Outcomes of mechanical support in a pediatric lung transplant center

Lung Re-transplantation after prolonged veno-venous extracorporeal membrane oxygenation (ECMO) in a child with chronic lung allograft dysfunction

BACKGROUND

Extracorporeal Membrane Oxygenation (ECMO) may be used as a bridge to lung transplantation in selected patients with end-stage respiratory failure. Historically, ECMO use in this setting has been associated with poor outcomes Puri V et.al, J Thorac Cardiovasc Surg, 140:427. More recently, technical advances and the implementation of rehabilitation and ambulation while awaiting transplantation on ECMO have led to improved surgical and post-transplant outcomes Kirkby S et.al, J Thorac Dis, 6:1024.

METHODS

We illustrate the case of a 6-year-old child who received prolonged ECMO support as a bridge to lung re-transplantation secondary to Chronic Lung Allograft Dysfunction (CLAD).

RESULTS

Early rehabilitation was key in improving the overall pre-transplant conditioning during ECMO.

CONCLUSIONS

Despite challenges associated with awake/ambulatory ECMO, the use of this strategy as a bridge to lung transplantation is feasible and has resulted in improved pre-transplant conditioning and post-transplant outcomes.

Lung transplantation in children

Lung transplantation is a well-established treatment for children facing advanced lung disease and pulmonary vascular disorders. However, organ shortage remains highest in children. For fitting the small chest of children, transplantation of downsized adult lungs, lobes, or even segments were successfully established. The worldwide median survival after pediatric lung transplantation is currently 5.7 years, while under consideration of age, underlying disease, and peri- and posttransplant center experience, median survival of more than 10 years is reported. Timing of referral for transplantation, ischemia-reperfusion injury, primary graft dysfunction, and acute and chronic rejection after transplantation remain the main challenges.

Poor functional status at the time of waitlist for pediatric lung transplant is associated with worse pretransplant outcomes

BACKGROUND

Whether functional status is associated with survival to pediatric lung transplant is unknown. We hypothesized that completely dependent functional status at waitlist registration, defined using Lansky Play Performance Scale (LPPS), would be associated with worse outcomes.

METHODS

Retrospective cohort study of pediatric lung transplant registrants utilizing United Network for Organ Sharing's Standard Transplant Analysis and Research files (2005-2020). Primary exposure was completely dependent functional status, defined as LPPS score of 10-40. Primary outcome was waitlist removal for death/deterioration with cause-specific hazard ratio (CSHR) regression. Subdistribution hazard regression (SHR, Fine and Gray) was used for the secondary outcome of waitlist removal due to transplant/improvement with a competing risk of death/deterioration. Confounders included: sex, age, race, diagnosis, ventilator dependence, extracorporeal membrane oxygenation, year, and listing center volume.

RESULTS

A total of 964 patients were included (63.5% ≥ 12 years, 50.2% cystic fibrosis [CF]). Median waitlist days were 95; 20.1% were removed for death/deterioration and 68.2% for transplant/improvement. Completely dependent functional status was associated with removal due to death/deterioration (adjusted CSHR 5.30 [95% CI 2.86-9.80]). This association was modified by age (interaction p = 0.0102), with a larger effect for age ≥12 years, and particularly strong for CF. In the Fine and Gray model, completely dependent functional status did not affect the risk of removal due to transplant/improvement with a competing risk of death/deterioration (adjusted SHR 1.08 [95% CI 0.77-1.49]).

CONCLUSIONS

Pediatric lung transplant registrants with the worst functional status had worse pretransplant outcomes, especially for adolescents and CF patients. Functional status at waitlist registration may be a modifiable risk factor to improve survival to lung transplant.

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 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.

Mortality after Lung Transplantation for Children Bridged with Extracorporeal Membrane Oxygenation

RATIONALE

Extracorporeal membrane oxygenation (ECMO) is increasingly used to bridge waitlisted children failing conventional respiratory support to lung transplantation.

OBJECTIVES

To compare in-hospital mortality and a composite outcome of 1-year mortality or re-transplantation in children bridged with ECMO with those on mechanical ventilation (MV), and neither support.

METHODS

The United Network for Organ Sharing (UNOS) was used to analyze lung transplant recipients, aged ≤ 20 y, from January 2004 to August 2019. Recipients were categorized according to level of respiratory support at time of transplant, including ECMO, MV, or neither. Multivariable analysis was used to evaluate support type and in-hospital mortality.

RESULTS

Of 1,014 children undergoing lung transplant, 68 (6.7%) required ECMO as a bridge-to-transplant, 144 (14.2%) MV, and 802 (79.1%) neither. Primary diagnosis in the ECMO cohort included cystic fibrosis (43%), pneumonia/ARDS (10.3%), interstitial pulmonary fibrosis (7.4%) and pulmonary hypertension (5.9%). Number of patients bridged with ECMO increased throughout the study period from none in 2004 to 16.7% in 2018. Multivariable analysis showed bridging with both ECMO (aOR = 3.57; 95% CI: 1.42, 8.97) and MV (aOR = 2.67; 95% CI: 1.26, 5.57) increased in-hospital mortality after lung transplantation. However, there was no difference in composite outcome of mortality and re-transplantation at 1-year between the three groups.

