Improving Outcomes for Children Requiring Extracorporeal Membrane Oxygenation Therapy Following Hematopoietic Stem Cell Transplantation

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.

Outcomes of extracorporeal membrane oxygenation support in pediatric hemato-oncology patients

BACKGROUND

In this study, we reviewed the outcomes of pediatric patients with malignancies who underwent hematopoietic stem cell transplantation (HSCT) and extracorporeal membrane oxygenation (ECMO).

METHODS

We retrospectively analyzed the records of pediatric hemato-oncology patients treated with chemotherapy or HSCT and who received ECMO in the pediatric intensive care unit (PICU) at Seoul National University Children's Hospital from January 2012 to December 2020.

RESULTS

Over a 9-year period, 21 patients (14 males and 7 females) received ECMO at a single pediatric institute; 10 patients (48%) received veno-arterial (VA) ECMO for septic shock (n=5), acute respiratory distress syndrome (ARDS) (n=3), stress-induced myopathy (n=1), or hepatopulmonary syndrome (n=1); and 11 patients (52%) received veno-venous (VV) ECMO for ARDS due to pneumocystis pneumonia (n=1), air leak (n=3), influenza (n=1), pulmonary hemorrhage (n=1), or unknown etiology (n=5). All patients received chemotherapy; 9 received anthracycline drugs and 14 (67%) underwent HSCT. Thirteen patients (62%) were diagnosed with malignancies and 8 (38%) were diagnosed with non-malignant disease. Among the 21 patients, 6 (29%) survived ECMO in the PICU and 5 (24%) survived to hospital discharge. Among patients treated for septic shock, 3 of 5 patients (60%) who underwent ECMO and 5 of 10 patients (50%) who underwent VA ECMO survived. However, all the patients who underwent VA ECMO or VV ECMO for ARDS died.

CONCLUSIONS

ECMO is a feasible treatment option for respiratory or heart failure in pediatric patients receiving chemotherapy or undergoing HSCT.

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.

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.

Surgical Science and the Evolution of Critical Care Medicine

Surgical science has driven innovation and inquiry across adult and pediatric disciplines that provide critical care regardless of location. Surgically originated but broadly applicable knowledge has been globally shared within the pages Critical Care Medicine over the last 50 years.

Extracorporeal Membrane Oxygenation for Adult Patients With Neoplasms: Outcomes and Trend Over the Last 2 Decades

Extracorporeal membrane oxygenation (ECMO) is utilized in the management of severe respiratory and circulatory failure. Advanced malignancy is a relative contraindication, but the indication for ECMO in the oncologic population has not been clearly established because of the wide spectrum of malignant disease and prognoses. The Extracorporeal Life Support Organization database was queried for patients older than 18 years with an International Classification of Diseases code of neoplasm over the past 2 decades (2000-2019). The data were divided into 2 decades to analyze and compare the trends with background and outcomes. One thousand six-hundred ninety-seven patients met inclusion criteria from the latest decade which is over 15 times the previous decade (n = 110). Compared with the previous decade, ECMO was used more in patients with older age (56 vs . 50.5 years old; p < 0.001), cardiac and extracorporeal cardiopulmonary resuscitation (ECPR) support type ( p = 0.011), and lower oxygenation index (23.0 vs . 35.6; p < 0.001) in the latest decade. Although overall survival did not show significant improvement overall (38.9% vs . 33.6%; p = 0.312), survival in pulmonary ECMO has significantly improved in the latest decade (41.6% vs . 29.1%; p = 0.032). Compared with the previously reported data for all adult ECMO, our patients had a significantly lower survival with pulmonary (41.6% vs . 61.1%; p < 0.001) and cardiac (38.4% vs . 44.3%; p = 0.008) support while not with ECPR.

Extracorporeal membrane oxygenation in patients with hematologic malignancies: a systematic review and meta-analysis

Hematological malignancies (HM) have been, until recently, viewed as contraindications to extracorporeal membrane oxygenation (ECMO) due to bleeding and infectious complications. However, conflicting literature regarding whether ECMO should be used for patients with HM still exists. We conducted a random effects meta-analysis to investigate the outcomes of patients with HM on ECMO. We searched Medline, Embase, Scopus, and Cochrane through 10 October 2021. Risk of bias and certainty of evidence were assessed using the JBI checklists and GRADE approach respectively. Thirteen observational studies (422 patients with HM, 9778 controls without HM) were included. The pooled in-hospital mortality for patients with HM and those with hematopoietic stem cell transplants for HM indications needing ECMO were 79.1% (95%CI: 70.2-86.9%) and 87.7% (95%CI: 80.4-93.8%), respectively. Subgroup analyses found that mortality was higher in adults than children (85.1% vs 67.9%, p_interaction = 0.003), and in Asia compared to North America and Europe (93.8% vs 69.6%, p_interaction < 0.001). Pooled ECMO duration was 10.0 days (95%CI: 7.5-12.5); pooled ICU and hospital lengths of stay were 19.8 days (95%CI: 12.4-27.3) and 43.9 days (95%CI: 29.4-58.4) respectively. Age (regression coefficient [B]: 0.008, 95%CI: 0.003-0.014), proportion of males (B: 1.799, 95%CI: 0.079-3.519), and ECMO duration (B: - 0.022, 95%CI: - 0.043 to - 0.001) were significantly associated with higher mortality. In-hospital mortality of patients with HM who needed ECMO was 79.1%, with better outcomes in children, and in North America and Europe. ECMO should not be regarded as routine support therapy in these patients but can be carefully considered on a case-by-case basis.

