Oxygen delivery in pediatric cardiac surgery and its association with acute kidney injury using machine learning.

OBJECTIVE: Acute kidney injury (AKI) after pediatric cardiac surgery with cardiopulmonary bypass (CPB) is a frequently reported complication. In this study we aimed to determine the oxygen delivery indexed to body surface area (Do2i) threshold associated with postoperative AKI in pediatric patients during CPB, and whether it remains clinically important in the context of other known independent risk factors. METHODS: A single-institution, retrospective study, encompassing 396 pediatric patients, who underwent heart surgery between April 2019 and April 2021 was undertaken. Time spent below Do2i thresholds were compared to determine the critical value for all stages of AKI occurring within 48 hours of surgery. Do2i threshold was then included in a classification analysis with known risk factors including nephrotoxic drug usage, surgical complexity, intraoperative data, comorbidities and ventricular function data, and vasoactive inotrope requirement to determine Do2i predictive importance. RESULTS: Logistic regression models showed cumulative time spent below a Do2i value of 350 mL/min/m2 was associated with AKI. Random forest models, incorporating established risk factors, showed Do2i threshold still maintained predictive importance. Patients who developed post-CPB AKI were younger, had longer CPB and ischemic times, and required higher inotrope support postsurgery. CONCLUSIONS: The present data support previous findings that Do2i during CPB is an independent risk factor for AKI development in pediatric patients. Furthermore, the data support previous suggestions of a higher threshold value in children compared with that in adults and indicate that adjustments in Do2i management might reduce incidence of postoperative AKI in the pediatric cardiac surgery population.

Outcomes in small children on Berlin Heart EXCOR support: age and body surface area as clinical predictive factors.

OBJECTIVES: The Berlin Heart EXCOR (BHE) offers circulatory support across all paediatric ages. Clinically, the necessary care and the outcomes differ in various age groups. The EUROMACS database was used to study age- and size-related outcomes for this specific device. METHODS: All patients <19 years of age from the EUROMACS database supported with a BHE between 2000 and November 2021 were included. Maximally selected rank statistics were used to determine body surface area (BSA) cut-off values. Multivariable Cox proportional hazard regression using ridge penalization was performed to identify factors associated with outcomes. RESULTS: In total, 303 patients were included [mean age: 2.0 years (interquartile range: 0.6-8.0, males: 48.5%)]. Age and BSA were not significantly associated with mortality (n = 74, P = 0.684, P = 0.679). Factors associated with a transplant (n = 175) were age (hazard ratio 1.07, P = 0.006) and aetiology other than congenital heart disease (hazard ratio 1.46, P = 0.020). Recovery rates (n = 42) were highest in patients with a BSA of <0.53 m2 (21.8% vs 4.3-7.6% at 1 year, P = 0.00534). Patients with a BSA of ≥0.73 m2 had a lower risk of early pump thrombosis but a higher risk of early bleeding compared to children with a BSA of <0.73 m2. CONCLUSIONS: Mortality rates in Berlin Heart-supported patients cannot be predicted by age or BSA. Recovery rates are remarkably high in the smallest patient category (BSA <0.53 m2). This underscores that the BHE is a viable therapeutic option, even for the smallest and youngest patients.

Cerebrovascular accidents in paediatric patients supported by the Berlin Heart EXCOR.

