Serum biomarkers of brain injury to classify outcome after pediatric cardiac arrest*

Verification of the termination of resuscitation rules in pediatric out-of-hospital cardiac arrest cases

Aim

Pediatric out-of-hospital cardiac arrest has an unfavorable prognosis; therefore, making accurate predictions of outcomes is crucial for tailoring treatment plans. The termination of resuscitation rules must accurately predict unfavorable outcomes. In this study, we aimed to assess if the current termination of resuscitation rules for adults can predict factors associated with unfavorable outcomes in pediatric out-of-hospital cardiac arrest and examine the relationship between these factors and unfavorable outcomes.

Methods

A retrospective nationwide cohort study of pediatric cases registered in the Japanese Association for Acute Medicine Multicenter Out-of-Hospital Cardiac Arrest Registry from June 1, 2014, to December 31, 2020, was conducted. The association between the current termination of resuscitation rules and outcomes, such as 30-day mortality and unfavorable 30-day neurological outcomes following out-of-hospital cardiac arrest, was evaluated.

Results

A total of 1,216 participants were included. The positive predictive value for predicting 30-day mortality for each termination of resuscitation rule exceeded 0.9. The specificity and positive predictive value for predicting unfavorable 30-day neurological outcomes were 1.00, indicating that no rules identified favorable outcomes. Factors such as no bystander witness, no return of spontaneous circulation before hospital arrival, no automated external defibrillator or defibrillator use, and no bystander cardiopulmonary resuscitation were associated with poor 30-day mortality and neurological outcomes.

Conclusion

Adult termination of resuscitation rules had a high positive predictive value for predicting pediatric out-of-hospital cardiac arrest. However, surviving cases make it challenging to use these rules for end-of-resuscitation decisions, indicating the need for identifying new rules to help predict neurological outcomes.

Serum tau protein and myelin basic protein in pediatric patients with congenital heart defects undergoing cardiac surgery: preliminary assessment as novel neuromarkers of brain injury

INTRODUCTION

Neurological impairment is a big concern in the development of patients with congenital heart defects (CHD). A number of neuromarkers have been studied in search of a diagnostic or prognostic marker for brain injury during the vulnerable perioperative period. Our aim was to assess two novel neuromarkers, myelin basic protein (MBP) and protein Tau (pTau), as diagnostic markers for brain injury in perioperative period in children with CHD.

METHODS

Forty patients were enrolled and dichotomized based on peripheric oxygen saturation in cyanotic and non-cyanotic group. Blood samples were collected preoperative, after the induction of anesthesia, and in postoperative day 1. Neuromarker concentrations were measured using commercially available ELISA kits.

RESULTS

Neuromarkers' values were increased postoperative, with statistical significance reached only in non-cyanotic group (p < 0.0001). A significant positive correlation was observed between preoperatory MBP and albumin level, hemoglobin level, height, and weight of patients. Association with cerebral saturations were analyzed by a coefficient defined as ≥ 20% reduction in cerebral saturation measured by near-infrared spectroscopy during perioperative period. An acceptable predicting model was observed with pTau in cyanotic group (AUC = 0.7).

CONCLUSION

We evaluated MBP and pTau as potential biomarkers of brain injury in children with CHD undergoing cardiac surgery. Elevated postoperative pTau and MBP concentrations were observed in both groups. Elevated pTau values were associated with perioperative hypoxemia.

Exploratory factor analysis yields grouping of brain injury biomarkers significantly associated with outcomes in neonatal and pediatric ECMO

In this two-center prospective cohort study of children on ECMO, we assessed a panel of plasma brain injury biomarkers using exploratory factor analysis (EFA) to evaluate their interplay and association with outcomes. Biomarker concentrations were measured daily for the first 3 days of ECMO support in 95 participants. Unfavorable composite outcome was defined as in-hospital mortality or discharge Pediatric Cerebral Performance Category > 2 with decline ≥ 1 point from baseline. EFA grouped 11 biomarkers into three factors. Factor 1 comprised markers of cellular brain injury (NSE, BDNF, GFAP, S100β, MCP1, VILIP-1, neurogranin); Factor 2 comprised markers related to vascular processes (vWF, PDGFRβ, NPTX1); and Factor 3 comprised the BDNF/MMP-9 cellular pathway. Multivariable logistic models demonstrated that higher Factor 1 and 2 scores were associated with higher odds of unfavorable outcome (adjusted OR 2.88 [1.61, 5.66] and 1.89 [1.12, 3.43], respectively). Conversely, higher Factor 3 scores were associated with lower odds of unfavorable outcome (adjusted OR 0.54 [0.31, 0.88]), which is biologically plausible given the role of BDNF in neuroplasticity. Application of EFA on plasma brain injury biomarkers in children on ECMO yielded grouping of biomarkers into three factors that were significantly associated with unfavorable outcome, suggesting future potential as prognostic instruments.

2023 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation engages in a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation and first aid science. Draft Consensus on Science With Treatment Recommendations are posted online throughout the year, and this annual summary provides more concise versions of the final Consensus on Science With Treatment Recommendations from all task forces for the year. Topics addressed by systematic reviews this year include resuscitation of cardiac arrest from drowning, extracorporeal cardiopulmonary resuscitation for adults and children, calcium during cardiac arrest, double sequential defibrillation, neuroprognostication after cardiac arrest for adults and children, maintaining normal temperature after preterm birth, heart rate monitoring methods for diagnostics in neonates, detection of exhaled carbon dioxide in neonates, family presence during resuscitation of adults, and a stepwise approach to resuscitation skills training. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, using Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces list priority knowledge gaps for further research. Additional topics are addressed with scoping reviews and evidence updates.

Neuromonitoring after Pediatric Cardiac Arrest: Cerebral Physiology and Injury Stratification

BACKGROUND

Significant long-term neurologic disability occurs in survivors of pediatric cardiac arrest, primarily due to hypoxic-ischemic brain injury. Postresuscitation care focuses on preventing secondary injury and the pathophysiologic cascade that leads to neuronal cell death. These injury processes include reperfusion injury, perturbations in cerebral blood flow, disturbed oxygen metabolism, impaired autoregulation, cerebral edema, and hyperthermia. Postresuscitation care also focuses on early injury stratification to allow clinicians to identify patients who could benefit from neuroprotective interventions in clinical trials and enable targeted therapeutics.

METHODS

In this review, we provide an overview of postcardiac arrest pathophysiology, explore the role of neuromonitoring in understanding postcardiac arrest cerebral physiology, and summarize the evidence supporting the use of neuromonitoring devices to guide pediatric postcardiac arrest care. We provide an in-depth review of the neuromonitoring modalities that measure cerebral perfusion, oxygenation, and function, as well as neuroimaging, serum biomarkers, and the implications of targeted temperature management.

RESULTS

For each modality, we provide an in-depth review of its impact on treatment, its ability to stratify hypoxic-ischemic brain injury severity, and its role in neuroprognostication.

CONCLUSION

Potential therapeutic targets and future directions are discussed, with the hope that multimodality monitoring can shift postarrest care from a one-size-fits-all model to an individualized model that uses cerebrovascular physiology to reduce secondary brain injury, increase accuracy of neuroprognostication, and improve outcomes.

2023 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation engages in a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation and first aid science. Draft Consensus on Science With Treatment Recommendations are posted online throughout the year, and this annual summary provides more concise versions of the final Consensus on Science With Treatment Recommendations from all task forces for the year. Topics addressed by systematic reviews this year include resuscitation of cardiac arrest from drowning, extracorporeal cardiopulmonary resuscitation for adults and children, calcium during cardiac arrest, double sequential defibrillation, neuroprognostication after cardiac arrest for adults and children, maintaining normal temperature after preterm birth, heart rate monitoring methods for diagnostics in neonates, detection of exhaled carbon dioxide in neonates, family presence during resuscitation of adults, and a stepwise approach to resuscitation skills training. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, using Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces list priority knowledge gaps for further research. Additional topics are addressed with scoping reviews and evidence updates.

Utility of Brain Injury Biomarkers in Children With Congenital Heart Disease Undergoing Cardiac Surgery

BACKGROUND

Congenital heart disease (CHD) affects roughly 40,000 children annually. Despite advancements, children undergoing surgery for CHD are at an increased risk for adverse neurological outcomes. At present, there is no gold standard for the diagnosis of cerebral injury during the perioperative period.

OBJECTIVE

To determine the utility of brain injury biomarkers in children undergoing cardiac surgery.

METHODS

We searched PUBMED, EMBASE, LILACS, EBSCO, ClinicalTrials.gov, Cochrane Databases, and OVID interface to search MEDLINE through July 2021 and assessed the literature following the snowball method. The search terms used were "congenital heart disease," "cardiopulmonary bypass," "biomarkers," "diagnosis," "prognosis," and "children." No language or publication date restrictions were used. Papers studying inflammatory and imaging biomarkers were excluded. The risk of bias, strengths, and limitations of the study were reported. Study was registered in PROSPERO ID: CRD42021258385.

