Evaluation of Bivalirudin As an Alternative to Heparin for Systemic Anticoagulation in Pediatric Extracorporeal Membrane Oxygenation

Bivalirudin as an anticoagulation strategy for acute hemodialysis in children: Two cases with a summary of recent literature

Unfractionated heparin is the most used anticoagulative agent for extracorporeal settings in children, including acute hemodialysis modalities. In certain situations, such as heparin-induced thrombocytopenia, alternatives must be applied. The direct thrombin inhibitor bivalirudin has come forth as an attractive substitute. Bivalirudin is currently only approved for adult use in specific percutaneous coronary intervention settings. However, it has a growing off-label popularity in different contexts for both adult and pediatric patients. Experience with bivalirudin in children is mainly limited to extracorporeal membrane oxygenation, ventricular assist devices and during cardiopulmonary bypass surgery. Literature about its use as anticoagulation strategy for pediatric hemodialysis is very scarce. Here, we present two pediatric cases where bivalirudin was used during acute hemodialysis, followed by a short summary of recent literature.

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.

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.

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.

Unified Methodology for the Primary Preclinical In Vivo Screening of New Anticoagulant Pharmaceutical Agents from Hematophagous Organisms

The development of novel anticoagulants requires a comprehensive investigational approach that is capable of characterizing different aspects of antithrombotic activity. The necessary experiments include both in vitro assays and studies on animal models. The required in vivo approaches include the assessment of pharmacokinetic and pharmacodynamic profiles and studies of hemorrhagic and antithrombotic effects. Comparison of anticoagulants with different mechanisms of action and administration types requires unification of the experiment scheme and its adaptation to existing laboratory conditions. The rodent thrombosis models in combination with the assessment of hemostasis parameters and hematological analysis are the classic methods for conducting preclinical studies. We report an approach for the comparative study of the activity of different anticoagulants in vivo, including the investigation of pharmacodynamics and the assessment of hemorrhagic effects (tail-cut bleeding model) and pathological thrombus formation (inferior vena cava stenosis model of venous thrombosis). The reproducibility and uniformity of our set of experiments were illustrated on unfractionated heparin and dabigatran etexilate (the most common pharmaceuticals in antithrombic therapy) as comparator drugs and an experimental drug variegin from the tick Amblyomma variegatum. Variegin is notorious since it is a potential analogue of bivalirudin (Angiomax, Novartis AG, Basel, Switzerland), which is now being actively introduced into antithrombotic therapy.

Comparison of bleeding and thrombotic outcomes in veno-venous extracorporeal membrane oxygenation: Heparin versus bivalirudin

OBJECTIVES

We aimed to evaluate thrombotic and hemorrhagic complications with heparin versus bivalirudin use in veno-venous extracorporeal membrane oxygenation (V-V ECMO).

METHODS

We performed a retrospective cohort study of adult patients placed on V-V ECMO with intravenous anticoagulation with either heparin or bivalirudin. Time to thrombotic event and major bleed were analyzed in addition to related outcomes.

RESULTS

We identified 95 patients placed on V-V ECMO: 61 receiving heparin, 34 bivalirudin. The bivalirudin group had a higher rate of severe COVID-19, higher BMI, and longer ECMO duration. Despite this, bivalirudin was associated with reduced risk of thrombotic event (HR 0.14, 95% CI 0.06-0.32, p < .001) and increased average lifespan of the circuit membrane lung (16 vs. 10 days, p = 0.004). While there was no difference in major bleeding, the bivalirudin group required fewer transfusions of packed red blood cells and platelets per 100 ECMO days (means of 13 vs. 39, p = 0.004; 5 vs. 19, p = .014, respectively). Lastly, the bivalirudin group had improved survival to ECMO decannulation in univariate analysis (median OS 53 vs. 26 days, p = .015).

CONCLUSIONS

In this real-world analysis of bivalirudin versus heparin, bivalirudin is a viable option for V-V ECMO and associated with lower risk of thrombotic complications and fewer transfusion requirements.

Patient-tailored platelet transfusion practices for children supported by extracorporeal membrane oxygenation

BACKGROUND AND OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) serves as cardiopulmonary therapy in critically ill patients with respiratory/heart failure and often necessitates multiple blood product transfusions. The administration of platelet transfusions during ECMO is triggered by the presence or risk of significant bleeding. Most paediatric ECMO programmes follow guidelines that recommend a platelet transfusion threshold of 80-100 × 109/L. To reduce exposure to platelets, we developed a practice to dynamically lower the threshold to ~20 × 109/L. We describe our experience with patient-tailored platelet thresholds and related bleeding outcomes.

MATERIALS AND METHODS

We retrospectively evaluated our platelet transfusion policy, bleeding complications and patient outcome in 229 ECMO-supported paediatric patients in our unit.

RESULTS

We found that more than 97.4% of patients had a platelet count <100 × 109/L at some point during their ECMO course. Platelets were transfused only on 28.5% of ECMO days; and 19.2% of patients never required a platelet transfusion. The median lowest platelet count in children who had bleeding events was 25 × 109/L as compared to 33 × 109/L in children who did not bleed (p < 0.001). Our patients received fewer platelet transfusions and did not require more red blood cell transfusions, nor did they experience more haemorrhagic complications.

