Mortality after Lung Transplantation for Children Bridged with Extracorporeal Membrane Oxygenation

Impact of Functional Status at the Time of Transplant on Short-Term Pediatric Lung Transplant Outcomes in the USA

PURPOSE

Poor functional status is associated with pediatric lung transplant (LTx) waitlist mortality. We investigate how pre-transplant functional status affects post-LTx survival.

METHODS

A retrospective analysis was performed using The United Network for Organ Sharing (UNOS) Registry data. Pediatric first-time lung transplant candidates between ages 1 and 18 years with reported Lansky Play-Performance Scores (LPPS) at the time of waitlist and/or transplant were included from 2005 and 2021. Functional status by the LPPS scores is defined as severe limitation for LPPS score 10-40, mild limitation for LPPS score 50-70, and normal activity for LPPS score 80-100. Univariate analyses, multivariable Cox regression, and Kaplan-Meier plots were used to assess the impact of functional status on 1-year post-LTx survival.

RESULTS

There were 913 and 610 patients at the time of LTx listing and transplant with LPPS scores, respectively. Poor functional status as determined by the LPPS score at the time of LTx, but not at the time of waitlist, was associated with worse 1-year post-LTx outcome (p value 0.0025 vs. 0.071). Multivariable survival analysis using Cox proportional hazards regression identified that a severely limited functional status at the time of LTx was the most profound risk factor for worse 1-year post-LTx survival outcomes when compared to a normal functional status (HR 2.16; 95% CI 1.15-4.07, p value 0.017).

CONCLUSIONS

Children with severely limited functional status at the time of LTx have worse 1-year post-LTx outcome. It is important to develop strategies to optimize the functional status of children for improved post-LTx outcomes.

Trends in racial and ethnic disparities in pediatric lung transplantation in the United States

BACKGROUND

Racial and ethnic disparities in pediatric lung transplantation (LTx) related to the shifting cystic fibrosis (CF) population receiving highly effective modulator therapy (HEMT) has not been well investigated.

METHODS

The UNOS Registry was queried for patients age 1-25 years undergoing bilateral LTx between 1 January 2012 and 31 December 2021. Race and ethnicity were classified as non-Hispanic White, non-Hispanic Black, Hispanic, or none of the above. The primary outcome was posttransplant mortality. Trends in the association between race/ethnicity and mortality were examined using transplant year as a continuous variable and stratifying year based on introduction of HEMT (triple combination therapy) in November 2019.

RESULTS

In the study sample (N = 941), 7% of patients were non-Hispanic Black, 15% were Hispanic, and 2% were some other racial or ethnic group. One hundred (11%) received LTx after approval of triple combination therapy, and 407 (43%) died during follow-up. We identified a statistically significant disparity in mortality hazard (hazard ratio: 1.91; 95% confidence interval: 1.31, 2.80) in non-Hispanic Black compared to non-Hispanic White patients in the pre-triple combination therapy era.

CONCLUSIONS

We found higher mortality hazard among non-Hispanic Black compared to non-Hispanic White children undergoing LTx in the United States. Further monitoring of LTx outcomes to identify and address disparities is needed in the current era of triple combination therapy for CF.

The Year in Cardiothoracic Transplant Anesthesia: Selected Highlights From 2022 Part I: Lung Transplantation

These highlights focus on the research in lung transplantation (LTX) that was published in 2022 and includes the assessment and optimization of candidates for LTX, donor optimization, the use of organs from donation after circulatory death, and outcomes when using marginal or novel donors; recipient factors affecting LTX, including age, disease, the use of extracorporeal life support; and special situations, such as coronavirus disease2019, pediatric LTX, and retransplantation. The remainder of the article focuses on the perioperative management of LTX, including the perioperative risk factors for acute renal failure (acute kidney injury); the incidence and management of phrenic nerve injury, delirium, and pain; and the postoperative management of hyperammonemia, early postoperative infections, and the use of donor-derived cell-free DNA to detect rejection.