RESULTS

A total of 1449 articles were retrieved, and 27 were included. Eight neurological biomarkers were examined. Outcomes assessed included prognosis of poor neurological outcome, mortality, readmission, and diagnosis of brain injury. Results from these studies support that significant perioperative elevations in brain injury biomarkers in cerebrospinal fluid and serum, including S100B, GFAP, NSE, and activin A, may be diagnostic of real-time brain injury and serve as an independent predictor of adverse neurological outcomes in patients with CHD undergoing cardiopulmonary bypass.

CONCLUSIONS

There are limited homogeneous data in the field, limiting the generalizability and comparability of the results. Further large-scale longitudinal studies addressing neurological biomarkers in children undergoing CHD corrective surgery are required to support the routine use of neuronal biomarkers in this population.

Serum Markers of Brain Injury in Pediatric Patients with Congenital Heart Defects Undergoing Cardiac Surgery: Diagnostic and Prognostic Role

Introduction: The objectives of this study were to assess the role of neuromarkers like glial fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF), protein S100 (pS100), and neuron-specific enolase (NSE) as diagnostic markers of acute brain injury and also as prognostic markers for short-term neurodevelopmental impairment. Methods: Pediatric patients with congenital heart defects (CHDs) undergoing elective cardiac surgery were included. Neurodevelopmental functioning was assessed preoperatively and 4-6 months postoperatively using the Denver Developmental Screening Test II. Blood samples were collected preoperatively and postoperatively. During surgery, regional cerebral tissue oxygen saturation was monitored using near-infrared spectroscopy (NIRS). Results: Forty-two patients were enrolled and dichotomized into cyanotic and non-cyanotic groups based on peripheric oxygen saturation. Nineteen patients (65.5%) had abnormal developmental scores in the non-cyanotic group and eleven (84.6%) in the cyanotic group. A good diagnostic model was observed between NIRS values and GFAP in the cyanotic CHD group (AUC = 0.7). A good predicting model was observed with GFAP and developmental scores in the cyanotic CHD group (AUC = 0.667). A correlation was found between NSE and developmental quotient scores (r = 0.09, p = 0.046). Conclusions: From all four neuromarkers studied, only GFAP was demonstrated to be a good diagnostic and prognostic factor in cyanotic CHD patients. NSE had only prognostic value.

Evaluation of Serum Biomarkers and Electroencephalogram to Determine Survival Outcomes in Pediatric Post-Cardiac-Arrest Patients

Cardiac arrest causes primary and secondary brain injuries. We evaluated the association between neuron-specific enolase (NSE), serum S-100B (S100B), electroencephalogram (EEG) patterns, and post-cardiac arrest outcomes in pediatric patients. A prospective observational study was conducted in the pediatric intensive care unit and included 41 post-cardiac arrest patients who underwent EEG and serum sampling for NSE and S100B. The participants were aged 1 month to 18 years who experienced cardiac arrest and underwent CPR after a sustained return of spontaneous circulation for ≥48 h. Approximately 19.5% (n = 8) of patients survived until ICU discharge. Convulsions and sepsis were significantly associated with higher mortality (relative risk: 1.33 [95% CI = 1.09-1.6] and 1.99 [95% CI = 0.8-4.7], respectively). Serum NSE and S100B levels were not statistically associated with the outcome (p = 0.278 and 0.693, respectively). NSE levels were positively correlated with the duration of CPR. EEG patterns were significantly associated with the outcome (p = 0.01). Non-epileptogenic EEG activity was associated with the highest survival rate. Post-cardiac arrest syndrome is a serious condition with a high mortality rate. Management of sepsis and convulsions affects prognosis. We believe that NSE and S100B may have no benefit in survival evaluation. EEG can be considered for post-cardiac arrest patients.

Limbic pathway vulnerability associates with neurologic outcome in children after cardiac arrest

AIM

To analyze whether brain connectivity sequences including diffusion tensor imaging (DTI) and resting state functional magnetic resonance imaging (rsfMRI) identify vulnerable brain regions and networks associated with neurologic outcome after pediatric cardiac arrest.

METHODS

Children aged 2 d-17 y with cardiac arrest were enrolled in one of 2 parent studies at a single center. Clinically indicated brain MRI with DTI and rsfMRI and performed within 2 weeks after arrest were analyzed. Tract-wise fractional anisotropy (FA) and axial, radial, and mean diffusivity assessed DTI, and functional connectivity strength (FCS) assessed rsfMRI between outcome groups. Unfavorable neurologic outcome was defined as Pediatric Cerebral Performance Category score 4-6 or change > 1 between 6 months after arrest vs baseline.

RESULTS

Among children with DTI (n = 28), 57% had unfavorable outcome. Mean, radial, axial diffusivity and FA of varying direction of magnitude in the limbic tracts, including the right cingulum parolfactory, left cingulum parahippocampal, corpus callosum forceps major, and corpus callosum forceps minor tracts, were associated with unfavorable neurologic outcome (p < 0.05). Among children with rsfMRI (n = 12), 67% had unfavorable outcome. Decreased FCS in the ventromedial and dorsolateral prefrontal cortex, insula, precentral gyrus, anterior cingulate, and inferior parietal lobule were correlated regionally with unfavorable neurologic outcome (p < 0.05 Family-Wise Error corrected).

CONCLUSION

Decreased multimodal connectivity measures of paralimbic tracts were associated with unfavorable neurologic outcome after pediatric cardiac arrest. Longitudinal analysis correlating brain connectivity sequences with long term neuropsychological outcomes to identify the impact of pediatric cardiac arrest in vulnerable brain networks over time appears warranted.

Association of EEG and Blood-Based Brain Injury Biomarker Accuracy to Prognosticate Mortality After Pediatric Cardiac Arrest: An Exploratory Study

BACKGROUND

Evaluate the accuracy of brain-based blood biomarkers neuron-specific enolase (NSE) and S100b and electroencephalography (EEG) features alone and in combination with prognosticate 6-month mortality after pediatric cardiac arrest. We hypothesized that the combination of blood brain-based biomarkers and EEG features would have superior classification accuracy of outcome versus either alone.

METHODS

Children (n = 58) aged between 1 week and 17 years admitted to the ICU following cardiac arrest at a tertiary care children's hopital were eligible for this secondary study. Blood NSE and S100b were measured closest to 24 hours after return of spontaneous circulation (ROSC). EEGs closest to 24 hours (median 11, interquartile range [IQR] 6 to 16 h) post-ROSC were evaluated by two epileptologists. EEG grade was informed by background frequency, amplitude, and continuity. Sleep spindles were present or absent. Mortality was assessed at six months post-ROSC. Area under the receiver operator curve (AUC) was performed for individual and combined brain-based biomarkers and EEG features.

RESULTS

Children were aged 2.6 (IQR 0.6 to 10.4) years, and 25 (43%) died. Children who died had increased blood NSE (49.7 [28.0 to 63.1] vs 18.2 [9.8 to 31.8] ng/mL) and S100b (0.118 [0.036 to 0.296] vs 0.012 [0.003 to 0.021] ng/mL) and poor (discontinuous or isoelectric) EEG grade (76% vs 33%) more frequently than survivors (P < 0.05). AUC for NSE to predict mortality was 0.789, and was 0.841 when combined with EEG grade and spindles. S100b AUC for mortality was 0.856 and was optimal alone.

CONCLUSIONS

In this exploratory study, the combination of brain-based biomarkers and EEG features may provide more accurate prognostication than either test alone after pediatric cardiac arrest.

Use of Magnetic Resonance Imaging in Neuroprognostication After Pediatric Cardiac Arrest: Survey of Current Practices

BACKGROUND

Use of magnetic resonance imaging (MRI) as a tool to aid in neuroprognostication after cardiac arrest (CA) has been described, yet details of specific indications, timing, and sequences are unknown. We aim to define the current practices in use of brain MRI in prognostication after pediatric CA.

METHODS

A survey was distributed to pediatric institutions participating in three international studies. Survey questions related to center demographics, clinical practice patterns of MRI after CA, neuroimaging resources, and details regarding MRI decision support.

RESULTS

Response rate was 31% (44 of 143). Thirty-four percent (15 of 44) of centers have a clinical pathway informing the use of MRI after CA. Fifty percent (22 of 44) of respondents reported that an MRI is obtained in nearly all patients with CA, and 32% (14 of 44) obtain an MRI in those who do not return to baseline neurological status. Poor neurological examination was reported as the most common factor (91% [40 of 44]) determining the timing of the MRI. Conventional sequences (T1, T2, fluid-attenuated inversion recovery, and diffusion-weighted imaging/apparent diffusion coefficient) are routinely used at greater than 97% of centers. Use of advanced imaging techniques (magnetic resonance spectroscopy, diffusion tensor imaging, and functional MRI) were reported by less than half of centers.

CONCLUSIONS

Conventional brain MRI is a common practice for prognostication after CA. Advanced imaging techniques are used infrequently. The lack of standardized clinical pathways and variability in reported practices support a need for higher-quality evidence regarding the indications, timing, and acquisition protocols of clinical MRI studies.

Association of Blood-Based Brain Injury Biomarker Concentrations With Outcomes After Pediatric Cardiac Arrest

IMPORTANCE

Families and clinicians have limited validated tools available to assist in estimating long-term outcomes early after pediatric cardiac arrest. Blood-based brain-specific biomarkers may be helpful tools to aid in outcome assessment.

