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

Bleeding Definitions in Pediatric Extracorporeal Membrane Oxygenation (ECMO) Studies: A Systematic Review and Meta-Analysis

Extracorporeal membrane oxygenation (ECMO) supports severe cardiorespiratory failure but carries a significant bleeding risk. This systematic review aims to report bleeding definitions in studies involving neonates and children treated with ECMO and to determine how heterogeneity in bleeding definition affects bleeding prevalence. We conducted a meta-analysis including all studies from database inception until April 26, 2024. We evaluated the description of bleeding definitions and the reported prevalence of bleeding on ECMO. Of 6,482 screened studies, 169 were included (n = 154,046 subjects). There were 69 distinct bleeding definitions; intracranial hemorrhage (n = 42 studies) and the Extracorporeal Life Support Organization (ELSO) definition (n = 35 studies) were the most common bleeding definitions. The need for intervention, including transfusions, was included in bleeding definitions in 57% of the studies. The overall pooled prevalence of bleeding was 33%. Excluding studies that reported solely intracranial bleeding, the pooled prevalence of bleeding was 41% in studies using the ELSO definition and 39% in studies using other definitions, with high heterogeneity. Variations in bleeding definitions may account for the variability in the reported prevalence of bleeding in children on ECMO. Furthermore, variability in clinical practices regarding interventions to control bleeding may affect estimates of the prevalence of bleeding.

Analysis of platelet transfusion efficacy during extracorporeal membrane oxygenation (ECMO) treatment in pediatric patients post-cardiac surgery-a retrospective cohort study

BACKGROUND

Postoperative extracorporeal membrane oxygenation (ECMO) may be necessary for pediatric patients following cardiac surgery, with associated risks of thrombocytopenia and bleeding. Prophylactic platelet transfusions are utilized to mitigate these risks, but the effectiveness of platelet transfusion cannot be reliably predicted. The aim of this study was to investigate the effect of platelet transfusion during postoperative treatment with ECMO in children undergoing cardiac surgery and to explore the optimal transfusion thresholds to reduce the number of platelet transfusions in patients and reduce the risk of death.

METHODS

We included in our study patients from the Pediatric Cardiac Surgery Department at the First Affiliated Hospital of Tsinghua University who underwent cardiac surgery and received ECMO treatment from January 1, 2019, to December 31, 2023, and received platelets transfusion at least once during the ECMO therapy. The platelet counts were determined both before and 24 hours posttransfusion of the platelet product. The corrected count increment (CCI) was calculated for the effectiveness estimation of platelet transfusion. The research subjects were divided into 3 groups based on the platelet count before transfusion (pretransfusion platelet count ≤30×109/L was the low-threshold group, pretransfusion count 31-50×109/L was the medium-threshold group, and ≥51×109/L was the high-threshold group) and the effective rates of each group were calculated.

RESULTS

A total of 11 patients received 47 platelet transfusions, an average of 4.27 ± 1.67 per patient. According to the 24-hour postinfusion platelet (Plt) corrected critical control increase index (24-hour CCI) ≥4500, the infusion was considered to be effective, and ineffective when the CCI was <4500. Out of these, 22 transfusions (46.8%) proved effective, whereas 25 (53.2%) were deemed ineffective. The effective transfusion rates across the 3 groups were 69.2%, 50%, and 27.7%, respectively.

CONCLUSION

The efficacy of platelet transfusion may be higher if a low threshold of platelet transfusion is chosen during ECMO treatment, on the premise of ensuring life safety.

Heparin Versus Bivalirudin in Pediatric Patients Assisted With Mechanical Circulatory Support: A Retrospective Before-and-after Study

OBJECTIVES

Children assisted with mechanical circulatory support experience bleeding and thrombotic complications that may depend upon anticoagulation strategies. The primary aim of this study was to compare the incidence of thrombotic events in pediatric heart failure patients assisted with mechanical circulatory support with the use of bivalirudin versus heparin anticoagulation. A secondary aim was to compare the percentage of out-of-range partial thromboplastin time values between these anticoagulants.

DESIGN

Retrospective cohort study.

SETTING

Tertiary pediatric cardiac intensive care unit.

PARTICIPANTS

Pediatric patients undergoing mechanical circulatory support for cardiac failure.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 36 pediatric patients on mechanical support treated with either heparin (n.18) or bivalirudin (n.18) during the first 30 days of intensive care unit admission were compared. Bivalirudin group data were retrieved from February 2018 to August 2020 while data on the heparin group were extrapolated from 2015 to 2017. A comparison of anticoagulation was conducted specifically in EXCOR Berlin Heart and extracorporeal membrane oxygenation patients. Berlin Heart patients showed 1 (12.5%) versus 8 (80%) thrombotic episodes in the bivalirudin and heparin groups, respectively (p = 0.005), 0 and 3 (30%) cerebrovascular events, and 0 versus 3 (30%) death episodes, respectively (p = 0.054). In extracorporeal membrane oxygenation patients, the bivalirudin and heparin groups showed 0 versus 1 (8.3%) patient with a thrombosis episode (p = 0.40), 0 and 0 cerebrovascular events, and 5 (50%) versus 3 (25%) death episodes, respectively (p = 0.169). The number of out-of-range partial thromboplastin time values was higher in the heparin group both in Berlin Heart and extracorporeal membrane oxygenation patients (p < 0.0001).

CONCLUSIONS

In a cohort of children with heart failure, bivalirudin use was associated with a reduction in thrombotic events in Berlin Heart patients compared with heparin over a period of 30 days.

Electroencephalographic Findings Add Prognostic Value to Clinical Features Associated with Mortality on Venoarterial Extracorporeal Support

BACKGROUND

The objective of this study was to identify clinical and continuous electroencephalogram (cEEG) variables associated with outcomes of pediatric venoarterial (V-A) extracorporeal membrane oxygenation support (ECMO).

METHODS

We conducted a retrospective single-center study of pediatric patients on V-A ECMO between January 1, 2015, and September 30, 2020. Serial clinical and cEEG variables were collected to assess the relationship of pre- and on-ECMO variables with hospital mortality in patients who underwent cEEG monitoring.

RESULTS

Ninety-four patients undergoing V-A ECMO had cEEG monitoring, with a hospital mortality of 43%. Nonsurvivors had significantly lower pH and higher lactate levels prior to ECMO initiation. Nineteen (20%) had seizures, with 7 (7%) developing status epilepticus. In the first 24 h patients were on ECMO, unfavorable background score and lack of cEEG variability or reactivity were associated with mortality. A multivariable model investigating in-hospital mortality that included pH and lactate level 2 h prior to ECMO initiation, presence of electrographic seizures, and asymmetry on cEEG as variables, had an area under the receiver operating characteristic curve (AUROC) of 0.8 (95% confidence interval [CI] 0.74-0.86, p < 0.02). The model for on-ECMO mortality (ECMO nonsurvivors) that included pH 2 h prior to ECMO initiation, presence of electrographic seizures, and lack of variability/reactivity at any point on cEEG as variables had an AUROC of 0.85 (95% CI 0.8-0.9, p < 0.001).

CONCLUSIONS

These data demonstrate an association of evolving pre-ECMO impaired tissue oxygenation and on-ECMO neurophysiologic impairment, measured by cEEG, with mortality. They provide preliminary evidence that the timing of ECMO initiation, in relation to worsening tissue oxygenation, should be investigated further, and cEEG may be used to evaluate the potential impact on both neurologic injury and mortality.

[Explanation and interpretation of blood transfusion provisions for critically ill and severely bleeding pediatric patients in the national health standard "Guideline for pediatric transfusion"]

To guide clinical blood transfusion practices for pediatric patients, the National Health Commission has issued the health standard "Guideline for pediatric transfusion" (WS/T 795-2022). Critically ill children often present with anemia and have a higher demand for transfusions compared to other pediatric patients. This guideline provides guidance and recommendations for blood transfusions in cases of general critical illness, septic shock, acute brain injury, extracorporeal membrane oxygenation, non-life-threatening bleeding, and hemorrhagic shock. This article interprets the background and evidence of the blood transfusion provisions for critically ill and severely bleeding children in the "Guideline for pediatric transfusion", aiming to enhance understanding and implementation of this aspect of the guidelines. Citation:Chinese Journal of Contemporary Pediatrics, 2025, 27(4): 395-403.