Pediatric Lung Transplantation for Pulmonary Vascular Diseases: Recent Advances and Challenges

Pediatric lung transplantation for pulmonary vascular diseases has seen notable advancements and trends. Medical therapies, surgical options, and bridging techniques like extracorporeal membrane oxygenation and different forms of transplants have expanded treatment possibilities. Current challenges include ensuring patient adherence to post-transplant therapies, addressing complications like primary graft dysfunction and rejection, and conducting further research in less common conditions like pulmonary veno-occlusive disease and pulmonary vein stenosis. In this review article, the authors will explore the advancements, emerging trends, and persistent challenges in pediatric lung transplantation for pulmonary vascular diseases.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights From 2023

This special article is the 16th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series, namely the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology. The major themes selected for 2023 are outlined in this introduction, and each highlight is reviewed in detail in the main article. The literature highlights in the specialty for 2023 begin with an update on perioperative rehabilitation in cardiothoracic surgery, with a focus on novel methods to best assess patients in the preoperative and postoperative periods, and the impact of rehabilitation on outcomes. The second major theme is focused on cardiac surgery, with the authors discussing new insights into inhaled pulmonary vasodilators, coronary revascularization surgery, and discussion of causes of coronary graft failure after surgery. The third theme is focused on cardiothoracic transplantation, with discussions focusing on bridge-to-transplantation strategies. The fourth theme is focused on mechanical circulatory support, with discussions focusing on both temporary and durable support. The fifth and final theme is an update on medical cardiology, with a focus on outcomes of invasive approaches to heart disease. The themes selected for this article are only a few of the diverse advances in the specialty during 2023. These highlights will inform the reader of key updates on various topics, leading to improved perioperative outcomes for patients with cardiothoracic and vascular disease.

Cystic fibrosis year in review 2022

Remarkable medical advancements have been made for people with cystic fibrosis (CF) in recent years, with an abundance of research continuing to be conducted worldwide. With concern for limitations in access to highly effective CFTR modulators, as well as the recent Coronavirus Disease-19 pandemic, there has been a consistent effort to understand and improve CF screening, disease burden, diagnosis, and management. Our aim in this review is to present articles from 2022 with an emphasis on clinically relevant studies. We hope this will serve as a broad overview of the research published in the past year.

Extracorporeal membrane oxygenation bridge to pediatric lung transplantation: Modern era analysis

BACKGROUND

Survival outcomes of children on extracorporeal membrane oxygenation (ECMO) at time of lung transplant (LTx) remain unclear.

METHODS

Pediatric first-time LTx recipients transplanted between January 2000 and December 2020 were identified in the United Network for Organ Sharing Registry to compare post-transplant survival according to ECMO support at time of transplant. For a comprehensive analysis of the data, univariate analysis, multivariable Cox regression, and propensity score matching were performed.

RESULTS

During the study period, 954 children under 18 years of age underwent LTx with 40 patients on ECMO. We did not identify a post-LTx survival difference between patients receiving ECMO when compared to those that did not. A multivariable Cox regression model (Hazard ratio = 0.83; 95% confidence interval: 0.47, 1.45; p = .51) did not demonstrate an increased risk for death post-LTx. Lastly, a propensity score matching analysis, retaining 33 ECMO and 33 non-ECMO patients, further confirmed no post-LTx survival difference comparing ECMO to no ECMO cohorts (Hazard ratio = 0.98; 95% confidence interval: 0.48, 2.00; p = .96).

CONCLUSIONS

In this contemporary cohort of children, the use of ECMO at the time of LTx did not negatively impact post-transplant survival.

Extracorporeal Membrane Oxygenation Then and Now; Broadening Indications and Availability

Extracorporeal membrane oxygenation (ECMO) is a life support technology provided to children to support respiratory failure, cardiac failure, or cardiopulmonary resuscitation after failure of conventional management. Over the decades, ECMO has expanded in use, advanced in technology, shifted from experimental to a standard of care, and evidence supporting its use has increased. The expanded ECMO indications and medical complexity of children have also necessitated focused studies in the ethical domain such as decisional authority, resource allocation, and equitable access.

Advances in Extracorporeal Support Technologies in Critically Ill Children

The field of pediatric heart failure is evolving, and the patient population is growing as survival after complex congenital heart surgeries is improving. Mechanical circulatory support and extracorporeal respiratory support in critically ill children has progressed to a mainstay rescue modality in pediatric intensive care medicine. The need for mechanical circulatory support is growing, since the number of organ donors does not meet the necessity. This article aims to review the current state of available mechanical circulatory and respiratory support systems in acute care pediatrics, with an emphasis on the literature discussing the challenges associated with these complex support modalities.

Extracorporeal Membrane Oxygenation in Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

To systematically review and assimilate literature on children receiving extracorporeal membrane oxygenation (ECMO) support in pediatric acute respiratory distress syndrome (PARDS) with the goal of developing an update to the Pediatric Acute Lung Injury Consensus Conference recommendations and statements about clinical practice and research.

DATA SOURCES

Electronic searches of MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

The search used a medical subject heading terms and text words to capture studies of ECMO in PARDS or acute respiratory failure. Studies using animal models and case reports were excluded from our review.

