Factors Associated with Bleeding and Thrombosis in Children Receiving Extracorporeal Membrane Oxygenation

Clinical course and outcome after treatment with ventricular assist devices in paediatric patients: A single-centre experience

BACKGROUND

Heart failure is a rare condition in the paediatric population, associated with high morbidity and mortality. When medical therapy is no longer sufficient, mechanical circulatory support such as a ventricular assist device can be used to bridge these children to transplant or recovery. Coagulation-related complications such as thrombi, embolism and bleeding events represent the greatest challenge in paediatric patients on mechanical support. We aimed to describe the outcomes and coagulation-related complications in this patient population at our institution.

METHODS

A total of 20 patients with either Berlin Heart EXCOR® or HeartWare® implantation were reviewed in this retrospective study. Study endpoints were survival to heart transplant, weaning due to recovery or death. Thrombotic events were defined as thrombus formation in the device or in the patient, or cardioembolic strokes. Bleeding events were defined as events requiring interventional surgery or transfusion of red blood cells.

RESULTS

The aetiology of heart failure included cardiomyopathy (n = 12), end-stage congenital heart disease (n = 6) and myocarditis (n = 2). Of the 20 patients, 12 were bridged to transplant, 7 recovered and could be weaned and 1 died. The median duration of mechanical support was 84 days (range: 20-524 days). At least one major or minor bleeding event occurred in 45% of the patients. Thrombotic events occurred 21 times in 10 patients. Four of the patients (20%) had no bleeding or thromboembolic event.

CONCLUSION

In all, 95% of the patients were successfully bridged to transplant or recovery. Bleeding events and thrombotic events were common.

Characteristics of Pediatric Extracorporeal Membrane Oxygenation Programs in the United States and Canada

The aim of this study was to evaluate the current infrastructure and practice characteristics of pediatric extracorporeal membrane oxygenation (ECMO) programs. A 40-question survey of center-specific demographics, practice structure, program experience, and support network utilized to cannulate and maintain a pediatric patient on ECMO was designed via a web-based survey tool. The survey was distributed to pediatric ECMO programs in the United States and Canada. Of the 101 centers that were identified to participate, 41 completed the survey. The majority of responding centers are university affiliated (73%) and have an intensive care unit (ICU) with 15-25 beds (58%). Extracorporeal membrane oxygenation has been offered for >10 years in 85% of the centers. The median number of total cannulations per center in 2017 was 15 (interquartile range [IQR] = 5-30), with the majority occurring in the cardiovascular intensive care unit (median = 13, IQR = 5-25). Fifty-seven percent of responding centers offer ECPR, with a median number of four cases per year (IQR = 2-7). Most centers cannulate in an operating room or ICU; 11 centers can cannulate in the pediatric ED. Sixty-three percent of centers have standardized protocols for postcannulation management. The majority of protocols guide anticoagulation, sedation, or ventilator management; left ventricle decompression and reperfusion catheter placement are the least standardized procedures. The majority of pediatric ECMO centers have adopted the infrastructure recommendations from the Extracorporeal Life Support Organization. However, there remains broad variability of practice characteristics and organizational infrastructure for pediatric ECMO centers across the United States and Canada.

Context-Responsive Anticoagulation Reduces Complications in Pediatric Extracorporeal Membrane Oxygenation

Purpose: We sought to determine the impact of a comprehensive, context-responsive anticoagulation and transfusion guideline on bleeding and thrombotic complication rates and blood product utilization during extracorporeal membrane oxygenation (ECMO). Design: Single-center, observational pre- and post-implementation cohort study. Setting: Academic pediatric hospital. Patients: Patients in the PICU, CICU, and NICU receiving ECMO support. Interventions: Program-wide implementation of a context-responsive anticoagulation and transfusion guideline. Measurements: Pre-implementation subjects consisted of all patients receiving ECMO between January 1 and December 31, 2012, and underwent retrospective chart review. Post-implementation subjects consisted of all ECMO patients between September 1, 2013, and December 31, 2014, and underwent prospective data collection. Data collection included standard demographic and admission data, ECMO technical specifications, non-ECMO therapies, coagulation parameters, and blood product administration. A novel grading scale was used to define hemorrhagic complications (major, intermediate, and minor) and major thromboembolic complications. Main Results: Seventy-six ECMO patients were identified: 31 during the pre-implementation period and 45 in the post-implementation period. The overall observed mortality was 33% with no difference between groups. Compared to pre-implementation, the post-implementation group experienced fewer major hemorrhagic and major thrombotic complications and less severe hemorrhagic complications and received less RBC transfusion volume per kg. Conclusions: Use of a context-responsive anticoagulation and transfusion guideline was associated with a reduction in hemorrhagic and thrombotic complications and reduced RBC transfusion requirements. Further evaluation of guideline content, compliance, performance, and sustainability is needed.

Extracorporeal membrane oxygenation in critically ill neonatal and pediatric patients with acute respiratory failure: a guide for the clinician

Intro: Extracorporeal membrane oxygenation for neonatal and pediatric respiratory failure continues to demonstrate improving outcomes, largely due to advances in technology along with refined management strategies despite mounting patient acuity and complexity. Successful use of ECMO requires thoughtful initiation and candidacy strategies, along with reducing the risk of ventilator induced lung injury and the progression to multiorgan failure.Areas Covered: This review describes current ECMO management strategies for neonatal and pediatric patients with acute refractory respiratory failure and summarizes relevant published literature. ECMO initiation and candidacy, along with ventilator and sedation management, are highlighted. Additionally, rapidly expanding areas of interest such as anticoagulation strategies, transfusion thresholds, rehabilitation on ECMO, and drug pharmacokinetics are described.Expert Opinion: Over the last few decades, published studies supporting ECMO use for acute refractory respiratory failure, along with institutional experience, have resulted in increased utilization although more randomized-controlled trials are needed. Future research should focus on filling the knowledge gaps that remain regarding anticoagulation, transfusion thresholds, ventilator strategies, sedation, and approaches to rehabilitation to subsequently implement into clinical practice. Additionally, efforts should focus on well-designed trials, including population pharmacokinetic studies, to develop dosing recommendations.

Anticoagulation and Transfusion Management During Neonatal and Pediatric Extracorporeal Membrane Oxygenation: A Survey of Medical Directors in the United States

OBJECTIVES

To compare current practices within the United States of anticoagulation management and blood transfusion in neonatal and pediatric extracorporeal membrane oxygenation patients with a 2013 international report.

DESIGN

Cross-sectional survey distributed between August and December 2019.

SETTING

Extracorporeal Life Support Organization-registered neonatal and pediatric extracorporeal membrane oxygenation centers in the United States.

PARTICIPANTS

Extracorporeal membrane oxygenation medical directors.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eighty-three medical directors at 108 centers responded. After removing four duplicate responses, 79 surveys were analyzed. Seventy-nine percent (n = 62) report a written extracorporeal membrane oxygenation protocol for both anticoagulation and blood product management. Ninety-four percent (n = 74) report unfractionated heparin as their primary anticoagulant; the remaining use the direct thrombin inhibitor, bivalirudin. Ninety percent (n = 71) report measuring antifactor Xa levels. Most centers report using a combination of assays to monitor heparin therapy, either antifactor Xa and activated partial thromboplastin time (54%) or more commonly antifactor Xa and activated clotting time (68%). Forty-one percent use viscoelastic tests to aid management. Goal monitoring levels and interventions generated by out of range values are variable. Fifty-one percent will replace antithrombin. Platelet transfusion thresholds vary by age and center with ranges from 50,000 to 100,000 cells/µL. Eighty-two percent of respondents are willing to participate in a randomized controlled trial comparing anticoagulation strategies for patients receiving extracorporeal membrane oxygenation.

CONCLUSIONS

Compared with the 2013 pediatric population, extracorporeal membrane oxygenation center anticoagulation and blood transfusion approaches continue to vary widely. Most report continued use of heparin as their primary anticoagulant and follow a combination of monitoring assays with the majority using the antifactor Xa assay in their practices, a significant shift from prior results. Antithrombin activity levels and viscoelastic tests are followed by a growing number of centers. Platelet transfusion thresholds continue to vary widely. Future research is needed to establish optimal anticoagulation and blood transfusion management.

