Guidelines for the determination of brain death in infants and children: An update of the 1987 Task Force recommendations*:

Diagnostic Sensitivity of the Revised Venous System in Brain Death in Children

BACKGROUND/OBJECTIVES

While ancillary tests for brain death diagnosis are not routinely recommended in guidelines, they may be necessary in specific clinical scenarios. Computed tomography angiography (CTA) is particularly advantageous in pediatric patients due to its noninvasive nature, accessibility, and rapid provision of anatomical information. This study aims to assess the diagnostic sensitivity of a revised venous system (ICV-SPV) utilizing a 4-point scoring system in children clinically diagnosed with brain death.

MATERIALS AND METHODS

A total of 43 pediatric patients clinically diagnosed with brain death who underwent CTA were retrospectively analyzed. Imaging was performed using a standardized brain death protocol. Three distinct 4-point scoring systems (A20-V60, A60-V60, ICV-SPV) were utilized to assess vessel opacification in different imaging phases. To evaluate age-dependent sensitivity, patients were categorized into three age groups: 26 days-1 year, 2-6 years, and 6-18 years. The sensitivity of each 4-point scoring system in diagnosing brain death was calculated for all age groups.

RESULTS

The revised venous scoring system (ICV-SPV) demonstrated the highest overall sensitivity in confirming brain death across all age groups, significantly outperforming the reference 4-point scoring systems. Furthermore, the ICV-SPV system exhibited the greatest sensitivity in patients with cranial defects.

CONCLUSIONS

The revised 4-point venous CTA scoring system, which relies on the absence of ICV and SPV opacification, is a reliable tool for confirming cerebral circulatory arrest in pediatric patients with clinical brain death.

Pediatric Organ Donation, Transplantation, and Updated Brain Death Criteria: An Overview for Pediatricians

Pediatricians follow patients longitudinally and hold a unique position to address multiple issues, medical and psychosocial, that affect organ donation and transplantation. They are wellpositioned to provide anticipatory guidance during well-child visits and during care for children with end-stage organ failure and can either assist these patients with ongoing medical management or refer these patients for organ transplantation assessment. A pediatrician's trusted relationship with families and patients allows for guidance on medical and ethical issues surrounding brain death, organ donation, and transplantation. A clear understanding of end-of-life care, criteria for the determination of neurologic and circulatory death, the process of organ donation, and posttransplant management is vital for pediatricians. The American Academy of Pediatrics (AAP) recognizes and supports the important role of the pediatrician in the global need for organ donation and transplantation awareness. This article, as well as the updated AAP policy on Pediatric Organ Donation and Transplantation and the revised American Academy of Neurology consensus statement for the determination of neurologic death for children and adults, provides guidance to help shape public opinion, public policy, and care of the pediatric organ donor and the transplant recipient.

Nuclear Medicine Cerebral Perfusion Studies as an Ancillary Test to Support Evaluation of Brain Death/Death by Neurologic Criteria: Single-Center Experience in Infants, 2005-2022

OBJECTIVE

To describe the use of nuclear medicine cerebral perfusion studies as an ancillary test for brain death/death by neurologic criteria (BD/DNC) in infants aged under 1 year.

DESIGN

Retrospective case series.

SETTING

Single-center, quaternary, academic children's hospital in the United States.

PATIENTS

Patients younger than 1 year of age whose evaluation for BD/DNC included a nuclear medicine cerebral perfusion study as an ancillary test, 2005-2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Ten infants were identified from local databases. Mechanisms of brain injury included hypoxic-ischemic injury (8/10), traumatic brain injury (1/10), and intracranial hemorrhage (1/10). Testable components of the first BD/DNC examination were consistent with BD/DNC in all patients. Apnea testing was consistent with BD/DNC in 5 of 10 patients and deferred or terminated prematurely in 5 of 10 patients. All patients underwent ancillary testing with a nuclear medicine scan to assess cerebral perfusion using 99mTc-ethyl cysteinate dimer (99mTc-ECD). Indications were inability to complete the apnea test (5/10), presence of a confounder to the clinical examination (3/10), and clinician discretion (2/10). Nine studies were consistent with BD/DNC. The patient whose ancillary test was inconsistent with BD/DNC had their examination limited by the inability to assess the pupillary reflex and subsequently underwent withdrawal of life-sustaining technology.

CONCLUSIONS

Radionuclide cerebral perfusion studies using 99mTc-ECD were used in our setting to support the determination of BD/DNC in infants aged younger than 1 year of age.

Management of Potential Organ Donor: Indian Society of Critical Care Medicine-Position Statement

This position statement is documented based on the input from all contributing coauthors from the Indian Society of Critical Care Medicine (ISCCM), following a comprehensive literature review and summary of current scientific evidence. Its objective is to provide the standard perspective for the management of potential organ/tissue donors after brain death (BD) in adults only, regardless of the availability of technology. This document should only be used for guidance only and is not a substitute for proper clinical decision making in particular circumstances of any case. Endorsement by the ISCCM does not imply that the statements given in the document are applicable in all or in a particular case; however, they may provide guidance for the users thus facilitating maximum organ availability from brain-dead patients. Thus, the care of potential brain-dead organ donors is "caring for multiple recipients."

How to cite this article

Zirpe K, Pandit R, Gurav S, Mani RK, Prabhakar H, Clerk A, et al. Management of Potential Organ Donor: Indian Society of Critical Care Medicine-Position Statement. Indian J Crit Care Med 2024;28(S2):S249-278.

