Management of the pediatric organ donor to optimize lung donation

Improved Outcomes for Infants and Young Children Undergoing Lung Transplantation at Three Years of Age and Younger

Rationale: Since its inception, older children and adolescents have predominated in pediatric lung transplantation. Most pediatric lung transplant programs around the world have transplanted few infants and young children. Early mortality after lung transplantation and inadequate donor organs have been perceived as limitations for success in lung transplantation at this age. Objectives: Our aim was to describe our experience in a large pediatric lung transplant program with respect to lung transplantation in infants and young children, focusing on diagnosis, waitlist, and mortality. Methods: We performed a retrospective review of infants and young children under 3 years of age at the time of transplant in our program from 2002 through 2020. Results: The patient cohort represented a severely morbid recipient group, with the majority hospitalized in the intensive care unit on mechanical ventilation just before transplantation. There was a marked heterogeneity of diagnoses distinct from diagnoses in an older cohort. Waitlist time was shorter than in older age cohorts. There was a decrease in early mortality, lower incidence of allograft rejection, and satisfactory long-term survival in this age group compared with the older cohort and published experience. Severe viral infection was an important cause of early mortality after transplant. Nonetheless, survival is comparable to older patients, with better enduring survival in those who survive the early transplant period in more recent years. Conclusions: Carefully selected infants and young children with end-stage lung and pulmonary vascular disease are appropriate candidates for lung transplantation and are likely underserved by current clinical practice.

Differential donor management of pediatric vs adult organ donors and potential impact on pediatric lung transplantation

BACKGROUND

Despite clinical progress over time, a shortage of suitable donor organs continues to limit solid organ transplantation around the world. Lungs are the organs most likely to be assessed as unsuitable during donor management among all transplantable organs. Although the number of lung transplants performed in children is limited, death on the wait list remains a barrier to transplant success for many potential transplant candidates. Optimizing organ donor management can yield additional organs for transplant candidates.

METHODOLOGY

We accessed the Donor Management Goal (DMG) Registry to evaluate the efficiency and efficacy of donor management in the procurement of lungs for transplantation. Further, we stratified donors by age and compared pediatric age cohorts to adult cohorts with respect to attainment of donor management target goals and successful pathway to transplantation. We utilized recipient data from the Organ Procurement Transplantation Network (OPTN) to put this data into context. The DMG bundle consists of nine physiologic parameters chosen as end-points guiding donor management for potential organ donors. The number of parameters fulfilled has been regarded as an indication of efficacy of donor management.

RESULTS

We noted a markedly lower number of organ donors in the pediatric age group compared to adults. On the other hand, the number of donors greatly exceeds the number of infants, children and adolescents who undergo lung transplantation. Organs transplanted per donor peaks in the adolescent age group. At initial donor referral, DMG bundle attainment is lower in all age groups and improves during donor management. With respect to oxygenation, there is less overall improvement in younger donors compared to older donors during donor management. When donors who yield lungs for transplantation are compared to those whose lungs were not transplanted, oxygenation improved more substantially during donor management. Furthermore, improved oxygenation correlated with the total number of organs transplanted per donor.

CONCLUSIONS

In the face of continued wait list mortality on the pediatric lung transplant wait list, the number of young donors may not be a limiting factor. We believe that this dataset provides evidence that management of young pediatric donors is not as consistent or efficient as the management of older donors, potentially limiting the number of life-saving organs for pediatric lung transplant candidates. Across all ages, optimizing donor lung management may increase the potential to transplant multiple other organs.

International Society for Heart and Lung Transplantation consensus statement for the standardization of bronchoalveolar lavage in lung transplantation

Bronchoalveolar lavage (BAL) is a key clinical and research tool in lung transplantation (LTx). However, BAL collection and processing are not standardized across LTx centers. This International Society for Heart and Lung Transplantation-supported consensus document on BAL standardization aims to clarify definitions and propose common approaches to improve clinical and research practice standards. The following 9 areas are covered: (1) bronchoscopy procedure and BAL collection, (2) sample handling, (3) sample processing for microbiology, (4) cytology, (5) research, (6) microbiome, (7) sample inventory/tracking, (8) donor bronchoscopy, and (9) pediatric considerations. This consensus document aims to harmonize clinical and research practices for BAL collection and processing in LTx. The overarching goal is to enhance standardization and multicenter collaboration within the international LTx community and enable improvement and development of new BAL-based diagnostics.

