Development of Risk Indices for Neonatal Respiratory Extracorporeal Membrane Oxygenation

Optimizing Outcomes in Extracorporeal Membrane Oxygenation Postcardiotomy in Pediatric Population

Extracorporeal membrane oxygenation (ECMO) is a rapidly emerging advanced life support technique used in cardiorespiratory failure refractory to other treatments. There has been an influx in the number of studies relating to ECMO in recent years, as the technique becomes more popular. However, there are still significant gaps in the literature including complications and their impacts and methods to predict their development. This review evaluates the available literature on the complications of ECMO postcardiotomy in the pediatric population. Areas explored include renal, cardiovascular, hematological, infection, neurological, and hepatic complications. Incidence, risk factors and potential predictors, and scoring systems for the development of these complications have been evaluated.

Circuit change in neonatal and pediatric extracorporeal membrane oxygenation is associated with adverse outcomes

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) circuits may be changed during the run for multiple reasons; however, these circuit changes may be associated with adverse events. Predictors for undergoing a circuit change (CC) and their outcomes remain unclear. We hypothesized that neonatal and pediatric CC correlates with increased morbidity and mortality.

METHODS

Pediatric and neonatal patients who underwent one ECMO run lasting <30 days at a tertiary children's hospital from 2011 through 2017 were retrospectively reviewed. Bivariate regression analysis evaluated factors associated with ECMO mortality and morbidity. LASSO logistic regression models identified independent risk factors for undergoing a CC. p < .05 was significant.

RESULTS

One hundred 85 patients were included; 137 (74%) underwent no CC, while 48 (26%) underwent one or more. Undergoing a CC was associated with longer ECMO duration (p < .001), higher blood transfusion volumes (p < .001), increased hemorrhagic complications (p < .001) and increased mortality (p = .002). Increased platelet (p = .001) and FFP (p = .016) transfusion volumes at any time while on ECMO were independent factors associated with undergoing a CC.

CONCLUSIONS

Changing the circuit during the ECMO run occurs frequently and may be associated with poorer outcomes. Understanding the outcomes and predictors for CC may guide management protocols for more efficient circuit changes given its important association with overall outcomes.

Cardiac Dysfunction Biomarkers Are Associated With Potential for Successful Separation From Extracorporeal Membrane Oxygenation in Children

Biomarkers of cardiac dysfunction may aid in decision making about organ recovery and optimal timing of separation from extracorporeal membrane oxygenation (ECMO). We conducted a prospective observational study of children from 0 to <18 years who underwent ECMO between 7/2010 and 6/2015 in a single center. In this pilot study, we aimed to determine whether Suppression of tumorigenicity 2 (ST2), N -terminal pro-B-type natriuretic peptide (NT-proBNP), galectin-3, and endostatin were associated with ability to separate from ECMO. Fifty neonatal and pediatric participants supported on venoarterial ECMO were included (median age 13 days, 50% male). Twelve (24%) participants were unable to separate from extracorporeal support. Plasma ST2 concentrations at cannulation were higher in children who were ultimately unable to separate versus those who successfully separated from ECMO (median 395.3 ng/mL vs. 207.4 ng/mL, p = 0.012). ST2 and NT-proBNP concentrations decreased significantly from the first to the last ECMO day in patients successfully separated from ECMO ( p < 0.0001 and p = 0.017, respectively). Endostatin concentrations increased significantly from the first to the last ECMO day in both groups. Galectin-3 concentrations were not associated with the ability to separate from ECMO. Cardiac dysfunction biomarkers, particularly ST2, may aid in decannulation decision-making in pediatric ECMO patients. These results should be validated with a larger study.

Management of the CDH patient on ECLS

Congenital diaphragmatic hernia (CDH) is the most common indication for respiratory extracorporeal life support (ECLS) in neonates. The survival rate of CDH neonates treated with ECLS is 50%, and this figure has remained relatively stable over the last few decades. This is likely because the current population of CDH neonates who require ECLS have a higher risk profile [1]. The management of neonates with CDH has evolved over time to emphasize postnatal stabilization, gentle ventilation, and multi-modal treatment of pulmonary hypertension. In order to minimize practice variation, many centers have adopted CDH-specific clinical practice guidelines, however care is not standardized between different centers and outcomes vary [3]. The purpose of this review is to summarize our current understanding of issues central to the care of neonates with CDH treated with ECLS and specifically highlight how the use of the Extracorporeal Life Support Organization (ELSO) data have added to our understanding of CDH.