Role of Clinical and Multimodality Neuroimaging in the Evaluation of Brain Death/Death by Neurologic Criteria and Recent Highlights from 2023 Updated Guidelines

Purpose of Review: This review aims to provide a comprehensive overview of the diagnosis of brain death/death by neurologic criteria (BD/DNC) by emphasizing the clinical criteria established by the American Academy of Neurology (AAN) in light of their updated guidelines released in 2023. In this review, we will focus on the current implementation of ancillary tests including the catheter cerebral angiogram, nuclear scintigraphy, and transcranial Doppler, which provide support in diagnoses when clinical examination and apnea tests are inconclusive. Finally, we will also provide examples to discuss the implementation of certain imaging studies in the context of diagnosing BD/DNC. Recent Findings: Recent developments in the field of neurology have emphasized the importance of clinical criteria for diagnosing BD/DNC, with the AAN providing clear updated guidelines that include coma, apnea, and the absence of brainstem reflexes. Current ancillary tests, including the catheter cerebral angiogram, nuclear scintigraphy, and transcranial Doppler play a crucial role in confirming BD/DNC when the clinical assessment is limited. The role of commonly used imaging studies including computed tomography and magnetic resonance angiographies of the brain as well as CT/MR perfusion studies will also be discussed in the context of these new guidelines. Summary: BD/DNC represents the permanent cessation of brain functions, including the brainstem. This review article provides the historical context, clinical criteria, and pathophysiology that goes into making this diagnosis. Additionally, it explores the various ancillary tests and selected imaging studies that are currently used to diagnose BD/DNC under the newly updated AAN guidelines. Understanding the evolution of how to effectively use these diagnostic tools is crucial for healthcare professionals who encounter these BD/DNC cases in their practice.

New developments in guidelines for brain death/death by neurological criteria

The declaration of brain death (BD), or death by neurological criteria (DNC), is medically and legally accepted throughout much of the world. However, inconsistencies in national and international policies have prompted efforts to harmonize practice and central concepts, both between and within countries. The World Brain Death Project was published in 2020, followed by notable revisions to the Canadian and US guidelines in 2023. The mission of these initiatives was to ensure accurate and conservative determination of BD/DNC, as false-positive determinations could have major negative implications for the medical field and the public's trust in our ability to accurately declare death. In this Review, we review the changes that were introduced in the 2023 US BD/DNC guidelines and consider how these guidelines compare with those formulated in Canada and elsewhere in the world. We address controversies in BD/DNC determination, including neuroendocrine function, consent and accommodation of objections, summarize the legal status of BD/DNC internationally and discuss areas for further BD/DNC research.

Death and Ultrasound Evidence of the Akinetic Heart in Pediatric Cardiac Arrest

Point-of-care ultrasound (POCUS) is an expanding noninvasive diagnostic modality used for the management of patients in multiple intensive care and pediatric specialties. POCUS is used to assess cardiac activity and pathology, pulmonary disease, intravascular volume status, intra-abdominal processes, procedural guidance including vascular access, lumbar puncture, thoracentesis, paracentesis, and pericardiocentesis. POCUS has also been used to determine anterograde flow following circulatory arrest when organ donation after circulatory death is being considered. Published guidelines exist from multiple medical societies including the recent guidelines for the use of POCUS in neonatology for diagnostic and procedural purposes.

Update on Pediatric Nuclear Medicine in Acute Care

Various radiopharmaceuticals are available for imaging pediatric patients in the acute care setting. This article focuses on the common applications used on a pediatric patient in acute care. To confirm the clinical diagnosis of brain death, brain scintigraphy is considered accurate and has been favorably compared with other methods of detecting the presence or absence of cerebral blood flow. Ventilation-perfusion lung scans are easy and safe to perform with less radiation exposure than computed tomography pulmonary angiography and remain an appropriate procedure to perform on children with suspected pulmonary embolism as a first imaging test in a hemodynamically stable patient with no history of lung disease and normal chest radiograph. 99mTc-pertechnetate scintigraphy (Meckel's scan) is the best noninvasive procedure to establish the diagnosis of ectopic gastric mucosa in Meckel's diverticulum. 99mTcred blood cell scintigraphy generally is useful for assessing lower GI bleeding in patients from any cause. Hepatobiliary scintigraphy is the most accurate diagnostic imaging modality for acute cholecystitis. 99mTc-dimercaptosuccinic acid scintigraphy is the simplest, and the most reliable and sensitive method for the early diagnosis of focal or diffuse functional cortical damage. 99mTcmercaptoacetyltriglycine scintigraphy is used to evaluate for early and late complications of renal transplantation. Bone scintigraphy is a sensitive and noninvasive technique for diagnosis of bone disorders such as osteomyelitis and fracture. 18F-fluorodeoxyglucose-positron emission tomography could be valuable in the evaluation of fever of unknown origin in pediatric patients, with better sensitivity and significantly less radiation exposure than a gallium scan. Moving forward, further refinement of pediatric radiopharmaceutical administered activities, including dose reduction, greater radiopharmaceutical applications, and updated consensus guidelines is warranted, with the use of radionuclide imaging likely to increase.

Brain Death Confirmation by 18F-FDG PET/CT: A Case Series

OBJECTIVES

Brain death is a state of irreversible loss of brain function in the cortex and brainstem. Diagnosis of brain death is established by clinical assessments of cranial nerves and apnea tests. Different conditions can mimic brain death. In addition, confirmatory tests may be falsely positive in some cases. In this study, we aimed to evaluate the role of positron emission tomography-computed tomography scan with 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG-PET/CT) as an ancillary test in diagnosing brain death.

MATERIALS AND METHODS

We analyzed 6 potential brain death donors for the confirmatory diagnosis of brain death using FDG-PET/CT. All 6 donors were brain dead by clinical criteria. All patients had electroencephalogram and brain computed tomography. Other than FDG-PET/CT, transcranial Doppler was performed in 1 patient, with other patients having no confirmatory ancillary imaging tests. Patients had nothing by mouth for 6 hours before imaging. Patients were supine in a semi-dark, noiseless, and odorless room with closed eyes. After 60 minutes of uptake,the brain PET/CT scan was performed with sequential time-of-flight-PET/CT (Discovery 690 PET/CT with 64 slices, GE Healthcare). The PET scan consisted of LYSO (Lu1.8Y0.2 SiO5) crystals with dimensions of 4.2 × 6.3 × 25 mm3. Three-dimension images were with scan duration of 10 minutes.

RESULTS

The PET scan confirmed brain death in 5 of the 6 cases. However, we ruled out brain death using PET/CT in a 3-year-old child, although all clinical tests confirmed brain death.