Organ Donation Following Neurologic and Circulatory Determination of Death

OBJECTIVES

To describe important considerations during the process of caring for critically ill children who may be potential organ donors and supporting the family during the death of their child.

DESIGN

Literature review and expert commentary.

MEASUREMENT AND MAIN RESULTS

Medical literature focusing on pediatric donation, best pediatric donation practices, donor management, and factors influencing donation were reviewed. Additional pediatric data were obtained and reviewed from the U.S. Organ Procurement and Transplantation Network. Achieving successful organ donation requires the coordinated efforts of the critical care team, organ donation organization, and transplant team to effectively manage a potential donor and recover suitable organs for transplantation. Collaboration between these teams is essential to ensure that all potential organs are recovered in optimal condition, to reduce death and morbidity in children on transplantation waiting lists as well as fulfilling the family's wishes for their dying child to become a donor.

CONCLUSIONS

Organ donation is an important component of end-of-life care and can help the healing process for families and medical staff following the death of a child. The process of pediatric organ donation requires healthcare providers to actively work to preserve the option of donation before the death of the child and ensure donation occurs after consent/authorization has been obtained from the family. Medical management of the pediatric organ donor requires the expertise of a multidisciplinary medical team skilled in the unique needs of caring for children after neurologic determination of death and those who become donors following circulatory death after withdrawal of life-sustaining medical therapies.

Deceased Organ Donation From Pediatric Donors: Does the Literature Really Help Us? Implication for More Powerful Guidelines

BACKGROUND

Brain-dead pediatric donors have always been the focus of attention because of the higher quality, utility, and possibility of their organ donation. However, donors under the age of 5 years always necessitate making more challenging management efforts, which are not clearly implied in most parts of the guidelines.

METHODS

The data obtained from 79 brain-dead pediatric donors of the Organ Procurement Unit of Masih Daneshvari Hospital, Tehran, Iran, were assessed. The donors were divided into 2 groups, including donors under 5 years of age (group A) and those between 5 and 12 years of age (group B). Metabolic, hemodynamic, hematologic, and electrolyte status as well as the suitability for donation were compared in the study groups.

RESULTS

Of 1252 donors, 6.3% were under 12 years of age. Trauma and drug toxicity were the two primary causes of brain death in group A. In comparison, trauma and brain tumor were the leading causes of brain death in group B. The prevalence of both hyperglycemia and respiratory acidosis was significantly higher in group A (P < .05). However, severe anemia and coagulopathy were more prevalent in group B (P < .05). The high-dose inotropic administration was used for 42.4% of the donors in group A, whereas only 26% of the donors in group B needed a high dose of inotropes (P < .05). The mean quantity of organ harvested per donor was 2.1 and 2.25 in groups A and B, respectively. Furthermore, donor loss was not significantly different in both groups.

CONCLUSIONS

The occurrence of different complications in donors under the age of 5 years requires special treatment considerations that should be the center of attention in the related guidelines. Organ donation per donor indicates that donors under the age of 5 years are a valuable resource for organ procurement.

Variation in Pediatric Organ Donor Management Practices Among US Organ Procurement Organizations

INTRODUCTION

Reports of actual pediatric organ donor management practice among US organ procurement organizations are sparse, and the use of standardized management guidelines is unknown. A recent consensus statement from the Society of Critical Care Medicine, the American College of Chest Physicians, and the Association of Organ Procurement Organizations offers guidelines for the management of the pediatric organ donor.

RESEARCH QUESTION

To describe the use of guidelines and routine practices in the management of the pediatric organ donor with respect to hemodynamics, lung and ventilator management, fluid and electrolytes, hormonal replacement therapy, the use of blood products, thermoregulation, and prophylactic antibiotics.

