Faculty Bibliography

Apnea is one of the three cardinal findings in brain death (BD). Apnea testing (AT) is physiologically and practically complex. We sought to review described modifications of AT, safety and complication rates, monitoring techniques, performance of AT on extracorporeal membrane oxygenation (ECMO), and other relevant considerations regarding AT. We conducted a systematic scoping review to answer these questions by searching the literature on AT in English language available in PubMed or EMBASE since 1980. Pediatric or animal studies were excluded. A total of 87 articles matched our inclusion criteria and were qualitatively synthesized in this review. A large body of the literature on AT since its inception addresses a variety of modifications, monitoring techniques, complication rates, ways to perform AT on ECMO, and other considerations such as variability in protocols, lack of uniform awareness, and legal considerations. Only some modifications are widely used, especially methods to maintain oxygenation, and most are not standardized or endorsed by brain death guidelines. Future updates to AT protocols and strive for unification of such protocols are desirable.

OBJECTIVE:We sought to identify similarities and differences in the diagnostic requirements for ancillary testing for determination of brain death/death by neurologic criteria (BD/DNC) around the world. METHODS:We reviewed diagnostic requirements for ancillary testing for BD/DNC in 78 unique official national BD/DNC protocols obtained from contacts worldwide between January 2018 and April 2019. RESULTS:Details provided on the performance and interpretation of ancillary tests for determination of BD/DNC were variably provided and inconsistent. Approximately half of all protocols that included each ancillary test provided details about study performance: 63% of protocols that included conventional cerebral angiography, 55% of protocols that included electroencephalography, 50% of protocols that included somatosensory evoked potentials, 48% of protocols that included transcranial Doppler ultrasonography, 43% of protocols that included nuclear medicine flow study and 41% of protocols that included brainstem auditory evoked potentials. Similarly, about half of all protocols that included each ancillary test provided details about study interpretation: 66% of protocols that included electroencephalography, 59% of protocols that included brainstem auditory evoked potentials, 56% of protocols that included somatosensory evoked potentials, 55% of protocols that included transcranial Doppler ultrasonography, 52% of protocols that included conventional cerebral angiography and 49% of protocols that included nuclear medicine flow study. INTERPRETATION/CONCLUSIONS:Diagnostic requirements for ancillary testing in BD/DNC determination vary around the world. We hope that the World Brain Death Project will improve worldwide consensus on the diagnostic requirements for ancillary testing in BD/DNC, both for performance and interpretation.

This is a patient with multiple meningoencephaloceles which resulted in bacterial meningitis and subsequent status epilepticus. We identify impressive imaging findings demonstrating herniation of the meninges from nasal and bitemporal skull base defects possibly as a result of intracranial hypertension.

There are varying medical, legal, social, religious and philosophical perspectives about the distinction between life and death. Death can be declared using cardiopulmonary or neurologic criteria throughout much of the world. After solicitation of brain death/death by neurologic criteria (BD/DNC) protocols from contacts around the world, we found that the percentage of countries with BD/DNC protocols is much lower in Africa than other developing regions. We performed an informal review of the literature to identify barriers to declaration of BD/DNC in Africa. We found that there are numerous medical, legal, social and religious barriers to the creation of BD/DNC protocols in Africa including 1) limited number of healthcare facilities, critical care resources and clinicians with relevant expertise; 2) absence of a political and legal framework codifying death; and 3) cultural and religious perspectives that present ideological conflict with the idea of BD/DNC, in particular, and between traditional and Western medicine, in general. Because there are a number of unique barriers to the creation of BD/DNC protocols in Africa, it remains to be seen how the World Brain Death Project, which is intended to create minimum standards for BD/DNC around the world, will impact BD/DNC determination in Africa.

PURPOSE/OBJECTIVE:Neurologic determination of death (NDD) is legally accepted as death in Canada but remains susceptible to misunderstandings. In some cases, families request continued organ support after NDD. Conflicts can escalate to formal legal challenges, causing emotional, financial, and moral distress for all involved. We describe prevalence, characteristics, and common experiences with requests for continued organ support following NDD in Canada. METHODS:Mixed-methods design combining anonymous online survey with semi-structured interviews of Canadian critical care physicians (448 practitioners, adult and pediatric). RESULTS:One hundred and six physicians responded to the survey and 12 participated in an interview. Fifty-two percent (55/106) of respondents had encountered a request for continued organ support after NDD within two years, 47% (26/55) of which involved threat of legal action. Requests for continued support following NDD ranged from appeals for time for family to gather before ventilator removal to disagreement with the concept of NDD. Common responses to requests included: consultation with an additional physician (54%), consultation with spiritual services (41%), and delay of one to three days for NDD acceptance (49%). Respondents with prior experience were less likely to recommend ancillary tests (P = 0.004) or consultation with bioethics services (P = 0.004). Qualitative analysis revealed perceptions that requests for continued organ support were driven by mistrust, tensions surrounding decision-making, and cultural differences rather than a lack of specific information about NDD. CONCLUSIONS:Family requests for continued somatic support following NDD were encountered by half our sample of Canadian critical care physicians. Mitigation strategies require attention to the multifaceted social contexts surrounding these complex scenarios.