CONCLUSIONS

A PET scan illustrates a hollow skull phenomenon suggestive of brain death. It can be a powerful diagnostic tool to assess brain death.

Brain Death: Ethical and Legal Challenges

Although the fundamental principle behind the Uniform Determination of Death Act (UDDA), the equivalence of death by circulatory-respiratory and neurologic criteria, is accepted throughout the United States and much of the world, some families object to brain death/death by neurologic criteria. Clinicians struggle to address these objections. Some objections have been brought to court, particularly in the United States, leading to inconsistent outcomes and discussion about potential modifications to the UDDA to minimize ethical and legal controversies related to the determination of brain death/death by neurologic criteria.

Adverse Events During Apnea Testing for the Determination of Death by Neurologic Criteria: A Single-Center, Retrospective Pediatric Cohort

OBJECTIVES

To report the prevalence of adverse events in children undergoing apnea testing as part of the determination of death by neurologic criteria (DNC).

DESIGN

Single-center, retrospective study.

SETTING

Academic children's hospital that is a Level I Trauma Center.

PATIENTS

All children who underwent apnea testing to determine DNC from July 2013 to June 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We abstracted the medical history, blood gases, ventilator settings, blood pressures, vasoactive infusions, intracranial pressures, chest radiographs, and echocardiograms for all apnea tests as well as any ancillary test. Adverse events were defined as hypotension, hypoxia, pneumothorax, arrhythmia, intracranial hypertension, and cardiac arrest. Fifty-eight patients had 105 apnea tests. Adverse events occurred in 21 of 105 apnea tests (20%), the most common being hypotension (15/105 [14%]) and hypoxia (4/105 [4%]). Five of 21 apnea tests (24%) with adverse events were terminated prematurely (three for hypoxia, one for hypotension, and one for both hypoxia and hypotension) but the patients did not require persistent escalation in care. In the other 16 of 21 apnea tests (76%) with adverse events, clinical changes were transient and managed by titrating vasoactive infusions or completing the apnea test.

CONCLUSIONS

In our center, 20% of all apnea tests were associated with adverse events. Only 5% of all apnea tests required premature termination and the remaining 15% were completed and the adverse events resolved with medical care.

Ancillary investigations for death determination in infants and children: a systematic review and meta-analysis

PURPOSE

We performed a systematic review and meta-analysis to determine the diagnostic test accuracy of ancillary investigations for declaration of death by neurologic criteria (DNC) in infants and children.

SOURCE

We searched MEDLINE, EMBASE, Web of Science, and Cochrane databases from their inception to June 2021 for relevant randomized controlled trials, observational studies, and abstracts published in the last three years. We identified relevant studies using Preferred Reporting Items for Systematic Reviews and Meta-Analysis methodology and a two-stage review. We assessed the risk of bias using the QUADAS-2 tool, and applied Grading of Recommendations Assessment, Development, and Evaluation methodology to determine the certainty of evidence. A fixed-effects model was used to meta-analyze pooled sensitivity and specificity data for each ancillary investigation with at least two studies.

PRINCIPAL FINDINGS

Thirty-nine eligible manuscripts assessing 18 unique ancillary investigations (n = 866) were identified. The sensitivity and specificity ranged from 0.00 to 1.00 and 0.50 to 1.00, respectively. The quality of evidence was low to very low for all ancillary investigations, with the exception of radionuclide dynamic flow studies for which it was graded as moderate. Radionuclide scintigraphy using the lipophilic radiopharmaceutical 99mTc-hexamethylpropyleneamine oxime (HMPAO) with or without tomographic imaging were the most accurate ancillary investigations with a combined sensitivity of 0.99 (95% highest density interval [HDI], 0.89 to 1.00) and specificity of 0.97 (95% HDI, 0.65 to 1.00).

CONCLUSION

The ancillary investigation for DNC in infants and children with the greatest accuracy appears to be radionuclide scintigraphy using HMPAO with or without tomographic imaging; however, the certainty of the evidence is low. Nonimaging modalities performed at the bedside require further investigation.

STUDY REGISTRATION

PROSPERO (CRD42021278788); registered 16 October 2021.

Brain death in children: is computed tomography angiography reliable as an ancillary test?

BACKGROUND

The diagnosis of brain death is primarily clinical. Sometimes ancillary tests are needed.

OBJECTIVE

This study compared sensitivity and interobserver agreement of the 10-, 7- and 4-point CT angiography scoring systems for the diagnosis of brain death in children.

MATERIALS AND METHODS

CT angiography examinations of 50 pediatric patients with a clinical diagnosis of brain death were evaluated according to 10-, 7- and 4-point scoring systems. Images were evaluated by two radiologists who considered the vessel opacification first in the arterial phase (A₀-V₅₀) and then in the venous phase (A₀-V₅₀). We evaluated interobserver agreement for the assessment of vessel opacification and diagnosis of brain death. We compared the differences among brain death diagnoses between children with craniotomy-craniectomy defects, open fontanelles and preserved bone integrity. We subdivided children into two groups according to age: ≤ 2 years and > 2 years. We calculated sensitivities according to age groups.

RESULTS

Using the clinical exam as the reference standard, we found sensitivities for 10-, 7- and 4-point scoring systems to be 70%, 88% and 92% in the A₀-V₅₀ method and 40%, 82% and 82% in the A₅₀-V₅₀ method, respectively. Percentage agreement between readers was 78% for the 7-point scale using the A₀-V₅₀ method and more than 90% for other scoring systems for both the A₀-V₅₀ method and the A₅₀-V₅₀ method. The sensitivity was much lower in children with open anterior fontanelles compared to the groups with preserved bone integrity and with a craniotomy-craniectomy defect.

CONCLUSION

Just as in adult age groups, in children the 4-point scale appears to be more sensitive than the 10- and 7-point scales for CT angiography-based assessment of brain death. Because the scoring systems have similar sensitivities, they could be used as ancillary tests in pediatric cases.

Use of duplex echoencephalography to evaluate brain death in children: A novel approach to the diagnosis

BACKGROUND AND PURPOSE

Brain death is defined as the irreversible cessation of brain function with a known etiology. This study aims to establish the value of duplex echoencephalography (DEG) in children fulfilling clinical brain death diagnostic criteria.

