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

Electroencephalographic Findings Add Prognostic Value to Clinical Features Associated with Mortality on Venoarterial Extracorporeal Support

BACKGROUND

The objective of this study was to identify clinical and continuous electroencephalogram (cEEG) variables associated with outcomes of pediatric venoarterial (V-A) extracorporeal membrane oxygenation support (ECMO).

METHODS

We conducted a retrospective single-center study of pediatric patients on V-A ECMO between January 1, 2015, and September 30, 2020. Serial clinical and cEEG variables were collected to assess the relationship of pre- and on-ECMO variables with hospital mortality in patients who underwent cEEG monitoring.

RESULTS

Ninety-four patients undergoing V-A ECMO had cEEG monitoring, with a hospital mortality of 43%. Nonsurvivors had significantly lower pH and higher lactate levels prior to ECMO initiation. Nineteen (20%) had seizures, with 7 (7%) developing status epilepticus. In the first 24 h patients were on ECMO, unfavorable background score and lack of cEEG variability or reactivity were associated with mortality. A multivariable model investigating in-hospital mortality that included pH and lactate level 2 h prior to ECMO initiation, presence of electrographic seizures, and asymmetry on cEEG as variables, had an area under the receiver operating characteristic curve (AUROC) of 0.8 (95% confidence interval [CI] 0.74-0.86, p < 0.02). The model for on-ECMO mortality (ECMO nonsurvivors) that included pH 2 h prior to ECMO initiation, presence of electrographic seizures, and lack of variability/reactivity at any point on cEEG as variables had an AUROC of 0.85 (95% CI 0.8-0.9, p < 0.001).

CONCLUSIONS

These data demonstrate an association of evolving pre-ECMO impaired tissue oxygenation and on-ECMO neurophysiologic impairment, measured by cEEG, with mortality. They provide preliminary evidence that the timing of ECMO initiation, in relation to worsening tissue oxygenation, should be investigated further, and cEEG may be used to evaluate the potential impact on both neurologic injury and mortality.

Extracorporeal Membrane Oxygenation in Pediatric Patients With Congenital Heart Disease: Surgical Considerations

The use of extracorporeal membrane oxygenation (ECMO) in the paediatric population has increased over time, with the ability to rescue pulmonary and cardiovascular deterioration. ECMO can be utilised by neonates and children with congenital heart disease in both preoperative and postoperative settings to improve survival and minimise morbidity. ECMO cannulation strategy must be tailored to the age, weight, and physiologic state of the patient. Careful patient selection and rapid deployment of ECMO may improve survival and morbidity in patients with congenital heart disease.

Cardiac Catheterization and Interventions in Pediatric Patients on ECMO: Analysis of the IMPACT Registry

Background

There are limited published studies on the performance and safety of cardiac catheterization in pediatric patients on extracorporeal membrane oxygenation (ECMO). We sought to understand the utilization and procedural safety of cardiac catheterization in pediatric patients on ECMO. We also aimed to understand differences in the types of interventions and outcomes in patients with single ventricle (SV) physiology compared to those with biventricular physiology.

Methods

Characteristics and outcomes for patients undergoing cardiac catheterization while on ECMO were collected from the American College of Cardiology National Cardiovascular Data Registry: IMPACT (Improving Pediatric and Adult Congenital Treatment) Registry from 2011-2022.

Results

There were 3473 cardiac catheterizations performed on 2980 pediatric patients during the study period. Patients with SV comprised 31.6% of the population. Survival to hospital discharge was 53.2% overall, 45.2% in patients with SV, and 56.8% in patients with 2 ventricles. Interventional procedures occurred in 52.5% of cases. Major adverse events occurred in 11.5%, with arrhythmia, bleeding events, and unplanned cardiac/other surgeries being the commonest. Regression analysis found SV was significantly associated with major adverse events, as were interventional procedures, female sex, non-Hispanic race, diabetes mellitus, procedure status classified as salvage vs elective, and systemic heparinization.

Conclusions

This is the first large, multicenter review of safety and outcomes in pediatric patients undergoing cardiac catheterization while on ECMO. The study identifies common adverse events during the procedure as well as risk factors associated with the same. The presented data can serve for benchmarking, quality assessment as well as potential future research.

Race-Conscious Research Using Extracorporeal Life Support Organization Registry Data: A Narrative Review

Race-conscious research identifies health disparities with 1) rigorous and responsible data collection, 2) intentionality and considered analyses, and 3) interpretation of results that advance health equity. Individual registries must overcome specific challenges to promote race-conscious research, and this paper describes ways to achieve this with a focus on the international Extracorporeal Life Support Organization (ELSO) registry. This article reviews ELSO registry publications that studied race with outcomes to consider whether research outputs align with race-conscious concepts and describe the direction of associations reported. Studies were identified via secondary analysis of a comprehensive scoping review on ECMO disparities. Of 32 multicenter publications, two (6%) studied race as the primary objective. Statistical analyses, confounder adjustment, and inclusive, antibiased language were inconsistently used. Only two (6%) papers explicitly discussed mechanistic drivers of inequity such as structural racism, and five (16%) discussed race variable limitations or acknowledged unmeasured confounders. Extracorporeal Life Support Organization registry publications demonstrated more adverse ECMO outcomes for underrepresented/minoritized populations than non-ELSO studies. With the objective to promote race-conscious ELSO registry research outputs, we provide a comprehensive understanding of race variable limitations, suggest reasoned retrospective analytic approaches, offer ways to interpret results that advance health equity, and recommend practice modifications for data collection.