Clinical outcomes in critically ill children on extracorporeal membrane oxygenation with severe thrombocytopenia

IntroductionAs international guidelines suggest keeping the platelet count between 50 and 100 × 109 cells/L in children on extracorporeal membrane oxygenation (ECMO), platelet transfusions are administered to two-thirds of ECMO days, and up to 70% of these patients still bleed. We aim to describe outcomes in critically ill children who develop severe thrombocytopenia on ECMO.MethodsSingle-center retrospective study, enrolling critically ill children on ECMO admitted at Children's Memorial Hermann, TX, between 1/2018 and 12/2022, with at least one platelet count below 50 × 109 cells/L (severe thrombocytopenia). Platelet counts were measured four times a day. We report platelet transfusion, bleeding, hemolysis, and clotting events within 6 h after transfusion, as well as ECMO duration and mortality.ResultsWe enrolled 54 patients representing 337 ECMO days and 1190 platelet counts. Median weight was 3.7 kg and 54% were male. Severe thrombocytopenia was observed in 56% of platelet counts. Severe thrombocytopenia was not associated with bleeding in the subsequent 6 h (18% vs 20%, p = .95), but was associated with more frequent platelet transfusions (18% vs 11%, p = .001). There was no correlation between time spent with severe thrombocytopenia and the duration of ECMO (R2 = 0.03). While the time spent with severe thrombocytopenia was not associated with on-ECMO mortality rate (p = .36), there was an association with in-hospital mortality rate (p = .003).ConclusionsOur results indicate a restrictive platelet transfusion strategy is not associated with higher proportions of subsequent bleeding, duration of ECMO, or on-ECMO mortality rate. Multicenter studies are needed to evaluate further the appropriateness of this strategy.

Comparison of red blood cell transfusions and hemostatic transfusions and their relation to thromboses in pediatric patients receiving extracorporeal membrane oxygenation therapy

ObjectiveTo evaluate the association of RBC transfusions with thrombosis in pediatric patients on extracorporeal membrane oxygenation (ECMO) and compare this with the transfusion of other blood products and their association with thrombosis.MethodsThis was a secondary analysis of the Bleeding and Thrombosis during ECMO (BATE) study, which was a multicenter prospective observational study involving patients less than 19 years of age treated with ECMO.Results514 patients were analyzed, of which 282 (55%) were neonates (≤31 days) and 302 (58.7%) were male. When analyzing the entire cohort independently of other blood products, each 10 mL/kg of packed red blood cells (PRBCs) was associated with a 1.0% increase in the average number of thromboses (1.010; 1.008,1.013; p < .001). In neonates, each 10 mL/kg of PRBC was associated with a 0.9% increase in the average number of thromboses (1.009; 1.003,1.013; p < .001). In pediatric patients, each 10 mL/kg of PRBC was associated with a 1.2% increase in the average number of thromboses (1.012; 1.008,1.012; p < .001). The percent increase in the average number of thromboses was similar between PRBCs, platelets, and FFP, but increased significantly with cryoprecipitate.ConclusionsRBC transfusions and hemostatic transfusions are likely associated with thromboses in pediatric patients on ECMO.

Infectious diseases and infection control prevention strategies in adult and pediatric population on ECMO

As survival after ECMO improves and use of ECMO support increases in both pediatric and adult population, there is a need to focus on both the morbidities and complications associated with ECMO and how to manage and prevent them. Infectious complications during ECMO often have a significant clinical impact, resulting in increased morbidity or mortality irrespective of the underlying etiology necessitating cardiorespiratory support. In this review article, we discuss the prevention, management, challenges, and differences of infectious complications in adult and pediatric patients receiving ECMO support.

Platelet transfusion stated practices among neonatal and paediatric veno-arterial extracorporeal membrane oxygenation providers: A survey

BACKGROUND AND OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) provides cardiopulmonary support to over 4000 neonates and children annually worldwide. Although potentially lifesaving, ECMO carries bleeding and thromboembolic risks, often managed with platelet transfusions to maintain specific thresholds. Platelet transfusions themselves carry many risks. This survey aimed to describe stated prophylactic platelet transfusion practices among paediatric veno-arterial (VA)-ECMO providers and identify factors influencing transfusion decisions.

MATERIALS AND METHODS

This is a cross-sectional electronic survey of paediatric ECMO providers from 10 centres evaluating platelet transfusion thresholds based on six patient scenarios (non-bleeding, minimally bleeding and resolved bleeding in neonates and children). Descriptive statistics were used for analysis.

RESULTS

The survey response rate was 56% (114 of 204). Paediatric intensivists comprised 66% of respondents. The median pre-transfusion platelet count varied across VA-ECMO scenarios, with a threshold of 50 × 109/L (interquartile range [IQR] 45-75) for non-bleeding children and 70 × 109/L (IQR 50-85) for non-bleeding neonates. The threshold for minimally bleeding children, minimally bleeding neonates and resolved bleeding in children was 75 × 109/L (IQR 50-100). The threshold for resolved bleeding in neonates was 80 × 109/L (IQR 50-100). There was significant heterogeneity between and within sites (p < 0.001). Uncertainty about the level of evidence was high (59%), with clinical judgement being the most influential factor in transfusion decisions (85%).

CONCLUSION

Prophylactic platelet transfusion practices in paediatric ECMO vary widely, highlighting uncertainty and the need for clinical trials to improve patient outcomes.

ECMO Support in Pediatric Populations with the Newborn ECMOLife Centrifugal Pump

Background and Objectives: Pediatric ECMO is a valid support mechanism for refractory cardiac and/or respiratory failure. Magnetic levitation technology applied to the centrifugal pump has reduced the hemolysis caused by this procedure, which can be particularly dangerous, especially in neonates and small children. ECMOLife, a new magnetic levitation centrifugal pump, has been introduced for these patients. Materials and Methods: Four patients were supported with the ECMOLife System in a newborn setting, with veno-venous application in two cases and veno-arterial in the other two. All parameters related to pump functioning, anticoagulation, hemolysis, and inflammation were recorded for the duration of the support. Results: All patients survived the procedure, in three cases achieving recovery, while one veno-arterial ECMO was switched to VAD, and then the patient underwent heart transplantation. All recorded parameters were compatible with clinical conditions. In particular, free haemoglobin was close to 0 g/L in all recorded samples. The possibility of monitoring pump functioning parameters, venous and arterial O2 saturation, and venous and arterial pressures creates an opportunity to check the adequacy of mechanical support for the clinical condition of the patient. Conclusions: This is the first reported experiment in a newborn setting with ECMOLife mechanical support. At present, ECMOLife represents the only system with a newborn and pediatric pump, allowing for the continuous monitoring of perfusion and hemodynamic parameters, with a large number of facilities for transportation available.

Lethal Myocardial Infarction in a Neonate During Extracorporeal Membrane Oxygenation

•CDH may increase risk for a prothrombotic state. •Neonatal MI is rare and serious with limited treatment options. •TNE can assess cardiac function during ECMO. •TNE can assess ECMO cannula for thrombus.

Prospective Randomized Pilot Study Comparing Bivalirudin Versus Heparin in Neonatal and Pediatric Extracorporeal Membrane Oxygenation

OBJECTIVES

To test feasibility of a randomized controlled trial (RCT) with an endpoint of time at goal anticoagulation in children on extracorporeal membrane oxygenation (ECMO) randomized to receive bivalirudin vs. unfractionated heparin.

DESIGN

Open-label pilot RCT (NCT03318393) carried out 2018-2021.

SETTING

Single-center quaternary U.S. pediatric hospital.

PATIENTS

Children 0 days to younger than 18 years old supported with ECMO in the PICU or cardiovascular ICU.

INTERVENTIONS

Randomization to bivalirudin vs. unfractionated heparin while on ECMO.