Neonatal respiratory and cardiac ECMO in Europe

Neonatal extracorporeal membrane oxygenation (ECMO) is a life-saving procedure for critically ill neonates suffering from a potentially reversible disease, causing severe cardiac and/or respiratory failure and refractory to maximal conventional management. Since the 1970s, technology, management, and clinical applications of neonatal ECMO have changed. Pulmonary diseases still represent the principal neonatal diagnosis, with an overall 74% survival rate, and up to one-third of cases are due to congenital diaphragmatic hernia. The overall survival rate in cardiac ECMO is lower, with congenital heart defect representing the main indication. This review provides an overview of the available evidence in the field of neonatal ECMO. We will address the changing epidemiology, basic principles, technologic advances in circuitry, and monitoring, and deliver a current multidisciplinary management framework, focusing on ECMO applications, complications, and long-term morbidities. Lastly, areas for further research will be highlighted.Conclusions: ECMO is a life support with a potential impact on long-term patients' outcomes. In the next years, advances in knowledge, technology, and expertise may push neonatal ECMO boundaries towards more premature and increasingly complex infants, with the final aim to reduce the burden of ECMO-related complications and improve overall patients' outcomes. What is Known: • ECMO is a life-saving option in newborns with refractory respiratory and/or cardiac failure. • The multidisciplinary ECMO management is challenging and may expose neonates to complications with an impact on long-term outcomes. What is New: • Advances in technology and biomaterials will improve neonatal ECMO management and, eventually, the long-term outcome of these complex patients. • Experimental models of artificial placenta and womb technology are under investigation and may provide clinical translation and future research opportunities.

Conversion From Activated Clotting Time to Anti-Xa Heparin Activity Assay for Heparin Monitoring During Extracorporeal Membrane Oxygenation

OBJECTIVES

Anticoagulation with unfractionated heparin remains the most common therapy used to prevent circuit thrombosis during extracorporeal membrane oxygenation, but no consensus exists on the optimal method or targets for heparin monitoring. From 2015 to 2018, we switched from monitoring heparin during extracorporeal membrane oxygenation using activated clotting times to anti-Xa heparin activity assays. This study describes the transition from activated clotting time to anti-Xa heparin activity assay monitoring and the associated clinical changes.

DESIGN

Retrospective analysis at single institution.

SETTING

Referral Children's Hospital.

PATIENTS

A total of 145 pediatric patients over 152 extracorporeal membrane oxygenation runs using 206 extracorporeal membrane oxygenation circuits.

INTERVENTIONS

Anticoagulation protocol quality improvement.

MEASUREMENTS AND MAIN RESULTS

From 2015 to 2018, heparin monitoring during extracorporeal membrane oxygenation changed from hourly activated clotting time to anti-Xa heparin activity assay every 6 hours with an associated 75% reduction in the circuit changes per extracorporeal membrane oxygenation day. Over the 4 years, patients with an average anti-Xa heparin activity assay of at least 0.25 U/mL showed a 59% reduction in circuit changes per extracorporeal membrane oxygenation day compared with less than 0.15 U/mL. In addition to its association with reduced circuit changes, anti-Xa heparin activity assay monitoring was also associated with reduced heparin dose changes per day from 11 ± 4 to 2 ± 1 (p < 0.001), smaller heparin dose changes (less variation in dose), and reduced diagnostic phlebotomy volumes from 41 ± 6 to 25 ± 11 mL/day (p < 0.001). The number of patients with reported bleeding decreased from 69% using activated clotting time to 51% (p = 0.03). Transfusion rates did not change.

CONCLUSIONS

Over 4 years, we replaced the activated clotting time assay with the anti-Xa heparin activity assay for heparin monitoring during extracorporeal membrane oxygenation. Minimum anti-Xa heparin activity assay levels of 0.25 U/mL were associated with reduced circuit changes. Further studies are needed to determine the optimum anti-Xa heparin activity assay therapeutic range during extracorporeal membrane oxygenation.

Centrifugal and Roller Pumps in Neonatal and Pediatric Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis of Clinical Outcomes

Extracorporeal membrane oxygenation (ECMO) is an invaluable means of supporting critically ill children with refractory respiratory or cardiac failure. Controversy remains; however, whether roller or centrifugal pumps are superior, particularly in infants. We performed a comprehensive search on PubMed, Embase, and Scopus for studies comparing the use of centrifugal and roller pumps in the pediatric and neonatal population from 1973 until March 1, 2020. All prospective and retrospective comparative studies were screened. Single-arm studies and those that included adult patients were excluded. The primary endpoint was survival to discharge. Secondary endpoints were complications (mechanical, cardiac, pulmonary, neurologic, renal, and hemolytic) and requirements for inotropic support. Random effects meta-analyses across all clinical endpoints were conducted. A total of four studies with 9111 patients were included. There was a statistically significant difference in in-hospital mortality, favoring the groups where roller pumps were used. Roller pumps were associated with fewer episodes of hemolysis, mechanical complications, cardiac complications, renal complications, and less inotropic support. ECMO with roller pumps may be associated with lower mortality in children. Roller pumps were associated with fewer complications, as well as reduced hemolysis and use of inotropes.

Joint Society of Critical Care Medicine-Extracorporeal Life Support Organization Task Force Position Paper on the Role of the Intensivist in the Initiation and Management of Extracorporeal Membrane Oxygenation

OBJECTIVES

To define the role of the intensivist in the initiation and management of patients on extracorporeal membrane oxygenation.

DESIGN

Retrospective review of the literature and expert consensus.

SETTING

Series of in-person meetings, conference calls, and emails from January 2018 to March 2019.

SUBJECTS

A multidisciplinary, expert Task Force was appointed and assembled by the Society of Critical Care Medicine and the Extracorporeal Life Support Organization. Experts were identified by their respective societies based on reputation, experience, and contribution to the field.

INTERVENTIONS

A MEDLINE search was performed and all members of the Task Force reviewed relevant references, summarizing high-quality evidence when available. Consensus was obtained using a modified Delphi process, with agreement determined by voting using the RAND/UCLA scale, with score ranging from 1 to 9.

MEASUREMENTS AND MAIN RESULTS

The Task Force developed 18 strong and five weak recommendations in five topic areas of extracorporeal membrane oxygenation initiation and management. These recommendations were organized into five areas related to the care of patients on extracorporeal membrane oxygenation: patient selection, management, mitigation of complications, coordination of multidisciplinary care, and communication with surrogate decision-makers. A common theme of the recommendations is extracorporeal membrane oxygenation is best performed by a multidisciplinary team, which intensivists are positioned to engage and lead.

CONCLUSIONS

The role of the intensivist in the care of patients on extracorporeal membrane oxygenation continues to evolve and grow, especially when knowledge and familiarity of the issues surrounding extracorporeal membrane oxygenation selection, cannulation, and management are applied.

Morbidity and Mortality in Critically Ill Children. II. A Qualitative Patient-Level Analysis of Pathophysiologies and Potential Therapeutic Solutions

OBJECTIVES

To describe at the individual patient level the pathophysiologic processes contributing to morbidity and mortality in PICUs and therapeutic additions and advances that could potentially prevent or reduce morbidity and mortality.

DESIGN

Qualitative content analysis of intensivists' conclusions on pathophysiologic processes and needed therapeutic advances formulated by structured medical record review.

SETTING

Eight children's hospitals affiliated with the Eunice Kennedy Shriver National Institute of Child Health and Human Development Collaborative Pediatric Critical Care Research Network.

PATIENTS

A randomly selected cohort of critically ill children with a new functional morbidity or mortality at hospital discharge. New morbidity was assessed using the Functional Status Scale and defined as worsening by two or more points in a single domain from preillness baseline.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 292 children, 175 (59.9%) had a new morbidity and 117 (40.1%) died. The most common pathophysiology was impaired substrate delivery (n = 158, 54.1%) manifesting as global or regional hypoxia or ischemia due to low cardiac output or cardiac arrest. Other frequent pathophysiologies were inflammation (n = 104, 35.6%) related to sepsis, respiratory failure, acute respiratory distress syndrome, or multiple organ dysfunction; and direct tissue injury (n = 64, 21.9%) including brain and spinal cord trauma. Chronic conditions were often noted (n = 156, 53.4%) as contributing to adverse outcomes. Drug therapies (n = 149, 51.0%) including chemotherapy, inotropes, vasoactive agents, and sedatives were the most frequently proposed needed therapeutic advances. Other frequently proposed therapies included cell regeneration (n = 115, 39.4%) mainly for treatment of neuronal injury, and improved immune and inflammatory modulation (n = 79, 27.1%).

