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

Acute respiratory distress syndrome: A review of ARDS across the life course

Acute respiratory distress syndrome (ARDS) is a multifactorial, inflammatory lung disease with significant morbidity and mortality that predominantly requires supportive care in its management. Although initially described in adult patients, the diagnostic definitions for ARDS have evolved over time to accurately describe this disease process in pediatric and, more recently, neonatal patients. The management of ARDS in each age demographic has converged in the application of lung-protective ventilatory strategies to mitigate the primary disease process and prevent its exacerbation by limiting ventilator-induced lung injury. However, differences arise in the preferred ventilatory strategies or adjunctive pulmonary therapies used to mitigate each type of ARDS. In this review, we compare and contrast the epidemiology, common etiologies, pathophysiology, diagnostic criteria, and outcomes of ARDS across the lifespan. Additionally, we discuss in detail the different management strategies used for each subtype of ARDS and spotlight how these strategies were applied to mitigate poor outcomes during the COVID-19 pandemic. This review is geared toward both clinicians and clinician-scientists as it not only summarizes the latest information on disease pathogenesis and patient management in ARDS across the lifespan but also highlights knowledge gaps for further investigative efforts. We conclude by projecting how future studies can fill these gaps in research and what improvements may be envisioned in the management of NARDS and PARDS based on the current breadth of literature on adult ARDS treatment strategies.

Why do children not survive extracorporeal membrane oxygenation?

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is used in critically ill children with cardiac and/or respiratory failure. Use is increasing in children with high-risk comorbidities. Reasons children do not survive ECMO are poorly described.

AIMS

Describe characteristics and cause of death, compare mortality in children with high-risk comorbidities, evaluate mortality trends over a decade.

METHOD

All children <18 years old who received ECMO at this institution from 1 January 2011 to 31 December 2020 were described and categorised by outcome: died on or <48 h post-ECMO, died ≥48 h post-ECMO, survived to hospital discharge. Children who did not survive ECMO (DNSE) were categorised to: ECMO withdrawal for irrecoverable original condition, withdrawal for poor prognosis neurological condition, brain death, withdrawal for poor prognosis with multiple complex conditions, and unsupportable. Poison regression was used to analyse survival trends.

RESULTS

Four hundred twenty-eight children received ECMO, 19% DNSE, 14% died ≥48 h post-ECMO and 67% survived. ECMO was electively withdrawn for irrecoverable original condition (39%), poor prognosis for neurological condition (32%) or multiple complex conditions (18%). One hundred twenty-two children had ≥1 high-risk comorbidity. Children with genetic syndromes (58%), risk-adjusted congenital heart surgery score-1 ≥4 (53%), primary immunodeficiency (50%) had lower hospital survival. No children with malignancy/bone marrow transplant survived to hospital discharge. Overall hospital survival was 67%, with no significant change during the study period (P-trend = 0.99).

CONCLUSION

Children who DNSE have therapy electively withdrawn for irrecoverable disease or poor prognosis. Children with high-risk comorbidities have a reasonable chance of survival. This study informs clinicians ECMO may be a therapeutic option.

Intravascular Hemolysis and AKI in Children Undergoing Extracorporeal Membrane Oxygenation

Key Points

The incidence of AKI while undergoing ECMO in pediatric patients is high and independently increases mortality. Laboratory markers consistent with intravascular hemolysis increase the hazard of a composite outcome of AKI or RRT while undergoing ECMO. Further research into appropriate monitoring or treatment of ECMO-associated hemolysis may lead to important interventions to prevent AKI.

Background

AKI is common in patients requiring extracorporeal membrane oxygenation (ECMO), with a variety of proposed mechanisms. We sought to describe the effect of laboratory evidence of ECMO-associated intravascular hemolysis on AKI and RRT.

Methods

This retrospective cohort study included patients treated with ECMO at a single center over 10 years. The primary outcome was a composite of time to RRT or AKI (by creatinine-based Kidney Disease Improving Global Outcomes criteria) after ECMO start. Serum creatinine closest to ECMO start time was considered the pre-ECMO baseline and used to determine abnormal kidney function at ECMO start. The patient's subsequent creatinine values were used to identify AKI on ECMO. Multivariable cause-specific Cox proportional hazards models were used to assess the effect of separate markers of intravascular hemolysis on the time to the composite outcome after controlling for confounders.

