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.

Acetaminophen clearance during ex vivo continuous renal replacement therapies.

Intravenous acetaminophen is an adjuvant to opioid use in critically ill and surgical patients requiring continuous renal replacement therapy (CRRT). The objective of this study was to determine the ex vivo transmembrane clearance of intravenous acetaminophen during continuous hemofiltration and hemodialysis. Transmembrane clearance was assessed using a validated ex vivo bovine blood model for CRRT using an F8 or HF1400 hemodiafilter. Ultrafiltrate and dialysate flow rates were 1, 2, and 3 L/h. Urea and acetaminophen clearances were calculated and compared. Acetaminophen was readily cleared by continuous hemofiltration with both hemodiafilters. Acetaminophen clearance rates were 92-98% of ultrafiltrate production rates. Similarly, dialytic acetaminophen clearances approximated dialysate flow rates for both hemodiafilters. Acetaminophen is readily cleared by CRRT. Patients receiving CRRT and acetaminophen may require increased doses for adequate pain control.

Prospective Side by Side Comparison of Outcomes and Complications With a Simple Versus Intensive Anticoagulation Monitoring Strategy in Pediatric Extracorporeal Life Support Patients.

OBJECTIVES: A continuous infusion of unfractionated heparin is the most common anticoagulant used for pediatric patients on extracorporeal life support. The objective of this study was to compare extracorporeal life support complications and outcomes between two large-volume pediatric extracorporeal life support centers that use different anticoagulation strategies. DESIGN: Prospective, observational cohort study. SETTING: The University of Michigan used simple anticoagulation monitoring, whereas the University of Alberta used an intensive anticoagulation monitoring strategy. PATIENTS: Pediatric patients on extracorporeal life support. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was major bleeding per extracorporeal life support run defined as bleeding that was retroperitoneal, pulmonary, or involved the CNS; bleeding greater than 20 mL/kg over 24 hours; or bleeding that required surgical intervention. Secondary outcomes measured were patient thrombosis per run, circuit thrombosis per run, and survival to hospital discharge per patient. Eighty-eight patients (95 runs) less than 18 years old were enrolled at the two centers over 2 years. The two centers enrolled different extracorporeal life support populations; University of Alberta enrolled more postcardiac surgical patients (74% vs 47%; p = 0.005). The indication for extracorporeal life support support also varied by center (p = 0.04). The two centers used similar proportions of VA extracorporeal life support (p = 0.3). Median (interquartile range) unfractionated heparin doses were similar between University of Michigan and University of Alberta, 30 (21-34) U/kg/hr and 26 (22-31) U/kg/hr, p value equals to 0.3, respectively. Median (interquartile range) antifactor Xa was lower in the University of Michigan cohort (0.23 [0.19-0.28] vs 0.41 [0.36-0.46] U/mL; p < 0.001). There was no significant difference in major bleeding (15% University of Michigan vs 21% University of Alberta; p = 0.6) or in patient thromboses (18% University of Michigan vs 13% University of Alberta; p = 0.5). There was no significant difference in survival to hospital discharge (University of Michigan 63% vs University of Alberta 73%; p = 0.1). CONCLUSIONS: Although this prospective cohort study compared different pediatric extracorporeal life support populations, the results did not identify a significant difference in outcomes between simple and intensive anticoagulation monitoring strategies.

Development and Validation of the Neonatal Risk Estimate Score for Children Using Extracorporeal Respiratory Support.

OBJECTIVE: To develop and validate the Neonatal Risk Estimate Score for Children Using Extracorporeal Respiratory Support, which estimates the risk of in-hospital death for neonates prior to receiving respiratory extracorporeal membrane oxygenation (ECMO) support. STUDY DESIGN: We used an international ECMO registry (2008-2013); neonates receiving ECMO for respiratory support were included. We divided the registry into a derivation sample and internal validation sample, by calendar date. We chose candidate variables a priori based on published evidence of association with mortality; variables independently associated with mortality in logistic regression were included in this parsimonious model of risk adjustment. We evaluated model discrimination with the area under the receiver operating characteristic curve (AUC), and we evaluated calibration with the Hosmer-Lemeshow goodness-of-fit test. RESULTS: During 2008-2013, 4592 neonates received ECMO respiratory support with mortality of 31%. The development dataset contained 3139 patients treated in 2008-2011. The Neo-RESCUERS measure had an AUC of 0.78 (95% CI 0.76-0.79). The validation cohort had an AUC = 0.77 (0.75-0.80). Patients in the lowest risk decile had an observed mortality of 7.0% and a predicted mortality of 4.4%, and those in the highest risk decile had an observed mortality of 65.6% and a predicted mortality of 67.5%. CONCLUSIONS: Neonatal Risk Estimate Score for Children Using Extracorporeal Respiratory Support offers severity-of-illness adjustment for neonatal patients with respiratory failure receiving ECMO. This score may be used to adjust patient survival to assess hospital-level performance in ECMO-based care.