OBJECTIVES: Ventricular assist device support as a bridge to transplant or recovery is a well-established therapy in children on the cardiac transplant waiting list. The goal of this study was to investigate the incidence of and the associated factors for cerebrovascular accidents in paediatric patients supported by a Berlin Heart EXCOR. METHODS: All patients <19 years of age supported by a Berlin Heart EXCOR between January 2011 and January 2021 from the European Registry for Patients with Mechanical Circulatory Support were included. RESULTS: In total, 230 patients were included. A total of 140 (60.9%) patients had a diagnosis of dilated cardiomyopathy. 46 patients (20.0%) sustained 55 cerebrovascular accidents, with 70.9% of the episodes within 90 days after the ventricular assist device was implanted. The event rate of cerebrovascular accidents was highest in the first era (0.75). Pump thrombosis and secondary need for a right ventricular assist device were found to be associated with a cerebrovascular accident (hazard ratio 1.998, P = 0.040; hazard ratio 11.300, P = 0.037). At the 1-year follow-up, 44.4% of the patients had received a transplant, 13.1% were weaned after recovery and 24.5% had died. Event rates for mortality showed a significantly decreasing trend. CONCLUSIONS: Paediatric ventricular assist device support is associated with important adverse events, especially in the early phase after the device is implanted. Pump thrombosis and the need for a secondary right ventricular assist device are associated with cerebrovascular accidents. Furthermore, an encouragingly high rate of recovery in this patient population was shown, and death rates declined. More complete input of data into the registry, especially concerning anticoagulation protocols, would improve the data.

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): third Paediatric (Paedi-EUROMACS) report.

OBJECTIVES: A third paediatric report has been generated from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). The purpose of EUROMACS, which is operated by the European Association for Cardio-Thoracic Surgery, is to gather data related to durable mechanical circulatory support for scientific purposes and to publish reports with respect to the course of mechanical circulatory support therapy. Since the first report issued, efforts to increase compliance and participation have been extended. Additionally, the data provided the opportunity to analyse patients of younger age and lower weight. METHODS: Participating hospitals contributed pre-, peri- and long-term postoperative data on mechanical circulatory support implants to the registry. Data for all implants in paediatric patients (<19 years of age) performed from 1 January 2000 to 31 December 2020 were analysed. This report includes updates of patient characteristics, implant frequency, outcome (including mortality rates, transplants and recovery rates) as well as adverse events including neurological dysfunction, device malfunction, major infection and bleeding. RESULTS: Twenty-five hospitals contributed 537 registered implants in 480 patients. The most frequent aetiology of heart failure was any form of cardiomyopathy (59%), followed by congenital heart disease and myocarditis (15% and 14%, respectively). Competing outcomes analysis revealed that a total of 86% survived to transplant or recovery or are ongoing; at the 2-year follow-up examination, 21.9% died while on support. At 12 months, 45.1% received transplants, 7.5% were weaned from their device and 20.8% died. The 3-month adverse events rate was 1.59 per patient-year for device malfunction including pump exchange, 0.7 for major bleeding, 0.78 for major infection and 0.71 for neurological events. CONCLUSIONS: The overall survival rate was 79.2% at 12 months following ventricular assist device implant. The comparison of survival rates of the early and later eras shows no significant difference. A focus on specific subgroups showed that survival was less in patients of younger age (<1 year of age; P = 0.01) and lower weight (<20 kg; P = 0.015). Transplant rates at 6 months continue to be low (33.2%).

Pediatric heart transplantation following donation after circulatory death, distant procurement, and ex-situ perfusion.

BACKGROUND: Limited availability of suitable donor hearts remains a challenge to pediatric heart transplantation, contributing to waitlist mortality. Controlled donation after circulatory death (DCD) has demonstrated success in adults. Early series of pediatric DCD heart transplantation using cold storage alone reported significant early mortality. We report a collaboration between 2 centers in the United Kingdom, combining expertise in adult DCD organ retrieval and pediatric transplantation. METHODS: This retrospective series comprises 6 children (4 male, all >20 kg) undergoing DCD heart transplantation at Great Ormond Street Hospital between 1 February and 30 September 2020, following retrieval with direct procurement and perfusion using portable normothermic machine perfusion by the Royal Papworth Hospital service. Baseline characteristics and 1-year follow-up were compared to 9 children who underwent donation after brain death (DBD) transplants contemporaneously. RESULTS: Mean DCD donor age was 24.67 years and mean DCD recipient age was 13.83 years. Mean functional warm ischemic time was 28.5 minutes and ex-situ heart perfusion time was 280 minutes. Median ICU and hospital stay were 9 and 17 days, respectively. All children survived to 1-year post-transplant. Survival and ICU and hospital stay were similar between the DCD and DBD cohorts. Performing DCD transplants resulted in a 66.7% increase in transplants for children >20 kg at GOSH during the study. CONCLUSIONS: This series demonstrates that DCD heart transplant can be performed safely with excellent short-term survival in children. Although the cohort is small, there was no significant difference in major outcomes compared to a DBD cohort.