CONCLUSION

We have shown that a restrictive, 'patient-tailored' rather than 'goal-directed' platelet transfusion policy is feasible and safe, which can greatly reduce the use of platelet products. Although there was a difference in the lowest platelet counts in children who bled versus those who did not, the median counts were much lower than current recommendations.

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.

Successful decompressive laparotomy in a neonate with abdominal compartment syndrome on extracorporeal membrane oxygenation following congenital diaphragmatic hernia repair

Abdominal compartment syndrome (ACS) is a rare complication of extracorporeal membrane oxygenation (ECMO) and is associated with high morbidity and mortality. Despite being the treatment of choice for ACS, decompressive laparotomy (DL) has been a matter of debate in children supported with ECMO due to high bleeding risk and presumed futility. We report the first neonatal DL for ACS while on ECMO following congenital diaphragmatic hernia (CDH) repair. Given its excellent outcomes, our case challenges current literature and supports prompt bedside laparotomy to treat ACS on neonatal ECMO.

Management of Bivalirudin Dosing and Replacement Fluid During Therapeutic Plasma Exchange in Children on Extracorporeal Membrane Oxygenation

The use of bivalirudin as the primary anticoagulant for children supported on extracorporeal membrane oxygenation (ECMO) is growing. Ideal management of bivalirudin dosing during therapeutic plasma exchange (TPE) on ECMO is unknown. We performed a single-center retrospective study of ECMO patients anticoagulated with bivalirudin who underwent TPE from January 2019 to December 2021. Therapeutic plasma exchange sessions were analyzed individually by bivalirudin dosing strategy (no change [NC] versus increased dose [dose change {DC} bivalirudin group]) and replacement fluid (all fresh-frozen plasma [FFP] versus all albumin or FFP and albumin [FFP/Albumin]). Primary outcomes included bleeding, coagulopathy, and circuit thrombosis within 24 hours of TPE. Secondary outcomes included change in bivalirudin dose and coagulation parameters following TPE. There were 60 unique TPE sessions. Bivalirudin dosing or replacement fluid strategies were not associated with bleeding, coagulopathy, or thrombosis post-TPE. All albumin or fresh frozen plasma and albumin combinations (FFP/Albumin) group had longer post-TPE thromboelastography (TEG) reaction time, clot time, and more acute angle. The FFP/Albumin group had increased post-TPE international normalization ratio (INR) and partial thrombin time (PTT). Therapeutic plasma exchange for children on ECMO and bivalirudin anticoagulation is feasible; however, optimal dosing during TPE requires further investigation. Replacement fluid with FFP/Albumin is associated with more coagulopathic laboratory parameters. Patients may benefit from all FFP fluid replacement strategy. Further investigation is needed to prove generalizability.

Outcomes of a Vial-Sparing Antithrombin III Protocol in Pediatric Extracorporeal Membrane Oxygenation

Exogenous antithrombin III (AT3) may be administered to pediatric patients supported by extracorporeal membrane oxygenation (ECMO) to achieve a greater systemic response to heparin. Antithrombin III administration and dosing practices vary between ECMO centers. This study compared the outcomes of two different AT3 replacement protocols used by a single pediatric ECMO center for 47 patients between December 2013 and August 2021. In May 2016, a weight-based continuous infusion protocol (WBP) was transitioned to a vial-sparing protocol (VSP) as a cost-saving measure. No difference was observed in the percentage of heparin monitoring levels within goal range, with a median of 56.5% therapeutic levels on the WBP compared with a median of 60.7% on the VSP ( p = 0.170). No significant differences were observed in amount of exogenous blood products administered, number of hemorrhagic or thrombotic events, number of mechanical failures, or number of circuit changes required. The VSP resulted in fewer AT3 dispenses ( p < 0.001) and units dispensed ( p = 0.005), resulting in a significant median cost reduction from $15,610.62 on the WBP to $7,765.56 on the VSP ( p = 0.005). A vial-sparing AT3 replacement protocol resulted in significant cost savings with similar efficacy and safety outcomes.

Comparison of net adverse clinical events between bivalirudin and heparin as anticoagulants for percutaneous coronary intervention in Chinese patients