Candidacy for Extracorporeal Life Support in Children After Hematopoietic Cell Transplantation: A Position Paper From the Pediatric Acute Lung Injury and Sepsis Investigators Network's Hematopoietic Cell Transplant and Cancer Immunotherapy Subgroup

OBJECTIVES

The last decade has seen improved outcomes for children requiring extracorporeal life support as well as for children undergoing hematopoietic cell transplantation. Thus, given the historically poor survival of hematopoietic cell transplantation patients using extracorporeal life support, the Pediatric Acute Lung Injury and Sepsis Investigators' hematopoietic cell transplantation and cancer immunotherapy subgroup aimed to characterize the utility of extracorporeal life support in facilitating recovery from critical cardiorespiratory illnesses in pediatric hematopoietic cell transplantation patients.

DATA SOURCES

All available published data were identified using a set of PubMed search terms for pediatric extracorporeal life support and hematopoietic cell transplantation.

STUDY SELECTION

All articles that provided original reports of pediatric hematopoietic cell transplantation patients who underwent extracorporeal life support were included. Sixty-four manuscripts met search criteria. Twenty-four were included as primary reports of pediatric hematopoietic cell transplantation patients who underwent extracorporeal life support (11 were single case reports, four single institution case series, two multi-institution case series, and seven registry reports from Extracorporeal Life Support Organization, Pediatric Heath Information System, and Virtual Pediatric Systems).

DATA EXTRACTION

All 24 articles were reviewed by first and last authors and a spread sheet was constructed including sample size, potential biases, and conclusions.

DATA SYNTHESIS

Discussions regarding incorporation of available evidence into our clinical practice were held at biannual meetings, as well as through email and virtual meetings. An expert consensus was determined through these discussions and confirmed through a modified Delphi process.

CONCLUSIONS

Extracorporeal life support in hematopoietic cell transplantation patients is being used with increasing frequency and potentially improving survival. The Pediatric Acute Lung Injury and Sepsis Investigators hematopoietic cell transplantation-cancer immunotherapy subgroup has developed a framework to guide physicians in decision-making surrounding extracorporeal life support candidacy in pediatric hematopoietic cell transplantation patients. In addition to standard extracorporeal life support considerations, candidacy in the hematopoietic cell transplantation population should consider the following six factors in order of consensus agreement: 1) patient comorbidities; 2) underlying disease necessitating hematopoietic cell transplantation; 3) hematopoietic cell transplantation toxicities, 4) family and patient desires for goals of care; 5) hematopoietic cell transplantation preparatory regimen; and 6) graft characteristics. Although risk assessment may be individualized, data are currently insufficient to clearly delineate ideal candidacy. Therefore, we urge the onco-critical care community to collaborate and capture data to provide better evidence to guide physicians' decision-making in the future.

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.

Extracorporeal Membrane Oxygenation Candidacy in Pediatric Patients Treated With Hematopoietic Stem Cell Transplant and Chimeric Antigen Receptor T-Cell Therapy: An International Survey

Introduction

Pediatric patients who undergo hematopoietic cell transplant (HCT) or chimeric antigen receptor T-cell (CAR-T) therapy are at high risk for complications leading to organ failure and the need for critical care resources. Extracorporeal membrane oxygenation (ECMO) is a supportive modality that is used for cardiac and respiratory failure refractory to conventional therapies. While the use of ECMO is increasing for patients who receive HCT, candidacy for these patients remains controversial. We therefore surveyed pediatric critical care and HCT providers across North America and Europe to evaluate current provider opinions and decision-making and institutional practices regarding ECMO use for patients treated with HCT or CAR-T.

Methods

An electronic twenty-eight question survey was distributed to pediatric critical care and HCT providers practicing in North America (United States and Canada) and Europe through the Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network and individual emails. Responses to the survey were recorded in a REDCap^® database.

Results

Two-hundred and ten participants completed the survey. Of these, 159 (76%) identified themselves as pediatric critical care physicians and 47 (22%) as pediatric HCT physicians or oncologists. The majority (99.5%) of survey respondents stated that they would consider patients treated with HCT or CAR-T therapy as candidates for ECMO support. However, pediatric critical care physicians identified more absolute and relative contraindications for ECMO than non-pediatric critical care physicians. While only 0.5% of respondents reported that they consider HCT as an absolute contraindication for ECMO, 6% of respondents stated that ECMO is contraindicated in HCT patients within their institution and only 23% have an institutional protocol or policy to guide the evaluation for ECMO candidacy of these patients. Almost half (49.1%) of respondents would accept a survival to hospital discharge of 20-30% for pediatric HCT patients requiring ECMO as adequate.

Conclusions

ECMO use for pediatric patients treated with HCT and CAR-T therapy is generally acceptable amongst physicians. However, there are differences in the evaluation and decision-making regarding ECMO candidacy amongst providers across medical specialties and institutions. Therefore, multidisciplinary collaboration is an essential component in establishing practice guidelines and advancing ECMO outcomes for these patients.

Extracorporeal Membrane Oxygenation in Children With Cancer or Hematopoietic Cell Transplantation: Single-Center Experience in 20 Consecutive Patients

Extracorporeal membrane oxygenation (ECMO) is a rescue therapy for severe respiratory and/or circulatory failure. Few data exist on the potential benefit of ECMO in immunocompromised pediatric patients with cancer and/or hematopoietic cell transplantation (HCT). Over a period of 12 years, eleven (1.9%) of 572 patients with new diagnosis of leukemia/lymphoma and nine (3.5%) of 257 patients post allogeneic HCT underwent ECMO at our center. Five (45%) and two (22%) patients, respectively, survived to hospital discharge with a median event-free survival of 4.2 years. Experiences and outcomes in this cohort may aid clinicians and families when considering ECMO for individual patients.