METHODS

DEG must show intracranial brain structures. Power Doppler is used to assess venous flow when feasible. Color Doppler patterns in all major arteries are assessed. Spectral analysis of arterial flow is divided into four grades: grade 1: inverted flow during entire diastole with time average peak velocity (TAPV) less or equal to zero; grade 2: disappearance of the inverted diastolic flow at the end of diastole; grade 3: oscillating pattern in early diastole; and grade 4: no diastolic flow with systolic blip. To fulfill diagnosis of brain death, brain perfusion must be lost for 30 minutes.

RESULTS

DEG is performed in 41 pediatric patients. In infants, loss of venous flow occurs regardless of the etiology. Grade 1 is the most common arterial color flow pattern and TAPV is always below zero. A pulsatile color flow is associated with three other types of flow patterns (grades 2-4). TAPV is not calculated, when there is loss of diastolic flow. Diagnosis of brain death is validated using nuclear brain scan in 4 patients. Two have a grade 1 flow pattern, while the other two have a grade 4 flow pattern.

CONCLUSIONS

In children, DEG following a strict protocol can be used to confirm diagnosis of brain death in the appropriate clinical setting.

Brain contrast-enhanced ultrasonography and elastography in infants

Advanced ultrasound techniques, including brain contrast-enhanced ultrasonography and elastography, are increasingly being explored to better understand infant brain health. While conventional brain ultrasonography provides a convenient, noninvasive means of assessing major intracranial pathologies, its value in revealing functional and physiologic insights into the brain lags behind advanced imaging techniques such as magnetic resonance imaging. In this regard, contrast-enhanced ultrasonography provides highly precise functional information on macrovascular and microvascular perfusion, while brain elastography offers information on brain stiffness that may be associated with relevant physiological factors of diagnostic, therapeutic, and/or prognostic utility. This review details the technical background, current understanding and utility, and future directions of these two emerging advanced ultrasound techniques for neonatal brain applications.

PICU in the MICU: How Adult ICUs Can Support Pediatric Care in Public Health Emergencies

Initial waves of the COVID-19 pandemic have largely spared children. With the advent of vaccination in many older age groups and the spread of the highly contagious Delta variant, however, children now represent a growing percentage of COVID-19 cases. PICU capacity is far less than that of adult ICUs. Adult ICUs may need to support pediatric care, much as PICUs provided adult care earlier in the pandemic. Critically ill children selected for care in adult settings should be at least 12 years of age and ideally have conditions common in children and adults alike (eg, community-acquired sepsis, trauma). Children with complex, pediatric-specific disorders are best served in PICUs and are not recommended for transfer. The goal of such transfers is to maintain critical capacity for those children in greatest need of the PICU's unique abilities, therefore preserving systems of care for all children.

Evaluation of Pediatric Brain Death and Organ Donation: 10-Year Experience in a Pediatric Intensive Care Unit in Turkey

OBJECTIVE

We aimed to investigate the rate of brain death (BD) determinations and organ donations (OD) in our tertiary pediatric intensive care unit (PICU), and to report the data on the demographic pattern and supplementary descriptive data on BD declarations.

METHODS

The study was designed as a retrospective, single-center, descriptive cohort study. We evaluated all children who were determined to meet the criteria for BD in our tertiary PICU between January 2011 and December 2020.

RESULTS

During study period, BD was identified in 24 patients among 225 total deaths (10.7%). Their median age was 85 months (8-214) and the male-to-female ratio was 1 : 1. The most common diagnosis was meningoencephalitis in 25%, followed by traumatic intracranial hemorrhage (16.7%). The median time from admission to PICU until BD diagnosis was 6.5 days. The time from the first BD physical examination to the declaration of BD was 27.5 hours. There was no statistically important difference between donors and non-donors. The apnea test (AT) was the most performed ancillary method (100%), followed by electroencephalogram (EEG) (66.7%), and magnetic resonance angiography or computed tomography angiography (MRA/ CTA) (54.2%). Hyperglycemia developed in 79.2% of the cases, and 70.8% developed diabetes insipidus (DI). Five patients (20.8%) were organ donors in study group. In the study, 13 solid organ and 4 tissue transplantations were performed after OD.

CONCLUSION

Awareness of the incidence and etiology may contribute to the timely diagnosis and declaration of brain death, and with the help of good donor care, may help in increasing OD rates in the pediatric population.

Revise the UDDA to Align the Law with Practice through Neuro-Respiratory Criteria

Although the Uniform Determination of Death Act (UDDA) has served as a model statute for 40 years, there is a growing recognition that the law must be updated. One issue being considered by the Uniform Law Commission's Drafting Committee to revise the UDDA is whether the text “all functions of the entire brain, including the brainstem” should be changed. Some argue that the absence of diabetes insipidus indicates that some brain functioning continues in many individuals who otherwise meet the “accepted medical standards” like the American Academy of Neurology's. The concern is that the legal criteria and the medical standards used to determine death by neurologic criteria are not aligned. We argue for the revision of the UDDA to more accurately specify legal criteria that align with the medical standards: brain injury leading to permanent loss of the capacity for consciousness, the ability to breathe spontaneously, and brainstem reflexes. We term these criteria neurorespiratory criteria and show that they are well-supported in the literature for physiologic and social reasons justifying their use in the law.

The MRI of Jahi McMath and Its Implications for the Global Ischemic Penumbra Hypothesis

Jahi McMath was diagnosed brain dead on 12/12/2013 in strict accordance with both the pediatric and adult Guidelines, reinforced by 4 isoelectric electroencephalograms and a radionuclide scan showing intracranial circulatory arrest. Her magnetic resonance imaging scan 9 1/2 months later surprisingly showed gross integrity of cortex, basal ganglia, thalamus, and upper brainstem. The greatest damage was in the white matter, which was extensively demyelinated and cystic, and in the lower brainstem, most likely from partial herniation that resolved. The apparent integrity of gray matter and the ascending reticular activating system may have provided a potential structural basis for the reemergence of some limited brain functions, while the white matter and lower brainstem lesions would have caused severe motor disability, brainstem areflexia and apnea. The findings indicate that there could never have been a period of sustained intracranial circulatory arrest. Rather, at the time of brain death diagnosis, low blood flow below the detection threshold of the radionuclide scan was sufficient to maintain widespread neuronal viability, though insufficient to support synaptic function. Her case represents the first indirect confirmation of the reality and clinical relevance of global ischemic penumbra, hypothesized in 1999 as a generally unacknowledged and possibly common brain death mimic.