Bivalirudin, as a direct thrombin inhibitor, is considered to be safer compared with other anticoagulants, such as heparin; however, relevant data in China are unclear. The present study aimed to compare the safety of bivalirudin and heparin as anticoagulants in Chinese patients who underwent percutaneous coronary intervention (PCI). In the present study, 2,377 patients with ST-segment elevation myocardial infarction (STEMI), unstable angina, non-STEMI or stable coronary artery disease who underwent primary PCI while receiving bivalirudin or heparin (low molecular weight heparin or unfractionated heparin) were reviewed, and then analyzed as the bivalirudin group (n=944) and heparin group (n=1,433). The net adverse clinical events (NACEs) within 30 days were obtained, which were defined as major adverse cardiac and cerebral events (MACCEs) + Bleeding Academic Research Consortium (BARC) grade 2-5 bleeding events. Compared with the heparin group, the incidence of NACEs was reduced in the bivalirudin group (9.3 vs. 13.4%; P=0.003). However, no discrepancy was found in the incidence of MACCEs between the groups (5.9 vs. 7.6%; P=0.116). Moreover, the incidences of BARC 2-5 (4.8 vs. 8.7%; P<0.001) and BARC 3-5 bleeding events (1.9 vs. 4.4%; P=0.001) were decreased in the bivalirudin group compared with the heparin group. Following adjustment using multivariate logistic regression analysis, bivalirudin treatment (vs. heparin treatment) was independently associated with lower risks of NACEs [odds ratio (OR), 0.587; P<0.001], MACCEs (OR, 0.689; P=0.041) and BARC 2-5 (OR, 0.459; P<0.001) and 3-5 bleeding events (OR, 0.386; P=0.002). Overall, the present study demonstrated that bivalirudin decreased the risks of NACEs and bleeding events compared with heparin in Chinese patients who undergo PCI. However, further validation is required.

Anticoagulation with Intravenous Direct Thrombin Inhibitors in Pediatric Extracorporeal Membrane Oxygenation: A Systematic Review of the Literature

Although intravenous (IV) direct thrombin inhibitors (DTI) have gained interest in pediatric extracorporeal membrane oxygenation (ECMO), dosing and safety information is limited. The objective of this systematic review was to characterize DTI types, dosing, monitoring, and outcomes (bleeding and thromboembolic) in pediatric ECMO patients managed with IV DTIs. We conducted searches of MEDLINE (Ovid) and Embase (Elsevier) from inception through December 2022. Case reports, retrospective studies, and prospective studies providing per-patients or summary data for patient(s) <18 years of age receiving IV DTI for ECMO anticoagulation were included. Study selection and data extraction were conducted independently by two reviewers. A total of 28 studies: 14 case reports, 13 retrospective studies, and 1 prospective study were included, totaling 329 patients. Bivalirudin was utilized in 318 (96.7%), argatroban in 9 (2.7%), and lepirudin in 2 (0.6%) patients. Infusion dosing included: bivalirudin 0.14 ± 0.37 mg/kg/h, argatroban 0.69 ± 0.73 µg/kg/min, lepirudin 0.14 ± 0.02 mg/kg/h. Laboratory monitoring tests utilized were the activated clotting time, activated partial thromboplastin time (aPTT), diluted thrombin time, and thromboelastography measures. The aPTT was utilized in most patients (95%). Thromboembolism, bleeding, or death were observed in 17%, 17%, and 23% of bivalirudin, argatroban, and lepirudin patients, respectively. Bivalirudin appears to be the most frequently used DTI in pediatric ECMO. Dosing and laboratory monitoring varied, and bleeding and thromboembolic events were reported in 17% of patients. Prospective studies are warranted to establish dosing, monitoring, safety, and efficacy of bivalirudin and other IV DTI in pediatric ECMO.

Anticoagulation strategies in patients with extracorporeal membrane oxygenation: A network meta-analysis and systematic review

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) plays an important role in providing temporary life support for patients with severe cardiac or pulmonary failure, but requires strict anticoagulation and monitoring. This network meta-analysis systematically explored the most effective anticoagulation and monitoring strategies for patients receiving ECMO.

METHODS

MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials were searched up to January 31, 2023, for studies comparing unfractionated heparin (UFH), argatroban (Arg), bivalirudin (Biv), and/or nafamostat mesylate (NM) in patients receiving ECMO. The primary outcomes included device-related thrombosis, patient-related thrombosis, and major bleeding events. The secondary outcomes included ECMO survival, ECMO duration, and in-hospital mortality.

RESULTS

A total of 2522 patients from 23 trials were included in the study. Biv was associated with a decreased risk of device-related thrombosis (odd ratio [OR] 0.51, 95% confidence interval [CI]: 0.33-0.84) compared with UFH, whereas NM (OR 2.2, 95% CI: 0.24-65.0) and Arg (OR 0.92, 95% CI: 0.43-2.0) did not reduce the risk of device-related thrombosis compared with UFH. Biv was superior to Arg in decreasing the risk of device-related thrombosis (OR 0.14, 95% CI: 0.03-0.51). Biv reduced the risk of patient-related thrombosis compared with UFH (OR 0.44, 95% CI: 0.18-0.85); NM (OR 0.65, 95% CI: 0.14-3.3) and Arg (OR 3.1, 95% CI: 0.94-12.0) did not decrease risk of patient-related thrombosis compared with UFH. No significant difference was observed in the risk of major bleeding between three alternatives and UFH: Biv (OR 0.54, 95% CI: 0.23-1.3), Arg (OR 1.3, 95% CI: 0.34-5.8), and NM (OR 0.60, 95% CI: 0.13-2.6). NM showed a reduced risk of in-hospital mortality compared with UFH (OR 0.27, 95% CI: 0.091-0.77), whereas Arg (OR 0.43, 95% CI: 0.15-1.2) and Biv (OR 0.75, 95% CI: 0.52-1.1) did not decrease risk of in-hospital mortality.