Development of a Model for the Pediatric Survival After Veno-Arterial Extracorporeal Membrane Oxygenation Score: The Pedi-SAVE Score

Pediatric cardiac extracorporeal membrane oxygenation (ECMO) patients have high mortality rates. The purpose of our study was to develop and validate the Pediatric Survival After Veno-arterial ECMO (Pedi-SAVE) score for predicting survival at hospital discharge after pediatric cardiac veno-arterial (VA) ECMO. We used data for pediatric cardiac VA-ECMO patients from the Extracorporeal Life Support Organization registry (1/1/2001-12/31/2015). Development and validation cohorts were created using 2:1 random sampling. Predictors of survival to develop pre- and postcannulation models were selected using multivariable logistic regression and random forest models. ß-coefficients were standardized to create the Pedi-SAVE score. Of 10,091 pediatric cardiac VA-ECMO patients, 4,996 (50%) survived to hospital discharge. Pre- and postcannulation Pedi-SAVE scores predicted that the lowest risk patients have a 65% and 74% chance of survival at hospital discharge, respectively, compared to 33% and 22% in the highest risk patients. In the validation cohort, pre- and postcannulation Pedi-SAVE scores had c-statistics of 0.64 and 0.71, respectively. Precannulation factors associated with survival included: nonsingle ventricle congenital heart disease, older age, white race, lower STAT mortality category, higher pH, not requiring acid-buffer administration, <2 cardiac procedures, and indication for VA-ECMO other than failure to wean from cardiopulmonary bypass. Postcannulation, additional factors associated with survival included: lower ECMO pump flows at 24 hours and lack of complications. The Pedi-SAVE score is a novel validated tool to predict survival at hospital discharge for pediatric cardiac VA-ECMO patients, and is an important advancement in risk adjustment and benchmarking for this population.

Variation across centers in standardized mortality ratios for congenital diaphragmatic hernia receiving extracorporeal life support

BACKGROUND

We sought to elucidate the degree of variation across centers by calculating center-specific standardized mortality ratios (SMRs) for infants with congenital diaphragmatic hernia (CDH) requiring extracorporeal life support (ECLS).

METHODS

The Extracorporeal Life Support Organization (ELSO) registry data (2000-2019) were used to estimate SMRs. Center-specific SMRs and their 95% confidence intervals (CIs) were used to identify centers with mortality as significantly worse (SW), significantly better (SB), or not different (ND) relative to the median standardized mortality rate.

RESULTS

We identified 4,223 neonates with CDH from 109 centers. SMRs were risk-adjusted for pre-ECLS case-mix (birthweight, sex, race, 5 min Apgar, blood gases, gestational age, hernia side, prenatal diagnosis, pre-ECLS arrest, and comorbidities). Observed (unadjusted) mortality rates across centers varied substantially (range: 14.3%-90.9%; interquartile range [IQR]: 42.9%-62.1%). Thirteen centers (11.9%) had SB SMRs< 1 (SMR 0.52 to 0.84), 7 centers (6.4%) had SW SMRs>1 (SMR 1.25 to 1.43), and 89 centers (81.7%) had SMRs ND relative to the median SMR rate across all centers (i.e., SMR not different from one). Descriptive analyses demonstrated that SB centers had a lower proportion of cases with renal complications, infectious complications and discontinuation of ECLS owing to complications, as well as differences in pre-ECLS treatments and timing of CDH repair, compared to SW and ND centers.

CONCLUSION

This study specifically identified ECLS centers with higher and lower survival for patients with CDH, which may serve as a benchmark for institutional quality improvement. Future studies are needed to identify those specific processes at those centers that leads to favorable outcomes with the goal of improving care globally.

LEVEL OF EVIDENCE

Level III.

Mortality prediction in pediatric postcardiotomy veno-arterial extracorporeal membrane oxygenation: A comparison of scoring systems

Background

Pediatric postcardiotomy veno-arterial extracorporeal membrane oxygenation (VA-ECMO) patients have high mortality and morbidity. There are currently three scoring systems available to predict mortality: the Pediatric Extracorporeal Membrane Oxygenation Prediction (PEP) model, Precannulation Pediatric Survival After VA-ECMO (Pedi-SAVE) score, and Postcannulation Pedi-SAVE score. These methods provide risk stratification scores for pediatric patients requiring ECMO for cardiac support. However, comparative validation of these scoring systems remains scarce. We aim to assess the ability of these models to predict outcomes in a cohort of pediatric patients undergoing VA-ECMO after cardiac surgery, and identify predictors of in-hospital mortality.