Pediatric Death by Neurologic Criteria: The Ever-Changing Landscape and the Expanding Role of Palliative Care Professionals

Pediatric palliative care providers are especially suited to support families and medical teams facing a potential diagnosis of brain death, or death by neurologic criteria (DNC), when a child suffers a devastating brain injury. To support pediatric palliative care providers' effectiveness in this role, this article elucidates the clinical determination of DNC and the evolution of the ethical and legal controversies surrounding DNC. Conceptual definitions of death used in the context of DNC have been and continue to be debated amongst academicians, and children's families often have their own concept of death. Increasingly, families have brought legal cases challenging the definition of death, arguing for a right to refuse examination to diagnose DNC, and/or voicing religious objections. We describe these conceptual definitions and legal challenges then explore some potential reasons why families may dispute a determination of DNC. We conclude that working with patients, families, and healthcare providers facing DNC carries inherent and unique challenges suited to intervention by interdisciplinary palliative care teams.

The intractable problems with brain death and possible solutions

Brain death has been accepted worldwide medically and legally as the biological state of death of the organism. Nevertheless, the literature has described persistent problems with this acceptance ever since brain death was described. Many of these problems are not widely known or properly understood by much of the medical community. Here we aim to clarify these issues, based on the two intractable problems in the brain death debates. First, the metaphysical problem: there is no reason that withstands critical scrutiny to believe that BD is the state of biological death of the human organism. Second, the epistemic problem: there is no way currently to diagnose the state of BD, the irreversible loss of all brain functions, using clinical tests and ancillary tests, given potential confounders to testing. We discuss these problems and their main objections and conclude that these problems are intractable in that there has been no acceptable solution offered other than bare assertions of an 'operational definition' of death. We present possible ways to move forward that accept both the metaphysical problem - that BD is not biological death of the human organism - and the epistemic problem - that as currently diagnosed, BD is a devastating neurological state where recovery of sentience is very unlikely, but not a confirmed state of irreversible loss of all [critical] brain functions. We argue that the best solution is to abandon the dead donor rule, thus allowing vital organ donation from patients currently diagnosed as BD, assuming appropriate changes are made to the consent process and to laws about killing.

Pediatric brain death certification: a narrative review

In the five decades since its inception, brain death has become an accepted medical and legal concept throughout most of the world. There was initial reluctance to apply brain death criteria to children as they are believed more likely to regain neurologic function following injury. In spite of early trepidation, criteria for pediatric brain death certification were first proposed in 1987 by a multidisciplinary committee comprised of experts in the medical and legal communities. Protocols have since been developed to standardize brain death determination, but there remains substantial variability in practice throughout the world. In addition, brain death remains a topic of considerable ethical, philosophical, and legal controversy, and is often misrepresented in the media. In the present article, we discuss the history of brain death and the guidelines for its determination. We provide an overview of past and present challenges to its concept and diagnosis from biophilosophical, ethical and legal perspectives, and highlight differences between adult and pediatric brain death determination. We conclude by anticipating future directions for brain death as related to the emergence of new technologies. It is our position that providers should endorse the criteria for brain death diagnosis in children as proposed by the Society of Critical Care Medicine (SCCM), American Academy of Pediatrics (AAP), and Child Neurology Society (CNS), in order to prevent controversy and subjectivity surrounding what constitutes life versus death.

Evidence-Based Protocols in Child Neurology

Medical care has become more complex as the scientific method has expanded medical knowledge. Medicine is also now practiced across different medical systems of varying complexity, and creating standard treatment guidelines is one way of establishing uniform treatment across these systems. The creation of guidelines ensures the delivery of quality medical care and improved patient outcomes. Evidence-based medicine is the application of scientific research to produce these treatment guidelines. This article shall focus on the current treatment guidelines used for inpatient pediatric neurology.

Statement in Support of Revising the Uniform Determination of Death Act and in Opposition to a Proposed Revision

Discrepancies between the Uniform Determination of Death Act (UDDA) and the adult and pediatric diagnostic guidelines for brain death (BD) (the "Guidelines") have motivated proposals to revise the UDDA. A revision proposed by Lewis, Bonnie and Pope (the RUDDA), has received particular attention, the three novelties of which would be: (1) to specify the Guidelines as the legally recognized "medical standard," (2) to exclude hypothalamic function from the category of "brain function," and (3) to authorize physicians to conduct an apnea test without consent and even over a proxy's objection. One hundred seven experts in medicine, bioethics, philosophy, and law, spanning a wide variety of perspectives, have come together in agreement that while the UDDA needs revision, the RUDDA is not the way to do it. Specifically, (1) the Guidelines have a non-negligible risk of false-positive error, (2) hypothalamic function is more relevant to the organism as a whole than any brainstem reflex, and (3) the apnea test carries a risk of precipitating BD in a non-BD patient, provides no benefit to the patient, does not reliably accomplish its intended purpose, and is not even absolutely necessary for diagnosing BD according to the internal logic of the Guidelines; it should at the very least require informed consent, as do many procedures that are much more beneficial and less risky. Finally, objections to a neurologic criterion of death are not based only on religious belief or ignorance. People have a right to not have a concept of death that experts vigorously debate imposed upon them against their judgment and conscience; any revision of the UDDA should therefore contain an opt-out clause for those who accept only a circulatory-respiratory criterion.

Metabolic values precluding clinical death by neurologic Criteria/Brain death: Survey of neurocritical care society physicians

BACKGROUND

There are no established ranges for metabolic values prior to death by neurologic criteria/brain death determination (DNC/BD) and the thresholds required by institutional protocols and accepted by neurointensivists is unknown.