CONCLUSIONS

Low cardiac output and cardiac arrest, inflammation-related organ failures, and CNS trauma were the most common pathophysiologies leading to morbidity and mortality in PICUs. A research agenda focused on better understanding and treatment of these conditions may have high potential to directly impact patient outcomes.

Bridging the Gap Between Intensivists and Primary Care Clinicians in Extracorporeal Membrane Oxygenation for Respiratory Failure in Children: A Review

IMPORTANCE

Extracorporeal membrane oxygenation (ECMO) is a form of advanced life support that may be used in children with refractory respiratory or cardiac failure. While it is required infrequently, in the US, ECMO is used to support childhood respiratory failure as often as children receive kidney or heart transplants. ECMO is complex, resource intensive, and potentially lifesaving, but it is also associated with risks of short-term complications and long-term adverse effects, most importantly with neurodevelopmental outcomes that are relevant to all pediatric clinicians, even those remote from the child's critical illness.

OBSERVATIONS

The 2009 influenza A(H1N1) pandemic, along with randomized clinical trials of adult respiratory ECMO support and conventional management, have catalyzed sustained growth in the use of ECMO. The adult trials built on earlier neonatal ECMO randomized clinical trials that demonstrated improved survival in severe perinatal lung disease. For children outside of the neonatal period, there appear to have been no respiratory ECMO clinical trials. Applying evidence from adult respiratory failure or perinatal lung disease to children outside the neonatal period has important potential pitfalls. For these children, the underlying diseases and risks of ECMO are different. Despite these differences, both neonates and older children are at risk of neurologic complications, such as intracranial hemorrhage, ischemic stroke, and seizures, and those complications may contribute to adverse neurodevelopmental outcomes. Without specific screening, subtle neurodevelopmental impairments may be missed, but when they are identified, children have the opportunity to receive therapy to optimize long-term development.

CONCLUSIONS AND RELEVANCE

All pediatric clinicians should be aware not only of the potential benefits and complications of ECMO but also that survivors need effective screening, support, and follow-up.

The use of extracorporeal membrane oxygenation in children with acute fulminant myocarditis

Acute fulminant myocarditis (AFM) occurs as an inflammatory response to an initial myocardial insult. Its rapid and deadly progression calls for prompt diagnosis with aggressive treatment measures. The demonstration of its excellent recovery potential has led to increasing use of mechanical circulatory support, especially extracorporeal membrane oxygenation (ECMO). Arrhythmias, organ failure, elevated cardiac biomarkers, and decreased ventricular function at presentation predict requirement for ECMO. In these patients, ECMO should be considered earlier as the clinical course of AFM can be unpredictable and can lead to rapid haemodynamic collapse. Key uncertainties that clinicians face when managing children with AFM such as timing of initiation of ECMO and left ventricular decompression need further investigation.

Extracorporeal Life Support Organization (ELSO): Guidelines for Pediatric Cardiac Failure

These guidelines are applicable to neonates and children with cardiac failure as indication for extracorporeal life support. These guidelines address patient selection, management during extracorporeal membrane oxygenation, and pathways for weaning support or bridging to other therapies. Equally important issues, such as personnel, training, credentialing, resources, follow-up, reporting, and quality assurance, are addressed in other Extracorporeal Life Support Organization documents or are center-specific.

Pediatric Fibrinogen PART II-Overview of Indications for Fibrinogen Use in Critically Ill Children

Bleeding is frequently seen in critically ill children and is associated with increased morbidity and mortality. Fibrinogen is an essential coagulation factor for hemostasis and hypofibrinogenemia is an important risk factor for bleeding in pediatric and adult settings. Cryoprecipitate and fibrinogen concentrate are often given to critically ill children to prevent bleeding and improve fibrinogen levels, especially in the setting of surgery, trauma, leukemia, disseminated intravascular coagulopathy, and liver failure. The theoretical benefit of fibrinogen supplementation to treat hypofibrinogenemia appears obvious, yet the evidence to support fibrinogen supplementation in children is sparce and clinical indications are poorly defined. In addition, it is unknown what the optimal fibrinogen replacement product is in children and neonates or what the targets of treatment should be. As a result, there is considerable variability in practice. In this article we will review the current pediatric and applicable adult literature with regard to the use of fibrinogen replacement in different pediatric critical care contexts. We will discuss the clinical indications for fibrinogen supplementation in critically ill children and the evidence to support their use. We summarize by highlighting current knowledge gaps and areas for future research.

Brain Injury in Extracorporeal Membrane Oxygenation: A Multidisciplinary Approach

Extracorporeal membrane oxygenation (ECMO) represents an established technique to provide temporary cardiac and/or pulmonary support. ECMO, in veno-venous, veno-arterial or in extracorporeal carbon dioxide removal modality, is associated with a high rate of brain injuries. These complications have been reported in 7 to 15% of adults and 20% of neonates, and are associated with poor survival. Thromboembolic events, loss of cerebral autoregulation, alteration of the blood-brain barrier, and hemorrhage related to anticoagulation represent the main causes of severe brain injury during ECMO. The most frequent forms of acute neurological injuries in ECMO patients are intracranial hemorrhage (2-21%), ischemic stroke (2-10%), seizures (2-6%), and hypoxic-ischemic brain injury; brain death may also occur in this population. Other frequent complications are infarction (1-8%) and cerebral edema (2-10%), as well as neuropsychological and psychiatric sequelae, including posttraumatic stress disorder.

Low vs standardized dose anticoagulation regimens for extracorporeal membrane oxygenation: A meta-analysis

Background

To compare the safety and efficacy of low-dose anticoagulation (LA) with that of standardized dose anticoagulation (SA) for patients supported with extracorporeal membrane oxygenation (ECMO).

Methods

PubMed, MEDLINE, the Cochrane Library, and Web of Science were screened for original articles. Screening was performed using predefined search terms to identify cohort studies reporting the comparison of LA with SA in patients supported with ECMO from Nov 1990 to Jun 2020. The effect size was determined by the odds ratio (OR) with the 95% confidence interval (CI).

Results

An analysis of 7 studies including a total of 553 patients was performed. LA (Low-heparin group) was administered to 255 patients, whereas the other 298 patients received SA (Full-heparin group). The incidence of gastrointestinal tract hemorrhage (OR 0.36, 95% CI 0.20–0.64) and surgical site hemorrhage (OR 0.43, 95% CI 0.20–0.94) were significantly lower in patients who underwent LA compared with that in those who underwent SA. The rates of hospital mortality (OR 0.81, 95% CI 0.42–1.56), successfully weaning off of ECMO (OR 0.80, 95% CI 0.30–2.14), pulmonary embolism (OR 0.79, 95% CI 0.24–2.65), intracardiac thrombus (OR 0.34, 95% CI 0.09–1.30), intracranial hemorrhage (OR 0.62, 95% CI 0.22–1.74), and pulmonary hemorrhage (OR 0.77, 95% CI 0.30–1.93) were similar between the two groups.

Conclusions

This meta-analysis confirms that LA is a feasible and safe anticoagulation strategy in patients supported by ECMO. Future studies should focus on the long-term benefits of LA compared with SA.

Hirudotherapy for neonatal limb ischemia during ECMO support: A word of caution

INTRODUCTION

Disordered coagulation, clot formation and distal limb ischemia are complications of extracorporeal membrane oxygenation (ECMO) with significant morbidity and mortality. Medicinal leech therapy (hirudotherapy) has been attempted in plastic and orthopedic surgeries to improve venous congestion and salvage ischemic flaps. To our knowledge this has not been reported in pediatric cardiac surgery or during ECMO support. We present a complex neonate whose ECMO course was complicated by distal limb ischemia for whom leech therapy was attempted.

PATIENT AND INTERVENTION

A 2-week-old 2.7 kg infant required ECMO support secondary to perioperative multiorgan system dysfunction following repair of critical coarctation and ventricular septal defect. Despite systemic anticoagulation, his clinical course was complicated by arterial thrombus, vasopressor-induced vascular spasm and bilateral distal limb ischemia. Medicinal leech therapy was tried after initially failing conventional measures.

RESULT

Following the third leech application, this patient developed significant hemorrhage from the web space adjacent to the left great toe. An estimated 450 ml of blood loss occurred and more than 300 ml of blood product transfusions were required. He ultimately progressed to irreversible systemic end organ dysfunction and comfort care was provided.

CONCLUSION

The use of medicinal leech therapy in pediatric cardiac surgery may be considered to minimize the consequences of advanced limb ischemia and venous congestion. However, this should be used with caution while patients are systemically anticoagulated during ECMO support. A directed review is presented here to assist in determining optimal application and potential course of therapy.