MEASUREMENTS AND MAIN RESULTS

Sixteen patients were randomized to bivalirudin, and 14 patients were randomized to heparin. There was no difference in the primary outcome, time spent at goal anticoagulation, for patients randomized to bivalirudin compared with those randomized to heparin. While hemorrhagic complications were similar between study groups, thrombotic complications were higher with six of 16 patients in the bivalirudin group having one or more circuit changes compared with 0 of 14 patients in heparin group (mean difference, 37.5% [95% CI, 8.7-61.4%]; p = 0.02). Patients in the bivalirudin group received less packed RBC transfusions vs. those receiving heparin (median [interquartile range], 6.3 mL/kg/d [2.5-8.4 mL/kg/d] vs. 12.2 mL/kg/d [5.5-14.5 mL/kg/d]; p = 0.02).

CONCLUSIONS

In this single-center pilot RCT carried out 2018-2021, we found that the test of anticoagulation therapy of bivalirudin vs. heparin during ECMO was feasible. Larger multicenter studies are required to further assess the safety and efficacy of bivalirudin for pediatric ECMO.

Disruption of the Circulating Proteome in Neonates Receiving Extracorporeal Membrane Oxygenation Following Congenital Heart Disease Surgery: A Nested Case-Control Study

This nested case-control study identified broad dysregulation of the circulating proteome in neonates receiving postoperative extracorporeal membrane oxygenation support after congenital heart disease surgery, including differential responses in those not surviving to hospital discharge. Tissue hypoxia and mitochondrial-associated proteins may represent novel candidate biomarkers for poor extracorporeal membrane oxygenation outcomes.

The use of protective mechanical ventilation during extracorporeal membrane oxygenation for the treatment of acute respiratory failure

Acute respiratory failure (ARF) strikes an estimated two million people in the United States each year, with care exceeding US$50 billion. The hallmark of ARF is a heterogeneous injury, with normal tissue intermingled with a large volume of low compliance and collapsed tissue. Mechanical ventilation is necessary to oxygenate and ventilate patients with ARF, but if set inappropriately, it can cause an unintended ventilator-induced lung injury (VILI). The mechanism of VILI is believed to be overdistension of the remaining normal tissue known as the 'baby' lung, causing volutrauma, repetitive collapse and reopening of lung tissue with each breath, causing atelectrauma, and inflammation secondary to this mechanical damage, causing biotrauma. To avoid VILI, extracorporeal membrane oxygenation (ECMO) can temporally replace the pulmonary function of gas exchange without requiring high tidal volumes (VT) or airway pressures. In theory, the lower VT and airway pressure will minimize all three VILI mechanisms, allowing the lung to 'rest' and heal in the collapsed state. The optimal method of mechanical ventilation for the patient on ECMO is unknown. The ARDSNetwork Acute Respiratory Management Approach (ARMA) is a Rest Lung Approach (RLA) that attempts to reduce the excessive stress and strain on the remaining normal lung tissue and buys time for the lung to heal in the collapsed state. Theoretically, excessive tissue stress and strain can also be avoided if the lung is fully open, as long as the alveolar re-collapse is prevented during expiration, an approach known as the Open Lung Approach (OLA). A third lung-protective strategy is the Stabilize Lung Approach (SLA), in which the lung is initially stabilized and gradually reopened over time. This review will analyze the physiologic efficacy and pathophysiologic potential of the above lung-protective approaches.

Concordance and discordance of anticoagulation assays in children supported by ECMO: The truth is out there

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) provides critical support to patients in severe cardiac and respiratory failure, but it requires anticoagulation to prevent complications like bleeding and thrombosis. Heparin, the primary anticoagulant utilized, is monitored by activated partial thromboplastin time (aPTT) and anti-Factor Xa (AntiXa) levels. Discordance between the two assays complicates its titration and the impact on patient outcomes is not well-established. This study examines the prevalence of discordance, its impact on heparin dosing, and the association of bleeding, thrombosis, ICU-free days, and mortality in pediatric ECMO patients.

METHODS

This secondary analysis of the Bleeding and Thrombosis on Extracorporeal Membrane Oxygenation study consisted of 511 patients under 19 years. Demographics, laboratory results, ECMO indications, daily heparin doses, and clinical outcomes were collected. Discordance was categorized as major or minor, and adjustments to heparin dosing were analyzed for appropriateness based on normal ranges of aPTT and AntiXa. Logistic regression models assessed the impact of heparin titration strategies on bleeding, clotting, ICU-free days, and mortality.

RESULTS

Major discordance occurred on 17.5% of days with high aPTT and low AntiXa being most common. Titrating heparin based on AntiXa in scenarios of discordance was associated with an 11% lower incidence of bleeding compared to aPTT (p = .02). Higher proportion of concordance was independently associated with increased bleeding and/or clotting, but not significantly affect ICU-free days or mortality.

CONCLUSION

Discordance is common in pediatric ECMO patients. AntiXa-guided heparin titration, notably during discordant periods, is associated with fewer bleeding and clotting events. This emphasizes the need for improved anticoagulation protocols since discordance does not demonstrate worse ICU-free days or mortality.

Red Cell Damage During Extracorporeal Life Support

Sublethal damage to red blood cells (RBCs) during extracorporeal life support (ECLS) may lead to RBC loss. Using flow cytometry, phosphatidylserine-positive (PhS+) RBCs and RBC extracellular vesicles were quantified as measures of sublethal RBC injury in 41 pediatric ECLS runs, stored RBC units, and normal adult subjects. We estimated the clearance half-life of PhS+ RBCs and compared the rates of RBC loss during pediatric ECLS due to phlebotomy, intravascular hemolysis, and extravascular clearance of PhS+ RBCs. Extracorporeal life support patients had 0.9% PhS+ RBCs, sixfold higher than normal subjects ( p < 0.0001). Phosphatidylserine-positive RBCs were increased in stored RBC units (twofold in whole blood derived units, p = 0.0013; 12-fold in apheresis RBC units, p < 0.0001). Phosphatidylserine-positive RBCs were cleared with an average half-life of 15 hours. During ECLS, PhS+ RBC clearance accounted for 7% of RBC loss (1-60%), phlebotomy 12%, and intravascular hemolysis 12%. Increasing PhS+ RBCs occurred in 40% of patients that died on ECLS. Red blood cell extracellular vesicles, another marker of red cell injury/activation, were elevated fivefold during ECLS. Phosphatidylserine exposure on RBCs is increased during ECLS, marking these cells for extravascular clearance with a half-life of ~15 hours and accounting for ~7% of RBC loss.

Extracorporeal Membrane Oxygenation as Life Support in Neonatal Respiratory Failure: A Single-Center Cohort Study and a Systematic Review

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a life support in newborns with severe respiratory failure. Our main objective was to evaluate the mortality of patients and define positive and negative predictive factors of survival.

METHODS

We performed a Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)-conformed retrospective observational study and a systematic review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Our data were analyzed using R (v.4.2.1). We performed survival analysis, correlation analysis, and Fisher's exact test. The first endpoint was the mortality rate. The second endpoint was to evaluate all factors associated with survival. The third endpoint was focused on complications of ECMO.

RESULTS

Our study included 8 patients treated in our centers and 45 patients from the literature review. Survival was 79%. Positive predictive factors of survival were a length of ECMO of less than 10 days and male neonates, while prematurity and the presence of 2 complications were negative predictive factors.

CONCLUSIONS

ECMO functions as life support, although mortality and morbidity risks are high.

Managing medically refractory elevated intracranial pressure in a pediatric patient on ECMO: illustrative case

PURPOSE

We demonstrate the complexities of managing pediatric patients on extracorporeal membrane oxygenation (ECMO) therapy requiring neurosurgery, focusing on systemic anticoagulation, cardiac function, and medically refractory intracranial pressure (ICP).

METHODS

A 3.5-year-old female with Tetralogy of Fallot developed severe ischemic cerebral edema following post-operative cardiac arrest and required ECMO. This case, along with four additional cases of children requiring neurosurgery while on ECMO, was examined.

RESULTS

Emergency neurosurgical intervention in the primary case led to significant improvement, highlighting the delicate balance between managing ECMO-induced anticoagulation and urgent neurosurgical needs. The additional cases had variable outcomes, emphasizing the challenges of caring for these critically ill patients.

CONCLUSION

Successful management of children requiring ECMO support and neurosurgical intervention requires thoughtful multidisciplinary care. This report illustrates some of the nuances in such decision-making, and demonstrates one potential path to a good outcome.

