Temperature Control After Cardiac Arrest-A Rational Approach.

This Viewpoint discusses hypothermic temperature control for neuroprotection among survivors of out-of-hospital cardiac arrest and offers a rational approach to treating such patients as investigations continue.

Later Midline Shift Is Associated with Better Outcomes after Large Middle Cerebral Artery Stroke.

Background/Objective: Space occupying cerebral edema is the most feared early complication after large ischemic stroke, occurring in up to 30% of patients with middle cerebral artery (MCA) occlusion, and is reported to peak 2-4 days after injury. Little is known about the factors and outcomes associated with peak edema timing, especially when it occurs after 96 hours. We aimed to characterize differences between patients who experienced maximum midline shift (MLS) or decompressive hemicraniectomy (DHC) in the acute (<48 hours), average (48-96 hours), and subacute (>96 hours) groups and determine whether patients with subacute peak edema timing have improved discharge dispositions. Methods: We performed a two-center, retrospective study of patients with ≥1/2 MCA territory infarct and MLS. We constructed a multivariable model to test the association of subacute peak edema and favorable discharge disposition, adjusting for age, admission Alberta Stroke Program Early CT Score (ASPECTS), National Institute of Health Stroke Scale (NIHSS), acute thrombolytic intervention, cerebral atrophy, maximum MLS, parenchymal hemorrhagic transformation, DHC, and osmotic therapy receipt. Results: Of 321 eligible patients with MLS, 32%, 36%, and 32% experienced acute, average, and subacute peak edema. Subacute peak edema was significantly associated with higher odds of favorable discharge than non-subacute swelling, adjusting for confounders (aOR, 1.85; 95% CI, 1.05-3.31). Conclusions: Subacute peak edema after large MCA stroke is associated with better discharge disposition compared to earlier peak edema courses. Understanding how the timing of cerebral edema affects risk of unfavorable discharge has important implications for treatment decisions and prognostication.

Verification of Death by Neurologic Criteria: A Survey of 12 Organ Procurement Organizations Across the United States.

BACKGROUND: The Center for Medicare and Medicaid Services requires Organ Procurement Organizations (OPOs) to verify and document that any potential organ donor has been pronounced dead per applicable legal requirements of local, state, and federal laws. However, OPO practices regarding death by neurologic criteria (DNC) verification are not standardized, and little is known about their DNC verification processes. This study aimed to explore OPO practices regarding DNC verification in the United States. METHODS: An electronic survey was sent to all 57 OPOs in the United States from June to September 2023 to assess verification of policies and practices versus guidelines, concerns about policies and practices, processes to address concerns about DNC determination, and communication practices. RESULTS: Representatives from 12 OPOs across six US regions completed the entire survey; 8 of 12 reported serving > 50 referral hospitals. Most respondents (11 of 12) reported comparing their referral hospital's DNC policies with the 2010 American Academy of Neurology Practice Parameter and/or other (4 of 12) guidelines. Additionally, most (10 of 12) reported independently reviewing and verifying each DNC determination. Nearly half (5 of 12) reported concerns about guideline-discordant hospital policies, and only 3 of 12 thought all referral hospitals followed the 2010 American Academy of Neurology Practice Parameter in practice. Moreover, 9 of 12 reported concerns about clinician knowledge surrounding DNC determination, and most (10 of 12) reported having received referrals for patients whose DNC declaration was ultimately reversed. All reported experiences in which their OPO requested additional assessments (11 of 12 clinical evaluation, 10 of 12 ancillary testing, 9 of 12 apnea testing) because of concerns about DNC determination validity. CONCLUSIONS: Accurate DNC determination is important to maintain public trust. Nearly all OPO respondents reported a process to verify hospital DNC policies and practices with medical society guidelines. Many reported concerns about clinician knowledge surrounding DNC determination and guideline-discordant policies and practices. Educational and regulatory advocacy efforts are needed to facilitate systematic implementation of guideline-concordant practices across the country.

Association of large core middle cerebral artery stroke and hemorrhagic transformation with hospitalization outcomes.

Historically, investigators have not differentiated between patients with and without hemorrhagic transformation (HT) in large core ischemic stroke at risk for life-threatening mass effect (LTME) from cerebral edema. Our objective was to determine whether LTME occurs faster in those with HT compared to those without. We conducted a two-center retrospective study of patients with ≥ 1/2 MCA territory infarct between 2006 and 2021. We tested the association of time-to-LTME and HT subtype (parenchymal, petechial) using Cox regression, controlling for age, mean arterial pressure, glucose, tissue plasminogen activator, mechanical thrombectomy, National Institute of Health Stroke Scale, antiplatelets, anticoagulation, temperature, and stroke side. Secondary and exploratory outcomes included mass effect-related death, all-cause death, disposition, and decompressive hemicraniectomy. Of 840 patients, 358 (42.6%) had no HT, 403 (48.0%) patients had petechial HT, and 79 (9.4%) patients had parenchymal HT. LTME occurred in 317 (37.7%) and 100 (11.9%) had mass effect-related deaths. Parenchymal (HR 8.24, 95% CI 5.46-12.42, p < 0.01) and petechial HT (HR 2.47, 95% CI 1.92-3.17, p < 0.01) were significantly associated with time-to-LTME and mass effect-related death. Understanding different risk factors and sequelae of mass effect with and without HT is critical for informed clinical decisions.