CONCLUSIONS

ECMO to bridge children to lung transplantation has increased. Despite this, ECMO is a high-risk bridge strategy for children awaiting lung transplantation. Future research should target interventions that can be focused on improving survival in these patients.

Pediatric lung transplant: Correlation of pretransplant condition with post-transplant outcomes

BACKGROUND

It is generally accepted that patients who have greater functional capacity are better candidates for lung transplantation. Accurate assessment of physical condition is important in identifying appropriate candidates for transplant. The focus of this study was to determine which measures of pretransplant physical condition correlate with positive post-transplant outcomes in children undergoing lung transplant.

METHODS

A retrospective chart review was done on 44 patients, ages 5 to 21 years. The pretransplant data collected included functional status, 6MWT, ambulatory status, and mechanical support. Post-transplant outcome data included time on the ventilator, days in the ICU, length of hospitalization, and 12-month survival.

RESULTS

Results were analyzed using Fisher exact and Kruskal-Wallis tests. Patients with limited ambulation had more days in the ICU compared to the most ambulatory group (P = .043). Patients independent or needing some help with ADL had less time on the ventilator compared to patients needing total help. (P = .014). Patients with 6MWT result greater than 500' had fewer ICU days (P = .044) and marginally better 12-month survival (P = .057). The 12-month survival of children needing invasive ventilatory support pretransplant was not significantly worse than those who did not; however, they required significantly more time on the ventilator (P = .004), days in ICU (P = .013), and longer hospitalization.

DISCUSSION

This study demonstrated that pretransplant physical condition affects post-transplant outcomes in children. Measures associated with positive post-transplant outcomes were identified and could be beneficial in determining which patients are optimal candidates for lung transplant.

Pediatric and neonatal extracorporeal life support: current state and continuing evolution

The use of extracorporeal life support (ECLS) for the pediatric and neonatal population continues to grow. At the same time, there have been dramatic improvements in the technology and safety of ECLS that have broadened the scope of its application. This article will review the evolving landscape of ECLS, including its expanding indications and shrinking contraindications. It will also describe traditional and hybrid cannulation strategies as well as changes in circuit components such as servo regulation, non-thrombogenic surfaces, and paracorporeal lung-assist devices. Finally, it will outline the modern approach to managing a patient on ECLS, including anticoagulation, sedation, rehabilitation, nutrition, and staffing.

Surgical considerations in infant lung transplantation: Challenges and opportunities

Lung transplantation is a crucial component in the treatment of end-stage lung disease in infants. Traditionally, most lung transplants have been performed in older children and adults, resulting in a scarcity of data for infant patients. To address the challenges unique to this age group, novel strategies to provide the best preoperative, intraoperative, and postoperative care for these youngest patients are paramount. We review recent advances in bridge-to-transplantation therapy, including the use of a paracorporeal lung assist device, and differences in surgical technique, including bronchial artery revascularization, for incorporation into the overarching treatment strategy for infants undergoing lung transplantation.

Outcome of Bridge to Lung Transplantation With Extracorporeal Membrane Oxygenation in Pediatric Patients 12 Years and Older

BACKGROUND

There is a reluctance to using extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation in the pediatric population. Pediatric patients between ages 12 and 18 years are eligible for acuity-based lung transplantation using the Lung Allocation Score and may be suitable for adult allografts, increasing the donor pool and thus leading to a successful bridge to lung transplantation.

METHODS

The United Network for Organ Sharing dataset was queried for primary lung transplantation in pediatric patients (12-18 years) from 2005 to 2016. Groups were divided into those who were on ECMO (bridged [BG]) and not on ECMO (nonbridged [NBG]) at the time of listing for lung transplant.

RESULTS

The groups comprised 16 BG and 375 NBG patients. Fourteen BG patients (88%) survived the first 30 days. One-year (83.3% vs 86.2%, P = .78) and 3-year (66.7% vs 55.1%, P = .57) survivals were similar in the BG and NBG groups, respectively. Donors in the BG group were more likely to be adults. The median wait-list times were shorter (10.5 [interquartile range {IQR}, 11] vs 93 [IQR, 221] days, P < .001), with a higher Lung Allocation Score (89.8 vs 36.6, P < .001) and similar median ischemic times (5.19 [IQR, 2.32] vs 5.34 [IQR, 1.92] hours, P = .85) in the BG group compared with the NBG group. The median post-transplant length of stay was longer in the BG group (33 [IQR, 31] vs 17 [IQR, 12] days, P = .007) and was the only factor predictive of 3-year mortality. Longer wait-list time had a higher mortality in the BG group.

CONCLUSIONS

ECMO as a bridge to lung transplantation is a reasonable strategy in pediatric patients aged ≥ 12 years with acceptable operative mortality and similar 1- and 3-year survival compared with nonbridged patients despite higher acuity. Bridged patients were more likely to receive adult donor lungs.