Is there a role for extracorporeal membrane oxygenation in children with acute liver failure? A retrospective analysis of the Extracorporeal Life Support Organization Registry

Data describing the use of extracorporeal membrane oxygenation (ECMO) in pediatric acute liver failure (PALF) are scarce. Thus, we aimed to describe the use of ECMO in patients with PALF using the data from the Extracorporeal Life Support Organization (ELSO) Registry between January 1, 2010, to December 31, 2022. We described patients' characteristics at ECMO initiation, outcome, and factors associated with mortality. A total of 335 children underwent ECMO support in the context of PALF. Veno-arterial (VA) ECMO was the most prevalent mode (66.6%), followed by veno-venous (VV) ECMO (33.4%). Extracorporeal cardiopulmonary resuscitation (ECPR) was used in 21.5% of the cardiac arrest. In-hospital mortality was 66.6%. Both higher lactate (OR 1.128, CI 1.06-1.209, p < 0.001) and PaCO2 (OR 1.022, CI 1.001-1.047, p 0.05) levels before ECMO reported greater odds of mortality. Low body weight, persistence of hyperlactatemia (OR 0.985, CI 0.973-0.997, p 0.013), and hyperbilirubinemia (OR 2.477, CI 1.042-6.100, p 0.045) after 24 h from ECMO deployment were associated to greater odds of mortality.

CONCLUSIONS

Our results suggest that the use of ECMO for the management of respiratory and cardiac failure in patients with PALF should be considered with caution and that further research is needed to understand its role in this specific high-risk population.

WHAT IS KNOWN

• Pediatric acute liver failure (PALF) is a clinical syndrome associated with significant morbidity and mortality. • Data on the use of extracorporeal membrane oxygenation (ECMO) in the context of PALF are scarce and controversial.

WHAT IS NEW

• ECMO to manage acute respiratory and/or cardiac failure in the context of PALF should be considered with caution. • Bleeding and thrombotic complications in children with acute liver failure receiving ECMO are similar to the ones reported in the general pediatric population.

Identification of Early Risk Factors for Mortality in Pediatric Veno-Arterial Extra Corporeal Membrane Oxygenation: The Patient Matters

Objective

Pediatric Veno-Arterial Extra Corporeal Membrane Oxygenation (VA ECMO) is a life saving technology associated with high mortality. A successful VA ECMO course requires attention to multiple aspects of patient care, including ECMO and patient parameters. Early, potentially modifiable, risk factors associated with patient mortality should be analyzed and adjusted for when assessing VA ECMO risk profiles.

Method

Retrospective single center experience of pediatric patients requiring VA ECMO from January 2021 to October 2023. Laboratory and ECMO flow parameters were extracted from the patients record and analyzed. Risk factors were analyzed using a Cox proportion hazard regression.

Main Results

There were 45 patients studied. Overall survival was 51%. Upon uncorrected analysis there were no significant differences between the patients who survived and those who died. Utilizing a Cox proportion hazard regression, platelet count, fibrinogen level and creatine level were significant risk factors within the first twenty-four hours of a patient's ECMO course.

Significance

Although we did not find a significant difference among ECMO flow parameters in this study, this work highlights that granular ECMO flow data can be incorporated to risk analysis profiles and potential modeling in pediatric VA ECMO. This study demonstrated, that when controlling for ECMO flow parameters, kidney dysfunction and clotting regulation remain key risk factors for pediatric VA ECMO mortality.

Short-term neurologic outcomes in pediatric extracorporeal membrane oxygenation are proportional to bleeding severity graded by a novel bleeding scale

INTRODUCTION

This study aimed to characterize the severity of bleeding and its association with short-term neurologic outcomes in pediatric ECMO.

METHODS

Multicenter retrospective cohort study of pediatric ECMO patients at 10 centers utilizing the Pediatric ECMO Outcomes Registry (PEDECOR) database from December 2013-February 2019. Subjects excluded were post-cardiac surgery patients and those with neonatal pathologies. A novel ECMO bleeding scale was utilized to categorize daily bleeding events. Poor short-term neurologic outcome was defined as an unfavorable Pediatric Cerebral Performance Category (PCPC) or Pediatric Overall Performance Category (POPC) (score of >3) at hospital discharge.

RESULTS

This study included 283 pediatric ECMO patients with a median (interquartile range [IQR]) age of 1.3 years [0.1, 9.0], ECMO duration of 5 days [3.0, 9.5], and 44.1% mortality. Unfavorable PCPC and POPC were observed in 48.4% and 51.3% of patients at discharge, respectively. Multivariable logistic regression analysis included patient's age, cannulation type, duration of ECMO, need for cardiopulmonary resuscitation, acute kidney injury, new infection, and vasoactive-inotropic score. As the severity of bleeding increased, there was a corresponding increase in the likelihood of poor neurologic recovery, shown by increasing odds of unfavorable neurologic outcome (PCPC), with an adjusted odds ratio (aOR) of 0.77 (confidence interval [CI] 0.36-1.62), 1.87 (0.54-6.45), 2.97 (1.32-6.69), and 5.56 (0.59-52.25) for increasing bleeding severity (grade 1 to 4 events, respectively). Similarly, unfavorable POPC aOR (CI) was 1.02 (0.48-2.17), 2.05 (0.63-6.70), 5.29 (2.12-13.23), and 5.11 (0.66-39.64) for bleeding grade 1 to 4 events.

CONCLUSION

Short-term neurologic outcomes in pediatric ECMO are proportional to the severity of bleeding events. Strategies to mitigate bleeding events could improve neurologic recovery in pediatric ECMO.

Definitions of adverse events associated with extracorporeal membrane oxygenation in children: results of an international Delphi process from the ECMO-CENTRAL ARC

Extracorporeal membrane oxygenation (ECMO) is a high-risk and low-volume life support with increasing clinical study. However, heterogenous outcome definitions impede data assimilation into evidence to guide practice. The Academic Research Consortium (ARC), an international collaborative forum committed to facilitating the creation of stakeholder-driven consensus nomenclature and outcomes for clinical trials of medical devices, supported the ECMO Core Elements Needed for Trials Regulation And quality of Life (ECMO-CENTRAL) ARC. The ECMO-CENTRAL ARC was assembled to develop definitions of paediatric ECMO adverse events for use in clinical trials and regulatory device evaluation. An initial candidate list of ECMO adverse events derived from the mechanical circulatory support ARC was supplemented with a review of ECMO-relevant adverse event definitions collated from literature published between Jan 1, 1988, and Feb 20, 2023. Distinct teams of international topic experts drafted separate adverse event definitions that were harmonised to existing literature when appropriate. Draft definitions were revised for paediatric ECMO relevance with input from patients, families, and an international expert panel of trialists, clinicians, statisticians, biomedical engineers, device developers, and regulatory agencies. ECMO-CENTRAL ARC was revised and disseminated across research societies and professional organisations. Up to three rounds of internet-based anonymous surveys were planned as a modified Delphi process. The expert panel defined 13 adverse event definitions: neurological, bleeding, device malfunction, acute kidney injury, haemolysis, infection, vascular access-associated injury, non-CNS thrombosis, hepatic dysfunction, right heart failure, left ventricular overload, lactic acidaemia, and hypoxaemia. Definitional structure varied. Among 165 expert panel members, 114 were eligible to vote and 111 voted. Consensus was achieved for all proposed definitions. Agreement ranged from 82% to 95%. ECMO-CENTRAL ARC paired rigorous development with methodical stakeholder involvement and dissemination to define paediatric ECMO adverse events. These definitions will facilitate new research and the assimilation of data across clinical trials and ECMO device evaluation in children.

Circuit change in neonatal and pediatric extracorporeal membrane oxygenation is associated with adverse outcomes

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) circuits may be changed during the run for multiple reasons; however, these circuit changes may be associated with adverse events. Predictors for undergoing a circuit change (CC) and their outcomes remain unclear. We hypothesized that neonatal and pediatric CC correlates with increased morbidity and mortality.

METHODS

Pediatric and neonatal patients who underwent one ECMO run lasting <30 days at a tertiary children's hospital from 2011 through 2017 were retrospectively reviewed. Bivariate regression analysis evaluated factors associated with ECMO mortality and morbidity. LASSO logistic regression models identified independent risk factors for undergoing a CC. p < .05 was significant.