OBJECTIVE

To analyze the association of blood-based brain injury biomarker concentrations with outcomes 1 year after pediatric cardiac arrest.

DESIGN, SETTING, AND PARTICIPANTS

The Personalizing Outcomes After Child Cardiac Arrest multicenter prospective cohort study was conducted in pediatric intensive care units at 14 academic referral centers in the US between May 16, 2017, and August 19, 2020, with the primary investigators blinded to 1-year outcomes. The study included 120 children aged 48 hours to 17 years who were resuscitated after cardiac arrest, had pre-cardiac arrest Pediatric Cerebral Performance Category scores of 1 to 3 points, and were admitted to an intensive care unit after cardiac arrest.

EXPOSURE

Cardiac arrest.

MAIN OUTCOMES AND MEASURES

The primary outcome was an unfavorable outcome (death or survival with a Vineland Adaptive Behavior Scales, third edition, score of <70 points) at 1 year after cardiac arrest. Glial fibrillary acidic protein (GFAP), ubiquitin carboxyl-terminal esterase L1 (UCH-L1), neurofilament light (NfL), and tau concentrations were measured in blood samples from days 1 to 3 after cardiac arrest. Multivariate logistic regression and area under the receiver operating characteristic curve (AUROC) analyses were performed to examine the association of each biomarker with outcomes on days 1 to 3.

RESULTS

Among 120 children with primary outcome data available, the median (IQR) age was 1.0 (0-8.5) year; 71 children (59.2%) were male. A total of 5 children (4.2%) were Asian, 19 (15.8%) were Black, 81 (67.5%) were White, and 15 (12.5%) were of unknown race; among 110 children with data on ethnicity, 11 (10.0%) were Hispanic, and 99 (90.0%) were non-Hispanic. Overall, 70 children (58.3%) had a favorable outcome, and 50 children (41.7%) had an unfavorable outcome, including 43 deaths. On days 1 to 3 after cardiac arrest, concentrations of all 4 measured biomarkers were higher in children with an unfavorable vs a favorable outcome at 1 year. After covariate adjustment, NfL concentrations on day 1 (adjusted odds ratio [aOR], 5.91; 95% CI, 1.82-19.19), day 2 (aOR, 11.88; 95% CI, 3.82-36.92), and day 3 (aOR, 10.22; 95% CI, 3.14-33.33); UCH-L1 concentrations on day 2 (aOR, 11.27; 95% CI, 3.00-42.36) and day 3 (aOR, 7.56; 95% CI, 2.11-27.09); GFAP concentrations on day 2 (aOR, 2.31; 95% CI, 1.19-4.48) and day 3 (aOR, 2.19; 95% CI, 1.19-4.03); and tau concentrations on day 1 (aOR, 2.44; 95% CI, 1.14-5.25), day 2 (aOR, 2.28; 95% CI, 1.31-3.97), and day 3 (aOR, 2.04; 95% CI, 1.16-3.57) were associated with an unfavorable outcome. The AUROC models were significantly higher with vs without the addition of NfL on day 2 (AUROC, 0.932 [95% CI, 0.877-0.987] vs 0.871 [95% CI, 0.793-0.949]; P = .02) and day 3 (AUROC, 0.921 [95% CI, 0.857-0.986] vs 0.870 [95% CI, 0.786-0.953]; P = .03).

CONCLUSIONS AND RELEVANCE

In this cohort study, blood-based brain injury biomarkers, especially NfL, were associated with an unfavorable outcome at 1 year after pediatric cardiac arrest. Additional evaluation of the accuracy of the association between biomarkers and neurodevelopmental outcomes beyond 1 year is needed.

Chronic critical illness and post-intensive care syndrome: from pathophysiology to clinical challenges

Background

Post‐intensive care syndrome (PICS) encompasses physical, cognition, and mental impairments persisting after intensive care unit (ICU) discharge. Ultimately it significantly impacts the long‐term prognosis, both in functional outcomes and survival. Thus, survivors often develop permanent disabilities, consume a lot of healthcare resources, and may experience prolonged suffering. This review aims to present the multiple facets of the PICS, decipher its underlying mechanisms, and highlight future research directions.

Main text

This review abridges the translational data underlying the multiple facets of chronic critical illness (CCI) and PICS. We focus first on ICU-acquired weakness, a syndrome characterized by impaired contractility, muscle wasting, and persisting muscle atrophy during the recovery phase, which involves anabolic resistance, impaired capacity of regeneration, mitochondrial dysfunction, and abnormalities in calcium homeostasis. Second, we discuss the clinical relevance of post-ICU cognitive impairment and neuropsychological disability, its association with delirium during the ICU stay, and the putative role of low-grade long-lasting inflammation. Third, we describe the profound and persistent qualitative and quantitative alteration of the innate and adaptive response. Fourth, we discuss the biological mechanisms of the progression from acute to chronic kidney injury, opening the field for renoprotective strategies. Fifth, we report long-lasting pulmonary consequences of ARDS and prolonged mechanical ventilation. Finally, we discuss several specificities in children, including the influence of the child’s pre-ICU condition, development, and maturation.

Conclusions

Recent understandings of the biological substratum of the PICS’ distinct features highlight the need to rethink our patient trajectories in the long term. A better knowledge of this syndrome and precipitating factors is necessary to develop protocols and strategies to alleviate the CCI and PICS and ultimately improve patient recovery.

Serum levels of the cold stress hormones FGF21 and GDF-15 after cardiac arrest in infants and children enrolled in single center therapeutic hypothermia clinical trials

OBJECTIVE

Fibroblast Growth Factor 21 (FGF21) and Growth Differentiation Factor-15 (GDF-15) are putative neuroprotective cold stress hormones (CSHs) provoked by cold exposure that may be age-dependent. We sought to characterize serum FGF21 and GDF-15 levels in pediatric cardiac arrest (CA) patients and their association with use of therapeutic hypothermia (TH).

METHODS

Secondary analysis of serum samples from clinical trials. We measured FGF21 and GDF-15 levels in pediatric patients post-CA and compared levels to both pediatric intensive care (PICU) and healthy controls. Post-CA, we compared normothermia (NT) vs TH (33 °C for 72 h) treated cohorts at < 24 h, 24 h, 48 h, 72 h, and examined the change in CSHs over 72 h. We also assessed association between hospital mortality and initial levels.

RESULTS

We assessed 144 samples from 68 patients (27 CA [14 TH, 13 NT], 9 PICU and 32 healthy controls). Median initial FGF21 levels were higher post-CA vs. healthy controls (392 vs. 40 pg/mL, respectively, P < 0.001). Median GDF-15 levels were higher post-CA vs. healthy controls (7,089 vs. 396 pg/mL, respectively, P < 0.001). In the CA group, the median change in FGF21 from PICU day 1-3 (after 72 h of temperature control), was higher in TH vs. NT (231 vs. -20 pg/mL, respectively, P < 0.05), with no difference in GDF-15 over time. Serum GDF-15 levels were higher in CA patients that died vs. survived (19,450 vs. 5,337 pg/mL, respectively, P < 0.05), whereas serum FGF21 levels were not associated with mortality.

CONCLUSION

Serum levels of FGF21 and GDF-15 increased after pediatric CA, and FGF21 appears to be augmented by TH.

Biomarkers associated with mortality in pediatric patients with cardiac arrest and acute respiratory distress syndrome

AIMS

To identify plasma biomarkers associated with cardiac arrest in a cohort of children with acute respiratory distress syndrome (ARDS), and to assess the association of these biomarkers with mortality in children with cardiac arrest and ARDS (ARDS + CA).

METHODS

This was a secondary analysis of a single-center prospective cohort study of children with ARDS from 2014-2019 with 17 biomarkers measured. Clinical characteristics and biomarkers were compared between subjects with ARDS + CA and ARDS with univariate analysis. In a sub-cohort of ARDS + CA subjects, the association between biomarker levels and mortality was tested using univariate and bivariate logistic regression.

RESULTS

Biomarkers were measured in 333 subjects: 301 with ARDS (median age 5.3 years, 55.5% male) and 32 ARDS + CA (median age 8 years, 53.1% male). More arrests (69%) occurred out-of-hospital with a median CPR duration of 11 (IQR 5.5, 25) minutes. ARDS severity, PRISM III score, vasoactive-ionotropic score and extrapulmonary organ failures were worse in the ARDS + CA versus ARDS group. Eight biomarkers were elevated in the ARDS + CA versus ARDS cohort: sRAGE, nucleosomes, SP-D, CCL22, IL-6, HSP70, IL-8, and MIP-1b. sRAGE, SP-D, and CCL22 remained elevated when the cohorts were matched for illness severity. When controlling for severity of ARDS and cardiac arrest characteristics, sRAGE, IL-6 and granzyme B were associated with mortality in the ARDS + CA group.

CONCLUSION

sRAGE, IL-6 and granzyme B were associated with cardiac arrest mortality when controlling for illness severity. sRAGE was consistently higher in the ARDS + CA cohort compared to ARDS and retained independent association with mortality.