METHODS

We designed a survey that addressed 1) the metabolic tests required in institutional guidelines prior to brain death determination, 2) the metabolic tests the respondent reviewed prior to brain death determination, and 3) the metabolic test thresholds for laboratory tests that were perceived to preclude or permit clinical DNC/BD determination. The survey was distributed online to physicians in the Neurocritical Care Society from September to December 2019. Respondents were dichotomized based on the number of brain death evaluations they had performed (≤20 vs. > 20) and responses were compared between groups.

RESULTS

The survey was completed by 84 physicians. Nearly half (47.6%) of respondents did not believe their institutions required metabolic testing. The metabolic testing for which institutions most commonly provided a defined threshold were arterial pH (34.5%, 29/84), sodium (28.6%, 24/84), and glucose (15.5%, 13/84). Nearly all (97.6%) respondents routinely reviewed metabolic tests prior to brain death evaluation, the most common of which were: sodium (91.7%, 77/84), arterial pH (83.3%, 70/84), and glucose (79.8%, 67/84). Respondents who had performed > 20 evaluations were less likely to check thyroxine and total bilirubin (3.6%, 2/55 vs. 20.7%, 6/29 (p = 0.011) and 12.7%, 7/55 vs. 31%, 9/29 (p = 0.042), respectively), and had a more liberal upper limit of potassium (6.3 mEq/L vs 6.0 mEq/L, p = 0.045).

CONCLUSION

Prior to brain death evaluation, neurocritical care providers commonly review similar metabolic tests and have similar thresholds regarding values that would preclude clinical brain death determination. This finding is independent of experience with brain death determination.

Pediatric In-Hospital Cardiac Arrest and Cardiopulmonary Resuscitation in the United States: A Review

IMPORTANCE

Pediatric in-hospital cardiac arrest (IHCA) occurs frequently and is associated with high morbidity and mortality. The objective of this narrative review is to summarize the current knowledge and recommendations regarding pediatric IHCA and cardiopulmonary resuscitation (CPR).

OBSERVATIONS

Each year, more than 15 000 children receive CPR for cardiac arrest during hospitalization in the United States. As many as 80% to 90% survive the event, but most patients do not survive to hospital discharge. Most IHCAs occur in intensive care units and other monitored settings and are associated with respiratory failure or shock. Bradycardia with poor perfusion is the initial rhythm in half of CPR events, and only about 10% of events have an initial shockable rhythm. Pre-cardiac arrest systems focus on identifying at-risk patients and ensuring that they are in monitored settings. Important components of CPR include high-quality chest compressions, timely defibrillation when indicated, appropriate ventilation and airway management, administration of epinephrine to increase coronary perfusion pressure, and treatment of the underlying cause of cardiac arrest. Extracorporeal CPR and measurement of physiological parameters are evolving areas in improving outcomes. Structured post-cardiac arrest care focused on targeted temperature management, optimization of hemodynamics, and careful intensive care unit management is associated with improved survival and neurological outcomes.

CONCLUSIONS AND RELEVANCE

Pediatric IHCA occurs frequently and has a high mortality rate. Early identification of risk, prevention, delivery of high-quality CPR, and post-cardiac arrest care can maximize the chances of achieving favorable outcomes. More research in this field is warranted.

For Victims of Fatal Child Abuse, Who Has the Right to Consent to Organ Donation?

In rare circumstances, children who have suffered traumatic brain injury from child abuse are declared dead by neurologic criteria and are eligible to donate organs. When the parents are the suspected abusers, there can be confusion about who has the legal right to authorize organ donation. Furthermore, organ donation may interfere with the collection of forensic evidence that is necessary to evaluate the abuse. Under those circumstances, particularly in the context of a child homicide investigation, the goals of organ donation and collection and preservation of critical forensic evidence may seem mutually exclusive. In this Ethics Rounds, we discuss such a case and suggest ways to resolve the apparent conflicts between the desire to procure organs for donation and the need to thoroughly evaluate the evidence of abuse.

Does the Uniform Determination of Death Act Need to Be Revised?

Prompted by concerns raised by the rise in litigations, which challenge the legal status of brain death (BD), Lewis and colleagues recently proposed a revision of the Uniform Determination of Death Act (UDDA). The revision consists of (i) narrowing down the definition of BD to the loss of specific brain functions, namely those functions that can be assessed on bedside neurological examination; (ii) requiring that the determination of BD must be in accordance with the specific guidelines designated in the revision; and (iii) eliminating the necessity for obtaining consent prior to performing the tests for BD determination. By analyzing Lewis and colleagues' revision, this article shows that this revision is fraught with difficulties. Therefore, this article also proposes two approaches for an ethical revision of the UDDA; the first is in accordance with scientific realism and Christian anthropology, while the second is grounded in trust and respect for persons. If the UDDA is to be revised, then it should be based on sound ethical principles in order to resolve the ongoing BD controversies and rebuild public trust.

Summary

This article critically examines the recent revision of the Uniform Determination of Death Act (UDDA) advanced by Lewis and colleagues. The revision only further reinforces the status quo of brain death without taking into account the root cause of the litigations and controversies about the declaration of death by neurological criteria. In view of this deficiency, this article offers two approaches to revising the UDDA, both of which are founded on sound moral principles.

Transcutaneous Carbon Dioxide Monitoring During Apnea Testing for Determination of Neurologic Death in Children: A Retrospective Case Series

OBJECTIVES

Determination of neurologic death in children is a clinical diagnosis based on absence of neurologic function with irreversible coma and apnea. Apnea testing during determination of neurologic death assesses spontaneous respiration when PaCO2 increases to greater than or equal to 60 and greater than or equal to 20 mm Hg above pre-apneic baseline. The utility of transcutaneous carbon dioxide measurements during apnea testing in children is unknown. We seek to determine the degree of correlation between paired transcutaneous carbon dioxide and PaCO2 values during apnea testing for determination of neurologic death.

DESIGN

Single-center, retrospective case series.

SETTING

Twenty-eight bed PICU in a 259-bed, tertiary care, referral center.