RESULTS

One hundred 85 patients were included; 137 (74%) underwent no CC, while 48 (26%) underwent one or more. Undergoing a CC was associated with longer ECMO duration (p < .001), higher blood transfusion volumes (p < .001), increased hemorrhagic complications (p < .001) and increased mortality (p = .002). Increased platelet (p = .001) and FFP (p = .016) transfusion volumes at any time while on ECMO were independent factors associated with undergoing a CC.

CONCLUSIONS

Changing the circuit during the ECMO run occurs frequently and may be associated with poorer outcomes. Understanding the outcomes and predictors for CC may guide management protocols for more efficient circuit changes given its important association with overall outcomes.

Safety and feasibility of conversion from venoarterial to venovenous extracorporeal membrane oxygenation in pediatric patients: A case series

INTRODUCTION

In children requiring venoarterial (VA) extracorporeal membrane oxygenation (ECMO) for long durations, conversion to venovenous (VV) support may be advantageous. The purpose of this study was to evaluate the feasibility and safety of conversion from VA to VV ECMO.

METHODS

This is a retrospective review of all children who underwent conversion from VA to VV ECMO at a single institution, from 2015 to 2022. Indications for and methods of conversion were examined as well as adverse events including re-operation, ischemic complications, renal failure, and mortality.

RESULTS

Of 422 pediatric patients on initial VA ECMO, 4 children (0.9%) underwent conversion from VA to VV support. The indications for cannulation were: respiratory failure due to COVID19, respiratory failure due to congenital diaphragmatic hernia, cardiac dysfunction following heart transplant, and sepsis with associated left ventricular dysfunction. The indications for conversion were bleeding from the arterial cannula and ongoing respiratory failure. The median time to conversion was 6.5 days (range 4-54 days) and the median length of ECMO run was 34.5 days. Three patients required renal replacement therapy with two progressing to long-term dialysis. There were no ischemic limb complications although one patient developed a femoral artery pseudoaneurysm that required re-operation. Three patients survived to discharge. One patient was unable to be decannulated after conversion and mechanical support was withdrawn.

CONCLUSIONS

Conversion to VV ECMO from initial VA ECMO cannulation is feasible but a rare event. For patients with cardiac stability but continued need for respiratory support, conversion to VV ECMO can be considered.

Anti-Xa testing for pediatric and neonatal patients on extracorporeal membrane oxygenation

INTRODUCTION

To determine if anti-Xa testing is associated with improved outcomes for patients <19-years-old on ECMO.

METHODS

We evaluated the clinical benefit of anti-Xa heparin monitoring utilizing the Bleeding and Thrombosis during ECMO (BATE) database of 514 patients <19-years-old. The BATE database includes incidences of bleeding, thrombosis, and mortality. The database also describes anti-coagulation test utilization. We grouped and analyzed patients based on ECMO indication (cardiac, respiratory, or extracorporeal cardiopulmonary resuscitation [E-CPR]) and age (neonatal vs pediatric). We constructed multivariable logistic regression models to analyze the impact of anti-Xa testing on mortality, bleeding, and thrombosis in each group.

RESULTS

Across the entire population, anti-Xa testing did not have a significant effect on the incidence of mortality (43% with anti-Xa testing vs 49% without), bleeding (68% vs 74%), or thrombosis (37% vs 39%). However, among cardiac indicated patients on ECMO (n = 207), anti-Xa testing was significantly associated with reduced odds ratio (OR) of mortality (adjusted OR 0.527, p = .040) and bleeding (adjusted OR 0.369, p = .021). In addition, among neonatal patients on ECMO (n = 264), anti-Xa testing was associated with a significant reduction in the odds ratio of bleeding (adjusted OR 0.534, p = .046).

CONCLUSION

Anti-Xa testing is associated with improved outcomes among cardiac indicated and neonatal patients on ECMO. Additional research to find the optimal heparin monitoring regimen is needed to better support these critically ill patients. In the interim, we recommend clinicians consider utilizing anti-Xa assays as part of their heparin monitoring plan for neonatal and cardiac indicated patients on ECMO.

Massive Transfusion in Pediatric Patients on Extracorporeal Membrane Oxygenation: A Secondary Analysis of the Massive Transfusion in Children (MATIC) Study

Few data describe pediatric patients who receive massive transfusion for life-threatening hemorrhage (LTH) while on extracorporeal membrane oxygenation (ECMO). We present a retrospective secondary analysis of a multicenter prospective observational study to describe resource utilization and mortality in pediatric patients with LTH while on ECMO. Children who were on ECMO during an LTH were compared to children with LTH who were not on ECMO. Primary outcomes were volumes of blood products administered and 28 day mortality. Comparisons were assessed by two-sided Fisher's exact test or Wilcoxon rank sum test. A total of 449 children, including 36 on ECMO, were included. Compared to those not on ECMO, children on ECMO received a higher volume of blood products (110 [50-223] vs . 59 [28-113]) ml/kg, p = 0.002) and were more likely to receive antifibrinolytic therapy (39% vs . 10%, p < 0.001). Blood product ratios were similar. Extracorporeal membrane oxygenation patients had higher 28 day mortality (64% vs. 35%, p = 0.001), although 24 hour mortality was similar (17% vs . 23%, p = 0.5). In conclusion, children on ECMO with LTH experience high resource utilization and 28 day mortality. Studies are needed to identify children at risk for LTH and to evaluate ECMO-specific treatment strategies.

Factor XII promotes the thromboinflammatory response in a rat model of venoarterial extracorporeal membrane oxygenation

BACKGROUND

Factor XII (FXII) is a multifunctional protease capable of activating thrombotic and inflammatory pathways. FXII has been linked to thrombosis in extracorporeal membrane oxygenation (ECMO), but the role of FXII in ECMO-induced inflammatory complications has not been studied. We used novel gene-targeted FXII- deficient rats to evaluate the role of FXII in ECMO-induced thromboinflammation.

METHODS

FXII-deficient (FXII-/-) Sprague-Dawley rats were generated using CRISPR/Cas9. A minimally invasive venoarterial (VA) ECMO model was used to compare wild-type (WT) and FXII-/- rats in 2 separate experimental cohorts: rats placed on ECMO without pharmacologic anticoagulation and rats anticoagulated with argatroban. Rats were maintained on ECMO for 1 hour or until circuit failure occurred. Comparisons were made with unchallenged rats and rats that underwent a sham surgical procedure without ECMO.

RESULTS

FXII-/- rats were maintained on ECMO without pharmacologic anticoagulation with low resistance throughout the 1-hour experiment. In contrast, WT rats placed on ECMO without anticoagulation developed thrombotic circuit failure within 10 minutes. Argatroban provided a means to maintain WT and FXII-/- rats on ECMO for the 1-hour time frame without thrombotic complications. Analyses of these rats demonstrated that ECMO resulted in increased neutrophil migration into the liver that was significantly blunted by FXII deficiency. ECMO also resulted in increases in high molecular weight kininogen cleavage and complement activation that were abrogated by genetic deletion of FXII.

CONCLUSIONS

FXII initiates hemostatic system activation and key inflammatory sequelae in ECMO, suggesting that therapies targeting FXII could limit both thromboembolism and inopportune inflammatory complications in this setting.

Interpretation of coagulation laboratory tests for patients on ECMO

Extracorporeal membrane oxygenation (ECMO) is a type of circulatory life support for patients with severe lung failure. The use of ECMO has increased worldwide since the pandemic of H1N1 in 2009 and more recently SARS-CoV-2 in 2020 both of which caused severe respiratory failure. ECMO patients experience both increased risk of bleeding and thrombosis. This is due to the pathological insult that damages the lungs, the ECMO circuit, coagulopathy, inflammation and anticoagulation. ECMO presents unique demands on the coagulation laboratory both in tests required to manage the patients and result interpretation. This is a personal opinion of 20 years ECMO experience as a clinical scientist and a short current review of the literature. It will focus on the laboratory coagulation tests used to manage ECMO patients, including different anticoagulants used, testing frequency and interpretation of the results.