DESIGN

Cross-sectional observational study using a survey and follow-up telephone interview with respondents from all 58 US organ procurement organizations.

RESULTS

All 58 US Organ Procurement Organizations participated. A majority employed written guidelines for the management of pediatric donor hemodynamics, thermoregulation, fluids, and electrolytes. Management of blood products, the lung, and mechanical ventilation were less commonly committed to written guidelines, but common practices were described. All used various forms of hormonal replacement therapy and the majority administered empiric antibiotic therapy. Wide variation was observed in the management of the lung, mechanical ventilation, and glycemic control.

DISCUSSION

Most OPOs used forms of standardized donor management for the pediatric organ donor although variation in the content of that management exists. Barriers to an evidence-based approach to the pediatric donor need to be determined and addressed.

Survey of U.S. Organ Procurement Organizations Regarding Pediatric Organ Donor Management

OBJECTIVE

To describe the current practice of pediatric organ donor management in the United States for donors declared dead based upon neurologic criteria. The study directs particular attention to how pediatric donors are defined, the use of donor management guidelines, the use of donor management goals, and the involvement of pediatric critical care or transplantation expertise.

DESIGN

Cross-sectional observational study using a web-based survey and follow-up telephone interview with respondents from U.S. organ procurement organizations. The study also incorporated organ procurement organization-specific data on organ yield for the 4-year period (2010-2013) preceding the study.

SETTING

The 58 U.S. organ procurement organizations.

SUBJECTS

Respondents chosen by each organ procurement organization.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All 58 U.S. organ procurement organizations participated in the study. Fifty-two respondents (90%) indicated that their organ procurement organization distinguished pediatric from adult donors resulting in 28 unique pediatric definitions. Thirty-nine organ procurement organizations utilized some form of written pediatric management guidelines, and 27 (47%) maintained pediatric donor management goals; compliance was infrequently monitored for both guidelines (28%) and goals (33%). A pediatric intensivist was always or usually involved in pediatric donor management at 47 organ procurement organizations (81%); transplant/organ recovery surgeons were always or usually involved at 12 organ procurement organizations (21%). There was an increase in the number of organs transplanted per donor among donors 11-17 years old for organ procurement organizations that used donor management goals for the duration of the period studied (p < 0.01). There was also an increase in the ratio of observed/expected organs transplanted among donors of 0-10 years old for organ procurement organizations that always or usually consulted a transplant/organ recovery surgeon (p = 0.02) although this did not reach our threshold for statistical significance..

CONCLUSIONS

There is little consensus among organ procurement organizations regarding the definition of "pediatric" during organ donor management. Most organ procurement organizations employ written pediatric guidelines and use pediatric intensive care physicians for assistance in managing these donors. There is a positive association between the use of donor management goals and organ yield among pediatric donors in the 11- to 17-year age group.

Pediatric Deceased Donation-A Report of the Transplantation Society Meeting in Geneva

The Ethics Committee of The Transplantation Society convened a meeting on pediatric deceased donation of organs in Geneva, Switzerland, on March 21 to 22, 2014. Thirty-four participants from Africa, Asia, the Middle East, Oceania, Europe, and North and South America explored the practical and ethical issues pertaining to pediatric deceased donation and developed recommendations for policy and practice. Their expertise was inclusive of pediatric intensive care, internal medicine, and surgery, nursing, ethics, organ donation and procurement, psychology, law, and sociology. The report of the meeting advocates the routine provision of opportunities for deceased donation by pediatric patients and conveys an international call for the development of evidence-based resources needed to inform provision of best practice care in deceased donation for neonates and children.

Special considerations for the use of lung transplantation in pediatrics

Lung transplantation has become an accepted therapy in infants, children and adolescents suffering from end-stage lung diseases, an impaired quality of life as well as a reduced life expectancy. Within Europe, pediatric lung transplantation is largely performed in predominantly adult centers due to a relatively low overall case volume. Children do represent a specific and challenging cohort facing a transplant procedure, where the selection of potential candidates becomes a crucial step to maximize net survival benefit. Therefore, interdisciplinary evaluation and early listing in view of current indications and contraindications, adequate preoperative education of the child and family members, discussion of possibly required bridging procedures in case of deterioration, appropriate technical planning of the operation, adherence to postoperative medical treatment and follow-up are all crucial steps in this demanding puzzle. In this article, the authors review recent advances in the field of pediatric lung transplantation and outline challenges in the future.