PATIENTS

Children 0-18 years old undergoing determination of neurologic death between May 2017 and December 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Primary outcomes were paired transcutaneous carbon dioxide and PaCO2 values obtained during determination of neurologic death. Primary analyses included Pearson correlation coefficient, Bland-Altman bias and limits of agreement, and comparative statistics. Descriptive data included demographics, admission diagnoses, hemodynamics, Vasoactive Inotropic Scores, and arterial blood gas measurement. Eight children underwent 15 determination of neurologic death examinations resulting in 31 paired transcutaneous carbon dioxide and PaCO2 values for study. Transcutaneous carbon dioxide and PaCO2 correlated well (r = 0.94; p < 0.01). Bias between transcutaneous carbon dioxide and PaCO2 was -3.29 ± 7.14 mm Hg. Differences in means did not correlate with Vasoactive Inotropic Score (r = 0.2) or patient temperature (r = 0.11). Receiver operator characteristic curve of transcutaneous carbon dioxide after 3-10 minutes of apnea to discriminate positive apnea testing by the standard of PaCO2 yielded an area under the curve of 0.91 and threshold of greater than or equal to 64 mm Hg (sensitivity, 91.7%; specificity, 100%; positive predictive value, 100%; negative predictive value, 92.3%; accuracy, 95.9%).

CONCLUSIONS

During apnea testing for determination of neurologic death in children, noninvasive transcutaneous carbon dioxide monitoring demonstrated high correlation, accuracy, and minimal bias when compared with PaCO2. Further validation is required before any recommendation to replace PaCO2 with noninvasive transcutaneous carbon dioxide monitoring can be proposed. However, concurrent transcutaneous carbon dioxide data may limit unnecessary apnea time and associated hemodynamic instability or respiratory decompensation by approximating goal arterial blood sampling to document target PaCO2.

Normative and pathological values of hemodynamic and Doppler ultrasound arterial findings in children

Doppler ultrasound is an effective, useful and remarkably powerful tool in pediatric imaging. If possible, its use is always favored to avoid exposure to radiation or sedatives. By waveform spectrum analysis, Doppler ultrasound reveals information on blood flow and details on normal physiology and pathological processes undiscernible from gray-scale imaging alone. However, Doppler ultrasound remains underused, largely due to the difficult interpretation of changes in Doppler waveforms during childhood. This article provides a narrative review of the literature regarding the normative values and the physiological arterial changes through childhood according to age, weight or height, as well as frequent pathological arterial findings in children, classified by arterial territory.

Misinterpretations of Guidelines Leading to Incorrect Diagnosis of Brain Death: A Case Report and Discussion

Guidelines describe the process necessary for the diagnosis of brain death. We present a case of a 3-month-old former 36-week-gestation infant after a prolonged out-of-hospital cardiac arrest of 37 minutes who was clinically diagnosed as brain dead at 120 hours after the event. Unusual findings included a normal slightly sunken anterior fontanelle, normal cerebral blood flow perfusion scan at 73 hours after the event, only localized parieto-temporal edema on the latest computed tomographic (CT) scan of the brain at 48 hours after the event, and discussion of whether nonconvulsive seizures could have confounded the examination for brain death. In light of these unusual findings, we discuss and highlight what may be common misinterpretations of brain death guidelines that led to the mistaken diagnosis of death (as opposed to severe neurologic injury) in this child.

Clinical Determination of Brain Death in Children Supported by Extracorporeal Membrane Oxygenation

BACKGROUND/OBJECTIVE

Children supported by extracorporeal membrane oxygenation (ECMO) are at risk of catastrophic neurologic injury and brain death. Timely determination of brain death is important for minimizing psychological distress for families, resource allocation, and organ donation. Reports of successful determination of brain death in pediatric patients supported by ECMO are limited. The determination of brain death by clinical criteria requires apnea testing, which has historically been viewed as challenging in patients supported by ECMO. We report eight pediatric patients who underwent a total of 14 brain death examinations, including apnea testing, while supported by veno-arterial ECMO (VA-ECMO), resulting in six cases of clinical determination of brain death.

METHODS

We performed a retrospective review of the medical records of pediatric patients who underwent brain death examination while supported by VA-ECMO between 2010 and 2018 at a single tertiary care children's hospital.

RESULTS

Eight patients underwent brain death examination, including apnea testing, while supported by VA-ECMO. Six patients met criteria for brain death, while two had withdrawal of technical support after the first examination. During the majority of apnea tests (n = 13/14), the ECMO circuit was modified to achieve hypercarbia while maintaining oxygenation and hemodynamic stability. The sweep flow was decreased prior to apnea testing in ten brain death examinations, carbon dioxide was added to the circuit during three examinations, and ECMO pump flows were increased in response to hypotension during two examinations.

CONCLUSIONS

Clinical determination of brain death, including apnea testing, can be performed in pediatric patients supported by ECMO. The ECMO circuit can be effectively modified during apnea testing to achieve a timely rise in carbon dioxide while maintaining oxygenation and hemodynamic stability.

Aligning the Criterion and Tests for Brain Death

Disturbing cases continue to be published of patients declared brain dead who later were found to have a few intact brain functions. We address the reasons for the mismatch between the whole-brain criterion and brain death tests, and suggest solutions. Many of the cases result from diagnostic errors in brain death determination. Others probably result from a tiny amount of residual blood flow to the brain despite intracranial circulatory arrest. Strategies to lessen the mismatch include improving brain death determination training for physicians, mandating a test showing complete intracranial circulatory arrest, or revising the whole-brain criterion.

Management of the Pediatric Organ Donor

Management of the pediatric organ donor necessitates understanding the physiologic changes that occur preceding and after death determination. Recognizing these changes allows application of the therapeutic strategies designed to optimize hemodynamics and metabolic state to allow for preservation of end-organ function for maximal organ recovery and minimal damage to the donor grafts. The pediatric pharmacist serves as the medication expert and may collaborate with the organ procurement organizations for provision of pharmacologic hemodynamic support, hormone replacement therapy, antimicrobials, and nutrition for the pediatric organ donor.