Pediatric Highlights From the Extracorporeal Life Support Organization Registry: 2017-2022

The Extracorporeal Life Support Organization (ELSO) registry which collects data from hundreds of participating centers supports research in ECMO to help improve patient outcomes. The ELSO Scientific Oversight Committee, an international and diverse group of ECMOlogists ( https://www.elso.org/registry/socmembers.aspx ), selected the most impactful and innovative research articles on pediatric ECMO emerging from ELSO data. Here they present brief highlights of these publications.

Extracorporeal membrane oxygenation in paediatric cardiac surgery: 5-year single centre experience

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has become an integral part of paediatric cardiac surgery. We report the experience of a well-established ECMO service over 5 years.

METHODS

This retrospective study analysed all paediatric patients who required ECMO support following cardiac surgery from April 2015 to March 2020. Inclusion criteria were age less than 18 years and post-operative ECMO support. Patients were analysed dividing into groups according to the urgency for ECMO support (extracorporeal cardiopulmonary resuscitation (ECPR) and cardiac ECMO) and according to age (neonatal and paediatric ECMO groups). They were followed for 30-day, 6-month mortality, long-term survival, postoperative morbidity and the need for reintervention.

RESULTS

Forty-six patients were included who had a total of venoarterial (VA) 8 ECMO runs. The 5-year incidence of the need for VA ECMO after cardiac surgery was 3.3% (48 of the overall 1441 cases recorded). The median follow-up period was 3.5 (interquartile ranges, 0.8-4.7) years. Thirty-day, 6-month and follow-up survival rate was 85%, 65% and 52% respectively. At the 6-month follow-up, the ECPR group showed a trend towards worse survival compared with the cardiac ECMO group (47% vs. 55%) but with no statistical significance (p = 0.35). Furthermore, the survival rates between paediatric (60%) and neonatal (46%) ECMO groups were similar, with no statistical significance (p = 0.45). The rate of acute neurological events was 27% (13/48).

CONCLUSION

ECPR and neonatal ECMO groups had higher mortality. VA ECMO 30-day and 6-month survival rates were 85% and 65% respectively. Major neurological injury resulting in ECMO termination occurred in 3 patients. Accumulated experiences and protocols in ECMO management can improve mortality and morbidity.

Health Disparities in Extracorporeal Membrane Oxygenation Utilization and Outcomes: A Scoping Review and Methodologic Critique of the Literature

OBJECTIVES

To map the scope, methodological rigor, quality, and direction of associations between social determinants of health (SDoH) and extracorporeal membrane oxygenation (ECMO) utilization or outcomes.

DATA SOURCES

PubMed, Web of Science, Embase, and Cochrane Library databases were systematically searched for citations from January 2000 to January 2023, examining socioeconomic status (SES), race, ethnicity, hospital and ECMO program characteristics, transport, and geographic location (context) with utilization and outcomes (concept) in ECMO patients (population).

STUDY SELECTION

Methodology followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses scoping review extension. Two reviewers independently evaluated abstracts and full text of identified publications. Exclusion criteria included non-English, unavailable, less than 40 patients, and periprocedural or mixed mechanical support.

DATA EXTRACTION

Content analysis used a standardized data extraction tool and inductive thematic analysis for author-proposed mediators of disparities. Risk of bias was assessed using the Quality in Prognosis Studies tool.

DATA SYNTHESIS

Of 8,214 citations screened, 219 studies were identified. Primary analysis focuses on 148 (68%) including race/ethnicity/SES/payer variables including investigation of ECMO outcomes 114 (77%) and utilization 43 (29%). SDoH were the primary predictor in 15 (10%). Overall quality and methodologic rigor was poor with advanced statistics in 7%. Direction of associations between ECMO outcomes or utilization according to race, ethnicity, SES, or payer varied. In 38% adverse outcomes or lower use was reported in underrepresented, under-resourced or diverse populations, while improved outcomes or greater use were observed in these populations in 7%, and 55% had no statistically significant result. Only 26 studies (18%) discussed mechanistic drivers of disparities, primarily focusing on individual- and hospital-level rather than systemic/structural factors.

CONCLUSIONS

Associations between ECMO utilization and outcomes with SDoH are inconsistent, complicated by population heterogeneity and analytic shortcomings with limited consideration of systemic contributors. Findings and research gaps have implications for measuring, analyzing, and interpreting SDoH in ECMO research and healthcare.

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.