Methods

A retrospective analysis of 101 children admitted to Fuwai Hospital who received VA-ECMO from January 1, 2010 to December 31, 2020 was performed. Patients were divided into two groups, survivors (n = 49) and non-survivors (n = 52) according to in-hospital mortality. PEP model and Pedi-SAVE scores were calculated. The primary outcomes were the risk factors of in-hospital mortality, and the ability of the PEP model, Precannulation Pedi-SAVE and Postcannulation Pedi-SAVE scores to predict in-hospital mortality.

Results

Postcannulation Pedi-SAVE score accessing the entire ECMO process had the greatest area under receiver operator curve (AUROC), 0.816 [95% confidence interval (CI): 0.733–0.899]. Pre-ECMO PEP model could predict in-hospital mortality [AUROC = 0.691 (95% CI: 0.565–0.817)], and Precannulation Pedi-SAVE score had the poorest prediction [AUROC = 0.582(95% CI: 0.471–0.694)]. Lactate value at ECMO implantation [OR = 1.199 (1.064–1.351), P = 0.003] and infectious complications [OR = 5.169 (1.652–16.172), P = 0.005] were independent risk factors for in-hospital mortality.

Conclusion

Pediatric cardiac ECMO scoring systems, including multiple risk factors before and during ECMO, were found to be useful in this cohort. Both the pre-ECMO PEP model and the Postcannulation Pedi-SAVE score were found to have high predictive value for in-hospital mortality in pediatric postcardiotomy VA-ECMO.

Risk Factors for Brain Injury in Newborns Treated with Extracorporeal Membrane Oxygenation

OBJECTIVE

This study aimed to assess the association of clinical risk factors with severity of magnetic resonance imaging (MRI) brain injury in neonatal extracorporeal membrane oxygenation (ECMO) patients.

STUDY DESIGN

This is a single-center retrospective study conducted at an outborn level IV neonatal intensive care unit in a free-standing academic children's hospital. Clinical and MRI data from neonates treated with ECMO between 2005 and 2015 were reviewed. MRI injury was graded by two radiologists according to a modified scoring system that assesses parenchymal injury, extra-axial hemorrhage, and cerebrospinal fluid spaces. MRI severity was classified as none (score = 0), mild/moderate (score = 1-13.5), and severe (score ≥ 14). The relationship between selected risk factors and MRI severity was assessed by Chi-square, analysis of variance, and Kruskal-Wallis tests where appropriate. Combinative predictive ability of significant risk factors was assessed by logistic regression analyses.

RESULTS

MRI data were assessed in 81 neonates treated with ECMO. Veno-arterial (VA) patients had more severe injury compared with veno-venous patients. There was a trend toward less severe injury over time. After controlling for covariates, duration of ECMO remained significantly associated with brain injury, and the risk for severe injury was significantly increased in patients on ECMO beyond 210 hours.

CONCLUSION

Risk for brain injury is increased with VA ECMO and with longer duration of ECMO. Improvements in care may be leading to decreasing incidence of brain injury in neonatal ECMO patients.

KEY POINTS

· Veno-arterial ECMO is associated with more brain injury by MRI compared with veno-venous ECMO.. · Longer duration of ECMO is significantly associated with severe brain injury by MRI.. · Risk for neurologic injury may be decreasing over time with advances in neonatal ECMO..

Extracorporeal Support Prognostication-Time to Move the Goal Posts?

Advances in extracorporeal membrane oxygenation (ECMO) technology are associated with expanded indications, increased utilization and improved outcome. There is growing interest in developing ECMO prognostication scores to aid in bedside decision making. To date, the majority of available scores have been limited to mostly registry-based data and with mortality as the main outcome of interest. There continues to be a gap in clinically applicable decision support tools to aid in the timing of ECMO cannulation to improve patients' long-term outcomes. We present a brief review of the commonly available adult and pediatric ECMO prognostication tools, their limitations, and future directions.

External validation of the Pediatric Extracorporeal Membrane Oxygenation Prediction model for risk adjusting mortality

INTRODUCTION

The Pediatric Extracorporeal Membrane Oxygenation Prediction (PEP) model was created to provide risk stratification for all pediatric patients requiring extracorporeal life support (ECLS). Our purpose was to externally validate the model using contemporaneous cases submitted to the Extracorporeal Life Support Organization (ELSO) registry.