The Value of the Biomarkers Neuron-Specific Enolase and S100 Calcium-Binding Protein for Prediction of Mortality in Children Resuscitated After Cardiac Arrest

The aim of the present study was to assess the ability of the biomarkers neuron-specific enolase (NSE) and S100 calcium-binding protein b (S100b) to predict 30 day mortality in children resuscitated from cardiac arrest (CA). It was a prospective observational study at a single tertiary heart centre. Consecutive children were admitted after resuscitated in-hospital and out-of-hospital CA. Levels of NSE and S100b were analyzed from 12 to 24 hours, from 24 to 48 hours, and from 48 to 72 hours after admission. The primary endpoint was 30-day mortality. Differences in biomarker levels between survivors and non-survivors were analyzed with the Mann-Whitney U test. Receiver operating characteristics (ROC) curves were applied to assess the predictive ability of the biomarkers and the areas under the ROC curves (AUC) were presented. A total of 32 resuscitated CA patients were included, and 12 (38%) patients died within 30 days after resuscitation. We observed significantly higher levels of NSE and S100b in non-survivors compared to survivors at all timepoints from 12 to 72 hours after CA. NSE achieved AUCs from 0.91-0.98 for prediction of 30 day mortality, whereas S100b achieved AUCs from 0.93-0.94. An NSE cut-off of 61 μg/L sampled between 12-24 hours from admission achieved a sensitivity of 80% and a specificity of 100% for prediction of 30 day mortality. In children resuscitated from CA, the biomarkers NSE and S100b appear to be solid predictors of mortality after 30 days.

Serum Biomarkers of Regeneration and Plasticity are Associated with Functional Outcome in Pediatric Neurocritical Illness: An Exploratory Study

BACKGROUND/OBJECTIVE

Pediatric neurocritical care survivorship is frequently accompanied by functional impairments. Lack of prognostic biomarkers is a barrier to early identification and management of impairment. We explored the association between blood biomarkers and functional impairment in children with acute acquired brain injury.

METHODS

This study is a secondary analysis of a randomized control trial evaluating early versus usual care rehabilitation in the pediatric intensive care unit (PICU). Forty-four children (17 [39%] female, median age 11 [interquartile range 6-13] years) with acute acquired brain injury admitted to the PICU were studied. A single center obtained serum samples on admission days 0, 1, 3, 5, and the day closest to hospital discharge. Biomarkers relevant to brain injury (neuron specific enolase [NSE], S100b), inflammation (interleukin [IL-6], C-reactive protein), and regeneration (brain-derived neurotrophic factor [BDNF], vascular endothelial growth factor [VEGF]) were collected. Biomarkers were analyzed using a Luminex® bioassay. Functional status scale (FSS) scores were abstracted from the medical record. New functional impairment was defined as a (worse) FSS score at hospital discharge compared to pre-PICU (baseline). Individual biomarker fluorescence index (FI) values for each sample collection day were correlated with new functional impairment using Spearman rank correlation coefficient (ρ). Trends in repeated measures of biomarker FI over time were explored graphically, and the association between repeated measures of biomarker FI and new functional impairment was analyzed using covariate adjusted linear mixed-effect models.

RESULTS

Functional impairment was inversely correlated with markers of regeneration and plasticity including BDNF at day 3 (ρ =  - 0.404, p = .015), day 5 (ρ =  - 0.549, p = 0.005) and hospital discharge (ρ =  - 0.420, p = 0.026) and VEGF at day 1 (ρ =  - 0.282, p = 0.008) and hospital discharge (ρ =  - 0.378, p = 0.047), such that lower levels of both markers at each time point were associated with greater impairment. Similarly, repeated measures of BDNF and VEGF were inversely correlated with new functional impairment (B =  - 0.001, p = 0.001 and B =  - 0.001, p = 0.003, respectively). NSE, a biomarker of acute brain injury, showed a positive correlation between day 0 levels and new functional impairment (ρ = 0.320, p = 0.044).

CONCLUSIONS

Blood-based biomarkers of regeneration and plasticity may hold prognostic utility for functional impairment among pediatric patients with neurocritical illness and warrant further investigation.

Biomarkers and Immune Repertoire Metrics Identified by Peripheral Blood Transcriptomic Sequencing Reveal the Pathogenesis of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global crisis; however, our current understanding of the host immune response to SARS-CoV-2 infection remains limited. Herein, we performed RNA sequencing using peripheral blood from acute and convalescent patients and interrogated the dynamic changes of adaptive immune response to SARS-CoV-2 infection over time. Our results revealed numerous alterations in these cohorts in terms of gene expression profiles and the features of immune repertoire. Moreover, a machine learning method was developed and resulted in the identification of five independent biomarkers and a collection of biomarkers that could accurately differentiate and predict the development of COVID-19. Interestingly, the increased expression of one of these biomarkers, UCHL1, a molecule related to nervous system damage, was associated with the clustering of severe symptoms. Importantly, analyses on immune repertoire metrics revealed the distinct kinetics of T-cell and B-cell responses to SARS-CoV-2 infection, with B-cell response plateaued in the acute phase and declined thereafter, whereas T-cell response can be maintained for up to 6 months post-infection onset and T-cell clonality was positively correlated with the serum level of anti-SARS-CoV-2 IgG. Together, the significantly altered genes or biomarkers, as well as the abnormally high levels of B-cell response in acute infection, may contribute to the pathogenesis of COVID-19 through mediating inflammation and immune responses, whereas prolonged T-cell response in the convalescents might help these patients in preventing reinfection. Thus, our findings could provide insight into the underlying molecular mechanism of host immune response to COVID-19 and facilitate the development of novel therapeutic strategies and effective vaccines.

An Exploratory Assessment of Serum Biomarkers of Post-Cardiac Arrest Syndrome in Children

AIM

We hypothesized that serum biomarkers of inflammation including chemokine, cytokine, pituitary hormones, and growth factors following cardiac arrest in children would independently associate with 6-month neurologic outcome.

METHODS

In this prospective observational single center study of children with in-hospital and out-of-hospital cardiac arrest surviving to intensive care unit admission, serum was obtained twice per 24h period between 0h and 96h and once at approximately 196h post-cardiac arrest. Inflammatory mediators, hormones, and growth factors were analyzed by Luminex Multiplex Bead Immunoassay. We recorded demographics, resuscitation characteristics, and Pediatric Cerebral Performance Category (PCPC) at 6 months. We analyzed the association and area under the curve (AUC) of biomarker levels with favorable (PCPC 1-3) or unfavorable (PCPC 4-6, or >1 increase from baseline) outcome.

RESULTS

Forty-two children (50% female; median age of 2.5 [IQR: 0.4-10.2]) were enrolled and 18 (42%) died prior to 6-month follow up. Receiver operator curves for initial levels of ciliary neurotrophic factor (CNTF, AUC 0.84, 95% CI 0.73-0.96, p<0.001) and interleukin (IL-17, AUC 0.84, 95% CI 0.73-0.97, p<0.001) best classified favorable versus unfavorable 6-month outcome. In multivariable analysis, initial levels of CNTF and IL-17 remained associated with 6-month PCPC. Peak levels of interferon-γ-inducible protein 10 (IP-10), CNTF, and hepatocyte growth factor (HGF) were also independently associated with outcome.

CONCLUSION

Increased serum concentrations of CNTF and IL-17 associated with unfavorable 6-month neurologic outcome of children surviving cardiac arrest. Further investigation of the prognostic utility and roles of CNTF and IL-17 in the pathophysiology of post-cardiac arrest syndrome are warranted.

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.

Blood Biomarkers for Detection of Brain Injury in COVID-19 Patients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus attacks multiple organs of coronavirus disease 2019 (COVID-19) patients, including the brain. There are worldwide descriptions of neurological deficits in COVID-19 patients. Central nervous system (CNS) symptoms can be present early in the course of the disease. As many as 55% of hospitalized COVID-19 patients have been reported to have neurological disturbances three months after infection by SARS-CoV-2. The mutability of the SARS-COV-2 virus and its potential to directly affect the CNS highlight the urgency of developing technology to diagnose, manage, and treat brain injury in COVID-19 patients. The pathobiology of CNS infection by SARS-CoV-2 and the associated neurological sequelae of this infection remain poorly understood. In this review, we outline the rationale for the use of blood biomarkers (BBs) for diagnosis of brain injury in COVID-19 patients, the research needed to incorporate their use into clinical practice, and the improvements in patient management and outcomes that can result. BBs of brain injury could potentially provide tools for detection of brain injury in COVID-19 patients. Elevations of BBs have been reported in cerebrospinal fluid (CSF) and blood of COVID-19 patients. BB proteins have been analyzed in CSF to detect CNS involvement in patients with infectious diseases, including human immunodeficiency virus and tuberculous meningitis. BBs are approved by the U.S. Food and Drug Administration for diagnosis of mild versus moderate traumatic brain injury and have identified brain injury after stroke, cardiac arrest, hypoxia, and epilepsy. BBs, integrated with other diagnostic tools, could enhance understanding of viral mechanisms of brain injury, predict severity of neurological deficits, guide triage of patients and assignment to appropriate medical pathways, and assess efficacy of therapeutic interventions in COVID-19 patients.

