Association Between Early Change in Arterial Carbon Dioxide Tension and Outcomes in Neonates Treated by Extracorporeal Membrane Oxygenation

Can we reduce the risk of neurological injury in critically ill children on initiation of ECLS? A narrative review of potential modifiable factors

Neurological morbidity and mortality remain high in children requiring extracorporeal membrane oxygenation (ECMO). Although the severity of illness at the time of ECMO initiation and the nature of the underlying disease are strongly linked to the development of acute brain injury, several important factors are associated with neurological complications during ECMO support. Many of these factors, particularly those encountered during the early phase of ECMO initiation (first 24 hours), may be modifiable and represent potential targets for interventional studies aiming for improvement of neurological outcomes in pediatric ECMO patients. In this review from the European Extracorporeal Life Support Organization (EuroELSO) Working Group on Neurologic Monitoring and Outcome, we aim to summarize current knowledge on modifiable factors associated with brain injury during ECMO and their potential impact on outcome.

The role of extracorporeal membrane oxygenation in thoracic anesthesia

PURPOSE OF REVIEW

Circulatory and respiratory support with extracorporeal membrane oxygenation (ECMO) has gained widespread acceptance during high-end thoracic surgery. The purpose of this review is to summarize the recent knowledge and give an outlook for future developments.

RECENT FINDINGS

A personalized approach of ECMO use is state of the art for monitoring during surgery. Personalization is increasingly applied during anesthesia for high-end surgery nowadays. This is reflected in the point of care testing (POCT) for anticoagulation and cardiac function during surgery on ECMO combining specific patient data into tailored algorithms. For optimizing protective ventilation MP (mechanical power) is a promising parameter for the future. These personalized methods incorporating numerous patient data are promising for the improvement of morbidity and mortality in high-end thoracic surgery. However, clinical data supporting improvement are not available to date but can be awaited in the future.

SUMMARY

Clinical practice during surgery on ECMO is increasingly personalized. The effect of personalization on morbidity and mortality must be examined in the future. Undoubtedly, an increase in knowledge can be expected from this trend towards personalization.

Pa o2 and Mortality in Neonatal Extracorporeal Membrane Oxygenation: Retrospective Analysis of the Extracorporeal Life Support Organization Registry, 2015-2020

OBJECTIVES

Extracorporeal life support can lead to rapid reversal of hypoxemia but the benefits and harms of different oxygenation targets in severely ill patients are unclear. Our primary objective was to investigate the association between the Pa o2 after extracorporeal membrane oxygenation (ECMO) initiation and mortality in neonates treated for respiratory failure.

DESIGN

Retrospective analysis of the Extracorporeal Life Support Organization (ELSO) Registry data, 2015-2020.

PATIENTS

Newborns supported by ECMO for respiratory indication were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pa o2 24 hours after ECMO initiation (H24 Pa o2 ) was reported. The primary outcome was 28-day mortality. We identified 3533 newborns (median age 1 d [interquartile range (IQR), 1-3]; median weight 3.2 kg [IQR, 2.8-3.6]) from 198 ELSO centers, who were placed on ECMO. By 28 days of life, 731 (20.7%) had died. The median H24 Pa o2 was 85 mm Hg (IQR, 60-142). We found that both hypoxia (Pa o2 < 60 mm Hg) and moderate hyperoxia (Pa o2 201-300 mm Hg) were associated with greater adjusted odds ratio (aOR [95% CI]) of 28-day mortality, respectively: aOR 1.44 (95% CI, 1.08-1.93), p = 0.016, and aOR 1.49 (95% CI, 1.01-2.19), p value equals to 0.045.

CONCLUSIONS

Early hypoxia or moderate hyperoxia after ECMO initiation are each associated with greater odds of 28-day mortality among neonates requiring ECMO for respiratory failure.

The approach to extracorporeal cardiopulmonary resuscitation (ECPR) in children. A narrative review by the paediatric ECPR working group of EuroELSO

Extracorporeal Cardiopulmonary Resuscitation (ECPR) has potential benefits compared to conventional Cardiopulmonary Resuscitation (CCPR) in children. Although no randomised trials for paediatric ECPR have been conducted, there is extensive literature on survival, neurological outcome and risk factors for survival. Based on current literature and guidelines, we suggest recommendations for deployment of paediatric ECPR emphasising the requirement for protocols, training, and timely intervention to enhance patient outcomes. Factors related to outcomes of paediatric ECPR include initial underlying rhythm, CCPR duration, quality of CCPR, medications during CCPR, cannulation site, acidosis and renal dysfunction. Based on current evidence and experience, we provide an approach to patient selection, ECMO initiation and management in ECPR regarding blood and sweep flow settings, unloading of the left ventricle, diagnostics whilst on ECMO, temperature targets, neuromonitoring as well as suggested weaning and decannulation strategies.

Neurologic Statistical Prognostication and Risk Assessment for Kids on Extracorporeal Membrane Oxygenation-Neuro SPARK

This study presents Neuro-SPARK, the first scoring system developed to assess the risk of neurologic injury in pediatric and neonatal patients on extracorporeal membrane oxygenation (ECMO). Using the extracorporeal life support organization (ELSO) registry, we applied robust machine learning methodologies and clinical expertise to a 10 years dataset. We produced separate models for veno-venous (V-V ECMO) and veno-arterial (V-A ECMO) configurations due to their different risk factors and prevalence of neurologic injury. Our models identified 14 predictor variables for V-V ECMO and 20 for V-A ECMO, which demonstrated moderate accuracy in predicting neurologic injury as defined by the area under the receiver operating characteristic (AUROC) (V-V = 0.63, V-A = 0.64) and good calibration as measured by the Brier score (V-V = 0.1, V-A = 0.15). Furthermore, our post-hoc analysis identified high- and low-risk groups that may aid clinicians in targeted neuromonitoring and guide future research on ECMO-associated neurologic injury. Despite the inherent limitations, Neuro-SPARK lays the foundation for a risk-assessment tool for neurologic injury in ECMO patients, with potential implications for improved patient outcomes.