Childhood Extracorporeal Membrane Oxygenation Survivors: Parents Highlight Need for Structured Follow-Up and Support After Hospital Discharge.

OBJECTIVES: To examine parental experiences of childhood extracorporeal membrane oxygenation survivors to understand: 1) the problems children faced and 2) the support received following hospital discharge. DESIGN: Single-center descriptive study. SETTING: Nationally commissioned center for neonatal and pediatric extracorporeal membrane oxygenation. PATIENTS: All traceable survivors less than 18 years old who received extracorporeal membrane oxygenation from January 1998 to April 2013. INTERVENTION: Anonymized postal questionnaire completed by parents of extracorporeal membrane oxygenation survivors. MEASUREMENTS AND MAIN RESULTS: Parent-reported developmental problems, follow-up, and the degree of satisfaction with any follow-up experience. Parents of 89 of 366 extracorporeal membrane oxygenation survivors (24%) responded. Sixty-six (74%) reported having developmental concerns about their child, including speech and language (n = 32; 36%), concentration (n = 28; 31%), movement/physical difficulties (n = 26; 29%), and educational difficulties (n = 22; 25%); 46 (52%) indicated that their child had difficulties across multiple domains. Twenty-one (34%) of those with one or more reported developmental concerns were not receiving any follow-up. However, 57 (64%) attended our 1-year follow-up extracorporeal membrane oxygenation clinic and 54 of 57 (95%) found it very useful. Three themes related to perceived need were identified from parents' free-text comments: the need for an expert point of contact and follow-up at the extracorporeal membrane oxygenation center; more information on extracorporeal membrane oxygenation and any long-term effects; and more support from, and easier access to, community specialist services. CONCLUSIONS: A proportion of children who have undergone extracorporeal membrane oxygenation treatment have needs that are not being met, with variable access to service provision. Structured follow-up after discharge would enable early identification of developmental concerns, permit early referral or intervention, and provide support to families. Education and sharing of information about extracorporeal membrane oxygenation with general practitioners/family physicians, community professionals, and schools are essential.

The 1-Year Follow-Up Clinic for Neonates and Children After Respiratory Extracorporeal Membrane Oxygenation Support: A 10-Year Single Institution Experience.