CONCLUSIONS

Compared with UFH and Arg, Biv reduces the risk of thrombosis and appears to be a better choice for patients requiring ECMO. NM was associated with a reduced risk of in-hospital mortality.

Bivalirudin versus heparin anticoagulation in patients receiving extracorporeal membrane oxygenation

OBJECTIVE

Bivalirudin has been suggested as an alternative to heparin for anticoagulation in patients receiving extracorporeal membrane oxygenation (ECMO). Nevertheless, there is limited evidence about the benefit of bivalirudin in ECMO patients compared with heparin. Hence, we conducted a meta-analysis to assess the effect of bivalirudin versus heparin on clinical outcomes in patients receiving ECMO.

METHODS

PubMed, Embase, and the Cochrane Library were systematically searched from inception up to 1 April 2022 for cohort studies and randomized controlled trials comparing bivalirudin versus heparin in patients who received ECMO. The primary outcome was short-term death. Secondary outcomes included thrombotic events and bleeding events.

RESULTS

We selected 12 retrospective cohort studies with 1232 ECMO patients focusing on bivalirudin anticoagulation (n = 497) versus heparin anticoagulation (n = 735). Two hundred and one of 497 patients (40.4%) in the bivalirudin group versus 350 of 735 patients (47.6%) in the heparin group did not survive to hospital discharge. Compared with the heparin group, bivalirudin anticoagulation did not significantly decrease in-hospital mortality in patients receiving ECMO (RR, 0.95; 95% CI, 0.79-1.13; p = 0.546). Fifty-seven of 374 patients (15.2%) in the bivalirudin versus 99 of 381 patients (26.0%) in the heparin group suffered from thrombotic events. Compared with the heparin group, bivalirudin anticoagulation did not significantly decrease the rate of thrombotic events for patients receiving ECMO (RR, 0.78; 95% CI, 0.45-1.35; p = 0.378). However, bivalirudin anticoagulation significantly decreased the incidence of bleeding events compared to the heparin group (RR, 0.48; 95% CI, 0.25-0.95; p = 0.035).

CONCLUSIONS

Compared with heparin anticoagulation, bivalirudin did not decrease the rates of short-term mortality and thrombotic events, but reduced the incidence of bleeding events in patients receiving ECMO.

Bivalirudin or heparin for systemic anticoagulation during pediatric extracorporeal membrane oxygenation: Multicenter retrospective study

BACKGROUND

The objective of this study is to evaluate the outcomes of unfractionated heparin (UFH) compared to bivalirudin anticoagulation in pediatric ExtraCorporeal Membrane Oxygenation (ECMO).

METHODS

A multicenter retrospective study, that included pediatric patients <18 years of age, who were supported on ECMO between June 2017 and May 2020. Patients treated with UFH were matched 2:1 by age and type of ECMO support to the bivalirudin group.

RESULTS

The bivalirudin group (75 patients) were matched to 150 patients treated with UFH. Baseline characteristics and comorbidities of the two groups were similar. Veno-Arterial ECMO was the most common mode (141/225 [63 %]) followed by extracorporeal cardiopulmonary resuscitation (48/225 [21 %]). Bivalirudin treatment was associated with lower odds of bleeding events (aOR 0.23, 95%CI 0.12-0.45, p < 0.001) and lower odds of thrombotic events (aOR 0.48, 95%CI 0.23-0.98, p = 0.045). Patients who received bivalirudin had lesser odds for transfusion with fresh frozen plasma, and platelets (aOR 0.26, CI 0.12-0.57, p ≤0.001 and aOR 0.28, CI 0.15-0.53, p < 0.001, respectively). After adjusting for the type of ECMO support and adjusting for age, bivalirudin was associated with a decrease in hospital mortality by 50 % compared to the UFH group (aOR 0.50, 95%CI 0.27-0.93, p = 0.028). Similarly, for neurological disability at time of discharge, bivalirudin was associated with higher odds of intact neurological outcomes compared to UFH (OR 1.99 [95%CI 1.13-3.51], p = 0.017).

CONCLUSIONS

This study demonstrated that effective anticoagulation can be achieved with bivalirudin, which was associated with lesser odds of bleeding events and utilization of blood products. Bivalirudin, in comparison with UFH, was associated with greater odds of hospital survival and intact neurological function at the time of discharge. A prospective randomized trial is required to validate the results of this study.

Is it time to switch to bivalirudin for ECMO anticoagulation?

For decades, unfractionated heparin (hereafter, heparin) has been the primary anticoagulant used for extracorporeal membrane oxygenation (ECMO) support. More recently, however, bivalirudin, a direct thrombin inhibitor, has emerged as an alternative. This systematic review based on PRISMA guidelines, aims to summarize 16 comparative studies and 8 meta-analysis and review articles published from January, 2011 till May, 2023 which directly compares ECMO courses using heparin versus bivalirudin as the anticoagulant. While this comparison is complicated by the lack of a standardized definition of major bleeding or thrombosis, our overall findings suggest there is no statistical difference between heparin and bivalirudin in incidence of bleeding and thrombosis. That said, some studies found a statistical significance favoring bivalirudin in reducing major bleeding, thrombosis, and the need for transfusions. We also offer essential guidance for appropriately selecting an anticoagulant and monitoring its effect in ECMO settings.