METHODS

This multicenter, retrospective analysis included pediatric patients (<19 years) during their initial ECLS run for all indications between January 2012 and September 2014. Median values from the BATE dataset for activated partial thromboplastin time and internationalized normalized ratio were used as surrogates as these were missing in the ELSO group. Model discrimination was evaluated using area under the receiver operating characteristic curve (AUC), and goodness-of-fit was evaluated using the Hosmer-Lemeshow test.

RESULTS

A total of 4,342 patients in the ELSO registry were compared to 514 subjects from the bleeding and thrombosis on extracorporeal membrane oxygenation (BATE) dataset used to develop the PEP model. Overall mortality was similar (42% ELSO vs. 45% BATE). The c-statistic after external validation decreased from 0.75 to 0.64 and model calibration decreases most in the highest risk deciles.

CONCLUSION

Discrimination of the PEP model remains modest after external validation using the largest pediatric ECLS cohort. While the model overestimates mortality for the highest risk patients, it remains the only prediction model applicable to both neonates and pediatric patients who require ECLS for any indication and thus maintains potential for application in research and quality benchmarking.

Extracorporeal membrane oxygenation in the pediatric population - who should go on, and who should not

PURPOSE OF REVIEW

The role of extracorporeal membrane oxygenation (ECMO), a method of providing cardiorespiratory support in instances of cardiac or respiratory failure, in neonates and children continues to expand and evolve. This review details the current landscape of ECMO as it applies to neonates and children.

RECENT FINDINGS

Specifically, this review provides the most recent evidence for which patients should be considered for the various forms of ECMO including venovenous ECMO, venoarterial-ECMO, and extracorporeal cardiopulmonary resuscitation. Specific topics to be discussed include indications and contraindications for the different types of ECMO in neonates and children, anticoagulation strategies and ways to monitor end-organ function, outcomes specific to the different types and populations with a focus on meaningful survival to discharge and neurologic outcomes, and consideration of special populations such as low birth weight infants, traumatically injured patients, and children who received recent bone marrow transplants. This review also discusses still unanswered questions surrounding the most appropriate use of ECMO as its role and applications continue to evolve.

SUMMARY

With rapidly increasing utilization of ECMO, neonatologists and pediatricians should be aware of the most recent evidence guiding its indications, applications, and limitations.

Predictors of long ECMO runs for congenital diaphragmatic hernia

BACKGROUND

Although longer ECMO run times for patients with congenital diaphragmatic hernia (CDH) have been associated with worse outcomes, a large study has not been conducted to examine the risk factors for long ECMO runs.

METHODS

The Extracorporeal Life Support Organization (ELSO) Registry from 2000 to 2015 was used to identify predictors of long ECMO runs in CDH patients. A long run was any duration of ≥14 days. Multivariable logistic regression models were used to examine the association between demographics, pre-ECMO blood gas/ventilator settings, comorbid conditions, and therapies on long ECMO runs.

RESULTS

There were 4730 CDH-infants examined. The largest association with long ECMO runs was on-ECMO repair (OR: 3.72, 95% CI: 3.013-4.602, p < 0.001) and the use of THAM (OR: 1.463, 95% CI: 1.062-2.016, p = 0.02). Each drop in pH quartile was associated with an increased risk of long ECMO run: pH ≥ 7.3 (reference), pH 7.2-7.9 (OR 1.24, 95% CI: 0.98-1.57, p = 0.07), pH 7.08-7.19 (OR 1.46, 95% CI: 1.17-1.84, p = 0.001), pH ≤ 7.07 (OR 1.64, 95% CI: 1.29-2.07, p < 0.001).

CONCLUSIONS

We found a correlation between both pre-ECMO demographics/timing of repair and the subsequent risk of long ECMO runs, providing insight for both providers and parents about the risk factors for longer runs.

TYPE OF STUDY

Treatment Study.

LEVEL OF EVIDENCE

Level III.

The development of multiorgan dysfunction in CDH-ECMO neonates is associated with the level of pre-ECMO support

PURPOSE

Congenital diaphragmatic hernia (CDH) is the most common indication for neonatal extracorporeal membrane oxygenation (ECMO), but mortality remains at 50%. Multiorgan failure can occur in 25% and has been linked to worse outcomes. We sought to examine the factors that would increase the risk of multiorgan dysfunction (MOD).