Beyond the Final Heartbeat: Neurological Perspectives on Normothermic Regional Perfusion for Organ Donation after Circulatory Death.

Normothermic regional perfusion (NRP) has recently been used to augment organ donation after circulatory death (DCD) to improve the quantity and quality of transplantable organs. In DCD-NRP, after withdrawal of life-sustaining therapies and cardiopulmonary arrest, patients are cannulated onto extracorporeal membrane oxygenation to reestablish blood flow to targeted organs including the heart. During this process, aortic arch vessels are ligated to restrict cerebral blood flow. We review ethical challenges including whether the brain is sufficiently reperfused through collateral circulation to allow reemergence of consciousness or pain perception, whether resumption of cardiac activity nullifies the patient's prior death determination, and whether specific authorization for DCD-NRP is required. ANN NEUROL 2024;95:1035-1039.

A Modified Delphi Consensus Approach to Define Entrustable Professional Activities for Neurocritical Care Advanced Practice Providers.

OBJECTIVES: To define consensus entrustable professional activities (EPAs) for neurocritical care (NCC) advanced practice providers (APPs), establish validity evidence for the EPAs, and evaluate factors that inform entrustment expectations of NCC APP supervisors. DESIGN: A three-round modified Delphi consensus process followed by application of the EQual rubric and assessment of generalizability by clinicians not affiliated with academic medical centers. SETTING: Electronic surveys. SUBJECTS: NCC APPs (n = 18) and physicians (n = 12) in the United States with experience in education scholarship or APP program leadership. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The steering committee generated an initial list of 61 possible EPAs. The panel proposed 30 additional EPAs. A total of 47 unique nested EPAs were retained by consensus opinion. The steering committee defined six core EPAs addressing medical knowledge, procedural competencies, and communication proficiency which encompassed the nested EPAs. All core EPAs were retained and subsequently met the previously described cut score for quality and structure using the EQual rubric. Most clinicians who were not affiliated with academic medical centers rated each of the six core EPAs as very important or mandatory. Entrustment expectations did not vary by prespecified groups. CONCLUSIONS: Expert consensus was used to create EPAs for NCC APPs that reached a predefined quality standard and were important to most clinicians in different practice settings. We did not identify variables that significantly predicted entrustment expectations. These EPAs may aid in curricular design for an EPA-based assessment of new NCC APPs and may inform the development of EPAs for APPs in other critical care subspecialties.

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.

The Relationship Between Manifestation of Diabetes Insipidus and Estimated Glomerular Filtration Rate in Brain Death.

OBJECTIVES: Systematic reviews have revealed that up to 50% of patients with brain death have residual hypothalamic/pituitary activity based on the absence of central diabetes insipidus (DI). We hypothesized that different degrees of renal dysfunction may impact the presence of DI in patients with brain death. DESIGN: Single-center prospective data collection. SETTING: ICUs in a tertiary academic hospital. PATIENTS: All adult patients declared brain dead over 12 years. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: DI was diagnosed by polyuria, low urine specific gravity, and increasing serum sodium, measured in close proximity. Renal function was assessed by the estimated glomerular filtration rate (eGFR), calculated using the simplified modification of diet in renal disease equation. Analysis was completed in 192 of 234 patients with brain death after excluding those with missing data, those younger than 18 years and those on vasopressin infusions. One hundred twenty-two patients (63.5%) developed DI and 70 patients (36.5%) did not. The proportion of DI decreased significantly with decreasing eGFR: for eGFR greater than 60 mL/min, DI was present in 77.2%; for eGFR 15-60 mL/min, DI was present in 54.5%; for eGFR 14.9-9.8 mL/min, DI was present in 32%; none of the 14 patients with eGFR less than or equal to 9.7 mL/min ever experienced DI ( p < 0.001). Using logistic regression, for every 10 mL/min decrease in eGFR, the odds of DI decreased 0.83 times (95% CI, 0.76-0.90, p < 0.001). CONCLUSIONS: Renal dysfunction significantly impacts DI's clinical manifestation in brain death. We report that patients who experience brain death with severe renal dysfunction may not develop clinical signs of DI.

The 2023 American Academy of Neurology, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine Pediatric and Adult Brain Death/Death by Neurologic Criteria Determination Consensus Guidelines: What the Critical Care Team Needs to Know.