Systemic anticoagulation in ECMO

While unfractionated heparin (UFH) remains the mainstay of anticoagulation during pediatric extracorporeal life support, direct thrombin inhibitors (DTIs) are increasingly used. In this article, we will review most recent evidence regarding utilization of both UFH and DTIs and compare their known advantages and disadvantages. We will present anticoagulation monitoring strategies during ECMO and outline the most recent Extracorporeal Life Support Organization's anticoagulation guidelines, however with the caveat that there are no true consensus recommendations for anticoagulation management in pediatric ECMO. With these updates, we will serve as the bedside clinician's refresher on common practices for anticoagulation during "routine" ECMO. We will additionally highlight special circumstances, including high risk surgical procedures during ECMO, in which adjustments in anticoagulation and/or addition of antifibrinolytic therapy might mitigate risk.

Bivalirudin Compared to Heparin as the Primary Anticoagulant in Pediatric Berlin Heart Recipients

Bivalirudin has been used in increasing frequency as an alternative to unfractionated heparin (UFH) in pediatric recipients of Berlin Heart EXCOR ventricular assist devices (VAD). This single-center, retrospective review characterizes anticoagulant trends and outcomes in pediatric Berlin Heart VAD recipients implanted between September 1, 2013, and August 31, 2021, anticoagulated with either bivalirudin or UFH. Thirty-one patients were included; 65% who received bivalirudin and 35% who received UFH. The median age was 2.9 years, included 64.5% females, with 61.3% of patients diagnosed with dilated cardiomyopathy and 25.8% of patients with congenital heart disease. Therapeutic anticoagulation was achieved sooner in the bivalirudin group compared to UFH via anti-Xa monitoring (median 5.7 and 69.5 hours, respectively, p < 0.001). Bivalirudin had a greater number of therapeutic values comparatively to UFH (52% and 24%, respectively; p < 0.001) and a superior number of hours in the therapeutic range (67% and 32%, respectively; p < 0.001). Secondary outcomes were similar among the two groups, apart from greater chest tube output (UFH), more frequent events of elevated plasma-free hemoglobin (bivalirudin), and more frequent elevated inflammatory markers postimplant (bivalirudin). Prevalence of pump replacements secondary to significant clot burden and prevalence of stroke was comparable. In this patient cohort, bivalirudin demonstrated greater anticoagulation stability comparatively to UFH. Multicenter collaboration would be necessary to identify whether this further translates into improved patient outcomes.

50 Years of Pediatric Hemostasis: Knowledge, Diagnosis, and Treatment

Studies from the past 50 years have contributed to the expanding knowledge regarding developmental hemostasis. This is a dynamic process that begins in the fetal phase and is characterized by physiological variations in platelet counts and function, and concentrations of most coagulation factors and the native coagulation inhibitors in early life, as compared with adulthood. The developmental hemostasis studies since the 1980 to 1990s established the laboratory reference values for coagulation factors. It was only a decade or two later, that thromboelastography (TEG) or (rotational thromboelastometry [ROTEM]) as well as thrombin generation studies, provided special pediatric reference values along with the ability to evaluate clot formation and lysis. In addition, global whole blood-based clotting assays provided point of care guidance for proper transfusion support to children hospitalized in intensive care units or undergoing surgery. Although uncommon, thrombosis in children and neonates is gaining increasing recognition, typically as a secondary complication in sick children. Bleeding in children, and particularly intracerebral hemorrhage in newborns, still represent a therapeutic challenge. Notably, our review will outline the advancements in understanding developmental hemostasis and its manifestations, with respect to the pathophysiology of thrombosis and bleeding complications in young children. The changes of transfusion policy and approach to thrombophilia testing during the last decade will be mentioned. Subsequently, a brief summary of the data on anticoagulant treatments in pediatric patients will be presented. Finally, we will point out the 10 most cited articles in the field of pediatric and neonatal hemostasis.

Heparin-based versus bivalirudin-based anticoagulation in pediatric extracorporeal membrane oxygenation: A systematic review

Introduction

Optimal anticoagulation therapy is essential for the prevention of thrombotic and hemorrhagic complications in pediatric patients supported with extracorporeal membrane oxygenation (ECMO). Recent data have demonstrated bivalirudin has the potential to surpass and replace heparin as the anticoagulant of choice.

Methods

We conducted a systematic review comparing the outcomes of heparin-based versus bivalirudin-based anticoagulation in pediatric patients supported on ECMO to identify the preferred anticoagulant to minimize bleeding events, thrombotic complications, and associated mortality. We referenced the PubMed, Cochrane Library, and Embase databases. These databases were searched from inception through October 2022. Our initial search identified 422 studies. All records were screened by two independent reviewers using the Covidence software for adherence to our inclusion criteria, and seven retrospective cohort studies were identified as appropriate for inclusion.

Results

In total, 196 pediatric patients were anticoagulated with heparin and 117 were anticoagulated with bivalirudin while on ECMO. Across the included studies, it was found that for patients treated with bivalirudin, trends were noted toward lower rates of bleeding, transfusion requirements, and thrombosis with no difference in mortality. Overall costs associated with bivalirudin therapy were lower. Time to therapeutic anticoagulation varied between studies though institutions had different anticoagulation targets.