Neuromonitoring During ECMO Support in Children

Extracorporeal membrane oxygenation is a potentially lifesaving intervention for children with severe cardiac or respiratory failure. It is used with increasing frequency and in increasingly more complex and severe diseases. Neurological injuries are important causes of morbidity and mortality in children treated with extracorporeal membrane oxygenation and include ischemic stroke, intracranial hemorrhage, hypoxic-ischemic injury, and seizures. In this review, we discuss the epidemiology and pathophysiology of neurological injury in patients supported with extracorporeal membrane oxygenation, and we review the current state of knowledge for available modalities of monitoring neurological function in these children. These include structural imaging with computed tomography and ultrasound, cerebral blood flow monitoring with near-infrared spectroscopy and transcranial Doppler ultrasound, and physiological monitoring with electroencephalography and plasma biomarkers. We highlight areas of need and emerging advances that will improve our understanding of neurological injury related to extracorporeal membrane oxygenation and help to reduce the burden of neurological sequelae in these children.

Extracorporeal Membrane Oxygenation for Septic Shock in Adults and Children: A Narrative Review

Refractory septic shock is associated with a high risk of death. Circulatory support in the form of veno-arterial extracorporeal membrane oxygenation (VA ECMO) may function as a bridge to recovery, allowing for the treatment of the source of the sepsis. Whilst VA ECMO has been accepted as the means of hemodynamic support for children, in adults, single center observational studies show survival rates of only 70-90% for hypodynamic septic shock. The use of VA ECMO for circulatory support in hyperdynamic septic shock with preserved cardiac output or when applied late during cardio-pulmonary resuscitation is not recommended. With unresolving septic shock and a loss of ventriculo-arterial coupling, stress cardiomyopathy often develops. If the cardiac index (CI) approaches subnormal levels (CI < 2.5 L/min m-2) that do not match low systemic vascular resistance with a resulting loss of vital systemic perfusion pressure, VA ECMO support should be considered. A further decrease to the level of cardiogenic shock (CI < 1.8 L/min m-2) should be regarded as an indication for VA ECMO insertion. For patients who maintain a normal-to-high CI as part of their refractory vasoparalysis, VA ECMO support is justified in children and possibly in patients with a low body mass index. Extracorporeal support for septic shock should be limited to high-volume ECMO centers.

Pediatric extracorporeal life support for refractory status asthmaticus: ELSO Registry trends from the past decade

BACKGROUND

Extracorporeal life support (ECLS) for status asthmaticus (SA) is rare. Increased safety and experience may increase utilization of ECLS for SA.

METHODS

We reviewed pediatric (<18 years old) patients requiring ECLS for SA between 1998 and 2019 within the Extracorporeal Life Support Organization (ELSO) Registry and Nemours Children's Health (NCH) system. We compared patient characteristics, pre-ECLS medications, clinical data, complications, and survival to discharge between Early (1988-2008) and Late (2009-2019) eras.

RESULTS

From the ELSO Registry, we identified 173 children, 53 in Early and 120 in Late eras, with primary diagnosis of SA. Pre-ECLS hypercarbic respiratory failure was similar between eras (median pH 7.0 and pCO2 111 mm Hg). Venovenous mode (79% vs. 82%), median ECLS time (116 vs. 99 h), time to extubation (53 vs. 62 h), and hospital survival (89% vs. 88%) also remained similar. Intubation to cannulation time significantly decreased (20 vs. 10 h, p = 0.01). ECLS without complication occurred more in the Late era (19% vs. 39%, p < 0.01), with decreased hemorrhagic (24% vs. 12%, p = 0.05) and noncannula-related mechanical (19% vs. 6%, p = 0.008) complications. Within NCH, we identified six Late era patients. Pre-ECLS medication favored intravenous beta agonists, bronchodilators, magnesium sulfate, and steroids. One patient died from neurological complications following pre-ECLS cardiac arrest.

CONCLUSIONS

Collective experience supports ECLS as a rescue therapy for pediatric SA. Survival to discharge remains good, and complication rates have improved. Pre-ECLS cardiac arrest may potentiate neurologic injury and impact survival. Further study is needed to evaluate causal relationships between complications and outcomes.

Extracorporeal Membrane Oxygenation

The utilization of extracorporeal membrane oxygenation (ECMO) for cardiopulmonary support continues to increase globally, with > 190,000 ECMO cases reported to the international Extracorporeal Life Support Organization Registry. The present review aims to synthesize important contributions to the literature surrounding the management of mechanical ventilation, prone positioning, anticoagulation, bleeding complications, and neurologic outcomes for infants, children, and adults undergoing ECMO in 2022. Additionally, issues related to cardiac ECMO, Harlequin syndrome, and anticoagulation during ECMO will be discussed.

Editor's Choice Articles for July

This is another excellent issue of Pediatric Critical Care Medicine (PCCM) for July; congratulations to our authors and many thanks to all reviewers. This month, my Editor's Choice articles cover three topics: clinical pathophysiology in pediatric patients supported using extracorporeal membrane oxygenation (ECMO); unplanned extubation of endotracheal tubes in pediatric cardiac ICU (CICU) patients; and sepsis biomarkers in the low-middle income (LMIC) resource setting. The PCCM Connections for Readers focuses on a novel pediatric theme in lung mechanics physiology, i.e., mechanical power in pediatric acute respiratory distress syndrome (PARDS).