METHODS

The Extracorporeal Life Support Organization (ELSO) database was used to identify infants with CDH (2000-2015). The primary outcome was MOD, which was defined as the presence of organ failure in ≥2 organ systems. We used a multivariable logistic regression to examine the effect of demographics, pre-ECMO respiratory status, comorbidities, and therapies on MOD.

RESULTS

There were a total of 4374 CDH infants who were treated with ECMO. Overall mortality was 52.4%. The risk models demonstrated that pre-ECMO cardiac arrest (OR 1.458, CI: 1.146-1.861, p = 0.002) and hand-bagging (OR 1.461, CI: 1.094-1.963, p = 0.032) had the strongest association with MOD. In addition, other pre-ECMO indicators of disease severity (pH, HFOV, MAP, 5-min APGAR) and pre-ECMO therapies (bicarb, neuromuscular [NM] blockers) were also associated with MOD.

CONCLUSIONS

The level of pre-ECMO support has a significant association with the development of MOD, and initiation of ECMO prior to arrest seems to be critical to avoid complications.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

Extracorporeal Membrane Oxygenation for Severe Respiratory Failure During Respiratory Epidemics and Pandemics: A Narrative Review

Introduction: Epidemics and pandemics from zoonotic respiratory viruses, such as the 2019 novel coronavirus, can lead to significant global intensive care burden as patients progress to acute respiratory distress syndrome (ARDS). A subset of these patients develops refractory hypoxaemia despite maximal conventional mechanical ventilation and require extracorporeal membrane oxygenation (ECMO). This review focuses on considerations for ventilatory strategies, infection control and patient selection related to ECMO for ARDS in a pandemic. We also summarise the experiences with ECMO in previous respiratory pandemics. Materials and Methods: A review of pertinent studies was conducted via a search using MEDLINE, EMBASE and Google Scholar. References of articles were also examined to identify other relevant publications. Results: Since the H1N1 Influenza pandemic in 2009, the use of ECMO for ARDS continues to grow despite limitations in evidence for survival benefit. There is emerging evidence to suggest that lung protective ventilation for ARDS can be further optimised while receiving ECMO so as to minimise ventilator-induced lung injury and subsequent contributions to multi-organ failure. Efforts to improve outcomes should also encompass appropriate infection control measures to reduce co-infections and prevent nosocomial transmission of novel respiratory viruses. Patient selection for ECMO in a pandemic can be challenging. We discuss important ethical considerations and predictive scoring systems that may assist clinical decision-making to optimise resource allocation. Conclusion: The role of ECMO in managing ARDS during respiratory pandemics continues to grow. This is supported by efforts to redefine optimal ventilatory strategies, reinforce infection control measures and enhance patient selection. Ann Acad Med Singapore 2020;49:199–214 Key words: Acute Respiratory Distress Syndrome, Coronavirus disease 2019, ECMO, Infection control, Mechanical ventilation

Trends in Mortality and Risk Characteristics of Congenital Diaphragmatic Hernia Treated With Extracorporeal Membrane Oxygenation

Although the mortality of infants with congenital diaphragmatic hernia (CDH) has been improving since the late 1990s, this observation has not been paralleled among the CDH cohort receiving extracorporeal membrane oxygenation (ECMO). We sought to elucidate why the mortality rate in the CDH-ECMO population has remained at approximately 50% despite consistent progress in the field by examining the baseline risk profile/characteristics of neonates with CDH before ECMO (pre-ECMO). Neonates with a diagnosis of CDH were identified in the Extracorporeal Life Support Organization (ELSO) Registry from 1992 to 2015. Individual pre-ECMO risk score (RS) for mortality was categorized to pre-ECMO risk-stratified cohorts. Temporal trends based on individual-level mortality by risk cohorts were assessed by logistic regression. We identified 6,696 neonates with CDH. The mortality rates during this time period were approximately 50%. The average baseline pre-ECMO RS increased during this period: mean increase of 0.35 (95% confidence interval [CI]: 0.324–0.380). In the low-risk cohort, the likelihood of mortality increased over time: each 5 year change was associated with a 7.3% increased likelihood of mortality (odds ratio [OR]: 1.0726; 95% CI: 1.0060–1.1437). For the moderate-risk cohort, the likelihood of mortality decreased by 7.05% (OR: 0.9295; 95% CI: 0.8822–0.9793). There was no change in the odds of mortality for the high-risk cohort (OR: 0.9650; 95% CI: 0.8915–1.0446). Although the overall mortality rate remained approximately constant over time, the individual likelihood of death has declined over time in the moderate-risk cohort, increased in the low-risk cohort, and remained unchanged in the high-risk cohort.