Atrial septostomy in patients supported with venoarterial extracorporeal membrane oxygenation: Analysis of the IMPACT registry data

Background:

Patients with severe cardiac dysfunction, supported on extra-corporeal membrane oxygenation (ECMO), develop left atrial hypertension and often warrant atrial decompression. The procedural risks and outcomes, however, are not well established. Objective of this study is to understand the utilization, safety, and outcomes of atrial septostomy in children supported on venoarterial ECMO utilizing the IMPACT registry database.

Methods:

Data from 55 independent sites reporting to the registry was used for this descriptive study. Patients supported with cardiac ECMO that underwent percutaneous atrial septostomy (PAS) were included and data analyzed.

Results:

Between 2011 and 2018, 223 patients underwent atrial septostomy and were reported to the registry. Mean age was 4.65 years with 52% being males. Diagnoses of heart failure, sepsis, arrhythmia, and renal insufficiency were commonly noted prior to ECMO. The procedure was performed urgently or emergently in most cases (80%). PAS was associated with significant procedural complications such as arrhythmia (6.8%), tamponade (5.4%), and unplanned surgery (3.6%) but no procedural mortality. Overall hospital mortality was 46% (103/223) with 46 of these deaths occurring within 7 days of procedure. Regression analysis showed that African American race (vs Caucasian), race other than Caucasian, chronic lung disease and emergent procedure need were significantly associated with early post-procedural mortality (all p < 0.05).

Conclusion:

Using a large multicenter cardiac catheterization registry, we found that left atrial decompression can be performed without procedural mortality but is associated with significant morbidity. Impact of race, chronic lung disease and procedural urgency on early mortality warrant further studies.

Vitamin K and ECMO for neonatal hypoxic respiratory failure

INTRODUCTION

The objectives of this retrospective cohort study were to examine the effect of vitamin K administration on hemorrhagic and thrombotic complications, blood product utilization, and outcomes in neonatal extracorporeal membrane oxygenation (ECMO).

METHODS

In the pilot study, complications, blood product use, and outcome data for neonates who received (n = 21) or did not receive (n = 18) a single dose of vitamin K (5 mg) immediately after initiation of ECMO for respiratory failure between 2006 and 2010 were compared. In the validation cohort, complications and outcomes were compared for 74 consecutive neonates supported with ECMO for respiratory failure who received (n = 45) or did not receive (n = 29) additional vitamin K once daily for prothrombin time (PT) ⩾14 seconds during ECMO from 2014 to 2019.

RESULTS

In the pilot study, vitamin K at ECMO initiation was associated with fewer thrombotic complications and similar hemorrhagic complications. The volume of fresh frozen plasma was higher in neonates who received vitamin K, but total blood product and other component volume did not differ between groups. ECMO run time, survival off ECMO, survival to discharge, and length of stay did not differ between cohorts. In the validation cohort, neonates who received additional vitamin K during ECMO had longer ECMO run time and length of stay, but no difference in mortality was observed. Further, thrombotic and hemorrhagic complications as well as blood product exposure were similar between cohorts.

CONCLUSIONS

These data suggest that routine vitamin K administration may have limited or no benefit during neonatal ECMO.

Device-Induced Hemostatic Disorders in Mechanically Assisted Circulation

Mechanically assisted circulation (MAC) sustains the blood circulation in the body of a patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) or on ventricular assistance with a ventricular assist device (VAD) or on extracorporeal membrane oxygenation (ECMO) with a pump-oxygenator system. While MAC provides short-term (days to weeks) support and long-term (months to years) for the heart and/or lungs, the blood is inevitably exposed to non-physiological shear stress (NPSS) due to mechanical pumping action and in contact with artificial surfaces. NPSS is well known to cause blood damage and functional alterations of blood cells. In this review, we discussed shear-induced platelet adhesion, platelet aggregation, platelet receptor shedding, and platelet apoptosis, shear-induced acquired von Willebrand syndrome (AVWS), shear-induced hemolysis and microparticle formation during MAC. These alterations are associated with perioperative bleeding and thrombotic events, morbidity and mortality, and quality of life in MCS patients. Understanding the mechanism of shear-induce hemostatic disorders will help us develop low-shear-stress devices and select more effective treatments for better clinical outcomes.

Gastrointestinal haemorrhage in extracorporeal membrane oxygenation: insights from the national inpatient sample

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is associated with gastrointestinal haemorrhage (GIH), which may result from coagulopathy, systemic inflammation, reduced gastric perfusion, and arteriovenous malformation from non-pulsatile blood flow. Data are limited regarding the burden of this complication in the United States.

MATERIAL AND METHODS

We analysed the National Inpatient Sample (NIS) database for the years 2007 to 2011 to identify hospitalisations in which an ECMO procedure was performed. Hospitalizations complicated by GIH in this cohort were then identified by relevant codes.

RESULTS

Between 2007 and 2011, ECMO hospitalisations increased from 1869 to 3799 (p < 0.01). The proportion of hospitalisations complicated by GIH increased from 2.12% in 2007 to 7.46% in 2011 (p < 0.01). Gastrointestinal haemorrhage was more common in men (56.7%) and in Caucasians (57.4%). Common comorbidities in this population were renal failure (71%), anaemia (55%), and hypertension (26%). All-cause inpatient mortality showed a numerical but nonsignificant increase from 56.7% to 61.9% (p = 0.49). The average cost of care per hospitalisation with GIH associated with ECMO use increased from $132,420 in 2007 to $215,673 in 2011 (p < 0.01).

CONCLUSIONS

Gastrointestinal haemorrhage during ECMO hospitalisations occurred in small but significantly increasing proportions. The inpatient mortality rate and costs associated with GIH were substantial and increased significantly during the study period.

Transfusion management for children supported by extracorporeal membrane oxygenation

Due to the patients' underlying illness, in combination with circuit-induced coagulopathy, as well as PLT dysfunction, children supported by ECMO are a risk of receiving large volumes of blood components. Given the increasing use of modified blood products and newer biologics, it is unknown whether these products have equal efficacy and safety, in ECMO. The majority of guidance for transfusion therapy is based on expert opinion alone, and research on indications for RBC, plasma, and PLT transfusions for children on ECMO should be a priority.

Use of extracorporeal membrane oxygenation in postpartum patients with refractory shock or respiratory failure

Although extracorporeal membrane oxygenation (ECMO) is increasingly utilized, only a limited level of experience has been reported in postpartum cardiopulmonary failure. Ten critically ill postpartum patients who received ECMO were included between January 2010 and December 2018 in this retrospective observational study. The main indication for ECMO support was peripartum cardiomyopathy (n = 5), followed by postpartum hemorrhage (n = 2). Nine patients initially received veno-arterial ECMO, and one patient received veno-venous ECMO. Major bleeding occurred in six patients. The median number of units of red blood cells (RBC) transfused during ECMO was 14.5 units (interquartile range 6.8–37.8 units), and most RBC transfusions occurred on the first day of ECMO. The survival-to-discharge rate was 80%. Compared to the survival outcomes in female patients of similar age who received ECMO, the survival outcomes were significantly better in the study population (56% versus 80%, P = 0.0004). Despite the high risk of major bleeding, ECMO for patients with postpartum cardiac or respiratory failure showed excellent survival outcomes. ECMO is feasible in these patients and can be carried out with good outcomes in an experienced centre.

Current Understanding of Leukocyte Phenotypic and Functional Modulation During Extracorporeal Membrane Oxygenation: A Narrative Review

A plethora of leukocyte modulations have been reported in critically ill patients. Critical illnesses such as acute respiratory distress syndrome and cardiogenic shock, which potentially require extracorporeal membrane oxygenation (ECMO) support, are associated with changes in leukocyte numbers, phenotype, and functions. The changes observed in these illnesses could be compounded by exposure of blood to the non-endothelialized surfaces and non-physiological conditions of ECMO. This can result in further leukocyte activation, increased platelet-leukocyte interplay, pro-inflammatory and pro-coagulant state, alongside features of immunosuppression. However, the effects of ECMO on leukocytes, in particular their phenotypic and functional signatures, remain largely overlooked, including whether these changes have attributable mortality and morbidity. The aim of our narrative review is to highlight the importance of studying leukocyte signatures to better understand the development of complications associated with ECMO. Increased knowledge and appreciation of their probable role in ECMO-related adverse events may assist in guiding the design and establishment of targeted preventative actions.