Optimal VAsopressor TitraTION in patients 65 years and older (OVATION-65): protocol and statistical analysis plan for a randomised clinical trial

INTRODUCTION

Vasodilatory hypotension is common among intensive care unit (ICU) patients; vasopressors are considered standard of care. However, optimal mean arterial pressure (MAP) targets for vasopressor titration are unknown. The objective of the Optimal VAsopressor TitraTION in patients 65 years and older (OVATION-65) trial is to ascertain the effect of permissive hypotension (vasopressor titration to achieve MAP 60-65 mm Hg) versus usual care on biomarkers of organ injury in hypotensive patients aged ≥65 years.

METHODS AND ANALYSIS

OVATION-65 is an allocation-concealed randomised trial in 7 Canadian hospitals. Eligible patients are ≥65 years of age, in an ICU with vasodilatory hypotension, receiving vasopressors for ≤12 hours to maintain MAP ≥65 mm Hg during or after adequate fluid resuscitation, and expected to receive vasopressors for ≥6 additional hours. Patients are excluded for any of the following: active treatment for spinal cord or acute brain injury; vasopressors given solely for bleeding, ventricular failure or postcardiopulmonary bypass vasoplegia; withdrawal of life-sustaining treatments expected within 48 hours; death perceived as imminent; previous enrolment in OVATION-65; organ transplant within the last year; receiving extracorporeal life support or lack of physician equipoise. Patients are randomised to permissive hypotension versus usual care for up to 28 days. The primary outcome is high-sensitivity troponin T, a biomarker of cardiac injury, on day 3. Secondary outcomes include biomarkers of injury to other organs (brain, liver, intestine, skeletal muscle); lactate (a biomarker of global tissue dysoxia); resource utilisation; adverse events; mortality (90 days and 6 months) and cognitive function (6 months). Assessors of biomarkers, mortality and cognitive function are blinded to allocation.

ETHICS AND DISSEMINATION

This protocol has been approved at all sites. Consent is obtained from the eligible patient, the substitute decision-maker if the patient is incapable, or in a deferred fashion where permitted. End-of-grant dissemination plans include presentations, publications and social media platforms and discussion forums.

TRIAL REGISTRATION NUMBER

NCT03431181.

Personalising Outcomes after Child Cardiac Arrest (POCCA): design and recruitment challenges of a multicentre, observational study

INTRODUCTION

Blood and imaging biomarkers show promise in prognosticating outcomes after paediatric cardiac arrest in pilot studies. We describe the methods and early recruitment challenges and solutions for an ongoing multicentre (n=14) observational trial, Personalising Outcomes following Child Cardiac Arrest to validate clinical, blood and imaging biomarkers individually and together in a clinically relevant panel.

METHODS AND ANALYSIS

Children (n=164) between 48 hours and 17 years of age who receive chest compressions irrespective of provider, duration, or event location and are admitted to an intensive care unit are eligible. Blood samples will be taken on days 1-3 for the measurement of brain-focused biomarkers analysed to predict the outcome. Clinically indicated and timed brain MRI and spectroscopy biomarkers will be analysed to predict the outcome. The primary outcome for the trial is survival with favourable (Vineland Adaptive Behavioural Scale score >70) outcome at 1 year. Secondary outcomes include mortality and pre-event and postdischarge measures of emotional, cognitive, physical and family functioning and health-related quality of life. Early enrollment targets were not met due to prolonged regulatory and subcontract processes. Multiple, simultaneous interventions including modification to inclusion criteria, additional sites and site visits were implemented with successful improvement in recruitment. Study procedures including outcomes and biomarker analysis are ongoing.

ETHICS AND DISSEMINATION

Twelve of 14 sites will use the centralised Institutional Review Board (IRB) at the University of Pittsburgh (PRO14030712). Two sites will use individual IRBs: Children's Healthcare of Atlanta Institutional Review Board and Children's Hospital of Wisconsin IRB. Parents and/or guardians are consented and children assented (when possible) by the site Primary investigator (PI) or research coordinator for enrollment. Study findings will be disseminated through scientific conferences, peer-reviewed journal publications, public study website materials and invited lectures.

TRIAL REGISTRATION NUMBER

NCT02769026.

A Systematic Review of Neuromonitoring Modalities in Children Beyond Neonatal Period After Cardiac Arrest

OBJECTIVES

Postresuscitation care in children focuses on preventing secondary neurologic injury and attempts to provide (precise) prognostication for both caregivers and the medical team. This systematic review provides an overview of neuromonitoring modalities and their potential role in neuroprognostication in postcardiac arrest children.

DATA RESOURCES

Databases EMBASE, Web of Science, Cochrane, MEDLINE Ovid, Google Scholar, and PsycINFO Ovid were searched in February 2019.

STUDY SELECTION

Enrollment of children after in- and out-of-hospital cardiac arrest between 1 month and 18 years and presence of a neuromonitoring method obtained within the first 2 weeks post cardiac arrest. Two reviewers independently selected appropriate studies based on the citations.

DATA EXTRACTION

Data collected included study characteristics and methodologic quality, populations enrolled, neuromonitoring modalities, outcome, and limitations. Evidence tables per neuromonitoring method were constructed using a standardized data extraction form. Each included study was graded according to the Oxford Evidence-Based Medicine scoring system.

DATA SYNTHESIS

Of 1,195 citations, 27 studies met the inclusion criteria. There were 16 retrospective studies, nine observational prospective studies, one observational exploratory study, and one pilot randomized controlled trial. Neuromonitoring methods included neurologic examination, routine electroencephalography and continuous electroencephalography, transcranial Doppler, MRI, head CT, plasma biomarkers, somatosensory evoked potentials, and brainstem auditory evoked potential. All evidence was graded 2B-2C.

CONCLUSIONS

The appropriate application and precise interpretation of available modalities still need to be determined in relation to the individual patient. International collaboration in standardized data collection during the (acute) clinical course together with detailed long-term outcome measurements (including functional outcome, neuropsychologic assessment, and health-related quality of life) are the first steps toward more precise, patient-specific neuroprognostication after pediatric cardiac arrest.

Macrophage-specific protein perforin-2 is associated with poor neurological recovery and reduced survival after sudden cardiac arrest

BACKGROUND

Biomarkers involved in inflammation and stress response were implicated in patients who were successfully resuscitated from out of hospital cardiac arrest (sR-OHCA). Here we report that macrophage-expressed gene, perforin-2, an evolutionarily conserved protein with membrane attack domain, is associated with poor neurological outcomes and mortality after sR-OHCA.

OBJECTIVES

To examine the association between circulating perforin-2 protein measured within 6-h of sR-OHCA, mortality and neurological outcomes.

METHODS

We prospectively enrolled 144 sR-OHCA patients from 4 different tertiary care centers. We measured perforin-2 and other conventional clinical biomarkers and compared between survivors vs. non-survivors. The neurological outcomes were dichotomized as poor or good according to the cereberal performance score.

RESULTS

At the end of the hospital stay, 45% of the patients had died and 46% had poor neurological outcomes. Serum perforin-2 levels were significantly higher in patients with poor neurological recovery, compared to the ones with good neurological recovery (ng/mL, 13.7 ± 45.9 vs. 1.2 ± 7.0, p = 0.01). There were no differences in other routinely measured biomarkers and left ventricular ejection fraction. On multivariate logistic regression, elevated perforin-2 (OR: 12.78, 95% CI: 1.0-17.8, p = 0.02), comatose on presentation (OR: 27.82, 95% CI: 0.2-19.5, p = 0.02) and non-shockable rhythm (OR: 17.04, 95% CI: 0.7-15.7, p = 0.01) were the significant predictors of poor neurological outcome.

CONCLUSIONS

This study reports a novel macrophage-expressed circulating biomarker perforin-2 to be strongly associated with reduced survival and poor neurological outcomes in sR-OHCA. These data can guide clinicians to prognosticate survival and neurological outcomes in sR-OHCA, and also form the basis for future therapeutic approaches.

The current practice regarding neuro-prognostication for comatose children after cardiac arrest differs between and within European PICUs: A survey

PURPOSE

To describe current practices in European Paediatric Intensive Care Units (PICUs) regarding neuro-prognostication in comatose children after cardiac arrest (CA).

METHODS

An anonymous online survey was conducted among members of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC) and the European Paediatric Neurology Society (EPNS) throughout January and February 2019. The survey consisted of 49 questions divided into 4 sections: general information, cardiac arrest, neuro-prognostication and follow-up.

RESULTS

The survey was sent to 1310 EPNS and 611 ESPNIC members. Of the 108 respondents, 71 (66%) (23 countries, 45 PICUs) completed the "neuro-prognostication" section. Eight PICUs (20%) had a local neuro-prognostication guideline. The 3 methods considered as most useful were neurological examination (92%), magnetic resonance imaging (MRI) (82%) and continuous electroencephalography (cEEG) (45%). In 50% a Pediatric Cerebral Performance Category (PCPC) score ≥ 4 was considered as poor neurological outcome. In 63% timing of determining neurological prognosis was based on the individual patient. Once decided that neurological prognosis was futile, 55% indicated that withdrawing life-sustaining therapy (WLST) was (one of) the options, whereas 44% continued PICU treatment (with or without restrictions). In 28 PICUs (68%) CA-survivors were scheduled for follow-up visits.