OBJECTIVES: To establish the effectiveness of a "1-year extracorporeal membrane oxygenation follow-up clinic" and to characterize any neurodevelopmental concerns identified. DESIGN: Single-center retrospective cohort of respiratory extracorporeal membrane oxygenation survivors over 10 years. SETTING: Nationally commissioned center for neonatal and pediatric (> 28 d of life) respiratory extracorporeal membrane oxygenation. PATIENTS: Children attending the follow-up clinic 1 year after receiving respiratory extracorporeal membrane oxygenation between 2003 and 2013. INTERVENTIONS: Standardized follow-up 1 year after extracorporeal membrane oxygenation. MEASUREMENTS AND MAIN RESULTS: In 10 years, 290 children received extracorporeal membrane oxygenation, 194 (67%) survived; all were offered 1-year follow-up, and 98 (51%) attended the clinic. Among these, 51 of 98 (52%) had meconium aspiration syndrome, and 74 of 98 (75%) were on veno-arterial extracorporeal membrane oxygenation with a median (interquartile range) duration of 6 days (4-8 d). Neurodevelopmental problems were identified in 30 of 98 (30%). The specific abnormalities noted included neurologic (seizures, motor, or vision abnormalities) (n = 8), hearing with/without language delay (n = 8), and behavioral problems (as reported by parents) (n = 6), with eight of 30 (27%) having difficulties spanning these domains. An acute neurologic event on extracorporeal membrane oxygenation was found to be the only risk factor for neurodevelopmental concerns (p = 0.006 with odds ratio 5.4 [95% CI, 1.63-17.92]). Despite having neither a cardiac arrest nor an acute neurologic event documented, 18 of 74 (24.3%), 95% CI (15.1-35.7), had neurodevelopmental concerns at 1-year follow-up. Among the nonattenders, 30 (15%) had local follow-up, and 66 (34%) were lost to follow-up. CONCLUSIONS: All extracorporeal membrane oxygenation survivors need follow-up either at the extracorporeal membrane oxygenation center or in their community, as evidenced by the 1-year follow-up data. Our 1-year extracorporeal membrane oxygenation follow-up clinic provides an opportunity to engage with families, identify neurodevelopmental concerns, and signpost to appropriate services. Of concern, one third of survivors are lost to follow-up, some with an acute neurologic event on extracorporeal membrane oxygenation, a significant risk factor. A consensus-based standardized national follow-up program is vital.

Long-distance transport of critically ill children on extracorporeal life support in Australia.

BACKGROUND: The Royal Children's Hospital, Melbourne, Victoria, provides extracorporeal life support (ECLS) for infants and children from all around Australia. Since 2003, we have offered a mobile ECLS service to retrieve critically ill children whose condition is too unstable for conventional transport. The retrieval team comprises a paediatric intensive care unit specialist, an ECLS nurse specialist, a perfusionist and a cardiac surgeon. PATIENTS AND METHODS: Retrospective review of eight children (aged between 1 day and 8 years) who were transported on ECLS to the intensive care unit at the Royal Children's Hospital, Melbourne, between 2003 and 2007. RESULTS: Seven patients underwent cannulation by our team in the referring ICU, and one underwent cannulation by the referring centre before our retrieval team arrived. Seven children were placed on ECMO (veno-venous in two, veno-arterial in five), and one was placed on a left ventricular assist device. Five children were retrieved from interstate ICUs by air, and three were transported from a metropolitan ICU by road. The median distance from the referral centre to Melbourne was 803 km, and the median duration of retrieval was 13 hours. Median duration of ECLS was 270 hours. Five patients survived to hospital discharge. There were no adverse outcomes related to transport. CONCLUSIONS: This is the first report of ECLS transport in Australia. In our experience, children who would not otherwise be transportable can be safely transported long distances on ECLS, and should be offered this if appropriate resources exist. However, this approach should not replace the timely referral of patients who are likely to need ECLS.

A case of Commotio cordis in a young child caused by a fall.

Commotio cordis or ventricular fibrillation caused by a blow to the chest is a rare cause of cardiac arrest in a well child. We report a case of a young child falling from a low height landing chest first with rapid onset of unconsciousness, apnoea and cyanosis. Cardiopulmonary resuscitation was given by parents under telephone instruction from an ambulance dispatch centre. On arrival of officers, 7 min after the fall, ventricular fibrillation was present but responded to defibrillation (biphasic 3 J/kg). No clinical or CT evidence of chest or brain trauma was present and investigations (ECGs, cardiac MRI, echocardiography, viral tests, metabolic tests, drug tests, serum electrolytes) did not reveal any cardiac illness or abnormal cardiac anatomy. Specifically, a long QT was absent and a Flecainide challenge for Brugada syndrome was negative. There was no family history of sudden death. No further dysrrhythmia occurred and the child recovered neurologically well after 3 days of therapeutic hypothermia (for cerebral ischaemia) and 7 days of mechanical ventilation.