Conclusion

Bivalirudin may be a safe, cost-effective alternative to heparin in achieving anticoagulation in pediatric ECMO patients. Prospective multicenter studies and randomized control trials with standard anticoagulation targets are needed to accurately compare outcomes associated with heparin versus bivalirudin in pediatric ECMO patients.

Comparison of bivalirudin versus heparin in adult extracorporeal membrane oxygenation anticoagulant therapy: A retrospective case-control study

INTRODUCTION

There were controversial opinions on the use of bivalirudin versus heparin for anticoagulant therapy in extracorporeal membrane oxygenation. The aim of our present study is to evaluate the efficacy and safety of bivalirudin versus heparin for the maintenance of systemic anticoagulation during adult veno-venous extracorporeal membrane oxygenation (V-V ECMO).

METHODS

Adult patients who received V-V ECMO support in our center between February 2018and February 2022 were retrospectively recruited. We analyzed their ECMO support time, platelet count, coagulation indicators, blood product infusion volume, the incidence of thrombosis and bleeding, probability of successful weaning of ECMO, and in-hospital mortality.

RESULTS

A total of 58 patients received V-V ECMO support. Thirty-four patients were finally included according to the exclusion and inclusion criteria, 14 and 20 accepted bivalirudin and heparin for anticoagulant therapy, respectively. The Minimum platelet value (98.50 × 10⁹/L (85.50, 123.75) vs 49.50 × 10⁹/L (31.25, 83.00), p = 0.002) and mean platelet value (149.90 × 10⁹/L (127.40, 164.80) vs 74.55 × 10⁹/L (62.45, 131.60), p = 0.03) and the ratio of successful weaning of ECMO (92.8% vs 60.0%, p = 0.033) in bivalirudin group were significantly higher than those in heparin group. The red blood cell infusion volume (7.00 U (3.00, 13.25) vs 13.75 U (7.25, 22.63), p = 0.039), platelet infusion volume (0.00 mL (0.00, 75.00) vs 300 mL (0.00, 825.00), p = 0.027), and the incidence of major bleeding (0.00% vs 30%, p = 0.024) in bivalirudin group were significantly lower than those in heparin group.

CONCLUSIONS

In V-V ECMO-supported adult patients, systemic anticoagulation with bivalirudin has achieved the same anticoagulation targets as heparin with less frequency of major bleeding events and lower requirement for blood products without significantly increased risk of thrombosis. Bivalirudin most likely is a safe and effective anticoagulation method for adult patients supported by V-V ECMO.

Analysis of Wholesale Drug Acquisition and Laboratory Assessment Costs Between Heparin Compared With Bivalirudin-Based Systemic Anticoagulation Strategies in Adult Extracorporeal Membrane Oxygenation

OBJECTIVES

To assess the wholistic costs of systemic anticoagulation delivery in heparin versus bivalirudin-based maintenance of adult patients supported on extracorporeal membrane oxygenation (ECMO).

DESIGN

Single-center retrospective cohort study.

SETTING

Large academic ECMO center.

PATIENTS

Adults on ECMO receiving heparin or bivalirudin for primary maintenance systemic anticoagulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Electronic data were abstracted from a database maintained by our ECMO center, which transitioned to a preferred bivalirudin-based anticoagulation management in 2017. The pretransition group consisted of 126 patients (123 heparin and three bivalirudin), whereas the posttransition group included 275 patients (82 heparin and 193 bivalirudin). Drug costs were estimated using the wholesale acquisition cost, and laboratory assays costs were estimated using reimbursement fee schedules. Cost data were normalized to the duration of the ECMO run and reported in U.S. Dollar per ECMO day. Following the practice change, bivalirudin patients were less likely to receive AT supplementation (31.0 vs 12.4%; p < 0.0001) and had fewer coagulation assays ordered (6.1 vs 5.4 per ECMO day; p = 0.0004). After the transition, there was a dramatic decrease in costs related to AT assay assessments ($11.78 [interquartile range {IQR}, $9.48-$13.09] vs $1.03 [IQR, $0-$5.75]; p < 0.0001) and AT supplementation ($0 [IQR, $0-$312.82] vs $0 [IQR, $0-$0]; p < 0.0001) per ECMO day. Unadjusted survival at 28 days was higher posttransition (64.3 vs 74.9%; p = 0.0286).

CONCLUSIONS

Antithrombin assays and supplementation compromise a significant proportion of heparin-based anticoagulation costs in ECMO patients and is substantially reduced when a bivalirudin-based anticoagulation strategy is deployed. A favorable association exists between the aggregate cost of administration of bivalirudin compared with heparin-based systemic anticoagulation in adults supported on ECMO driven by reductions in antithrombin activity assessments and the cost of antithrombin replacement.

Superiority of bivalirudin over heparin anticoagulation therapy for extracorporeal membrane oxygenation? Too early to draw conclusions

Background

We aimed to compare the efficacy and safety of bivalirudin versus heparin as the anticoagulant in patients undergoing extracorporeal membrane oxygenation (ECMO).