CONCLUSION

Local guidelines for neuro-prognostication in comatose children after CA are uncommon. Methods to assess neurological outcome were mainly neurological examination, MRI and cEEG. Consequences of poor outcome differed between respondents. Inaccuracies in neuro-prognostication can result in premature WLST, thereby biasing outcome research and creating a self-fulfilling cycle. Further research is needed to develop scientifically based international guidelines for neuro-prognostication in comatose children after CA.

Circulating Neurofilament Light Chain Is Associated With Survival After Pediatric Cardiac Arrest

OBJECTIVES

To characterize neurofilament light levels in children who achieved return of spontaneous circulation following cardiac arrest compared with healthy controls and determine an association between neurofilament light levels and clinical outcomes.

DESIGN

Retrospective cohort study.

SETTING

Academic quaternary PICU.

PATIENTS

Children with banked plasma samples from an acute respiratory distress syndrome biomarker study who achieved return of spontaneous circulation after a cardiac arrest and healthy controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Neurofilament light levels were determined with a highly sensitive single molecule array digital immunoassay. Patients were categorized into survivors and nonsurvivors and into favorable (Pediatric Cerebral Performance Category score of 1-2 or unchanged from baseline) or unfavorable (Pediatric Cerebral Performance Category score of 3-6 or Pediatric Cerebral Performance Category score change ≥1 from baseline). Associations between neurofilament light level and outcomes were determined using Wilcoxon rank-sum test. We enrolled 32 patients with cardiac arrest and 18 healthy controls. Demographics, severity of illness, and baseline Pediatric Cerebral Performance Category scores were similar between survivors and nonsurvivors. Healthy controls had lower median neurofilament light levels than patients after cardiac arrest (5.5 [interquartile range 5.0-8.2] vs 31.0 [12.0-338.6]; p < 0.001). Neurofilament light levels were higher in nonsurvivors than survivors (78.5 [26.2-509.1] vs 12.4 [10.3-28.2]; p = 0.012) and higher in survivors than healthy controls (p = 0.009). The four patients who survived with a favorable outcome had neurofilament light levels that were not different from patients with unfavorable outcomes (21.9 [8.5--35.7] vs 37.2 [15.4-419.1]; p = 0.60) although two of the four patients who survived with favorable outcomes had progressive encephalopathies with both baseline and postcardiac arrest Pediatric Cerebral Performance Category scores of 4.

CONCLUSIONS

Neurofilament light is a blood biomarker of hypoxic-ischemic brain injury and may help predict survival and neurologic outcome after pediatric cardiac arrest. Further study in a larger, dedicated cardiac arrest cohort with serial longitudinal measurements is warranted.

Normoxic re-oxygenation ameliorates end-organ injury after cardiopulmonary bypass

Background

In a rabbit model of cardiopulmonary bypass (CPB) and cardioplegic arrest, we previously showed that hyperoxic myocardial reperfusion was associated with increased left ventricular (LV) systolic dysfunction and myocardial injury compared with normoxic reperfusion. The aim of this study was to evaluate in our experimental model the impact of post-CPB reperfusion conditions on other organs potentially vulnerable to ischemic injury such as the brain and kidney.

Methods

After 60 min of CPB, aortic cross-clamp, and cold cardioplegic arrest, rabbits were reperfused under hyperoxic or normoxic conditions for 120 min. Left ventricular systolic contractility (LV + dP/dt) and diastolic relaxation (LV –dP/dt) were continuously recorded, and end-organ injury was assessed by measuring circulating biomarkers specific for kidney (cystatin C and creatinine) and brain injury [S100B and neuron specific enolase (NSE)]. At completion of the protocol, kidney and brain tissues were harvested for measuring oxidant stress (OS), inflammation and apoptosis.

Results

Following aortic cross-clamp removal, rabbits exposed to normoxic reperfusion demonstrated preserved LV systolic and diastolic function compared with hyperoxic reperfusion (LV + dP/dt: 70 ± 14% of pre-CPB vs. 36 ± 21%, p = 0.018; LV -dP/dt: 72 ± 36% of pre-CPB vs. 33 ± 20%, p = 0.023). Similarly, CPB increased plasma creatinine, S100B and NSE that were significantly attenuated by normoxic reperfusion compared with hyperoxic reperfusion (creatinine: 4.0 ± 0.5 vs. 7.1 ± 0.8 mg/dL, p = 0.004; S100B: 4.0 ± 0.8 vs. 6.7 ± 1.0 ng/mL, p = 0.047; NSE: 57.7 ± 6.8 vs. 101.3 ± 16.1 pg/mL, p = 0.040). Furthermore, both kidney and brain tissues showed increased mRNA expression and activation of pathways for OS, inflammation, and apoptosis, that were reduced under normoxic compared with hyperoxic conditions.

Conclusions

Normoxic reperfusion ameliorates cardiac, renal and neural injury compared with hyperoxic reperfusion in an in vivo animal model of CPB and cardioplegic arrest. This protective effect of normoxic reperfusion may be due to a reduction in signaling pathways for OS, inflammation, and apoptosis.

How can neurological outcomes be predicted in comatose pediatric patients after out-of-hospital cardiac arrest?

The prognosis of patients who are comatose after resuscitation remains uncertain. The accurate prediction of neurological outcome is important for management decisions and counseling. A neurological examination is an important factor for prognostication, but widely used sedatives alter the neurological examination and delay the response recovery. Additional studies including electroencephalography, somatosensory-evoked potentials, brain imaging, and blood biomarkers are useful for evaluating the extent of brain injury. This review aimed to assess the usefulness of and provide practical prognostic strategy for pediatric postresuscitation patients. The principles of prognostication are that the assessment should be delayed until at least 72 hours after cardiac arrest and the assessment should be multimodal. Furthermore, multiple factors including unmeasured confounders in individual patients should be considered when applying the prognostication strategy.

Prognostic value of the delta neutrophil index in pediatric cardiac arrest

The delta neutrophil index (DNI), which reflects the ratio of circulating immature neutrophils, has been reported to be highly predictive of mortality in systemic inflammation. We investigated the prognostic significance of DNI value for early mortality and neurologic outcomes after pediatric cardiac arrest (CA). We retrospectively analyzed the data of eligible patients (<19 years in age). Among 85 patients, 55 subjects (64.7%) survived and 36 (42.4%) showed good outcomes at 30 days after CA. Cox regression analysis revealed that the DNI values immediately after the return of spontaneous circulation, at 24 hours and 48 hours after CA, were related to an increased risk for death within 30 days after CA (P < 0.001). A DNI value of higher than 3.3% at 24 hours could significantly predict both 30-day mortality (hazard ratio: 11.8; P < 0.001) and neurologic outcomes (odds ratio: 8.04; P = 0.003). The C statistic for multivariable prediction models for 30-day mortality (incorporating DNI at 24 hours, compression time, and serum sodium level) was 0.799, and the area under the receiver operating characteristic curve of DNI at 24 hours for poor neurologic outcome was 0.871. Higher DNI was independently associated with 30-day mortality and poor neurologic outcomes after pediatric CA.

Brain-Specific Serum Biomarkers Predict Neurological Morbidity in Diagnostically Diverse Pediatric Intensive Care Unit Patients

BACKGROUND

Unexpected neurological morbidity in Pediatric Intensive Care Units (PICUs) remains high and is difficult to detect proactively. Brain-specific biomarkers represent a novel approach for early detection of neurological injury. We sought to determine whether serum concentrations of neuron-specific enolase (NSE), myelin basic protein (MBP), and S100B, specific for neurons, oligodendrocytes, and glia, respectively, were predictive of neurological morbidity in critically ill children.

METHODS

Serum was prospectively collected on days 1-7 from diagnostically diverse PICU patients (n = 103). Unfavorable neurological outcome at hospital discharge was defined as Pediatric Cerebral Performance Category (PCPC) score of 3-6 with a deterioration from baseline. NSE, MBP, and S100B concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS

Peak biomarker levels were greater in patients with unfavorable versus favorable neurological outcome [NSE 39.4 ± 44.1 vs. 12.2 ± 22.9 ng/ml (P = 0.005), MBP 9.1 ± 11.5 vs. 0.6 ± 1.3 ng/ml (P = 0.003), S100B 130 ± 232 vs. 34 ± 70 pg/ml (P = 0.04), respectively; mean ± SD]. Peak levels were each independently associated with unfavorable neurological outcome when controlling for presence of primary neurologic admission diagnosis and poor baseline PCPC using logistic regression analysis (NSE, P = 0.04; MBP, P = 0.004; S100B, P = 0.04), and had the following receiver operating characteristics: NSE 0.75 (0.58, 0.92), MBP 0.81 (0.66, 0.94), and S100B 0.80 (0.67, 0.93) (area under the curve [95% confidence intervals]).