Epidemiology of the Use of Hemostatic Agents in Children Supported by Extracorporeal Membrane Oxygenation: A Pediatric Health Information System Database Study

Objectives: Children supported by extracorporeal membrane oxygenation (ECMO) are at high risk of bleeding. Though practitioners often prescribe blood components and/or medications to prevent or treat bleeding, the utilization of these hemostatic measures in children is not well-understood. We sought to evaluate the use of hemostatic blood products (platelet, plasma and cryoprecipitate transfusions) and medications [aminocaproic acid, tranexamic acid (TXA) and Factor VIIa] in children supported by ECMO. Design: Retrospective observational study using the Pediatric Health Information System (PHIS) database from 2011-2017. Setting: Fifty-one U.S. children's hospitals. Patients: Children (aged 0-18 years) supported by ECMO. Interventions: None. Measurements and Main Results: ECMO was employed in the care of 7,910 children for a total of 56,079 ECMO days. Fifty-five percent of the patients were male with a median (IQR) age of 0 (0-2) years. The median (IQR) length of ECMO was 5 (2-9) days with a hospital mortality rate of 34%. Platelets were transfused on 49% of ECMO days, plasma on 33% of ECMO days and cryoprecipitate on 17% of ECMO days. Twenty-two percent of children received TXA with the majority receiving it on the first day of ECMO and the use of TXA increased during the 6-year period studied (p < 0.001). Seven percent of children received aminocaproic acid and 3% received Factor VIIa. Conclusions: Children supported by ECMO are exposed to a significant number of hemostatic blood products. Antifibrinolytics, in particular TXA, are being used more frequently. Given the known morbidity and mortality associated with hemostatic blood products, studies are warranted to evaluate the effectiveness of hemostatic strategies.

Surgery in Neonatal and Pediatric ECMO Patients Other Than Congenital Diaphragmatic Hernia Repair: A 10-Year Experience

Aim of Study: The use of extracorporeal membrane oxygenation (ECMO) has increased as a result of technological developments and the expansion of indications. Relatedly, the number of patients undergoing surgery during ECMO is also rising, at least in the adult population. Little is known on surgery in children during ECMO-therapy. We therefore aimed to assess the frequencies and types of surgical interventions in neonatal and pediatric patients on ECMO and to analyze surgery-related morbidity and mortality. Methods: We retrospectively collected information of all patients on ECMO over a 10-year period in a single tertiary and designated ECMO-center, excluding patients undergoing cardiac surgery, and correction of congenital diaphragmatic hernia. Chi-squared test and Mann-Whitney U test were used to analyze data. Main Results: Thirty-two of 221 patients (14%) required surgery when on ECMO. Common interventions were thoracotomy (32%), laparotomy (23%), fasciotomy (17%), and surgical revision of ECMO (15%). Complications occurred in 28 cases (88%), resulting in a 50% in-hospital mortality rate. Surgical patients had a longer ICU stay and longer total hospital stay compared to those not receiving surgery during ECMO. No significant difference in mortality was found when comparing surgical to non-surgical patients (50 vs. 41%). Conclusions: Approximately one in seven neonatal or pediatric patients required surgical intervention during ECMO, of whom almost 90% developed a complication, resulting in a 50% mortality rate. These results should be taken into account in counseling.

Clinical Characteristics and Outcomes of Children With Extracorporeal Membrane Oxygenation in a Developing Country: An 11-Year Single-Center Experience

Introduction: Extracorporeal Membrane Oxygenation (ECMO) is a lifesaving procedure for patients with refractory cardiac or respiratory failure. The indications for ECMO are growing, and it is increasingly being used to support cardiopulmonary failure in children. However, the risks and benefits of ECMO should be weighed before deploying it on the patients. The objectives of this study were to identify the mortality risk factors and to determine the ECMO outcomes. Methods: The retrospective chart reviews were done for all patients aged 1 day-20 years old receiving ECMO between January 2010 and December 2020. Results: Seventy patients were enrolled in the study. The median age was 31.3 months. The incidence of VA and VV ECMO was 85.7 and 14.3%, respectively. The most common indication for ECMO was the failure to wean off cardiopulmonary bypass after cardiac surgery. Pre-existing acute kidney injury (OR 4.23; 95% CI 1.34-13.32, p = 0.014) and delayed enteral feeding (OR 3.85, 95% CI 1.23-12.02, p = 0.020), and coagulopathy (OD 12.64; 95% CI 1.13-141.13, p = 0.039) were associated with the higher rate of mortality. The rates of ECMO survival and survival to discharge were 70 and 50%, respectively. Conclusion: ECMO is the lifesaving tool for critically ill pediatric patients. Pre-existing acute kidney injury, delayed enteral feeding, and coagulopathy were the potential risk factors associated with poor outcomes in children receiving ECMO. However, ECMO setup can be done successfully in a developing country.

Vasoactive-Inotropic Score and Vasoactive-Ventilation-Renal Score as Outcome Predictors for Children on Extracorporeal Membrane Oxygenation

We aimed to determine the association of vasoactive-inotropic score (VIS) and vasoactive-ventilation-renal (VVR) score with in-hospital mortality and functional outcomes at discharge of children who receive ECMO. A sub-analysis of the multicenter, prospectively collected data by the Collaborative Pediatric Critical Care Research Network (CPCCRN) for Bleeding and Thrombosis on ECMO (BATE database) was conducted. Of the 514 patients who received ECMO across eight centers from December 2012 to February 2016, 421 were included in the analysis. Patients > 18 years of age, patients placed on ECMO directly from cardiopulmonary bypass or as an exit procedure, or patients with an invalid or missing VIS score were excluded. Higher VIS (OR = 1.008, 95% CI: 1.002-1.014, p = 0.011) and VVR (OR: 1.006, 95% CI: 1.001-1.012, p = 0.023) were associated with increased mortality. VIS was associated with worse Pediatric Cerebral Performance Category (PCPC) (OR = 1.027, 95% CI: 1.010-1.044, p = 0.002) and Pediatric Overall Performance Category (POPC) score (OR = 1.023, 95% CI: 1.009-1.038, p = 0.002) at discharge. No association was found between VIS or VVR and Functional Status Score (FSS) at discharge. Using multivariable analyses, controlling for ECMO mode, ECMO location, ECMO indication, primary diagnosis, and chronic diagnosis, extremely high VIS and VVR were still associated with increased mortality.

Mechanical circulatory support in paediatric population

Extra-corporeal membrane oxygenation is a life-saving modality to support the cardiac and/or pulmonary system as a form of life support in resuscitation, post-cardiotomy, as a bridge to cardiac transplantation and in respiratory failure. Its use in the paediatric and neonatal population has proven incredibly useful. However, extra-corporeal membrane oxygenation is also associated with a greater rate of mortality and complications, particularly in those with co-morbidities. As a result, interventions such as ventricular assist devices have been trialled in these patients. In this review, we provide a comprehensive analysis of the current literature on extra-corporeal membrane oxygenation for cardiac support in the paediatric and neonatal population. We evaluate its effectiveness in comparison to other forms of mechanical circulatory support and focus on areas for future development.

Evaluation of effect of scheduled fresh frozen plasma on ECMO circuit life: A randomized pilot trial

BACKGROUND

Factor consumption is common during ECMO complicating the balance of pro and anticoagulation factors. This study sought to determine whether transfusion of coagulation factors using fresh frozen plasma (FFP) increased ECMO circuit life and decreased blood product transfusion. Secondly, it analyzed the association between FFP transfusion and hemorrhagic and thrombotic complications.

STUDY DESIGN AND METHODS

Thirty-one pediatric ECMO patients between October 2013 and January 2016 at a quaternary care institution were included. Patients were randomized to FFP every 48 hours or usual care. The primary outcome was ECMO circuit change. Secondary outcomes included blood product transfusion, survival to decannulation, hemorrhagic and thrombotic complications, and ECMO costs.

RESULTS

Median (interquartile range [IQR]) number of circuit changes was 0 (0, 1). No difference was seen in percent days without a circuit change between intervention and control group, P = .53. Intervention group patients received median platelets of 15.5 mL/kg/d IQR (3.7, 26.8) vs 24.8 mL/kg/d (12.2, 30.8) for the control group (P = .16), and median packed red blood cells (pRBC) of 7.7 mL/kg/d (3.3, 16.3) vs 5.9 mL/kg/d (3.4, 18.7) for the control group, P = .60. FFP transfusions were similar with 10.2 mL/kg/d (5.0, 13.9) in the intervention group vs 8.8 (2.5, 17.7) for the control group, P = .98.