Results

Five hundred and one children were evaluated with a median age 1.2 years, 56% male. Four separate multivariable models, each with a different marker of hemolysis (plasma-free hemoglobin, lactate dehydrogenase (LDH), minimum platelet count, and minimum daily hemoglobin), were used to examine the effect on the composite outcome of AKI/RRT. An elevated plasma-free hemoglobin, the most specific of these hemolysis markers, demonstrated an almost three-fold higher adjusted hazard for the composite outcome (hazard ratio [HR], 2.9; P value < 0.01; 95% confidence interval [CI], 1.4 to 5.6). Elevated LDH was associated with an adjusted HR of 3.1 (P value < 0.01; 95% CI, 1.7 to 5.5). Effect estimates were also pronounced in a composite outcome of only more severe AKI, stage 2+ AKI/RRT: HR 6.6 (P value < 0.01; 95% CI, 3.3 to 13.2) for plasma-free hemoglobin and 2.8 (P value < 0.01; 95% CI, 1.5 to 5.6) for LDH.

Conclusions

Laboratory findings consistent with intravascular hemolysis on ECMO were independently associated with a higher hazard of a composite outcome of AKI/RRT in children undergoing ECMO.

Pediatric venoarterial and venovenous ECMO

Extracorporeal membrane oxygenation (ECMO) is an invaluable resource in the treatment of critically ill children with cardiopulmonary failure.  To date, over 36,000 children have been placed on ECMO and the utilization of this life saving treatment continues to expand with advances in ECMO technology.  This article offers a review of pediatric ECMO including modes and sites of ECMO cannulation, indications and contraindications, and cannulation techniques.  Furthermore, it summarizes the basic principles of pediatric ECMO including circuit maintenance, nutritional support, and clinical decision making regarding weaning pediatric ECMO and decannulation.  Finally, it gives an overview of common pediatric ECMO complications including overall mortality and long-term outcomes of ECMO survivors. The goal of this article is to provide a comprehensive review for healthcare professionals providing care for pediatric ECMO patients.

Quality improvement strategies in pediatric ECMO

Pediatric extracorporeal membrane oxygenation is an increasingly utilized, life-saving technology with high mortality and morbidity. A complex technology employed urgently or emergently for some of the sickest children in the hospital by a large multidisciplinary team, ECMO is an ideal area for using quality improvement strategies to reduce the variability in care and improve patient outcomes. We review critical concepts from quality improvement and apply them to patient selection and management, staffing, credentialing and continuing education, and the variability of management among providers and institutions.

Extracorporeal membrane oxygenation in children receiving haematopoietic cell transplantation and immune effector cell therapy: an international and multidisciplinary consensus statement

Use of extracorporeal membrane oxygenation (ECMO) in children receiving haematopoietic cell transplantation (HCT) and immune effector cell therapy is controversial and evidence-based guidelines have not been established. Remarkable advancements in HCT and immune effector cell therapies have changed expectations around reversibility of organ dysfunction and survival for affected patients. Herein, members of the Extracorporeal Life Support Organization (ELSO), Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network (HCT and cancer immunotherapy subgroup), the Pediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation (EBMT), the supportive care committee of the Pediatric Transplantation and Cellular Therapy Consortium (PTCTC), and the Pediatric Intensive Care Oncology Kids in Europe Research (POKER) group of the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) provide consensus recommendations on the use of ECMO in children receiving HCT and immune effector cell therapy. These are the first international, multidisciplinary consensus-based recommendations on the use of ECMO in this patient population. This Review provides a clinical decision support tool for paediatric haematologists, oncologists, and critical care physicians during the difficult decision-making process of ECMO candidacy and management. These recommendations can represent a base for future research studies focused on ECMO selection criteria and bedside management.

Mechanical circulatory support in paediatric population

Extra-corporeal membrane oxygenation is a life-saving modality to support the cardiac and/or pulmonary system as a form of life support in resuscitation, post-cardiotomy, as a bridge to cardiac transplantation and in respiratory failure. Its use in the paediatric and neonatal population has proven incredibly useful. However, extra-corporeal membrane oxygenation is also associated with a greater rate of mortality and complications, particularly in those with co-morbidities. As a result, interventions such as ventricular assist devices have been trialled in these patients. In this review, we provide a comprehensive analysis of the current literature on extra-corporeal membrane oxygenation for cardiac support in the paediatric and neonatal population. We evaluate its effectiveness in comparison to other forms of mechanical circulatory support and focus on areas for future development.