Guidelines for brain death/death by neurologic criteria (BD/DNC) determination were revised to provide a consistent and updated approach to BD/DNC evaluation across all ages by the American Academy of Neurology, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine. This article is intended to complement the guidelines and highlight aspects relevant to the critical care community; the actual guidelines should be used to update hospital protocols and dictate clinical practice. Because BD/DNC evaluations are conducted in the ICU, it is essential for members of the critical care community to familiarize themselves with these guidelines. The fundamental concept of BD/DNC has not changed; BD/DNC is permanent loss of function of the brain as a whole, including the brain stem, resulting in coma, brainstem areflexia, and apnea in the setting of an adequate stimulus. The BD/DNC evaluation requires a sufficient observation period to ensure there is no chance of recovery, followed by exclusion of potentially confounding conditions like hypothermia, hypotension, severe metabolic disturbances, or medication effects. Specific guidance is provided for patients who were treated with therapeutic hypothermia or medical or surgical interventions to manage intracranial hypertension. The guidelines outline a structured and meticulous neurologic examination and detail the responses consistent with BD/DNC. A protocol is provided for how to safely perform apnea testing, including modifications needed for patients on extracorporeal membrane oxygenation. Controversial issues such as consent, BD/DNC evaluation in pregnancy, preservation of neuroendocrine function, and primary posterior fossa injuries are addressed. The ultimate goal is to ensure a consistent and accurate approach to BD/DNC evaluation in patients of all ages, fostering public trust in the medical community's ability to determine death. By adhering to these guidelines, critical care clinicians can confidently navigate the challenging aspects of BD/DNC determination.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement From the American Heart Association and Neurocritical Care Society.

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement from the American Heart Association and Neurocritical Care Society.

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Increased task-relevant fMRI responsiveness in comatose cardiac arrest patients is associated with improved neurologic outcomes.

Early prediction of the recovery of consciousness in comatose cardiac arrest patients remains challenging. We prospectively studied task-relevant fMRI responses in 19 comatose cardiac arrest patients and five healthy controls to assess the fMRI's utility for neuroprognostication. Tasks involved instrumental music listening, forward and backward language listening, and motor imagery. Task-specific reference images were created from group-level fMRI responses from the healthy controls. Dice scores measured the overlap of individual subject-level fMRI responses with the reference images. Task-relevant responsiveness index (Rindex) was calculated as the maximum Dice score across the four tasks. Correlation analyses showed that increased Dice scores were significantly associated with arousal recovery (P < 0.05) and emergence from the minimally conscious state (EMCS) by one year (P < 0.001) for all tasks except motor imagery. Greater Rindex was significantly correlated with improved arousal recovery (P = 0.002) and consciousness (P = 0.001). For patients who survived to discharge (n = 6), the Rindex's sensitivity was 75% for predicting EMCS (n = 4). Task-based fMRI holds promise for detecting covert consciousness in comatose cardiac arrest patients, but further studies are needed to confirm these findings. Caution is necessary when interpreting the absence of task-relevant fMRI responses as a surrogate for inevitable poor neurological prognosis.

Dynamic trajectories of life-threatening mass effect in patients with large middle cerebral artery stroke.

Background: Life-threatening, space-occupying mass effect due to cerebral edema and/or hemorrhagic transformation is an early complication of patients with middle cerebral artery (MCA) stroke. Little is known about longitudinal trajectories of laboratory and vital signs leading up to radiographic and clinical deterioration related to this mass effect. Methods: We curated a granular retrospective dataset of 635 patients with large middle cerebral artery (MCA) stroke totaling 108,547 data points for repeated measurements of 10 covariates, and 40 time-independent covariates. We assessed longitudinal trajectories of the 10 longitudinal variables during the 72 hours preceding three outcomes representative of life-threatening mass effect: midline shift (MLS) ≥5mm, pineal gland shift (PGS) >4mm, and decompressive hemicraniectomy (DHC). We used a "backward looking" trajectory approach. Patients were aligned according to the time of outcome occurrence and the trajectory of each variable was assessed prior to that outcome by accounting for both cases and non-cases. Results: Of 635 patients, 49% were female, and mean age was 69 years. Thirty five percent of patients had MLS ≥ 5mm, 24.1% had PGS >4mm, and DHC occurred in 10.7%. For the three outcomes of interest, backward-looking trajectories showed mild increases in white blood cell count (10 up to 11 K/UL within 72 hours), temperature (up to half a degree within 24 hours), and sodium (1-3 mEq/L within 24 hours) leading up to outcomes. We also observed a decrease in heart rate (75 - 65 beats per minute) 24 hours prior to DHC. Conclusions: Univariable longitudinal profiling showed that temperature, white blood cell count, and sodium increase prior to radiographic and clinical indicators of space-occupying mass effect. These findings will inform development of multivariable dynamic risk models to aid prediction of life-threatening space-occupying mass effect.