CONCLUSIONS

Prospectively collected brain-specific serum biomarkers predict unfavorable neurological outcome in critically ill children. Serum biomarkers used in conjunction with clinical data could be used to generate models predicting early detection of neurological injury, allowing for more timely diagnostic and therapeutic interventions, potentially reducing neurological morbidity in the PICU.

Subphenotypes of Cardiac Arrest Patients Admitted to Intensive Care Unit: a latent profile analysis of a large critical care database

Cardiac arrest (CA) may occur due to a variety of causes with heterogeneity in their clinical presentation and outcomes. This study aimed to identify clinical patterns or subphenotypes of CA patients admitted to the intensive care unit (ICU). The clinical and laboratory data of CA patients in a large electronic healthcare database were analyzed by latent profile analysis (LPA) to identify whether subphenotypes existed. Multivariable Logistic regression was used to assess whether mortality outcome was different between subphenotypes. A total of 1,352 CA patients fulfilled the eligibility criteria were included. The LPA identified three distinct subphenotypes: Profile 1 (13%) was characterized by evidence of significant neurological injury (low GCS). Profile 2 (15%) was characterized by multiple organ dysfunction with evidence of coagulopathy (prolonged aPTT and INR, decreased platelet count), hepatic injury (high bilirubin), circulatory shock (low mean blood pressure and elevated serum lactate); Profile 3 was the largest proportion (72%) of all CA patients without substantial derangement in major organ function. Profile 2 was associated with a significantly higher risk of death (OR: 2.09; 95% CI: 1.30 to 3.38) whilst the mortality rates of Profiles 3 was not significantly different from Profile 1 in multivariable model. LPA using routinely collected clinical data could identify three distinct subphenotypes of CA; those with multiple organ failure were associated with a significantly higher risk of mortality than other subphenotypes. LPA profiling may help researchers to identify the most appropriate subphenotypes of CA patients for testing effectiveness of a new intervention in a clinical trial.

Standards for Studies of Neurological Prognostication in Comatose Survivors of Cardiac Arrest: A Scientific Statement From the American Heart Association

Significant improvements have been achieved in cardiac arrest resuscitation and postarrest resuscitation care, but mortality remains high. Most of the poor outcomes and deaths of cardiac arrest survivors have been attributed to widespread brain injury. This brain injury, commonly manifested as a comatose state, is a marker of poor outcome and a major basis for unfavorable neurological prognostication. Accurate prognostication is important to avoid pursuing futile treatments when poor outcome is inevitable but also to avoid an inappropriate withdrawal of life-sustaining treatment in patients who may otherwise have a chance of achieving meaningful neurological recovery. Inaccurate neurological prognostication leading to withdrawal of life-sustaining treatment and deaths may significantly bias clinical studies, leading to failure in detecting the true study outcomes. The American Heart Association Emergency Cardiovascular Care Science Subcommittee organized a writing group composed of adult and pediatric experts from neurology, cardiology, emergency medicine, intensive care medicine, and nursing to review existing neurological prognostication studies, the practice of neurological prognostication, and withdrawal of life-sustaining treatment. The writing group determined that the overall quality of existing neurological prognostication studies is low. As a consequence, the degree of confidence in the predictors and the subsequent outcomes is also low. Therefore, the writing group suggests that neurological prognostication parameters need to be approached as index tests based on relevant neurological functions that are directly related to the functional outcome and contribute to the quality of life of cardiac arrest survivors. Suggestions to improve the quality of adult and pediatric neurological prognostication studies are provided.

Pediatric Post–Cardiac Arrest Care: A Scientific Statement From the American Heart Association

Successful resuscitation from cardiac arrest results in a post–cardiac arrest syndrome, which can evolve in the days to weeks after return of sustained circulation. The components of post–cardiac arrest syndrome are brain injury, myocardial dysfunction, systemic ischemia/reperfusion response, and persistent precipitating pathophysiology. Pediatric post–cardiac arrest care focuses on anticipating, identifying, and treating this complex physiology to improve survival and neurological outcomes. This scientific statement on post–cardiac arrest care is the result of a consensus process that included pediatric and adult emergency medicine, critical care, cardiac critical care, cardiology, neurology, and nursing specialists who analyzed the past 20 years of pediatric cardiac arrest, adult cardiac arrest, and pediatric critical illness peer-reviewed published literature. The statement summarizes the epidemiology, pathophysiology, management, and prognostication after return of sustained circulation after cardiac arrest, and it provides consensus on the current evidence supporting elements of pediatric post–cardiac arrest care.

Lipidomics Detection of Brain Cardiolipins in Plasma Is Associated With Outcome After Cardiac Arrest

OBJECTIVES

Brain mitochondrial dysfunction limits neurologic recovery after cardiac arrest. Brain polyunsaturated cardiolipins, mitochondria-unique and functionally essential phospholipids, have unprecedented diversification. Since brain cardiolipins are not present in plasma normally, we hypothesized their appearance would correlate with brain injury severity early after cardiac arrest and return of spontaneous circulation.

DESIGN

Observational case-control study.

SETTING

Two medical centers within one city.

PARTICIPANTS (SUBJECTS)

We enrolled 41 adult cardiac arrest patients in whom blood could be obtained within 6 hours of resuscitation. Two subjects were excluded following outlier analysis. Ten healthy subjects were controls. Sprague-Dawley rats were used in asphyxial cardiac arrest studies.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We developed a high-resolution liquid chromatography/mass spectrometry method and determined cardiolipins speciation in human brain, heart, and plasma within 6 hours of (return of spontaneous circulation) from 39 patients with cardiac arrest, 5 with myocardial infarction, and 10 healthy controls. Cerebral score was derived from brain-specific cardiolipins identified in plasma of patients with varying neurologic injury and outcome. Using a rat model of cardiac arrest, cardiolipins were quantified in plasma, brain, and heart. Human brain exhibited a highly diverse cardiolipinome compared with heart that allowed the identification of brain-specific cardiolipins. Nine of 26 brain-specific cardiolipins were detected in plasma and correlated with brain injury. The cerebral score correlated with early neurologic injury and predicted discharge neurologic/functional outcome. Cardiolipin (70:5) emerged as a potential point-of-care marker predicting injury severity and outcome. In rat cardiac arrest, a significant reduction in hippocampal cardiolipins corresponded to their release from the brain into systemic circulation. Cerebral score was significantly increased in 10 minutes versus 5 minutes no-flow cardiac arrest and naïve controls.

CONCLUSIONS

Brain-specific cardiolipins accumulate in plasma early after return of spontaneous circulation and proportional to neurologic injury representing a promising novel biomarker.

The prognostic value of quantitative diffusion-weighted MRI after pediatric cardiopulmonary arrest

OBJECTIVES

The prognostic value of quantitative diffusion-weighted magnetic resonance imaging (DWI MRI) in predicting neurologic outcomes after pediatric cardiopulmonary arrest (CPA) has not been determined. The aim of this study was to identify a DWI MRI threshold for brain volume percent that correlates with neurologic outcome in children who remain comatose or display significant neurologic deficits immediately after resuscitation from CPA.

METHODS

This single-center retrospective study analyzed DWI MRIs of pediatric patients who remained neurologically impaired after CPA. Any MRI obtained within 2 weeks after CPA was analyzed. The apparent diffusion coefficient (ADC) value of each voxel within the brain was determined. Percentage brain volume with voxels below each ADC threshold between 300 and 1200 × 10^-6 mm²/s with a step of 50 were calculated. Area under the receiver operating characteristics curve (AUC) was used to identify optimal DWI MRI thresholds for brain volume percent most predictive of poor neurologic outcome. The primary outcome measure was neurologic outcome 6-months after CPA based on Pediatric Cerebral Performance Category (PCPC) score. Poor neurologic outcome was defined as PCPC score of 3-6, or a worsening from baseline score ≥1 if baseline PCPC score was ≥3.

RESULTS

Twenty-six patients were included in this study. The median age was 8.5 years (2.2-14) and median time from CPA to MRI was 4 days (2-7). Two ADC thresholds for brain volume percent had the largest AUC for predicting poor neurologic outcome. An ADC threshold of <600 × 10^-6 mm²/s in ≥7% of brain volume; and <650 × 10^-6 mm²/s in ≥11% of brain volume both demonstrated a specificity of 1.0 (0.76-1.0, 95% CI) and a sensitivity of 0.8 (0.44-0.96, 95% CI) for poor outcome.

CONCLUSIONS

In pediatric patients who remain comatose or have significant neurologic deficits after CPA, quantitative DWI MRI correlates with neurologic outcome. Both an ADC threshold of <600 × 10^-6 mm²/s in ≥7% of brain volume and <650 × 10^-6 mm²/s in ≥11% of brain volume are highly specific for predicting poor neurologic outcome. A prospective trial to validate these thresholds is needed.

Timing and modes of death after pediatric out-of-hospital cardiac arrest resuscitation

AIM

To determine the timing and modes of death of children admitted to a pediatric critical care unit (PICU) of a tertiary care center after an out-of-hospital cardiac arrest (OHCA).