A narrative review of neuromonitoring modalities in critically ill children

Acute neurologic injury is common in critically ill children. Some conditions - such as traumatic brain injury, meningitis, and hypoxic-ischemic injury following cardiac arrest - require careful consideration of cerebral physiology. Specialized neuromonitoring techniques provide insight regarding patient-specific and disease-specific insight that can improve diagnostic accuracy, aid in targeting therapeutic interventions, and provide prognostic information. In this review, we will discuss recent innovations in invasive (e.g., intracranial pressure monitoring and related computed indices) and noninvasive (e.g., transcranial doppler, near-infrared spectroscopy) neuromonitoring techniques used in traumatic brain injury, central nervous system infections, and after cardiac arrest. We will discuss the pertinent physiological mechanisms interrogated by each technique and discuss available evidence for potential clinical application. We will also discuss the use of innovative neuromonitoring techniques to detect and manage neurologic complications in critically ill children with systemic illness, focusing on sepsis and cardiorespiratory failure requiring extracorporeal membrane oxygenation.

Recommendations on Monitoring and Replacement of Antithrombin, Fibrinogen, and Von Willebrand Factor in Pediatric Patients on Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic review informed, modified Delphi consensus regarding monitoring and replacement of specific coagulation factors during pediatric extracorporeal membrane oxygenation (ECMO) support for the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric ECMO support.

DATA EXTRACTION

Two authors reviewed all citations independently, with conflicts resolved by a third reviewer if required. Twenty-nine references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. A panel of 48 experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. We developed one weak recommendation and four expert consensus statements.

CONCLUSIONS

There is insufficient evidence to formulate recommendations on monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric patients on ECMO. Optimal monitoring and parameters for replacement of key hemostasis parameters is largely unknown.

Anticoagulant Medications: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding the medications used for anticoagulation for pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE (PEACE).

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

Included studies assessed anticoagulation used in pediatric ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third reviewer adjudicating any conflicts. Eighteen references were used for data extraction as well as for creation of recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-informed recommendations and, when evidence was lacking, expert-based consensus statements, or good practice statements for anticoagulation during pediatric ECMO. A web-based modified Delphi process was used to build consensus via the Research and Development/University of California Appropriateness Method. Consensus was based on a modified Delphi process with agreement defined as greater than 80%. Two recommendations, two consensus statements, and one good practice statement were developed, and, in all, agreement greater than 80% was reached.

CONCLUSIONS

There is insufficient evidence to formulate optimal anticoagulation therapy during pediatric ECMO. Additional high-quality research is needed to inform evidence-based practice for anticoagulation during pediatric ECMO.

Fibrinolysis as a Causative Mechanism for Bleeding Complications on Extracorporeal Membrane Oxygenation: A Pilot Observational Prospective Study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is associated with a high risk of bleeding complications. The specific impact of ECMO on fibrinolysis remains unexplored. The objective of the current pilot observational prospective study was to investigate the longitudinal dynamics of fibrinolytic markers-i.e., changes over time-in the context of bleeding events in patients on ECMO.

METHODS

Longitudinal dynamics of contact phase components (kininogen and bradykinin) and fibrinolysis markers (tissue plasminogen activator [tPA], plasminogen activator inhibitor-1 [PAI-1], their complexes [tPA•PAI-1], plasmin-antiplasmin complexes, plasminogen, and D-dimer) were measured in patients undergoing venovenous and venoarterial ECMO, before implantation, at 0, 6, and 12 h after implantation, and daily thereafter.

RESULTS

The cohort consisted of 30 patients (214 ECMO days). The concentrations of tPA, D-dimer, plasmin-antiplasmin complexes, PAI-1, and tPA•PAI-1 complexes were increased, whereas plasminogen decreased compared to normal values. A noteworthy divergence was observed between hemorrhagic and nonhemorrhagic patients: in bleeding patients, D-dimer, plasmin-antiplasmin, tPA, PAI-1, and tPA•PAI-1 followed an increasing kinetics before hemorrhage and then decreased to their baseline level; conversely, nonbleeding patients showed a decreasing kinetics in these markers. Also, D-dimer and tPA followed an increasing kinetics in bleeding patients compared to nonbleeding patients (median values for D-dimer dynamics: 1,080 vs. -440 ng/ml, P = 0.05; tPA dynamics: 0.130 vs. 0.100 nM, P = 0.038), and both markers significantly increased the day before hemorrhage. A tPA concentration above 0.304 nM was associated with bleeding events (odds ratio, 4.92; 95% CI, 1.01 to 24.08; P = 0.049).

CONCLUSIONS

Contact activation induces fibrinolysis in ECMO patients, especially in patients experiencing bleeding. This finding supports the role of this mechanism as a possible causal factor for hemorrhages during ECMO and open new avenues for novel therapeutic perspectives.

EDITOR’S PERSPECTIVE

Priorities for Clinical Research in Pediatric Extracorporeal Membrane Oxygenation Anticoagulation From the Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To identify and prioritize research questions for anticoagulation and hemostasis management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus.

DATA SOURCES

Systematic review was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial consensus conferences of international, interprofessional experts in the management of ECMO for critically ill neonates and children.

STUDY SELECTION

The management of ECMO anticoagulation for critically ill neonates and children.

DATA EXTRACTION

Within each of the eight subgroups, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts.

DATA SYNTHESIS

Following the systematic review of MEDLINE, EMBASE, and Cochrane Library databases from January 1988 to May 2021, and the consensus process for clinical recommendations and consensus statements, PEACE panel experts constructed research priorities using the Child Health and Nutrition Research Initiative methodology. Twenty research topics were prioritized, falling within five domains (definitions and outcomes, therapeutics, anticoagulant monitoring, protocolized management, and impact of the ECMO circuit and its components on hemostasis).

CONCLUSIONS

We present the research priorities identified by the PEACE expert panel after a systematic review of existing evidence informing clinical care of neonates and children managed with ECMO. More research is required within the five identified domains to ultimately inform and improve the care of this vulnerable population.

Extracorporeal Membrane Oxygenation After Liver Transplant in Children: A Review of the ELSO Registry

There are minimal data describing use of extracorporeal membrane oxygenation (ECMO) in pediatric patient after a liver transplantation (LT). This study aimed at describing ECMO run in this specific situation using the data from Extracorporeal Life Support Organization (ELSO) Registry between January 1, 2010, to December 31, 2022. We described patients' characteristics at ECMO initiation, outcome and mortality risk factors. We identified 27 patients with a median age of 2.7 years (interquartile range (IQR) = 1.5-9.9). Main indication for ECMO support was respiratory (14/27 [52%]) followed by extracorporeal cardiopulmonary resuscitation (ECPR) (7/27 [26%]) and cardiac (6/27 [22%]). Overall in-hospital mortality was 63% (17/27). Mortality rate according to ECMO indications was 50% for both respiratory and cardiac failure and reached 100% for ECPR patients. Overall, nonsurvivors experienced significantly more complications under ECMO support ( p = 0.007). Main on-ECMO complications were hemorrhagic (11/27 [41%]) and thrombotic (7/27 [26%]). No clinical or biologic factors was predictive of patients' outcome. Our results suggest that ECMO support is a viable option for cardiac and respiratory indications after pediatric LT. Occurrence of complications while on ECMO are associated with unfavorable outcomes. The extremely high mortality rate in ECPR patients merits further research.

Anticoagulation Monitoring and Targets: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding anticoagulation monitoring assays and target levels in pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

Anticoagulation monitoring of pediatric patients on ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool or the revised Cochrane risk of bias for randomized trials, as appropriate and the evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for clinical recommendations focused on anticoagulation monitoring and targets, using a web-based modified Delphi process to build consensus (defined as > 80% agreement). One weak recommendation, two consensus statements, and three good practice statements were developed and, in all, agreement greater than 80% was reached. We also derived some resources for anticoagulation monitoring for ECMO clinician use at the bedside.

CONCLUSIONS

There is insufficient evidence to formulate optimal anticoagulation monitoring during pediatric ECMO, but we propose one recommendation, two consensus and three good practice statements. Overall, the available pediatric evidence is poor and significant gaps exist in the literature.