Methods

We conducted a search in PubMed, Embase and the Cochrane Library for all the studies in which bivalirudin was compared to heparin as the anticoagulant for ECMO. Efficacy outcomes were defined as the time to reach therapeutic levels, time within therapeutic range (TTR), thrombotic events, circuit thrombosis, circuit exchanges. Safety outcomes were reported as heparin-induced thrombocytopenia (HIT), major bleeding events, minor bleeding events. Other outcomes included hospital length of stay (LOS), ICU LOS, mortality, 30-day mortality and in-hospital mortality.

Results

Ten studies with 1091 patients were included for meta-analysis. A significant reduction in thrombotic events [OR 0.51, 95%CI 0.36,0.73, p = 0.0002, I² = 0%], major bleeding events [OR 0.31, 95%CI 0.10,0.92, p = 0.04, I² = 75%] and in-hospital mortality [OR 0.63, 95%CI 0.44,0.89, p = 0.009, I² = 0%] treated with bivalirudin were found compared with heparin. There were no significant differences between groups regarding the time to reach therapeutic levels [MD 3.53, 95%CI -4.02,11.09, p = 0.36, I² = 49%], TTR [MD 8.64, 95%CI -1.72,18.65, p = 0.10, I² = 77%], circuit exchanges [OR 0.92, 95%CI 0.27,3.12, p = 0.90, I² = 38%], HIT [OR 0.25, 95%CI 0.02,2.52, p = 0.24, I² = 0%], minor bleeding events [OR 0.93, 95%CI 0.38,2.29, p = 0.87, I² = 0%], hospital LOS [MD -2.93, 95%CI -9.01,3.15, p = 0.34, I² = 45%], ICU LOS [MD -4.22, 95%CI -10.07,1.62, p = 0.16, I² = 0%], mortality [OR 1.84, 95%CI 0.58,5.85, p = 0.30, I² = 60%] and 30-day mortality [OR 0.75, 95%CI 0.38,1.48, p = 0.41, I² = 0%].

Conclusion

Bivalirudin probably be a potential choice for ECMO anticoagulation. However, based on the included studies' limitation, the superiority of bivalirudin over heparin for anticoagulation in the ECMO population still require further prospective randomized controlled studies before a definite conclusion.

Extracorporeal Membrane Oxygenation in Acute Respiratory Failure

Venovenous (VV) extracorporeal membrane oxygenation (ECMO) is a form of mechanical life support that provides full respiratory bypass in patients with severe respiratory failure as a bridge to recovery or lung transplantation. The use of ECMO for respiratory failure and capable centers offering ECMO has expanded over the years, increasing its availability. As VV-ECMO provides an artificial mechanism for oxygenation and decarboxylation of native blood, it allows for an environment in which safer mechanical ventilatory care may be provided, allowing for treatment and resolution of underlying respiratory pathologies. Landmark clinical trials have provided a framework for better understanding patient selection criteria, resource utilization, and outcomes associated with ECMO when applied in settings of refractory respiratory failure. Maintaining close vigilance and management of complications during ECMO as well as identifying strategies post-ECMO (e.g., recovery, transplantation, etc.), are critical to successful ECMO support. In this review, we examine considerations for candidate selection for VV-ECMO, review the evidence of utilizing VV-ECMO in respiratory failure, and provide practical considerations for managing respiratory ECMO patients, including complication identification and management, as well as assessing for the ability to separate from ECMO support and the procedures for decannulation.

Monitoring Direct Thrombin Inhibitors With Calibrated Diluted Thrombin Time vs Activated Partial Thromboplastin Time in Pediatric Patients

OBJECTIVES

Activated partial thromboplastin time (aPTT) is the primary test used to monitor intravenous (IV) direct thrombin inhibitors (DTIs) but has many limitations. The plasma diluted thrombin time (dTT) has shown better correlation with DTI levels than aPTT. This study compared dose-response curves for dTT and aPTT in pediatric patients receiving argatroban and bivalirudin.

METHODS

A retrospective review of pediatric patients treated with argatroban (n = 45) or bivalirudin (n = 14) monitored with dTT and aPTT.

RESULTS

The dTT assay was calibrated to report DTI concentrations in µg/mL for argatroban and bivalirudin with good analytic sensitivity and specificity. The dTT was fivefold more likely to show a stable dose-response slope than the aPTT (P < .0002; odds ratio, 4.9). For patients in whom both dTT and aPTT showed a significant correlation between dose and assay results, dTT had a higher average correlation factor compared with aPTT (P = .007). Argatroban dose-response slopes showed more inter- and intrapatient variation than bivalirudin (dose-response slope coefficient of variation, 132% vs 52%).

CONCLUSIONS

The dTT assay was more likely to show a stable dose response and have a stronger correlation with DTI dose than aPTT. Argatroban shows more variation in dose response than bivalirudin.