Evaluating Mortality Risk Adjustment Among Children Receiving Extracorporeal Support for Respiratory Failure

This study evaluates whether three commonly used pediatric intensive care unit (PICU) severity of illness scores, pediatric risk of mortality score (PRISM) III, pediatric index of mortality (PIM) 2, and pediatric logistic organ dysfunction (PELOD), are the appropriate tools to discriminate mortality risk in children receiving extracorporeal membrane oxygenation (ECMO) support for respiratory failure. This study also evaluates the ability of the Pediatric Risk Estimate Score for Children Using Extracorporeal Respiratory Support (Ped-RESCUERS) to discriminate mortality risk in the same population, and whether Ped-RESCUERS' discrimination of mortality is improved by additional clinical and laboratory measures of renal, hepatic, neurologic, and hematologic dysfunction. A multi-institutional retrospective cohort study was conducted on children aged 29 days to 17 years with respiratory failure requiring respiratory ECMO support. Discrimination of mortality was evaluated with the area under the receiver operating curve (AUC); model calibration was measured by the Hosmer-Lemeshow goodness of fit test and Brier score. Admission PRISM-III, PIM-2, and PELOD were found to have poor ability to discriminate mortality with an AUC of 0.56 [0.46-0.66], 0.53 [0.43-0.62], and 0.57 [0.47-0.67], respectively. Alternatively, Ped-RESCUERS performed better with an AUC of 0.68 [0.59-0.77]. Higher alanine aminotransferase, ratio of the arterial partial pressure of oxygen the fraction of inspired oxygen, and lactic acidosis were independently associated with mortality and, when added to Ped-RESCUERS, resulted in an AUC of 0.75 [0.66-0.82]. Admission PRISM-III, PIM-2, and PELOD should not be used for pre-ECMO risk adjustment because they do not discriminate death. Extracorporeal membrane oxygenation population-derived scores should be used to risk adjust ECMO populations as opposed to general PICU population-derived scores.

The role of ECMO in the management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the most common indication for extra-corporeal membrane oxygenation (ECMO) for neonatal respiratory failure. CDH management is evolving with advanced prenatal diagnostic imaging modalities. The risk profiles of infants receiving ECMO for CDH are shifting towards higher risk. Many clinicians are developing and following clinical practice guidelines to standardize and optimize the care of CDH neonates. Despite these efforts, there are significant differences in the practice patterns among ECMO centers as to how and when they choose to initiate ECMO for CDH, when they believe repair is safe, as well as many other nuances that are based on center experience or style. The purpose of this report is to summarize our current understanding of the new and recent developments regarding management of infants with CDH managed with ECMO.

Development and Validation of Extracorporeal Membrane Oxygenation Mortality-Risk Models for Congenital Diaphragmatic Hernia

The purpose of our study was to develop and validate extracorporeal membrane oxygenation (ECMO)–specific mortality risk models for congenital diaphragmatic hernia (CDH). We utilized the data from the Extracorporeal Life Support Organization Registry (2000–2015). Prediction models were developed using multivariable logistic regression. We identified 4,374 neonates with CDH with an overall mortality of 52%. Predictive discrimination (C statistic) for pre-ECMO mortality model was C = 0.65 (95% confidence interval, 0.62–0.68). Within the highest risk group, based on the pre-ECMO risk score, mortality was 87% and 75% in the training and validation data sets, respectively. The pre-ECMO risk score included pre-ECMO ventilator settings, pH, prior diaphragmatic hernia repair, critical congenital heart disease, perinatal infection, and demographics. For the on-ECMO model, mortality prediction improved substantially: C = 0.73 (95% confidence interval, 0.71–0.76) with the addition of on-ECMO–associated complications. Within the highest risk group, defined by the on-ECMO risk score, mortality was 90% and 86% in the training and validation data sets, respectively. Mortality among neonates with CDH needing ECMO can be reliably predicted with validated clinical variables identified in this study. ECMO-specific mortality prediction tools can allow risk stratification to be used in research and quality improvement efforts, as well as with caution for individual case management.