Pediatric lung transplantation in the largest lung transplantation center of China: embarking on a long road

Lung transplantation (LT) has been an effective treatment for carefully selected children with end-stage lung diseases. The aim of this retrospective study is to introduce our experience at the largest LT center in Wuxi, China and to compare the outcomes of pediatric LT between children with idiopathic pulmonary arterial hypertension (IPAH) and other end-stage lung diseases. Ten pediatric patients undergoing LT from 2007 to 2019 were included. Sequential bilateral lung transplantation (BLT) with bilateral anterior thoracotomies was performed in all patients, seven of whom also underwent reduced size LT. Eight children survived until the end of our follow-up period on July 31st, 2019, with the longest survival of 11 years. Extracorporeal membrane oxygenation (ECMO) was intraoperatively used in all IPAH children and one non-IPAH child. Left heart function of IPAH children, though initially compromised, recovered after surgery. Statistically significant differences in operation time and post-operative mechanical ventilation between IPAH group and non-IPAH group were observed without discernible impact on post-LT survival. Pediatric LT appears to be a safe treatment for IPAH children to improve longevity and quality of life and ECMO may help reduce the risk of surgery and the postoperative complications.

Psychotropic medication use trends in a large pediatric and young adult solid organ transplant population

INTRODUCTION

This study describes psychotropic medication use in a pediatric and young adult solid organ transplant population.

METHODS

We conducted a retrospective review of the lifetime incidence of psychotropic medication use and associated characteristics in patients seen over a 6-year period at a large pediatric transplant center utilizing univariate and multivariate statistical analyses.

RESULTS

The lifetime incidence of psychotropic medication use was 36.5% in 393 patients. Transplant psychiatry provided psychopharmacological consultation to 21.9% of patients. Controlling for age and sex, there were significant associations between psychotropic use and thoracic organ disease (heart/lung) (AOR = 2.14; 95% CI: 1.2-3.8; P = 0.01), White race (P = 0.0002), histories of depressive/mood disorders (AOR = 3.68; 95% CI: 1.8-7.7; P = 0.0005), attention/learning disorders (AOR = 3.30; 95% CI: 1.6-6.9; P = 0.001), acute and post-traumatic stress disorders (AOR = 10.54; 95% CI: 2.6-42.8; P = 0.001), and experiencing bullying (AOR = 2.16; 95% CI: 1.03-4.55; P = 0.04). In unadjusted tests, significant associations were found between lifetime psychotropic usage and patient anxiety history (OR = 2.26; 95% CI: 1.5-3.5; P = 0.0002), end-of-life disease progression (OR = 3.04; 95% CI: 1.7-5.4; P = 0.0002), family psychiatric history (OR = 2.17; 95% CI: 1.4-3.4; P = 0.0007), and adherence concerns (OR = 2.67; 95% CI: 1.7-4.1; P < 0.0001).

DISCUSSION

The lifetime incidence of psychotropic medication use among pediatric and young adult transplant patients is substantial. Patients with thoracic organ disease, end-of-life illness, individual/family psychiatric histories, trauma, and bullying histories have particularly high rates. Integrating child psychiatry as part of pediatric transplant teams should be an important consideration for the care of these patients.

Behavioral health care in solid organ transplantation in a pediatric setting

This study examined the demographic, medical, and psychiatric characteristics of transplant patients across organ groups seen by transplant psychology/psychiatry clinicians at a pediatric institution between 2008 and 2014. Chart reviews were conducted to better understand the behavioral health care provided to SOT patients and the role of transplant-dedicated psychology and psychiatry clinicians. Transplant psychology/psychiatry was consulted a total of 1060 times on 399 unique SOT patients over a 6-year period. There were no significant differences in the distribution of age, sex, or ethnicity across organ groups. Common reasons for a consultation included pretransplant evaluation, anxiety, depression, agitation, and general coping. Rates varied by organ groups. Twenty percent of consults also received a psychopharmacological evaluation, with differences in rates between organ groups. Roughly one-third of patients required high frequency of transplant psychology/psychiatry involvement. Lung and heart patients had the highest utilization. Psychiatric diagnosis rates were identified, with adjustment (41.0%) and anxiety disorders (30.1%) being the most common. Pediatric psychology and psychiatry clinicians offer developmentally informed biopsychosocial approaches to treatment for SOT patients. Clarifying the prevalence and nature of behavioral health care provided by organ group can help pediatric providers better understand appropriate psychosocial interventions and resources utilized by this patient population and ultimately guide centers toward a more unified approach to care.

Pediatric lung transplantation

Pediatric lung transplantation is a highly specialized clinical endeavor. Since the late 1980's, there have only been slightly more than 2200 implants reported to the International Society for Heart and Lung transplantation registry. This review will discuss the historical aspects of pediatric lung transplantation. It will familiarize the reader with the current indications for transplant and the referral and listing process. The current state of lung assist devices as a bridge to pediatric lung transplantation is discussed in addition to the technical aspects of the transplant procedure. Finally, posttransplant outcomes, including anticipated morbidity and the role of retransplantation, are clarified.