Association of hospital-level volume of extracorporeal membrane oxygenation cases and mortality. Analysis of the extracorporeal life support organization registry.

RATIONALE: Recent pediatric studies suggest a survival benefit exists for higher-volume extracorporeal membrane oxygenation (ECMO) centers. OBJECTIVES: To determine if higher annual ECMO patient volume is associated with lower case-mix-adjusted hospital mortality rate. METHODS: We retrospectively analyzed an international registry of ECMO support from 1989 to 2013. Patients were separated into three age groups: neonatal (0-28 d), pediatric (29 d to <18 yr), and adult (≥18 yr). The measure of hospital ECMO volume was age group-specific and adjusted for patient-level case-mix and hospital-level variance using multivariable hierarchical logistic regression modeling. The primary outcome was death before hospital discharge. A subgroup analysis was conducted for 2008-2013. MEASUREMENTS AND MAIN RESULTS: From 1989 to 2013, a total of 290 centers provided ECMO support to 56,222 patients (30,909 neonates, 14,725 children, and 10,588 adults). Annual ECMO mortality rates varied widely across ECMO centers: the interquartile range was 18-50% for neonates, 25-66% for pediatrics, and 33-92% for adults. For 1989-2013, higher age group-specific ECMO volume was associated with lower odds of ECMO mortality for neonates and adults but not for pediatric cases. In 2008-2013, the volume-outcome association remained statistically significant only among adults. Patients receiving ECMO at hospitals with more than 30 adult annual ECMO cases had significantly lower odds of mortality (adjusted odds ratio, 0.61; 95% confidence interval, 0.46-0.80) compared with adults receiving ECMO at hospitals with less than six annual cases. CONCLUSIONS: In this international, case-mix-adjusted analysis, higher annual hospital ECMO volume was associated with lower mortality in 1989-2013 for neonates and adults; the association among adults persisted in 2008-2013.

Hemorrhagic complications in pediatric cardiac patients on extracorporeal membrane oxygenation: an analysis of the Extracorporeal Life Support Organization Registry.

OBJECTIVES: To determine the prevalence of and risk factors for hemorrhagic complications in children with cardiac disease requiring extracorporeal membrane oxygenation. DESIGN: Retrospective review of the Extracorporeal Life Support Organization Registry (2002-2013). SETTING: Participating Extracorporeal Life Support Organization centers. PATIENTS: Patients less than 18 years old on extracorporeal membrane oxygenation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 21,845 patients requiring extracorporeal membrane oxygenation during the study period, 8,905 (41%) had cardiac disease, and 79% of whom (6,995) had cardiac surgery. Hemorrhagic complications occurred in 8,480 patients (39% of overall cohort), with higher rates in cardiac versus noncardiac patients (49% vs 32%; p < 0.0001) related to cannulation and surgical site bleeding. Cardiac surgical patients had higher rates of hemorrhage compared with cardiac medical patients (57% vs 38%; p < 0.0001), and cardiac patients with hemorrhage had higher extracorporeal membrane oxygenation mortality compared with those without (42% vs 22% in medical patients and 34% vs 20% in surgical patients; both p < 0.0001). In multivariable analysis in both the cardiac medical and surgical groups, hemorrhage risk was higher in children greater than 1 year old and in patients with longer extracorporeal membrane oxygenation duration. Additional independent risk factors for hemorrhage in cardiac surgical patients included pre-extracorporeal membrane oxygenation mediastinal exploration (odds ratio, 3.6; 95% CI, 2.1-6.3), Society of Thoracic Surgeons morbidity category 4-5 (odds ratio, 1.2; 95% CI, 1.03-1.5), cannulation less than 24 hours after surgery (odds ratio, 1.6; 95% CI, 1.3-1.9), and longer cardiopulmonary bypass time (≥ 282 min [upper quartile]; odds ratio, 1.5; 95% CI, 1.3-1.9). CONCLUSIONS: In this large, multicenter analysis, hemorrhagic complications occurred in nearly half of children with heart disease on extracorporeal membrane oxygenation and were associated with a significant mortality risk. Several factors were associated with hemorrhagic complications in cardiac surgical patients including pre-extracorporeal membrane oxygenation mediastinal exploration, greater surgical complexity, early postoperative cannulation, and longer bypass times. Whether these risks can be mitigated by modifying or delaying systemic anticoagulation requires further investigation.