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development, and Evaluation approach was used to identify and summarize evidence and develop recommendations. There were 18 studies identified for full-text extraction. When pediatric data was lacking, adult and neonatal data from randomized clinical trials and observational studies were considered. Six clinical recommendations were generated related to ECMO indications, initiation, and management in PARDS. There were three good practice statements generated related to ECMO indications, initiation, and follow-up in PARDS. Two policy statements were generated involving the impact of ECMO team organization and training in PARDS. Last, there was one research statement.

CONCLUSIONS

Based on a systematic literature review, we propose clinical management, good practice and policy statements within the domains of ECMO indications, initiation, team organization, team training, management, and follow-up as they relate to PARDS.

Extracorporeal membrane oxygenation as a bridge to transplant in neonates with fatal pulmonary conditions: A review

Neonates with progressive respiratory failure should be referred early for subspecialty evaluation and lung transplantation consideration. ECMO should be considered for patients with severe cardiopulmonary dysfunction and a high likelihood of death while on maximal medical therapy, either in the setting of reversible medical conditions or while awaiting lung transplantation. While ECMO offers hope to neonates that experience clinical deterioration while awaiting transplant, the risks and benefits of this intervention should be considered on an individual basis. Owing to the small number of infant lung transplants performed yearly, large studies examining the outcomes of various bridging techniques in this age group do not exist. Multiple single-centre experiences of transplanted neonates have been described and currently serve as guidance for transplant teams. Future investigation of outcomes specific to neonatal transplant recipients bridged with advanced devices is needed.

Extracorporeal membrane oxygenation and paracorporeal lung assist devices as a bridge to pediatric lung transplantation

BACKGROUND

"Bridging" is a term used to describe the implementation of various treatment modalities to improve waitlist survival while a patient awaits lung transplantation. ECMO and PLAD are technologies used to bridge patients to lung transplantation. ECMO and PLAD are cardiopulmonary support systems that help move blood forward while using an artificial membrane to remove CO₂ from and add O₂ to the blood. Recent studies showed that these technologies are increasingly effective in bridging patients to lung transplantation, especially with optimizing patient selection, implementing physical rehabilitation and ambulation goals, standardization of management decisions, and increasing staff experience, among other considerations. We review these technologies, their roles as bridges to pediatric lung transplantation, as well as indications, contraindications, complications, and mortality rates.

CONCLUSION

Finally, we discuss the existing knowledge gaps and areas for future research to improve patient outcomes and understanding of lung assist devices.

Cystic fibrosis year in review 2021

People with cystic fibrosis (CF) have an amazing outlook with the treatment availability of highly effective modulators. Unfortunately, not all people with CF are eligible for modulators leading to continued pulmonary exacerbations and advanced lung disease. Additionally, optimizing diagnosis and evaluation for CF in the newborn period continues to be an area of focus for research. This review article will work to cover articles published in 2021 with high clinical relevance related to the above topics; however, due to the extensive body of research published, this review will not be comprehensive.

Extracorporeal membrane oxygenation for severe acute respiratory distress syndrome in children with leukemia/lymphoma: A retrospective case series

OBJECTIVE

The cancer patients with severe acute respiratory distress syndrome (ARDS) benefit from extracorporeal membrane oxygenation (ECMO) remains unanswered. We analyzed clinical characteristics and outcomes of pediatric patients with leukemia/lymphoma who developed ARDS and treated with ECMO.

METHODS

Pediatric leukemia or lymphoma patients with ARDS who underwent ECMO between August 2017 and December 2021 were retrospectively analyzed in a tertiary pediatric intensive care unit (PICU).

RESULTS

Seven patients with median age 53 (IQR 42-117) months and 4 males were included. Six cases of leukemia [5 of acute lymphocytic leukemia (ALL) and 1 of acute myelogenous leukemia (AML, M5)] and 1 of non-Hodgkin lymphoma with severe ARDS received ECMO on chemotherapy period. The etiology of ARDS is community or chemotherapy-associated bacterial or/and fungal or viral infection. All the patients received chemotherapy in the 2 weeks prior to ECMO and five were neutropenic at initial ECMO. Six cases underwent veno-arterial ECMO (VA ECMO) and 1 for veno-venous ECMO (VV-ECMO). The median duration of ECMO support was 122 (IQR 56-166) hours. Overall, 42.9% (three of seven) survived to hospital discharge and 6 months survival rate was 28.6% (two of seven). Bleeding was the main ECMO-associated complication occurring in 7 patients, followed by nosocomial infection in 4 cases. All the patients required vasopressor support, and 6 received continuous renal replacement therapy (CRRT).

CONCLUSION

Our experiences suggest that rescue ECMO provides a selective treatment strategy in childhood hematologic malignancies with severe ARDS.