Management of Extracorporeal Membrane Oxygenation Anticoagulation in the Perioperative Period: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic review-informed, modified Delphi consensus regarding the management of children on extracorporeal membrane oxygenation (ECMO) undergoing invasive procedures or interventions developed by the Pediatric Anticoagulation on ECMO CollaborativE (PEACE) Consensus Conference.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

ECMO anticoagulation and hemostasis management in the perioperative period and during procedures.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. Seventeen references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. Four good practice statements, 7 recommendations, and 18 consensus statements are presented.

CONCLUSIONS

Although agreement among experts was strong, important future research is required in this population for evidence-informed recommendations.

Management of Bleeding and Thrombotic Complications During Pediatric Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding the management of bleeding and thrombotic complications during pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE Consensus Conference.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

The management of bleeding and thrombotic complications of ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Twelve references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. Two good practice statements, 5 weak recommendations, and 18 consensus statements are presented.

CONCLUSIONS

Although bleeding and thrombotic complications during pediatric ECMO remain common, limited definitive data exist to support an evidence-based approach to treating these complications. Research is needed to improve hemostatic management of children supported with ECMO.

Antifibrinolytic and Adjunct Hemostatic Agents: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding antifibrinolytic and adjunct hemostatic agents in neonates and children supported with extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE consensus conference.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

Use of antifibrinolytics (epsilon-aminocaproic acid [EACA] or tranexamic acid), recombinant factor VII activated (rFVIIa), or topical hemostatic agents (THAs).

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Eleven references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

MEASUREMENTS AND MAIN RESULTS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. One weak recommendation and three consensus statements are presented.

CONCLUSIONS

Evidence supporting recommendations for administration of antifibrinolytics (EACA or tranexamic acid), rFVIIa, and THAs were sparse and inconclusive. Much work remains to determine effective and safe usage strategies.

The Influence of the Extracorporeal Membrane Oxygenation Circuit and Components on Anticoagulation Management: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding the influence of extracorporeal membrane oxygenation (ECMO) circuit components on anticoagulation practices for pediatric ECMO for the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

Management of ECMO anticoagulation in the setting of different ECMO circuit components.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Twenty-nine references were used for data extraction and informed recommendations, evidence-based consensus statements, and good practice statements. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements or good practice statements for the influence of ECMO circuit and components on anticoagulation management. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. One good practice statement, 2 weak recommendations, and 2 consensus statements are presented.

CONCLUSIONS

The incorporation of new component technologies into clinical practice has outpaced clinical investigations of anticoagulation strategies for pediatric ECMO. Future investigations should leverage academic and industrial collaborations, translational platforms, and modern biostatistical methods to improve patient outcomes.

Executive Summary: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE (PEACE) Consensus Conference

OBJECTIVES

To present recommendations and consensus statements with supporting literature for the clinical management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus conference.

DATA SOURCES

Systematic review was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial meetings of international, interprofessional experts in the management ECMO for critically ill children.

STUDY SELECTION

The management of ECMO anticoagulation for critically ill children.

DATA EXTRACTION

Within each of eight subgroup, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts.

DATA SYNTHESIS

A systematic review was conducted using MEDLINE, Embase, and Cochrane Library databases, from January 1988 to May 2021. Each panel developed evidence-based and, when evidence was insufficient, expert-based statements for the clinical management of anticoagulation for children supported with ECMO. These statements were reviewed and ratified by 48 PEACE experts. Consensus was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 23 recommendations, 52 expert consensus statements, and 16 good practice statements covering the management of ECMO anticoagulation in three broad categories: general care and monitoring; perioperative care; and nonprocedural bleeding or thrombosis. Gaps in knowledge and research priorities were identified, along with three research focused good practice statements.

CONCLUSIONS

The 91 statements focused on clinical care will form the basis for standardization and future clinical trials.

Prophylactic Transfusion Strategies in Children Supported by Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding prophylactic transfusions in neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed use of prophylactic blood product transfusion in pediatric ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Thirty-three references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

MEASUREMENTS AND MAIN RESULTS

The evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-informed recommendations and, when evidence was lacking, expert-based consensus statements or good practice statements for prophylactic transfusion strategies for children supported with ECMO. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was based on a modified Delphi process with agreement defined as greater than 80%. We developed two good practice statements, 4 weak recommendations, and three expert consensus statements.

CONCLUSIONS

Despite the frequency with which pediatric ECMO patients are transfused, there is insufficient evidence to formulate evidence-based prophylactic transfusion strategies.

Bleeding Complications in Neonates Receiving Extracorporeal Membrane Oxygenation and Controlled Hypothermia

OBJECTIVE

Safety and efficacy data on controlled hypothermia (CH) for neonates with moderate to severe hypoxic ischemic encephalopathy has been extrapolated to a subgroup of these patients who also require extracorporeal membrane oxygenation for refractory persistent pulmonary hypertension of the newborn (PPHN). However, safety data on the concomitant use of CH and extracorporeal membrane oxygenation (ECMO) are lacking.

METHODS

This is a single-center retrospective study of neonates ≥35 weeks' gestation with refractory PPHN who required ECMO between January 2010 and December 2020. Study groups were divided into those receiving CH/ECMO versus ECMO only. Baseline characteristics, short-term outcomes, and brain magnetic resonance imaging (MRI) data were compared.

RESULTS

A total of 36 neonates who received ECMO for refractory PPHN were included. Of these, 44.4% (n = 16) received CH/ECMO and 55.6% (n = 20) received ECMO only. Bleeding complications were more common in CH/ECMO group 50% (n = 8) versus ECMO only 15% (n = 3, p = 0.023). T1 brain MRI severity scores were higher in CH/ECMO group versus ECMO only group, however, there were no statistical difference in T2 and diffusion-weighted image scores. Functional status and survival to discharge were comparable between groups.

CONCLUSION

In our cohort, neonates who received CH/ECMO had higher bleeding complications than ECMO only group with comparable functional status and survival at discharge.

KEY POINTS

· Safety data on the concomitant use of CH and ECMO are lacking in neonates.. · In our cohort, neonates who received CH/ECMO had higher bleeding complications than ECMO only group.. · Functional status and survival to discharge were no differences between the two groups..

Brain development in newborns and infants after ECMO

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) not only significantly improves survival rates in severely ill neonates but also is associated with long-term neurodevelopmental issues. To systematically review the available literature on the neurodevelopmental outcomes of neonates and infants who have undergone ECMO treatment, with a focus on motor deficits, cognitive impairments, sensory impairments, and developmental delays. This review aims to understand the incidence, prevalence, and risk factors for these problems and to explore current nursing care and management strategies.

DATA SOURCES

A comprehensive literature search was performed across PubMed, EMBASE, and Web of Science using a wide array of keywords and phrases pertaining to ECMO, neonates, infants, and various facets of neurodevelopment. The initial screening involved reviewing titles and abstracts to exclude irrelevant articles, followed by a full-text assessment of potentially relevant literature. The quality of each study was evaluated based on its research methodology and statistical analysis. Moreover, citation searches were conducted to identify potentially overlooked studies. Although the focus was primarily on neonatal ECMO, studies involving children and adults were also included due to the limited availability of neonate-specific literature.

RESULTS

About 50% of neonates post-ECMO treatment exhibit varying degrees of brain injury, particularly in the frontal and temporoparietal white matter regions, often accompanied by neurological complications. Seizures occur in 18%-23% of neonates within the first 24 hours, and bleeding events occur in 27%-60% of ECMO procedures, with up to 33% potentially experiencing ischemic strokes. Although some studies suggest that ECMO may negatively impact hearing and visual development, other studies have found no significant differences; hence, the influence of ECMO remains unclear. In terms of cognitive, language, and intellectual development, ECMO treatment may be associated with potential developmental delays, including lower composite scores in cognitive and motor functions, as well as potential language and learning difficulties. These studies emphasize the importance of early detection and intervention of potential developmental issues in ECMO survivors, possibly necessitating the implementation of a multidisciplinary follow-up plan that includes regular neuromotor and psychological evaluations. Overall, further multicenter, large-sample, long-term follow-up studies are needed to determine the impact of ECMO on these developmental aspects.

