODS: This prospective, single-blind study included 66 patients for whom brain death was to be diagnosed. Primary outcome measures were ODUS measurements, Ophthalmic artery peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive indices (RI) measurements recorded during the brain death determination process. Secondary outcome measures were computed tomography angio (CTA), transcranial Doppler ultrasound (TDUS), and demographic data. RESULTS: This study investigating the effectiveness of ODUS in diagnosing brain death provided diagnostic success with 100% sensitivity and 93% specificity compared to CT angiography. It was noted that anatomical variations may limit its use. CONCLUSION: ODUS was found to have high sensitivity and specificity in the diagnosis of clinical brain death. It may assist in early prognostic assessment and shorten patient follow-up and diagnostic processes.

The conceptual injustice of the brain death standard.

Family disputes over the diagnosis of brain death have caused much controversy in the bioethics literature over the conceptual validity of the brain death standard. Given the tenuous status of brain death as death, it is pragmatically fruitful to reframe intractable debates about the metaphysical nature of brain death as metalinguistic disputes about its conceptual deployment. This new framework leaves the metaphysical debate open and brings into focus the social functions that are served by deploying the concept of brain death. In doing so, it highlights the epistemic injustice of medicolegal authorities that force people to uniformly accept brain death as a diagnosis of death based on normative considerations of institutional interests, such as saving hospital resources and organ supplies, rather than empirical evidence of brain death as death, which is insufficient at best and nonexistent at worst. In light of this injustice, I propose the rejection of the uniform standard of brain death in favor of a choice-based system that respects families' individualized views of death.

An Update on Brain Death/Death by Neurologic Criteria since the World Brain Death Project.

The World Brain Death Project (WBDP) is a 2020 international consensus statement that provides historical background and recommendations on brain death/death by neurologic criteria (BD/DNC) determination. It addresses 13 topics including: (1) worldwide variance in BD/DNC, (2) the science of BD/DNC, (3) the concept of BD/DNC, (4) minimum clinical criteria for BD/DNC determination, (5) beyond minimum clinical BD/DNC determination, (6) pediatric and neonatal BD/DNC determination, (7) BD/DNC determination in patients on ECMO, (8) BD/DNC determination after treatment with targeted temperature management, (9) BD/DNC documentation, (10) qualification for and education on BD/DNC determination, (11) somatic support after BD/DNC for organ donation and other special circumstances, (12) religion and BD/DNC: managing requests to forego a BD/DNC evaluation or continue somatic support after BD/DNC, and (13) BD/DNC and the law. This review summarizes the WBDP content on each of these topics and highlights relevant work published from 2020 to 2023, including both the 192 citing publications and other publications on BD/DNC. Finally, it reviews questions for future research related to BD/DNC and emphasizes the need for national efforts to ensure the minimum standards for BD/DNC determination described in the WBDP are included in national BD/DNC guidelines and due consideration is given to the recommendations about social and legal aspects of BD/DNC determination.

Consciousness and the Dying Brain.

The near-death experience has been reported since antiquity and is often characterized by the perception of light, interactions with other entities, and life recall. Near-death experiences can occur in a variety of situations, but they have been studied systematically after in-hospital cardiac arrest, with an incidence of 10 to 20%. Long attributed to metaphysical or supernatural causes, there have been recent advances in understanding the neurophysiologic basis of this unique category of conscious experience. This article reviews the epidemiology and neurobiology of near-death experiences, with a focus on clinical and laboratory evidence for a surge of neurophysiologic gamma oscillations and cortical connectivity after cardiac and respiratory arrest.

A Biophilosophical Approach to the Determination of Brain Death.

Technical and clinical developments have raised challenging questions about the concept and practice of brain death, culminating in recent calls for revision of the Uniform Determination of Death Act (UDDA), which established a whole brain standard for neurologic death. Proposed changes range from abandoning the concept of brain death altogether to suggesting that current clinical practice simply should be codified as the legal standard for determining death by neurologic criteria (even while acknowledging that significant functions of the whole brain might persist). We propose a middle ground, clarifying why whole brain death is a conceptually sound standard for declaring death, and offering procedural suggestions for increasing certainty that this standard has been met. Our approach recognizes that whole brain death is a functional, not merely anatomic, determination, and incorporates an understanding of the difficulties inherent in making empirical judgments in medicine. We conclude that whole brain death is the most defensible standard for determining neurologic death-philosophically, biologically, and socially-and ought to be maintained.

Pulmonary strain and end-expiratory lung volume during apnea test: a comparative analysis using electrical impedance tomography.

The apnea test, employed for brain death assessment, aims to demonstrate the absence of respiratory drive due to hypercapnia. The tracheal oxygen insufflation apnea test mode (I-AT) involves disconnecting the patient from invasive mechanical ventilation (iMV) for approximately 8 minutes while maintaining oxygenation. This test supports the diagnosis of brain death based on a specified increase in PaCO2. Common complications include hypoxemia and hemodynamic instability, and lung collapse-induced reduction in end-expiratory lung volume (EELV). In our case series utilizing electrical impedance tomography (EIT), we observed that continuous positive airway pressure during the apnea test (CPAP-AT) effectively mitigated lung collapse. This resulted in improved pulmonary strain compared to the disconnection of iMV. These findings suggest the potential benefits of routine CPAP-AT, particularly for potential lung donors, emphasizing the relevance of our study in providing quantitative insights into EELV loss and its association with pulmonary strain and potential lung injury.

La prueba de apnea es una técnica diagnóstica ampliamente utilizada para la evaluación de la muerte cerebral, con el objetivo de demostrar la ausencia de impulso respiratorio debido a la hipercapnia. La variante de la prueba de apnea con insuflación de oxígeno traqueal (I-AT) implica desconectar al paciente de la ventilación mecánica invasiva (iVM) durante aproximadamente 8 minutos, manteniendo la oxigenación mediante un catéter de insuflación. Esta prueba respalda el diagnóstico de muerte cerebral cuando se determina un aumento de la PaCO 2 superior a 20 mmHg en comparación con el valor inicial o un nivel de PaCO 2 superior a 60 mmHg al final de la prueba. En nuestra serie de casos, la implementación de la tomografía de impedancia eléctrica (EIT) reveló que la prueba de apnea con presión positiva continua (CPAPAT) mitiga eficazmente el colapso pulmonar. Este enfoque resulta en una mejora en la tensión pulmonar en comparación con la desconexión de iMV, demostrando su relevancia en el contexto de potenciales donantes de pulmones.

Organismal Superposition Problem and Nihilist Challenge in the Definition of Death.

According to the mainstream bioethical stance, death constitutes the termination of an organism. This essay argues that such an understanding of death is inappropriate in the usual context of determining death, since it also has a social bearing. There are two reasons to justify this argument. First, the mainstream bioethical definition generates an organismal superposition challenge, according to which a given patient in a single physiological state might be both alive and dead, like Schrödinger's cat. Therefore, there is no clear answer as to whether organ retrieval from a brain-dead patient is an act of killing or not. Second, when combined with the dead donor rule, the mainstream position in the definition of death might lead to ethically unacceptable verdicts, since there is a discrepancy between terminating an organism and depriving someone of moral status.