The evolving potential for pediatric ex vivo lung perfusion

Despite the rise in the number of adult lung transplantations performed, rates of pediatric lung transplantation remain low. Lung transplantation is an accepted therapy for pediatric end-stage lung disease; however, it is limited by a shortage of donor organs. EVLP has emerged as a platform for assessment and preservation of donor lung function. EVLP has been adopted in adult lung transplantation and has successfully led to increased adult lung transplantations and donor lung utilization. We discuss the future implications of EVLP utilization, specifically, its potential evolving role in overcoming donor shortages in smaller children and adolescents to improve the quality and outcomes of lung transplantation in pediatric patients.

Bronchoscopic procedures and lung biopsies in pediatric lung transplant recipients

Bronchoscopy remains a pivotal diagnostic and therapeutic intervention in pediatric patients undergoing lung transplantation (LTx). Whether performed as part of a surveillance protocol or if clinically indicated, fibre-optic bronchoscopy allows direct visualization of the transplanted allograft, and in particular, an assessment of the patency of the bronchial anastomosis (or tracheal anastomosis following heart-lung transplantation). Additionally, bronchoscopy facilitates differentiation of infective processes from rejection episodes through collection and subsequent assessment of bronchoalveolar lavage (BAL) and transbronchial biopsy (TBBx) samples. Indeed, the diagnostic criteria for the grading of acute cellular rejection is dependent upon the histopathological assessment of biopsy samples collected at the time of bronchoscopy. Typically, performed in an out-patient setting, bronchoscopy is generally a safe procedure, although complications related to hemorrhage and pneumothorax are occasionally seen. Airway complications, including stenosis, malacia, and dehiscence are diagnosed at bronchoscopy, and subsequent management including balloon dilatation, laser therapy and stent insertion can also be performed bronchoscopically. Finally, bronchoscopy has been and continues to be an important research tool allowing a better understanding of the immuno-biology of the lung allograft through the collection and analysis of collected BAL and TBBx samples. Whilst new investigational tools continue to evolve, the simple visualization and collection of samples within the lung allograft by bronchoscopy remains the gold standard in the evaluation of the lung allograft. This review describes the use and experience of bronchoscopy following lung transplantation in the pediatric setting.

The Physiology of Brain Death and Organ Donor Management

Brain death is associated with complex physiologic changes that may impact the management of the potential organ donor. Medical management is critical to actualizing the individual or family’s intent to donate and maximizing the benefit of that intent. This interval of care in the PICU begins with brain death and consent to donation and culminates with surgical organ procurement. During this phase, risks for hemodynamic instability and compromise of end organ function are high. The brain dead organ donor is in a distinct and challenging pathophysiologic condition that culminates in multifactorial shock. The potential benefits of aggressive medical management of the organ donor may include increased number of donors providing transplantable organs and increased number of organs transplanted per donor. This may improve graft function, graft survival, and patient survival in those transplanted. In this chapter, pathophysiologic changes occurring after brain death are reviewed. General and organ specific donor management strategies and logistic considerations are discussed. There is a significant opportunity for enhancing donor multi-organ function and improving organ utilization with appropriate PICU management.

Pediatric lung transplantation

Lung transplantation is an accepted therapy for selected pediatric patients with severe end-stage vascular or parenchymal lung disease. Collaboration between the patients' primary care physicians, the lung transplant team, patients, and patients' families is essential. The challenges of this treatment include the limited availability of suitable donor organs, the toxicity of immunosuppressive medications needed to prevent rejection, the prevention and treatment of obliterative bronchiolitis, and maximizing growth, development, and quality of life of the recipients. This article describes the current status of pediatric lung transplantation, indications for listing, evaluation of recipient and donor, updates on the operative procedure,graft dysfunction, and the risk factors, outcomes, and future directions.