CONCLUSIONS

The impact of ECMO on an infant's nervous system still requires further investigation with larger sample sizes for validation. Fine-tuned management, comprehensive nursing care, appropriate patient selection, proactive monitoring, nutritional support, and early rehabilitation may potentially contribute to improving the long-term outcomes for these infants.

Hemorrhage and thrombosis in COVID-19-patients supported with extracorporeal membrane oxygenation: an international study based on the COVID-19 critical care consortium

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a rescue therapy in patients with severe acute respiratory distress syndrome (ARDS) secondary to COVID-19. While bleeding and thrombosis complicate ECMO, these events may also occur secondary to COVID-19. Data regarding bleeding and thrombotic events in COVID-19 patients on ECMO are sparse.

METHODS

Using the COVID-19 Critical Care Consortium database, we conducted a retrospective analysis on adult patients with severe COVID-19 requiring ECMO, including centers globally from 01/2020 to 06/2022, to determine the risk of ICU mortality associated with the occurrence of bleeding and clotting disorders.

RESULTS

Among 1,248 COVID-19 patients receiving ECMO support in the registry, coagulation complications were reported in 469 cases (38%), among whom 252 (54%) experienced hemorrhagic complications, 165 (35%) thrombotic complications, and 52 (11%) both. The hazard ratio (HR) for Intensive Care Unit mortality was higher in those with hemorrhagic-only complications than those with neither complication (adjusted HR = 1.60, 95% CI 1.28-1.99, p < 0.001). Death was reported in 617 of the 1248 (49.4%) with multiorgan failure (n = 257 of 617 [42%]), followed by respiratory failure (n = 130 of 617 [21%]) and septic shock [n = 55 of 617 (8.9%)] the leading causes.

CONCLUSIONS

Coagulation disorders are frequent in COVID-19 ARDS patients receiving ECMO. Bleeding events contribute substantially to mortality in this cohort. However, this risk may be lower than previously reported in single-nation studies or early case reports. Trial registration ACTRN12620000421932 ( https://covid19.cochrane.org/studies/crs-13513201 ).

Predictors of mortality and transfusion requirements in venoarterial extracorporeal membrane oxygenation patients

OBJECTIVE

The aim of this study was to evaluate the prognostic impact of variables, including thrombocytopenia and the amount of platelet transfusion, for predicting survival in venoarterial extracorporeal membrane oxygenation (ECMO) recipients. Additionally, we aimed to identify the predictors of increased transfusion requirement during venoarterial ECMO support.

METHODS

All patients who received venoarterial ECMO between December 2008 and March 2020 were retrospectively analyzed. Univariate and multivariate Cox regressions were used to evaluate in-hospital mortality according to variables including thrombocytopenia and daily average of platelet concentrate transfusion. Stepwise multiple linear regression analysis was used to identify independent predictors for transfusion requirements.

RESULTS

Analysis of 218 patients demonstrated severe thrombocytopenia as an independent predictor of in-hospital mortality (hazard ratio = 2.840, 95% CI: 1.593-5.063, P < .001), along with age, pre-ECMO cardiac arrest, and pH. In contrast, the amount of platelet transfusion was not associated with in-hospital mortality. Multiple variables, including the type of indication for ECMO were associated with transfusion requirements.

CONCLUSION

Our findings identified severe thrombocytopenia as an independent prognostic factor of in-hospital mortality. However, daily average platelet transfusion was not associated with survival outcomes. Additionally, our study identified predictive variables of increased transfusion requirements.

Prognostic of red blood cell transfusion during extracorporeal membrane oxygenation therapy on mortality: A meta-analysis

BACKGROUND

This meta-analysis aimed to explore the impact of red blood cell (RBC) transfusion on mortality during extracorporeal membrane oxygenation (ECMO). Previous studies investigated the prognostic impact of RBC transfusion during ECMO on the risk of mortality, but no meta-analysis has been published before.

METHODS

The PubMed, Embase, and the Cochrane library were systematically searched for papers published up to 13 December 2021, using the MeSH terms "ECMO", "'Erythrocytes", and "Mortality" to identify meta-analyses. Total or daily RBC transfusion during ECMO and mortality were examined.

RESULTS

The random-effect model was used. Eight studies (794 patients, including 354 dead) were included. The total volume of RBC was associated with higher mortality standardized weighted difference (SWD = -0.62, 95% CI: -1.06,-0.18, p = .006; I2 = 79.7%, Pheterogeneity = 0.001). The daily volume of RBC was associated with higher mortality (SWD = -0.77, 95% CI: -1.11,-0.42, p < .001; I2 = 65.7%, Pheterogeneity = 0.020). The total volume of RBC was associated with mortality for venovenous (VV) (SWD = -0.72, 95% CI: -1.23, -0.20, p = .006) but not venoarterial ECMO (p = .126) or when reported together (p = .089). The daily volume of RBC was associated with mortality for VV (SWD = -0.72, 95% CI: -1.18, -0.26, p = 0.002; I2 = 0.0%, Pheterogeneity = 0.642) and venoarterial (SWD = -0.95, 95% CI: -1.32, -0.57, p < .001) ECMO, but not when reported together (p = .067). The sensitivity analysis suggested the robustness of the results.

CONCLUSION

When considering the total and daily volumes of RBC transfusion during ECMO, the patients who survived received smaller total and daily volumes of RBC transfusion. This meta-analysis suggests that RBC transfusion might be associated with a higher risk of mortality during ECMO.

Novel tubing connectors reduce ECMO circuit thrombosis

BACKGROUND

Thrombosis within extracorporeal membrane oxygenation (ECMO) circuits is a common complication that dominates clinical management of patients receiving mechanical circulatory support. Prior studies have identified that over 80% of circuit thrombosis can be attributed to tubing-connector junctions.

METHODS

A novel connector was designed that reduces local regions of flow stagnation at the tubing-connector junction to eliminate a primary source of ECMO circuit thrombi. To compare clotting between the novel connectors and the traditional connectors, both in vitro loops and an in vivo caprine model of long-term (48 h) ECMO were used to generate tubing-connector junction clots.

RESULTS

In vitro, the traditional connectors uniformly (9/9) formed large thrombi, while novel connectors formed a small thrombus in only one of nine (p < 0.0001). In the long-term goat ECMO circuits, the traditional connectors exhibited more thrombi (p < 0.04), and these thrombi were more likely to protrude into the lumen of the tubing (p < 0.001).

CONCLUSION

Both in vitro and in vivo validation experiments successfully recreated circuit thrombosis and demonstrate that the adoption of novel connectors can reduce the burden of circuit thrombosis.

Epidemiology of anticoagulation for children supported by extracorporeal membrane oxygenation in the United States: A Pediatric Hospital Information System database study

INTRODUCTION

Due to the risk of thrombosis, nearly all children supported by extracorporeal membrane oxygenation (ECMO) receive systemic anticoagulation. While heparin has traditionally been used, there are reports of increased use of direct thrombin inhibitors. We sought to describe the use of anticoagulation in children supported by ECMO in the United States using a large administrative database.

METHODS

We performed a retrospective cohort study of children supported by ECMO within the Pediatric Health Information System (PHIS) database. Pediatric encounters involving ECMO from 2012 to 2020 were identified. Data regarding demographics, diagnoses, anticoagulation, complications, and outcomes were extracted for eligible encounters.

RESULTS

Eleven thousand five hundred ninety-five encounters that involved ECMO were identified. Fifty-four percent were male with an age range of 0-17 years and a median (IQR) age of 0 (0-2) years. Unfractionated heparin (UFH) only was used in 94% (95% CI: 93.6-94.5%) of encounters and UFH followed by bivalirudin in 5% (95% CI: 4.3-5.1%) of cases. There was a significant difference in the use of bivalirudin from 2012 to 2020 (p < 0.001). Differences in anticoagulation regimens were observed between infants and children (p = 0.004) and between those with and without cardiac indications for ECMO (p < 0.001). Four percent (95% CI: 4.1-4.8%) of encounters were associated with diagnostic coding for thrombosis and differences in occurrence of thrombosis were observed between different anticoagulant regimens (p < 0.001).

CONCLUSIONS

Though the majority of children on ECMO in the United States receive heparin anticoagulation, there is an increase in use of direct thrombin inhibitors. Prospective studies must evaluate the efficacy of different anticoagulants in this patient population.