CONCLUSION

In this pilot randomized study, scheduled FFP did not increase circuit life. There was no difference in blood product transfusion of platelets, pRBCs, and FFP between groups. Further studies are needed to examine the association of scheduled FFP with blood product transfusion.

Coagulopathy Characterized by Rotational Thromboelastometry in a Porcine Pediatric ECMO Model

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used to support patients with reversible cardiopulmonary insufficiency. Although it is a lifesaving technology, bleeding, inflammation, and thrombosis are well-described complications of ECMO. Adult porcine models of ECMO have been used to recapitulate the physiology and hemostatic consequences of ECMO cannulation in adults. However, these models lack the unique physiology and persistence of fetal forms of coagulation factors and fibrinogen as in human infants. We aimed to describe physiologic and coagulation parameters of piglets cannulated and supported with VA-ECMO. Four healthy piglets (5.7-6.4 kg) were cannulated via jugular vein and carotid artery by cutdown and supported for a maximum of 20 hours. Heparin was used with a goal activated clotting time of 180-220 seconds. Arterial blood gas (ABG) was performed hourly, and blood was transfused from an adult donor to maintain hematocrit (Hct) > 24%. Rotational thromboelastometry (ROTEM) was performed at seven time points. All animals achieved adequate flow with a patent circuit throughout the run (pre- and post-oxygenator pressure gradient <10 mmHg). There was slow but significant hemorrhage at cannulation, arterial line, and bladder catheter sites. All animals required the maximum blood transfusion volume available. All animals became anemic after exhaustion of blood for transfusion. ABG showed progressively declining Hct and adequate oxygenation. ROTEM demonstrated decreasing fibrin-only ROTEM (FIBTEM) clot firmness. Histology was overall unremarkable. Pediatric swine are an important model for the study of pediatric ECMO. We have demonstrated the feasibility of such a model while providing descriptions of physiologic, hematologic, and coagulation parameters throughout. Weak whole-blood clot firmness by ROTEM suggested defects in fibrinogen, and there was a clinical bleeding tendency in all animals studied. This model serves as an important means to study the complex derangements in hemostasis during ECMO.

Intravascular Hemolysis and Complications During Extracorporeal Membrane Oxygenation

Venovenous and venoarterial extracorporeal membrane oxygenation (ECMO) remains a crucial lifesaving therapy for critically ill neonates with severe cardiorespiratory failure. Both the roller pump as well as the centrifugal pump are safe and efficient systems, and some red blood cell breakdown and hemolysis occurs in all ECMO systems. The roller pump functions by gravity whereas the centrifugal pump promotes the flow of blood by a magnetically driven spinning rotor to generate negative pressure. Extracorporeal Life Support Organization data indicate a significant increase in intravascular hemolysis in neonatal and pediatric patients receiving ECMO when the centrifugal pump is used compared with its use in adults. Risk factors for developing hemolysis during ECMO are small cannula size, high negative inlet pressure in the pump head, and thrombosis in the pump head and oxygenator. Excessive red blood cell breakdown and release of plasma free hemoglobin (pfHb) saturate physiologic neutralizing mechanisms such as haptoglobin and hemopexin. The increase in pro-oxidant and proinflammatory pfHb levels causes endothelial dysfunction in a dose-dependent manner. Hemolysis also increases the risk of in-hospital morbidities such as renal injury, direct hyperbilirubinemia, and thrombosis without an increase in mortality in patients receiving ECMO. Hemolysis is an unavoidable side effect of current ECMO technology and there are no approved treatments or treatment guidelines for the neonatal population. Therefore, increased vigilance, recognition of the severity of the hemolytic process, and prompt management are essential to prevent severe endothelial injury leading to proinflammatory and prothrombotic events.

Prospective Exploratory Experience With Bivalirudin Anticoagulation in Pediatric Extracorporeal Membrane Oxygenation

OBJECTIVES

Objective of this study was to determine if bivalirudin resulted in less circuit interventions than unfractionated heparin. A secondary objective was to examine associations between bivalirudin dose and partial thromboplastin time, international normalized ratio, and activated clotting time.

DESIGN

Prospective observational.

SETTING

Medical-surgical and cardiac PICUs.

PATIENTS

Neonatal and pediatric extracorporeal membrane oxygenation patients who received bivalirudin anticoagulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty extracorporeal membrane oxygenation runs in 18 patients used bivalirudin; 90% were venoarterial. Median (interquartile range) age was 4.5 months (1.6-35 mo). Thirteen patients (72%) had an underlying cardiac diagnosis. Of the 20 runs using bivalirudin, 16 (80%) were initially started on unfractionated heparin and transitioned to bivalirudin due to ongoing circuit thrombosis despite therapeutic anti-Xa levels (n = 13), ongoing circuit thrombosis with unfractionated heparin greater than or equal to 40 U/kg/hr (n = 2), or absence of increase in ACT after bolus of 100 U/kg of unfractionated heparin and escalation of unfractionated heparin infusion (n = 1). Initial bivalirudin dose ranged from 0.2 to 0.5 mg/kg/hr; no bolus doses were used. Median (range) bivalirudin dose was 0.9 mg/kg/hr (0.15-1.6 mg/kg/hr). Median (interquartile range) time on extracorporeal membrane oxygenation was 226.5 hours (150.5-393.0 hr) including 84 hours (47-335 hr) on bivalirudin. Nonparametric results are as follows: the rate of circuit intervention was significantly lower in patients on bivalirudin than on unfractionated heparin (median [interquartile range]: 0 [0-1] and 1 [1-2], respectively; Wilcoxon p = 0.0126). Bivalirudin dose was correlated to PTT (rs = 0.4760; p < 0.0001), INR (rs = 0.6833; p < 0.0001), and ACT (rs = 0.6161; p < 0.0001). Four patients had a significant bleeding complication on bivalirudin. Survival to hospital discharge was 56%.

CONCLUSIONS

Bivalirudin appears to be a viable option for systemic anticoagulation in pediatric extracorporeal membrane oxygenation patients who have failed unfractionated heparin, but questions remain namely its optimal monitoring strategy. This pilot study supports the need for larger prospective studies of bivalirudin in pediatric extracorporeal membrane oxygenation, particularly focusing on meaningful monitoring variables.

Severe SARS-CoV-2 Infection in a Pediatric Patient Requiring Extracorporeal Membrane Oxygenation

The overwhelming majority of pediatric cases of SARS-CoV-2 infection are mild or asymptomatic with only a handful of pediatric deaths reported. We present a case of severe COVID-19 infection in a pediatric patient with signs of hyperinflammation and consumptive coagulopathy requiring intubation and extracorporeal membrane oxygenation (ECMO) and eventual death due to ECMO complications.

Continuous Monitoring of Cerebral Autoregulation in Children Supported by Extracorporeal Membrane Oxygenation: A Pilot Study

OBJECTIVE

Cerebral autoregulation (CA) impairment may pose a risk factor for neurological complications among children supported by extracorporeal membrane oxygenation (ECMO). Our first objective was to investigate the feasibility of CA continuous monitoring during ECMO treatment and to describe its evolution over time. The second objective was to analyze the association between CA impairment and neurological outcome.

DESIGN

Observational prospective study.

PATIENTS AND SETTING

Twenty-nine children treated with veno-arterial or veno-venous ECMO in the PICU of Nantes University Hospital, France, and the PICU of the IRCCS Giannina Gaslini Institute in Genoa, Italy.

MEASUREMENTS

A correlation coefficient between the variations of regional cerebral oxygen saturation and the variations of mean arterial blood pressure (MAP) was calculated as an index of CA (cerebral oxygenation reactivity index, COx). A COx > 0.3 was considered as indicative of autoregulation impairment. COx-MAP plots were investigated allowing determining optimal MAP (MAPopt) and limits of autoregulation: lower (LLA) and upper (ULA). Neurological outcome was assessed by the onset of an acute neurological event (ANE) after ECMO start.