METHODS

This is a retrospective descriptive study at a tertiary care PICU of all consecutive patients <18 years old who received ≥1 min of chest compressions, had return of spontaneous circulation (ROSC) for ≥20 min, and were admitted to the PICU after an OHCA. Modes of death were classified as brain death (BD), withdrawal due to neurologic prognosis (W/D-neuro), withdrawal for refractory circulatory failure (W/D-RCF), and re-arrest without ROSC (RA).

RESULTS

191 consecutive patients were admitted to the PICU from February 2005 to May 2013 after an OHCA. Eighty-six(45%) patients died prior to discharge: BD in 47%(40/86), W/D-neuro in 34%(29/86), W/D-RCF in 10%(9/86), and RA in 9%(8/86). Time to death was longer for patients with W/D-neuro: 4 days [1, 5] and BD 4 days [1, 5](p < 0.01) as opposed to those with W/D-RCF (1 day[1, 2]) and RA(1 day[0.5, 1]). Of patients who underwent W/D-neuro, 9/29(31%) died within 3 days of PICU admission and 20/29(69%) ≥3 days. Of patients who died after W/D-neuro, 12/29(41%) received therapeutic hypothermia, 27/29(93%) underwent EEG monitoring, 21/29(72%) had a brain CT, and 13/29(45%) had a brain MRI. All MRIs showed signs of hypoxic-ischemic injury.

CONCLUSION

Neurologic injury was the most common mode of death post-resuscitation care OHCA after in a tertiary care center PICU. Neurologic prognostication impacts the outcome of a large proportion of patients after OHCA, and further studies are warranted to improve its reliability.

Singapore Paediatric Resuscitation Guidelines 2016

We present the revised 2016 Singapore paediatric resuscitation guidelines. The International Liaison Committee on Resuscitation's Pediatric Taskforce Consensus Statements on Science and Treatment Recommendations, as well as the updated resuscitation guidelines from the American Heart Association and European Resuscitation Council released in October 2015, were debated and discussed by the workgroup. The final recommendations for the Singapore Paediatric Resuscitation Guidelines 2016 were derived after carefully reviewing the current available evidence in the literature and balancing it with local clinical practice.

24 vs. 72 hours of hypothermia for pediatric cardiac arrest: A pilot, randomized controlled trial

AIM

Children surviving cardiac arrest (CA) lack proven neuroprotective therapies. The role of biomarkers in assessing response to interventions is unknown. We hypothesized that 72 versus 24 h of hypothermia (HT) would produce more favorable biomarker profiles after pediatric CA.

METHODS

This single center pilot randomized trial tested HT (33 ± 1 °C) for 24 vs. 72 h in 34 children with CA. Children comatose after return of circulation aged 1 week to 17 years and treated with HT by their physician were eligible. Serum was collected twice daily on days 1-4 and once on day 7. Mortality was assessed at 6 months.

RESULTS

Patient characteristics, baseline biomarker concentrations, and adverse events were similar between groups. Eight (47%) and 4 (24%) children died in the 24 h and 72 h groups, p = .3. Serum neuron specific enolase (NSE) concentration was increased in the 24 vs. 72 h group at 84 h-96 h (median [interquartile range] 47.7 [3.9, 79.9] vs. 1.4 [0.0, 11.1] ng/ml, p = .02) and on day 7 (18.2 [3.2, 74.0] vs. 2.6 [0.0, 12.8] ng/ml, p = .047). Serum S100b was increased in the 24 h vs. 72 h group at 12 h-24 h, 36 h-84 h, and on day 7, all p < 0.05. HT duration was associated with S100b (but not NSE or MBP) concentration on day 7 in multivariate analyses.

CONCLUSION

Serum biomarkers show promise as theragnostic tools in pediatric CA. Our biomarker and safety data also suggest that 72 h duration after pediatric CA warrants additional exploration.

Prognostic value of serum biomarkers of cerebral injury in classifying neurological outcome after paediatric resuscitation

AIM

To investigate if the serum biomarkers of cerebral injury, neuron-specific enolase and S100b protein, may classify unfavourable neurological outcome after paediatric cardiac arrest.

METHODS

We performed a retrospective study of neuron-specific enolase and S100b measurements from 95 children treated in our paediatric cardiac intensive care unit after cardiac arrest. Neurological outcome at discharge was evaluated using the paediatric cerebral performance category scale, with unfavourable outcome defined as a change of >1 compared to pre-arrest status or death.

RESULTS

Fifty-eight patients (61.1%) survived to discharge with 48 (50.5%) having a favourable neurological outcome. We observed significantly higher levels of both biomarkers in the unfavourable outcome group at designated time points (neuron-specific enolase at 24, 48, and 72h and S100b at 12, 24, and 48h after cardiac arrest, p<0.05). Receiver operating characteristic areas under the curve for neuron-specific enolase were 0.83, 0.80, and 0.73 at time points 24, 48, and 72h and 0.87, 0.81, and 0.82 for S100b at 12, 24, and 48h after cardiac arrest, respectively. Neuron-specific enolase measurement at 24h after cardiac arrest was an independent predictor of unfavourable outcome in a multivariable analysis.

CONCLUSIONS

Neuron-specific enolase and S100b classify unfavourable neurological outcome in this large paediatric cardiac arrest cohort. Further multi-institutional prospective studies to comprehensively evaluate the diagnostic accuracy of these biomarkers under various clinical conditions and to determine reliable cut-off values in children are warranted.

Neurologic Outcomes Following Care in the Pediatric Intensive Care Unit

Purpose of review

With increasing survival of children requiring admission to pediatric intensive care units (PICU), neurodevelopmental outcomes of these patients are an area of increased attention. Our goal was to systematically review recently published literature on neurologic outcomes of PICU patients.

Recent Findings

Decline in neurofunctional status occurs in 3%-20% of children requiring PICU care. This proportion varies based on primary diagnosis and severity of illness, with children admitted for primary neurologic diagnosis, children who suffer cardiac arrest or who require invasive interventions during the PICU admission, having worse outcomes. Recent research focuses on early identification and treatment of modifiable risk factors for unfavorable outcomes, and on long-term follow-up that moves beyond global cognitive outcomes and is increasingly including tests assessing multidimensional aspects of neurodevelopment.

Summary

The pediatric critical care research community has shifted focus from survival to survival with favorable neurologic outcomes of children admitted to the PICU.

Close correlation between arterial and central venous lactate concentrations of children in shock: A cross-sectional study

BACKGROUND

Arterial lactate (aLact) has been widely used to guide therapeutic decisions in children with shock. We evaluated the feasibility of central venous lactate (cvLact) in assessing aLact among children with shock.

METHODS

Pairs of arterial and central venous samples for lactate concentrations were collected simultaneously during the shock and hemodynamically stable states. The results were analyzed by using a Cobas 8000 analyzer.

RESULTS

Sixty-four blood paired samples were collected from 48 patients. The overall correlation between central venous and arterial lactate concentrations was r=0.962, p<0.0001, r²=0.965. The regression equation was aLact=(0.978×cvLact)-0.137. A similar correlation was found between central venous and arterial lactate concentrations during the states of shock and stable hemodynamics (r=0.970, p<0.0001, r²=0.966 and r=0.935, p<0.0001, r²=0.962, respectively). The mean difference between central venous and arterial lactate concentrations was 0.20mmol/l (95% CI: 0.08 to 0.32) and the limits of agreement were -0.74mmol/l (95% CI: -0.94 to -0.53) and 1.13 (95% CI: 0.93 to 1.34).

CONCLUSIONS

In situations of shock where a central venous catheter is required, samples from a central vein present an acceptable and timely alternative to arterial samples for quantitating lactate concentrations.

Prognostic utility of neuroinjury biomarkers in post out-of-hospital cardiac arrest (OHCA) patient management

Despite aggressive intervention, patients who survive an out-of-hospital cardiac arrest (OHCA) generally have very poor prognoses, with nationwide survival rates of approximately 10-20%. Approximately 90% of survivors will have moderate to severe neurological injury ranging from moderate cognitive impairment to brain death. Currently, few early prognostic indicators are considered reliable enough to support patients' families and clinicians' in their decisions regarding medical futility. Blood biomarkers of neurological injury after OHCA may be of prognostic value in these cases. When most bodily tissues are oxygen-deprived, cellular metabolism switches from aerobic to anaerobic respiration. Neurons are a notable exception, however, being dependent solely upon aerobic respiration. Thus, after several minutes without circulating oxygen, neurons sustain irreversible damage, and certain measurable biomarkers are released into the circulation. Prior studies have demonstrated value in blood biomarkers in prediction of survival and neurologic impairment after OHCA. We hypothesize that understanding peptide biomarker kinetics in the early return of spontaneous circulation (ROSC) period, especially in the setting of refractory cardiac arrest, may assist clinicians in determining prognosis earlier in acute resuscitation. Specifically, during and after immediate resuscitation and return of ROSC, clinicians and families face a series of important questions regarding patient prognosis, futility of care and allocation of scarce resources such as the early initiation of extracorporeal cardiopulmonary resuscitation (ECPR). The ability to provide early prognostic information in this setting is highly valuable. Currently available, as well as potential biomarkers that could be good candidates in prognostication of neurological outcomes after OHCA or in the setting of refractory cardiac arrest will be reviewed and discussed.