Therapeutic plasma exchange may improve hemodynamics and organ failure among children with sepsis-induced multiple organ dysfunction syndrome receiving extracorporeal life support.

OBJECTIVE: To determine the effect of therapeutic plasma exchange on hemodynamics, organ failure, and survival in children with multiple organ dysfunction syndrome due to sepsis requiring extracorporeal life support. DESIGN: A retrospective analysis. SETTING: A PICU in an academic children's hospital. PATIENTS: Fourteen consecutive children with sepsis and multiple organ dysfunction syndrome who received therapeutic plasma exchange while on extracorporeal life support from 2005 to 2013. INTERVENTIONS: Median of three cycles of therapeutic plasma exchange with median of 1.0 times the estimated plasma volume per exchange. MEASUREMENTS AND MAIN RESULTS: Organ Failure Index and Vasoactive-Inotropic Score were measured before and after therapeutic plasma exchange use. PICU survival in our cohort was 71.4%. Organ Failure Index decreased in patients following therapeutic plasma exchange (mean ± SD: pre, 4.1 ± 0.7 vs post, 2.9 ± 0.9; p = 0.0004). Patients showed improved Vasoactive-Inotropic Score following therapeutic plasma exchange (median [25th-75th]: pre, 24.5 [13.0-69.8] vs post, 5.0 [1.5-7.0]; p = 0.0002). Among all patients, the change in Organ Failure Index was greater for early therapeutic plasma exchange use than late use (early, -1.7 ± 1.2 vs late, -0.9 ± 0.6; p = 0.14), similar to the change in Vasoactive-Inotropic Score (early, -67.5 [28.0-171.2] vs late, -12.0 [7.2-18.5]; p = 0.02). Among survivors, the change in Organ Failure Index was greater among early therapeutic plasma exchange use than late use (early, -2.3 ± 1.0 vs late, -0.8 ± 0.8; p = 0.03), as was the change in Vasoactive-Inotropic Score (early, -42.0 [16.0-76.3] vs late, -12.0 [5.3-29.0]; p = 0.17). The mean duration of extracorporeal life support after therapeutic plasma exchange according to timing of therapeutic plasma exchange was not statistically different among all patients or among survivors. CONCLUSIONS: The use of therapeutic plasma exchange in children on extracorporeal life support with sepsis-induced multiple organ dysfunction syndrome is associated with organ failure recovery and improved hemodynamic status. Initiating therapeutic plasma exchange early in the hospital course was associated with greater improvement in organ dysfunction and decreased requirement for vasoactive and/or inotropic agents.

Blood biocompatibility of surface-bound multi-walled carbon nanotubes.

Blood clots when it contacts foreign surfaces following platelet activation. This can be catastrophic in clinical settings involving extracorporeal circulation such as during heart-lung bypass where blood is circulated in polyvinyl chloride tubing. Studies have shown, however, that surface-bound carbon nanotubes may prevent platelet activation, the initiator of thrombosis. We studied the blood biocompatibility of polyvinyl chloride, surface-modified with multi-walled carbon nanotubes in vitro and in vivo. Our results show that surface-bound multi-walled carbon nanotubes cause platelet activation in vitro and devastating thrombosis in an in vivo animal model of extracorporeal circulation. The mechanism of the pro-thrombotic effect likely involves direct multi-walled carbon nanotube-platelet interaction with Ca(2+)-dependant platelet activation. These experiments provide evidence, for the first time, that modification of surfaces with nanomaterials modulates blood biocompatibility in extracorporeal circulation.

Fluid overload and fluid removal in pediatric patients on extracorporeal membrane oxygenation requiring continuous renal replacement therapy.