RESULTS

We included 29 children (median age 84 days, weight 4.8 kg). MAPopt, LLA, and ULA were detected in 90.8% (84.3-93.3) of monitoring time. Mean COx was significantly higher during day 1 of ECMO compared to day 2 [0.1 (0.02-0.15) vs. 0.01 (- 0.05 to 0.1), p = 0.002]. Twelve children experienced ANE (34.5%). The mean COx and the percentage of time spent with a COx > 0.3 were significantly higher among ANE+ compared to ANE- patients [0.09 (0.01-0.23) vs. 0.04 (- 0.02 to 0.06), p = 0.04 and 33.3% (24.8-62.1) vs. 20.8% (17.3-23.7) p = 0.001]. ANE+ patients spent significantly more time with MAP below LLA [17.2% (6.5-32.9) vs. 5.6% (3.6-9.9), p = 0.02] and above ULA [13% (5.3-38.4) vs. 4.2% (2.7-7.4), p = 0.004], respectively.

CONCLUSION

CA assessment is feasible in pediatric ECMO. The first 24 h following ECMO represents the most critical period regarding CA. Impaired autoregulation is significantly more severe among patients who experience ANE.

Outcomes of pediatric patients with oncologic disease or following hematopoietic stem cell transplant supported on extracorporeal membrane oxygenation: The PEDECOR experience

BACKGROUND

Outcomes for patients with oncologic disease and/or after hematopoietic stem cell transplant (HSCT) requiring intensive care unit admission have improved, but indications for and outcomes after extracorporeal membrane oxygenation (ECMO) support in this population are poorly characterized.

PROCEDURE

We analyzed data from consecutive patients < 18 years with oncologic disease and/or after HSCT reported to a pediatric ECMO registry by nine pediatric centers in the United States between 2011 and 2018.

RESULTS

We identified 18 ECMO patients with oncologic disease and/or HSCT, and 415 ECMO controls matched with a propensity score algorithm based on age, gender, race, severity of illness at admission, and reason for ECMO. The primary indication for ECMO was respiratory failure in 66.7% in the oncologic disease and/or HSCT group, and in 70.7% in the matched ECMO control group. Eleven of 18 patients survived to hospital discharge (61.1%), similar to the matched control group (60.8%), P = 0.979. Children with oncologic disease and/or HSCT had lower mean platelet counts during ECMO and received higher volumes of platelets compared with the control group, mean 14.6 mL/kg/day (standard deviations [SD], 9.8) versus mean 9.3 mL/kg/day (SD, 10.4), P = 0.001. Of the 11 surviving children with oncologic disease and/or HSCT, five sustained new neurologic disorders (45.5%) versus 45 of 222 (20.3%) in the control group, P = 0.061. Bleeding complications were similar in the two groups.

CONCLUSIONS

Outcomes of patients with oncologic disease and/or HSCT supported on ECMO in the current era are not significantly different compared with matched ECMO controls and are improved from previously published reports.

Anti-Xa versus time-guided anticoagulation strategies in extracorporeal membrane oxygenation: a systematic review and meta-analysis

The purpose was to compare time-based vs anti-Xa-based anticoagulation strategies in patients on ECMO. We conducted a systematic review and meta-analysis using multiple electronic databases and included studies from inception to July 19, 2019. The proportion of bleeding, thrombosis, and mortality were evaluated.

Twenty-six studies (2,086 patients) were included. Bleeding occurred in 34.2% (95%CI 25.1;43.9) of the patients with anti-Xa-based versus 41.6% (95%CI 24.9;59.4) of the patients with time-based anticoagulation strategies. Thrombosis occurred in 32.6% (95%CI 19.1;47.7) of the patients with anti-Xa-based versus 38.4% (95%CI 22.2;56.1) of the patients with time-based anticoagulation strategies. And mortality rate was 35.4% (95%CI 28.9;42.1) of the patients with anti-Xa-based versus 42.9% (95%CI 36.9;48.9) of the patients with time-based anticoagulation strategies. Among the seven studies providing results from both anticoagulation strategies, significantly fewer bleeding events occurred in the anti-Xa-based anticoagulation strategy (adjusted OR 0.49 (95%CI 0.32;0.74), p < 0.001) and a significantly lower mortality rate (adjusted OR 0.61 (95%CI 0.40;0.95), p = 0.03). There was no significant difference in thrombotic events (adjusted OR 0.91 (95%CI 0.56;1.49), p = 0.71). In these seven observational studies, only a small fraction of the patients were adults, and data were insufficient to analyze the effect of the type of ECMO.

In this meta-analysis of observational studies of patients on ECMO, an anti-Xa-based anticoagulation strategy, when compared to a time-based strategy, was associated with fewer bleeding events and mortality rate, without an increase in thrombotic events.

Outcomes and factors associated with early mortality in pediatric postcardiotomy veno-arterial extracorporeal membrane oxygenation

Mortality and morbidity of children received veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support after cardiac surgery remain high despite remarkable advances in medical management and devices. The purpose of this study was to describe outcomes and risk factors of applying VA-ECMO in the surgical pediatric population. We retrospectively analyzed 85 consecutive pediatric patients (aged <18 years) who received postcardiotomy VA-ECMO from January 2010 to December 2018. Median (IQR) age at ECMO implantation in this cohort was 12.7 (6.4, 43.2) months, median weight was 8.5 (6.0, 12.8) kg, mean ECMO duration was 143.2 ± 81.6 hours and mean hospital length of stay was 48.4 ± 32.4 days. Seventy-five patients (88.2%) were indicated for postcardiotomy cardiogenic shock. The successful ECMO weaning rate was 70.6% and in-hospital mortality was 52.9%. The most common diagnosis was transposition of great arteries (n = 18, 21.2%), while acute kidney injury occurred most often (n = 64, 75.3%). Multivariate logistic regression analysis showed that thrombocytopenia, hemolysis, and nosocomial infection were positively correlated with in-hospital mortality. Multivariate Cox proportional hazard regression analysis presented that thrombocytopenia significantly increased the 180-day mortality in patients with successful weaning. Therefore, multiple factors had adverse effects on prognosis. Patient selection and procedures from ECMO implantation to weaning need to be closely monitored and performed in a timely manner to improve outcome.

Epidemiology of Hemostatic Transfusions in Children Supported by Extracorporeal Membrane Oxygenation

OBJECTIVE

To evaluate the epidemiology of hemostatic transfusions (plasma, platelet, and cryoprecipitate) in children supported by extracorporeal membrane oxygenation.

DESIGN

Secondary analysis of a large observational cohort study.

SETTING

Eight pediatric institutions within the Eunice Kennedy Shriver National Institute of Child Health and Human Development's Collaborative Pediatric Critical Care Research Network.

PATIENTS

Critically ill children supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Extracorporeal membrane oxygenation was used in the care of 514 consecutive children. Platelets were transfused on 68% of extracorporeal membrane oxygenation days, plasma on 34% of the days on extracorporeal membrane oxygenation, and cryoprecipitate on 14%. Only 24% of the days on extracorporeal membrane oxygenation were free of any hemostatic transfusions. Daily platelet transfusion dose was independently associated with chest tube output (p < 0.001), other bleeding requiring RBC transfusion (p = 0.03), and daily set platelet goal (p = 0.009), but not with total platelet count (p = 0.75). Daily plasma transfusion dose was independently associated with chest tube output (p < 0.001), other bleeding requiring RBC transfusion (p = 0.01), activated clotting time (p = 0.001), and antithrombin levels (p = 0.02), but not with international normalized ratio (p = 0.99) or activated partial thromboplastin time (p = 0.29). Daily cryoprecipitate transfusion dose was independently associated with younger age (p = 0.009), but not with chest tube bleeding (p = 0.18), other bleeding requiring RBC transfusion (p = 0.75), fibrinogen level (p = 0.67), or daily fibrinogen goal (p = 0.81).

CONCLUSIONS

Platelets were transfused on two third of the days on extracorporeal membrane oxygenation, plasma on one third, and cryoprecipitate on one sixth of the days. Although most hemostatic transfusions were independently associated with bleeding, they were not independently associated with the majority of hemostatic testing. Further studies are warranted to evaluate the appropriateness of these transfusion strategies.

Extracorporeal Membrane Oxygenation for Group B Streptococcal Sepsis in Neonates: A Retrospective Study of the Extracorporeal Life Support Organization Registry

OBJECTIVES

Neonatal group B streptococcal sepsis remains a leading cause of neonatal sepsis globally and is characterized by unique epidemiologic features. Extracorporeal membrane oxygenation has been recommended for neonatal septic shock refractory to conventional management, but data on extracorporeal membrane oxygenation in group B streptococcal sepsis are scarce. We aimed to assess outcomes of extracorporeal membrane oxygenation in neonates with group B streptococcal sepsis.