Development of the Pediatric Extracorporeal Membrane Oxygenation Prediction Model for Risk-Adjusting Mortality

OBJECTIVES

To develop a prognostic model for predicting mortality at time of extracorporeal membrane oxygenation initiation for children which is important for determining center-specific risk-adjusted outcomes.

DESIGN

Multivariable logistic regression using a large national cohort of pediatric extracorporeal membrane oxygenation patients.

SETTING

The ICUs of the eight tertiary care children's hospitals of the Collaborative Pediatric Critical Care Research Network.

PATIENTS

Five-hundred fourteen children (< 19 yr old), enrolled with an initial extracorporeal membrane oxygenation run for any indication between January 2012 and September 2014.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 514 first extracorporeal membrane oxygenation runs were analyzed with an overall mortality of 45% (n = 232). Weighted logistic regression was used for model selection and internal validation was performed using cross validation. The variables included in the Pediatric Extracorporeal Membrane Oxygenation Prediction model were age (pre-term neonate, full-term neonate, infant, child, and adolescent), indication for extracorporeal membrane oxygenation (extracorporeal cardiopulmonary resuscitation, cardiac, or respiratory), meconium aspiration, congenital diaphragmatic hernia, documented blood stream infection, arterial blood pH, partial thromboplastin time, and international normalized ratio. The highest risk of mortality was associated with the presence of a documented blood stream infection (odds ratio, 5.26; CI, 1.90-14.57) followed by extracorporeal cardiopulmonary resuscitation (odds ratio, 4.36; CI, 2.23-8.51). The C-statistic was 0.75 (95% CI, 0.70-0.80).

CONCLUSIONS

The Pediatric Extracorporeal Membrane Oxygenation Prediction model represents a model for predicting in-hospital mortality among children receiving extracorporeal membrane oxygenation support for any indication. Consequently, it holds promise as the first comprehensive pediatric extracorporeal membrane oxygenation risk stratification model which is important for benchmarking extracorporeal membrane oxygenation outcomes across many centers.

Neonatal Cardiac ECMO in 2019 and Beyond

Worldwide, the use of Extracorporeal Membrane Oxygenation (ECMO) for cardiac failure has been steadily increasing in the neonatal population and has become a widely accepted modality. Especially in centers caring for children with (congenital) heart disease, ECMO is now an essential part of care available for those with severe heart failure as a bridge to recovery, long term mechanical support, or transplantation. Short-term outcomes depend very much on indication. Hospital survival is ~40% for all neonatal cardiac ECMO patients combined. ECMO is being used for pre- and/or post-operative stabilization in neonates with congenital heart disease and in neonates with medical heart disease such as myocarditis, cardiomyopathy or refractory arrhythmias. ECMO use during resuscitation (ECPR) or for sepsis is summarized elsewhere in this special edition of Frontiers in Pediatrics. In this review article, we will discuss the indications for neonatal cardiac ECMO, the difficult process of patients' selection and identifying the right timing to initiate ECMO, as well as outline pros and cons for peripheral vs. central cannulation. We will present predictors of mortality and, very importantly, predictors of survival: what can be done to improve the outcomes for your patients. Furthermore, an overview of current insights regarding supportive care in neonatal cardiac ECMO is given. Additionally, we will address issues specific to neonates with single ventricle physiology on ECMO, for example cannulation strategies and the influence of shunt type (Blalock-Taussig shunt vs. "right ventricle to pulmonary artery" shunt). We will not only focus on short term outcomes, such as hospital survival, but also on the importance of long-term neuro-developmental outcomes, and we will end this review with suggestions for future research.

Predictors of Poor Outcomes in Pediatric Venoarterial Extracorporeal Membrane Oxygenation

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) provides respiratory and hemodynamic support to pediatric patients in severe cardiac failure. We aim to identify risk factors associated with poorer outcomes in this population.

METHODS

A retrospective chart review was conducted of pediatric patients requiring VA-ECMO support for cardiac indications at our institution from 2004 to 2015. Data were collected on demographics, indication, markers of cardiac output, ventricular assist device (VAD) insertion, heart transplantation, or left atrial (LA) decompression. Univariate Cox proportional hazards models were used to calculate hazard ratios (HRs) for variables associated with the composite primary outcome of transplant-free survival (TFS).