OBJECTIVE: In pediatric patients, fluid overload at continuous renal replacement therapy initiation is associated with increased mortality. The aim of this study was to characterize the association between fluid overload at continuous renal replacement therapy initiation, fluid removal during continuous renal replacement therapy, the kinetics of fluid removal and mortality in a large pediatric population receiving continuous renal replacement therapy while on extracorporeal membrane oxygenation. DESIGN: Retrospective chart review. SETTING: Tertiary children's hospital. PATIENTS: Extracorporeal membrane oxygenation patients requiring continuous renal replacement therapy from July 2006 to September 2010. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Overall intensive care unit survival was 34% for 53 patients that were initiated on continuous renal replacement therapy while on extracorporeal membrane oxygenation during the study period. Median fluid overload at continuous renal replacement therapy initiation was significantly lower in survivors compared to nonsurvivors (24.5% vs. 38%, p = .006). Median fluid overload at continuous renal replacement therapy discontinuation was significantly lower in survivors compared to nonsurvivors (7.1% vs. 17.5%, p = .035). After adjusting for percent fluid overload at continuous renal replacement therapy initiation, age, and severity of illness, the change in fluid overload at continuous renal replacement therapy discontinuation was not significantly associated with mortality (p = .212). Models investigating the rates of fluid removal in different periods, age, severity of illness, and fluid overload at continuous renal replacement therapy initiation found that fluid overload at continuous renal replacement therapy initiation was the most consistent predictor of survival. CONCLUSIONS: Our data demonstrate an association between fluid overload at continuous renal replacement therapy initiation and mortality in pediatric patients receiving extracorporeal membrane oxygenation. The degree of fluid overload at continuous renal replacement therapy discontinuation is also associated with mortality, but appears to reflect the effect of fluid overload at initiation. Furthermore, correction of fluid overload to ≤ 10% was not associated with improved survival. These results suggest that intervening prior to the development of significant fluid overload may be more clinically effective than attempting fluid removal after significant fluid overload has developed. Our findings suggest a role for earlier initiation of continuous renal replacement therapy in this population, and warrant further clinical studies.

2021 ELSO Adult and Pediatric Anticoagulation Guidelines.

DISCLAIMER: These guidelines for adult and pediatric anticoagulation for extracorporeal membrane oxygenation are intended for educational use to build the knowledge of physicians and other health professionals in assessing the conditions and managing the treatment of patients undergoing ECLS / ECMO and describe what are believed to be useful and safe practice for extracorporeal life support (ECLS, ECMO) but these are not necessarily consensus recommendations. The aim of clinical guidelines are to help clinicians to make informed decisions about their patients. However, adherence to a guideline does not guarantee a successful outcome. Ultimately, healthcare professionals must make their own treatment decisions about care on a case-by-case basis, after consultation with their patients, using their clinical judgment, knowledge and expertise. These guidelines do not take the place of physicians' and other health professionals' judgment in diagnosing and treatment of particular patients. These guidelines are not intended to and should not be interpreted as setting a standard of care or be deemed inclusive of all proper methods of care nor exclusive of other methods of care reasonably directed to obtaining the same results. The ultimate judgment must be made by the physician and other health professionals and the patient in light of all the circumstances presented by the individual patient, and the known variability and biological behavior of the clinical condition. These guidelines reflect the data at the time the guidelines were prepared; the results of subsequent studies or other information may cause revisions to the recommendations in these guidelines to be prudent to reflect new data, but ELSO is under no obligation to provide updates. In no event will ELSO be liable for any decision made or action taken in reliance upon the information provided through these guidelines.

A normal capillary refill time of ≤ 2 seconds is associated with superior vena cava oxygen saturations of ≥ 70%.

OBJECTIVE: To test the hypothesis that a normal capillary refill time (CRT) ≤ 2 seconds is associated with superior vena cava oxygen saturation (ScvO2) ≥ 70% in critically ill children. STUDY DESIGN: Two-year, prospective study in a tertiary-level pediatric intensive care unit. Whenever ScvO2 measurements were obtained, central (forehead/sternum) and peripheral (finger/toe) CRTs were concomitantly assessed. RESULTS: Central and peripheral CRTs ≤ 2 seconds were both associated with ScvO2 ≥ 70% (P < .01). Sensitivity/specificity analyses revealed that central CRT ≤ 2 seconds demonstrated a sensitivity of 84.4%, specificity of 71.4%, positive predictive value of 93.1%, and negative predictive value of 50.0% in predicting ScvO2 ≥ 70%. Peripheral CRT ≤ 2 seconds had a sensitivity of 71.9%, specificity of 85.7%, positive predictive value of 95.8%, and negative predictive value of 40.0% in predicting ScvO2 ≥ 70%. CONCLUSIONS: A normal CRT ≤ 2 seconds can be predictive of ScvO2 ≥ 70%. Our study corroborates the recommendations of the Pediatric Advanced Life Support curricula targeting a normal CRT ≤ 2 seconds as a therapeutic endpoint for goal-directed shock resuscitation. This clinical target remains particularly relevant in community hospitals when the ability to obtain central venous catheter access may be limited and ScvO2 data unavailable.