DESIGN

Retrospective study of the international registry of the Extracorporeal Life Support Organization.

SETTING

Extracorporeal membrane oxygenation centers contributing to Extracorporeal Life Support Organization registry.

PATIENTS

Patients less than or equal to 30 days treated with extracorporeal membrane oxygenation and a diagnostic code of group B streptococcal sepsis between January 1, 2007, and December 31, 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In-hospital mortality was the primary outcome. Univariable and multivariable logistic regression models to predict mortality were established. One hundred ninety-two runs in 191 neonates were identified meeting eligibility criteria, of which 55 of 191 (29%) died. One hundred thirty-seven (71%) were treated with venoarterial extracorporeal membrane oxygenation. One hundred sixty-nine runs (88%) occurred during the first week of life for early-onset sepsis and 23 (12%) after 7 days of life. The in-hospital mortality for extracorporeal membrane oxygenation used after 7 days of life was significantly higher compared with early-onset sepsis (65% vs 24%; p < 0.01). In addition, lower weight, lower pH, lower bicarbonate, and surfactant administration precannulation were significantly associated with mortality (p < 0.05). Adjusted analyses confirmed that age greater than 7 days, lower weight, and lower pH were associated with higher mortality (p < 0.05). One hundred fifty-one of 192 runs (79%) experienced a major complication. The number of major complications during extracorporeal membrane oxygenation was associated significantly with mortality (p < 0.001; adjusted odds ratio, 1.27 [1.08-1.49; p = 0.004]).

CONCLUSIONS

This large registry-based study indicates that treatment with extracorporeal membrane oxygenation for neonatal group B streptococcal sepsis is associated with survival in the majority of patients. Future quality improvement interventions should aim to reduce the burden of major extracorporeal membrane oxygenation-associated complications which affected four out of five neonatal group B streptococcal sepsis extracorporeal membrane oxygenation patients.

Durable circulatory support with a paracorporeal device as an option for pediatric and adult heart failure patients

OBJECTIVES

Not all patients in need of durable mechanical circulatory support are suitable for a continuous-flow left ventricular assist device. We describe patient populations who were treated with the paracorporeal EXCOR, including children with small body sizes, adolescents with complex congenital heart diseases, and adults with biventricular failure.

METHODS

Information on clinical data, echocardiography, invasive hemodynamic measurements, and surgical procedures were collected retrospectively. Differences between various groups were compared.

RESULTS

Between 2008 and 2018, a total of 50 patients (21 children and 29 adults) received an EXCOR as bridge to heart transplantation or myocardial recovery. The majority of patients had heart failure compatible with Interagency Registry for Mechanically Assisted Circulatory Support profile 1. At year 5, the overall survival probability for children was 90%, and for adults 75% (P = .3). After we pooled data from children and adults, the survival probability between patients supported by a biventricular assist device was similar to those treated with a left ventricular assist device/ right ventricular assist device (94% vs 75%, respectively, P = .2). Patients with dilated cardiomyopathy had a trend toward better survival than those with other heart failure etiologies (92% vs 70%, P = .05) and a greater survival free from stroke (92% vs 64%, P = .01). Pump house exchange was performed in nine patients due to chamber thrombosis (n = 7) and partial membrane rupture (n = 2). There were 14 cases of stroke in eleven patients.

CONCLUSIONS

Despite severe illness, patient survival on EXCOR was high, and the long-term overall survival probability following heart transplantation and recovery was advantageous. Treatment safety was satisfactory, although still hampered by thromboembolism, mechanical problems, and infections.

Antithrombin use during pediatric cardiac extracorporeal membrane oxygenation admission: insights from a national database

INTRODUCTION

The frequency of extracorporeal membrane oxygenation in pediatric patients continues to increase, especially in patients with complex congenital heart disease. Providing adequate anticoagulation is necessary for patients on extracorporeal membrane oxygenation and is achieved with adequate heparin administration. Antithrombin is administered to potentiate heparin's effects. However, the efficacy of antithrombin supplementation is unclear and a clear clinical benefit has not been established. We present a large retrospective study examining the effects of antithrombin on pediatric patients receiving extracorporeal membrane oxygenation.

METHODS

Data for this study were obtained from the Pediatric Health Information System and Pediatric Health Information System+ databases from 2004 to 2015. Pediatric patients receiving extracorporeal membrane oxygenation with a congenital heart disease diagnosis were included and divided into groups that did or did not utilize antithrombin. For all admissions, the following were captured: age of admission, gender, year of admission, length of stay, billed charges, inpatient mortality, the presence of specific congenital malformations of the heart, specific cardiac surgeries, and comorbidities.

RESULTS

A total of 9,193 admissions were included and 865 (9.4%) utilized antithrombin. Between groups, there were significantly different frequencies of co-morbidities, cardiac lesion types and antithrombin usage over the study period. There were significantly lower odds in the antithrombin group of venous thrombosis. Antithrombin was not significantly associated with hemorrhage; however, antithrombin was associated with increased inpatient mortality and a decrease in length of stay and billed charges.

CONCLUSION

Antithrombin administration is associated with increased mortality, a shorter length of stay, and decreased billing cost. Recently, antithrombin usage has been decreasing-potentially due to the reported lack of clinical benefit. Together, these results reinforce that antithrombin may not be indicated for all pediatric extracorporeal membrane oxygenation patients.

Neurological Monitoring and Complications of Pediatric Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation is extracorporeal life support for life-threatening cardiopulmonary failure. Since its introduction, the use of extracorporeal membrane oxygenation has expanded to patients with more complex comorbidities without change in patient mortality rates. Although many patients survive, significant neurological complications like seizures, ischemic strokes, and intracranial hemorrhage can occur during extracorporeal membrane oxygenation care. The risks of these complications often add to the complexity of decision-making surrounding extracorporeal membrane oxygenation support. In this review, we discuss the pathophysiology and incidence of neurological complications in children supported on extracorporeal membrane oxygenation, factors influencing the incidence of these complications, commonly used neurological monitoring modalities, and outcomes for this complex patient population. We discuss the current literature on the use of electroencephalography for both seizure detection and monitoring of background electroencephalographic changes, in addition to the use of less commonly used imaging modalities like transcranial Doppler. We summarize the knowledge gaps and the lack of clinical consensus guidelines for managing these potentially life-changing neurological complications. Finally, we discuss future work to further understand the pathophysiology of extracorporeal membrane oxygenation-related neurological complications.

Hospital-Associated Venous Thromboembolism in a Pediatric Cardiac ICU: A Multivariable Predictive Algorithm to Identify Children at High Risk

OBJECTIVES

Critically ill children with cardiac disease are at significant risk for hospital-associated venous thromboembolism, which is associated with increased morbidity, hospital length of stay, and cost. Currently, there are no widely accepted guidelines for prevention of hospital-associated venous thromboembolism in pediatrics. We aimed to develop a predictive algorithm for identifying critically ill children with cardiac disease who are at increased risk for hospital-associated venous thromboembolism as a first step to reducing hospital-associated venous thromboembolism in this population.

DESIGN

This is a prospective observational single-center study.

SETTING

Tertiary care referral children's hospital cardiac ICU.

PATIENTS

Children less than or equal to18 years old admitted to the cardiac ICU who developed a hospital-associated venous thromboembolism from December 2013 to June 2017 were included. Odds ratios and 95% CIs are reported for multivariable predictors.

MEASUREMENTS AND MAIN RESULTS

A total of 2,204 separate cardiac ICU encounters were evaluated with 56 hospital-associated venous thromboembolisms identified in 52 unique patients, yielding an overall prevalence of 25 hospital-associated venous thromboembolism per 1,000 cardiac ICU encounters. We were able to create a predictive algorithm with good internal validity that performs well at predicting hospital-associated venous thromboembolism. The presence of a central venous catheter (odds ratio, 4.76; 95% CI, 2.0-11.1), sepsis (odds ratio, 3.5; 95% CI, 1.5-8.0), single ventricle disease (odds ratio, 2.2; 95% CI, 1.2-3.9), and extracorporeal membrane oxygenation support (odds ratio, 2.7; 95% CI, 1.2-5.7) were independent risk factors for hospital-associated venous thromboembolism. Encounters with hospital-associated venous thromboembolism were associated with a higher rate of stroke (17% vs 1.2%; p < 0.001).

CONCLUSIONS

We developed a multivariable predictive algorithm to help identify children who may be at high risk of hospital-associated venous thromboembolism in the pediatric cardiac ICU.