RESULTS

Of the 68 reviewed patients, 65% were male, 84% were white, 38% had a prior surgery, 13% had a prior transplant, 10% had a prior ECMO support, and 87.5% required vasoactive support within six hours of cannulation. The ECMO indications included congenital heart disease repaired >30 days prior (12%), cardiomyopathy (41%), posttransplant rejection (7%), and cardiorespiratory failure (40%). The TFS was 54.5% at discharge and 47.7% at one year. Predictors of transplant and/or death include epinephrine use (hazard ratio [HR] = 2.269, P = .041), elevated lactate (HR = 1.081, P = 0005), and elevated creatinine (HR = 1.081, P = .005) within six hours prior to cannulation. Sixteen (23.6%) patients underwent LA decompression. Placement of VAD occurred in 16 (23.5%) patients, for which nonwhite race (HR = 2.94, P = .034) and prior ECMO (HR = 3.42, P = .053) were the only identified risk factors.

CONCLUSIONS

Need for VA-ECMO for cardiac support carries high inpatient morbidity and mortality. Epinephrine use and elevated lactate and creatinine were associated with especially poor outcomes. Patients who survived to discharge had good short-term follow-up results.

Pediatric Extracorporeal Life Support Organization Registry International Report 2016

The purpose of this report is to describe the international growth, outcomes, complications, and technology used in pediatric extracorporeal life support (ECLS) from 2009 to 2015 as reported by participating centers in the Extracorporeal Life Support Organization (ELSO). To date, there are 59,969 children who have received ECLS in the ELSO Registry; among those, 21,907 received ECLS since 2009 with an overall survival to hospital discharge rate of 61%. In 2009, 2,409 ECLS cases were performed at 157 centers. By 2015, that number grew to 2,992 cases in 227 centers, reflecting a 24% increase in patients and 55% growth in centers. ECLS delivered to neonates (0-28 days) for respiratory support was the largest subcategory of ECLS among children <18-years old. Overall, 48% of ECLS was delivered for respiratory support and 52% was for cardiac support or extracorporeal life support to support cardiopulmonary resuscitation (ECPR). During the study period, over half of children were supported on ECLS with centrifugal pumps (51%) and polymethylpentene oxygenators (52%). Adverse events including neurologic events were common during ECLS, a fact that underscores the opportunity and need to promote quality improvement work.

Evaluation of Combined Extracorporeal Life Support and Continuous Renal Replacement Therapy on Hemodynamic Performance and Gaseous Microemboli Handling Ability in a Simulated Neonatal ECLS System

The objective of this study was to evaluate the hemodynamic performance and gaseous microemboli (GME) handling ability of a simulated neonatal extracorporeal life support (ECLS) circuit with an in-line continuous renal replacement therapy (CRRT) device. The circuit consisted of a Maquet RotaFlow centrifugal pump or HL20 roller pump, Quadrox-iD Pediatric diffusion membrane oxygenator, 8-Fr arterial cannula, 10-Fr venous cannula, and Better-Bladder (BB) with "Y" connector. A second Quadrox-I Adult oxygenator was added postarterial cannula for GME experiments. The circuit and pseudo-patient were primed with lactated Ringer's solution and packed human red blood cells (hematocrit 40%). All hemodynamic trials were conducted at ECLS flow rates ranging from 200 to 600 mL/min and CRRT flow rate of 75 mL/min at 36°C. Real-time pressure and flow data were recorded with a data acquisition system and GME were detected and characterized using the Emboli Detection and Classification Quantifier System. CRRT was added at distinct locations such that blood entered CRRT between the pump and oxygenator (A), recirculated through the pump (B), or bypassed the pump (C). With the centrifugal pump, all CRRT positions had similar flow rates, mean arterial pressure (MAP), and total hemodynamic energy (THE) loss. With the roller pump, C demonstrated increased flow rates (293.2-686.4 mL/min) and increased MAP (59.4-75.5 mm Hg) (P < 0.01); B had decreased flow rates (129.7-529.7 mL/min), and MAP (34.2-45.0 mm Hg) (P < 0.01); A maintained the same when compared to without CRRT. At 600 mL/min C lost more THE (81.4%) (P < 0.01) with a larger pressure drop across the oxygenator (95.6 mm Hg) (P < 0.01) than without CRRT (78.3%; 49.1 mm Hg) (P < 0.01). C also demonstrated a poorer GME handling ability using the roller pump, with 87.1% volume and 17.8% count reduction across the circuit, compared to A and B with 99.9% volume and 65.8-72.3% count reduction. These findings suggest that, in contrast to A and B, adding CRRT at position C is unsafe and not advised for clinical use.