Hematologic concerns in extracorporeal membrane oxygenation.

This ISTH "State of the Art" review aims to critically evaluate the hematologic considerations and complications in extracorporeal membrane oxygenation (ECMO). ECMO is experiencing a rapid increase in clinical use, but many questions remain unanswered. The existing literature does not address or explicitly state many pertinent details that may influence hematologic complications and, ultimately, patient outcomes. This review aims to broadly introduce modern ECMO practices, circuit designs, circuit materials, hematologic complications, transfusion-related considerations, age- and size-related differences, and considerations for choosing outcome measures. Relevant studies from the 2019 ISTH Congress in Melbourne, which further advanced our understanding of these processes, will also be highlighted.

Extracorporeal Life Support Organization (ELSO): 2020 Pediatric Respiratory ELSO Guideline.

DISCLAIMER: This guideline describes prolonged extracorporeal life support (ECLS) and extracorporeal membrane oxygenation (ECMO), applicable to Pediatric respiratory failure. These guidelines describe useful and safe practice, prepared by ELSO and based on extensive experience and are considered consensus guidelines. These guidelines are not intended to define standard of care and are revised at regular intervals as new information, devices, medications, and techniques become available.

Mechanical component failures in 28,171 neonatal and pediatric extracorporeal membrane oxygenation courses from 1987 to 2006.

OBJECTIVE: To provide a descriptive summary of mechanical component failure associated with extracorporeal membrane oxygenation (ECMO), and to examine patient and ECMO variables that may be associated with mechanical component failure and guide further study. We hypothesized that duration of ECMO, era of ECMO, indication for ECMO, age of patient, and center ECMO volume would be associated with mechanical component failure. DESIGN: Retrospective cohort study. PATIENTS AND METHODS: Extracorporeal Life Support Organization registry was queried for all neonatal and pediatric ECMO courses recorded. Each ECMO course was treated as an independent event, and was included if duration was > or =25 hrs with occurrence between 1987 and 2007. Courses with a duration >458 hrs or with an indication for ECMO during cardiopulmonary resuscitation were excluded from analysis. Mechanical component failure data were extracted from the Extracorporeal Life Support Organization registry for the oxygenator, raceway, other tubing, pigtail connectors, heat exchanger, and air in the circuit. RESULTS: A total of 28,171 independent ECMO courses were included for analysis, of which 14.9% were associated with a mechanical component failure. Duration of ECMO, age group of patient, era of ECMO, and indication for ECMO were all associated with mechanical component failure. From our predictive model, we observed a continuous nonlinear relation suggesting increasing probability of mechanical component failure with increasing duration of ECMO support. CONCLUSIONS: Mechanical component failure over the course of this study was infrequent during neonatal and pediatric ECMO, and declined across eras as experience with the therapy grew. Increasing duration of ECMO was associated with an increasing probability of mechanical component failure. Indication for ECMO and patient age were also statistically associated with mechanical component failure probability, but ECMO center volume was not.

Risk factors for bleeding in pediatric post-cardiotomy patients requiring ECLS.

BACKGROUND/OBJECTIVE: There is limited literature documenting bleeding patterns in pediatric post-cardiotomy patients on extracorporeal life support (ECLS). This retrospective review details bleeding complications and identifies risk factors for bleeding in these patients. METHODS: Records from 145 patients were reviewed. Patients were divided into excessive (E) and non-excessive (NE) bleeding groups based on blood loss. RESULTS: Excessive bleeding occurred predominantly from 0-6h. Longer CPB duration (NE=174+/-8 min; E=212+/-16; p=0.02) and lower platelet counts (NE=104.8+/-50K; E=84.3+/-41K; p=0.01) were associated with excessive bleeding during the first 6h (p=0.005). Use of intraoperative protamine with normal platelets was associated with decreased bleeding from 7-12 h post-ECLS (p=0.002). Most mediastinal exploration occurred > 49 h post-ECLS, with decreased bleeding post-exploration in E patients. CONCLUSIONS: The majority of pediatric post-cardiotomy ECLS bleeding occurs early after support initiation. Longer CPB time and thrombocytopenia increased bleeding 0-6h post-ECLS. Since early bleeding may be coagulopathic in origin, an approach to minimize bleeding includes protamine administration and aggressive blood product replacement with target platelet counts of 100-120K. Surgical exploration should follow if additional hemostasis is necessary.