Brain death, or death by neurological criteria (BD/DNC), has been accepted conceptually, medically and legally for decades. Nevertheless, some areas remain controversial or understudied, pointing to a need for focused research to advance the field. Multiple recent contributions have increased our understanding of BD/DNC, solidified our practice and provided guidance where previously lacking. There have also been important developments on a global scale, including in low-to-middle income countries such as in South America. Although variability in protocols and practice still exists, new efforts are underway to reduce inconsistencies and better train practitioners in accurate and sound BD/DNC determination. Various legal challenges have required formal responses from national societies, and the American Academy of Neurology has filled this void with much needed guidance. Questions remain regarding concepts such as 'whole brain' versus 'brainstem' death, and the intersection of BD/DNC and rubrics of medical futility. These concepts are the subject of this review.

OBJECTIVE:We sought to review the literature on cerebrospinal fluid (CSF) testing in patients with COVID-19 for evidence of viral neuroinvasion by SARS-CoV-2. METHODS:We performed a systematic review of Medline and Embase between December 1, 2019 and November 18, 2020 to identify case reports or series of patients who had COVID-19 diagnosed based on positive SARS-CoV-2 polymerase chain reaction (PCR) or serologic testing and had CSF testing due to a neurologic symptom. RESULTS:We identified 242 relevant documents which included 430 patients with COVID-19 who had acute neurological symptoms prompting CSF testing. Of those, 321 (75%) patients had symptoms that localized to the central nervous system (CNS). Of 304 patients whose CSF was tested for SARS-CoV-2 PCR, there were 17 (6%) whose test was positive, all of whom had symptoms that localized to the central nervous system (CNS). The majority (13/17, 76%) of these patients were admitted to the hospital because of neurological symptoms. Of 58 patients whose CSF was tested for SARS-CoV-2 antibody, 7 (12%) had positive antibodies with evidence of intrathecal synthesis, all of whom had symptoms that localized to the CNS. Of 132 patients who had oligoclonal bands evaluated, 3 (2%) had evidence of intrathecal antibody synthesis. Of 77 patients tested for autoimmune antibodies in the CSF, 4 (5%) had positive findings. CONCLUSION:Detection of SARS-CoV-2 in CSF via PCR or evaluation for intrathecal antibody synthesis appears to be rare. Most neurological complications associated with SARS- CoV-2 are unlikely to be related to direct viral neuroinvasion.

BACKGROUND:The coronavirus disease 2019 (COVID-19) pandemic has severely affected ICUs and critical care health-care providers (HCPs) worldwide. RESEARCH QUESTION:How do regional differences and perceived lack of ICU resources affect critical care resource use and the well-being of HCPs? STUDY DESIGN AND METHODS:Between April 23 and May 7, 2020, we electronically administered a 41-question survey to interdisciplinary HCPs caring for patients critically ill with COVID-19. The survey was distributed via critical care societies, research networks, personal contacts, and social media portals. Responses were tabulated according to World Bank region. We performed multivariate log-binomial regression to assess factors associated with three main outcomes: limiting mechanical ventilation (MV), changes in CPR practices, and emotional distress and burnout. RESULTS:We included 2,700 respondents from 77 countries, including physicians (41%), nurses (40%), respiratory therapists (11%), and advanced practice providers (8%). The reported lack of ICU nurses was higher than that of intensivists (32% vs 15%). Limiting MV for patients with COVID-19 was reported by 16% of respondents, was lowest in North America (10%), and was associated with reduced ventilator availability (absolute risk reduction [ARR], 2.10; 95% CI, 1.61-2.74). Overall, 66% of respondents reported changes in CPR practices. Emotional distress or burnout was high across regions (52%, highest in North America) and associated with being female (mechanical ventilation, 1.16; 95% CI, 1.01-1.33), being a nurse (ARR, 1.31; 95% CI, 1.13-1.53), reporting a shortage of ICU nurses (ARR, 1.18; 95% CI, 1.05-1.33), reporting a shortage of powered air-purifying respirators (ARR, 1.30; 95% CI, 1.09-1.55), and experiencing poor communication from supervisors (ARR, 1.30; 95% CI, 1.16-1.46). INTERPRETATION:Our findings demonstrate variability in ICU resource availability and use worldwide. The high prevalence of provider burnout and its association with reported insufficient resources and poor communication from supervisors suggest a need for targeted interventions to support HCPs on the front lines.