Early Heart Rate Variability and Electroencephalographic Abnormalities in Acutely Brain-Injured Children Who Progress to Brain Death

OBJECTIVES

Heart rate variability is controlled by the autonomic nervous system. After brain death, this autonomic control stops, and heart rate variability is significantly decreased. However, it is unknown if early changes in heart rate variability are predictive of progression to brain death. We hypothesized that in brain-injured children, lower heart rate variability is an early indicator of autonomic system failure, and it predicts progression to brain death. We additionally explored the association between heart rate variability and markers of brain dysfunction such as electroencephalogram and neurologic examination between brain-injured children who progressed to brain death and those who survived.

DESIGN

Retrospective case-control study.

SETTING

PICU, single institution.

PATIENTS

Children up to 18 years with a Glasgow Coma Scale score of less than 8 admitted between August of 2016 and December of 2017, who had electrocardiographic data available for heart rate variability analysis, were included.

EXCLUSION CRITERIA

patients who died of causes other than brain death. Twenty-three patients met inclusion criteria: six progressed to brain death (cases), and 17 survived (controls). Five-minute electrocardiogram segments were used to estimate heart rate variability in the time domain (SD of normal-normal intervals, root mean square successive differences), frequency domain (low frequency, high frequency, low frequency/high frequency ratio), Poincaré plots, and approximate entropy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients who progressed to brain death exhibited significantly lower heart rate variability in the time domain, frequency domain, and Poincaré plots (p < 0.01). The odds of death increased with decreasing low frequency (odds ratio, 4.0; 95% CI, 1.2-13.6) and high frequency (odds ratio, 2.5; 95% CI, 1.2-5.4) heart rate variability power (p < 0.03). Heart rate variability was significantly lower in those with discontinuous or attenuated/featureless electroencephalogram versus those with slow/disorganized background (p < 0.03).

CONCLUSIONS

These results support the concept of autonomic system failure as an early indicator of impending brain death in brain-injured children. Furthermore, decreased heart rate variability is associated with markers of CNS dysfunction such as electroencephalogram abnormalities.

Apnea Threshold in Pediatric Brain Death: A Case with Variable Results Across Serial Examinations

Consensus guidelines currently exist for the evaluation of pediatric patients with suspected brain death. The guidelines include the requirement for two consistent examinations separated by an observation period and a threshold of 60 mm Hg for PaCO ₂ during apnea testing. We present a patient who met all prerequisites to perform brain death examination but had variability in examinations during apnea testing. We discuss our strategy in managing these unexpected findings, including the importance of open and ongoing communication with the family, and the implications for current guidelines for the determination of brain death in pediatric patients.

Bedside contrast-enhanced ultrasound diagnosing cessation of cerebral circulation in a neonate: A novel bedside diagnostic tool

Imaging diagnosis of brain death is performed with either four-vessel cerebral angiography or radionuclide cerebral blood flow studies. Unfortunately, timely performance of either study at a critically ill period is not only cumbersome but not feasible in many cases. We present a case of a 6-month-old male three hours status post-cardiac arrest of unknown etiology who underwent contrast-enhanced ultrasound (CEUS) for diagnosis of near absent perfusion, or near brain death. The patient passed away 30 minutes after the exam and clinical diagnosis of brain death was confirmed. The case report highlights the utility of CEUS for diagnosis of brain death. This can have significant clinical implications in neonates who may not be eligible for commonly used, cumbersome radiologic studies for diagnosis of brain death.

Advanced Pediatric Neurosonography Techniques: Contrast-Enhanced Ultrasonography, Elastography, and Beyond

Recent technical advances in neurosonography continue broadening the diagnostic utility, sensitivity, and specificity of ultrasound for detecting intracranial abnormalities bed side. The clinical and functional applications of neurosonography have significantly expanded since the 1980s when transcranial Doppler sonography first allowed anatomic and hemodynamic delineation of the intracranial vessels through the thin temporal skull. In the past few years, contrast-enhanced ultrasonography, elastography, 3D/4D reconstruction tools, and high-resolution microvessel imaging techniques have further enhanced the diagnostic significance of neurosonography. Given these advances, a thorough familiarity with these new techniques and devices is crucial for a successful clinical application allowing improved patient care. It is essential that future neurosonography studies compare these advanced techniques against the current "gold standard" computed tomography and magnetic resonance imaging to assure the accuracy of their diagnostic potential. This review will provide a comprehensive update on currently available advanced neurosonography techniques.

False-Positive Diagnosis of Brain Death Following the Pediatric Guidelines: Case Report and Discussion

A 2-year-old boy with severe head trauma was diagnosed brain dead according to the 2011 Pediatric Guidelines. Computed tomographic (CT) scan showed massive cerebral edema with herniation. Intracranial pressures were extremely high, with cerebral perfusion pressures around 0 for several hours. An apnea test was initially contraindicated; later, one had to be terminated due to oxygen desaturation when the Pco₂ had risen to 57.9 mm Hg. An electroencephalogram (EEG) was probably isoelectric but formally interpreted as equivocal. Tc-99m diethylene-triamine-pentaacetate (DTPA) scintigraphy showed no intracranial blood flow, so brain death was declared. Parents declined organ donation. A few minutes after withdrawal of support, the boy began to breathe spontaneously, so the ventilator was immediately reconnected and the death declaration rescinded. Two hours later, life support was again removed, this time for prognostic reasons; he did not breathe, and death was declared on circulatory-respiratory grounds. Implications regarding the specificity of the guidelines are discussed.

Brain Death

Death determined by neurologic criteria, commonly referred to as "brain death," occurs when function of the entire brain ceases, including the brain stem. Diagnostic criteria for brain death are explicit but controversy exists regarding nuances of the evaluation and potential confounders of the examination. Hospitals and ICU teams should carefully consider which clinicians will perform brain death testing and should use standard processes, including checklists to prevent diagnostic errors. Proper diagnosis is essential because misdiagnosis can be catastrophic. Timely, accurate brain death determination and aggressive physiologic support are cornerstones of both good end-of-life care and successful organ donation.