Use of bivalirudin for anticoagulation in pediatric extracorporeal membrane oxygenation (ECMO)

This study describes the use of bivalirudin in children on extracorporeal membrane oxygenation (ECMO). Pediatric patients receiving bivalirudin were compared to patients receiving heparin as the anticoagulant on ECMO. Data was collected for children under 18 years of age supported by ECMO from January 2016 to December 2019. Data collected included demographics, diagnosis, ECMO indication, type, and duration, indication for bivalirudin use, dose range, activated partial thromboplastin time (aPTT) levels, minor and major bleeding, hemolysis, and mortality. Forty pediatric patients received ECMO; eight received bivalirudin primarily for anticoagulation. The median age was 4 months (IQR 0.5, 92) in the heparin cohort, 0.6 months (IQR 0.0, 80.0) in the primary bivalirudin cohort. The indication for ECMO was respiratory in 5 patients (18%) in the heparin group versus 6 (75%) in the primary bivalirudin group, cardiac in 18 (67%) in heparin versus 1 (12.5%) in primary bivalirudin, and extracorporeal-cardiopulmonary resuscitation (E-CPR) in 4 (15%) in heparin versus 1 (12.5%) in primary bivalirudin. Bivalirudin was the initial anticoagulant for eight patients (66.6%) while three (25%) were switched due to concern for heparin-induced thrombocytopenia (HIT) and one (8%) for heparin resistance. The median time to achieve therapeutic aPTT was 14.5 hours compared to 12 hours in the heparin group. Sixty-five percent of aPTT values in the bivalirudin and 44% of values in the heparin group were in the therapeutic range in the first 7 days. Patients with primary bivalirudin use had significantly lower dose requirement at 12 (p = 0.003), 36 (p = 0.007), and 48 (p = 0.0002) hours compared to patients with secondary use of bivalirudin. One patient (12.5%) had major bleeding, and two patients (25%) required circuit change in the primary bivalirudin cohort. Bivalirudin may provide stable and successful anticoagulation in children. Further large, multicenter studies are needed to confirm these findings.

Direct thrombin inhibitors as alternatives to heparin to preserve lung growth and function in a murine model of compensatory lung growth

Infants with congenital diaphragmatic hernia (CDH) may require cardiopulmonary bypass and systemic anticoagulation. Expeditious lung growth while on bypass is essential for survival. Previously, we demonstrated that heparin impairs lung growth and function in a murine model of compensatory lung growth (CLG). We investigated the effects of the direct thrombin inhibitors (DTIs) bivalirudin and argatroban. In vitro assays of lung endothelial cell proliferation and apoptosis were performed. C57BL/6 J mice underwent left pneumonectomy and subcutaneous implantation of osmotic pumps. Pumps were pre-loaded with normal saline (control), bivalirudin, argatroban, or heparin and outcomes were assessed on postoperative day 8. Heparin administration inhibited endothelial cell proliferation in vitro and significantly decreased lung volume in vivo, while bivalirudin and argatroban preserved lung growth. These findings correlated with changes in alveolarization on morphometric analysis. Treadmill exercise tolerance testing demonstrated impaired exercise performance in heparinized mice; bivalirudin/argatroban did not affect exercise tolerance. On lung protein analysis, heparin decreased angiogenic signaling which was not impacted by bivalirudin or argatroban. Together, this data supports the use of DTIs as alternatives to heparin for systemic anticoagulation in CDH patients on bypass. Based on this work, clinical studies on the impact of heparin and DTIs on CDH outcomes are warranted.

Updates in Neonatal Extracorporeal Membrane Oxygenation and the Artificial Placenta

Extracorporeal life support, initially performed in neonates, is now commonly used for both pediatric and adult patients requiring pulmonary and/or cardiac support. Data suggests the clinical feasibility of Extracorporeal Membrane Oxygenation for premature infants (29-33 weeks estimated gestational age [EGA]). For extremely premature infants less than 28 weeks EGA, an artificial placenta has been developed to recreate the fetal environment. This approach is investigational but clinical translation is promising. In this article, we discuss the current state and advances in neonatal and "preemie Extracorporeal Membrane Oxygenation" and the development of an artificial placenta and its potential use in extremely premature infants.

Evaluation of Bivalirudin Dosing in Pediatric Extracorporeal Membrane Oxygenation with Renal Insufficiency or Renal Replacement Therapy

Bivalirudin offers several important advantages of relevance to the management of extracorporeal membrane oxygenation (ECMO) patients. This multicenter retrospective analysis evaluated the bivalirudin dosing in pediatric ECMO and correlated these doses with the severity of renal dysfunction. A total of 75 patients were included in this analyses: estimated glomerular filtration rate (eGFR) > 60 ml/min/1.73 m 2 (n = 29), eGFR 30-60 (n = 18), eGFR < 30 (n = 28), and of those 23 were on renal replacement therapy (RRT). The initial bivalirudin dose used to reach therapeutic anticoagulation in patients with eGFR > 60 was significantly higher than the dose required in those with renal impairment (0.25 mg/kg/hr in patients with eGFR > 60 and 0.19 mg/kg/hr in patients on RRT, 0.18 mg/kg/hr in patients with eGFR 30-60 and 0.13 mg/kg/hr in patients with eGFR < 30 with no RRT). Progressive dose escalations (two to threefold increase) were required to maintain therapeutic range over the initial 4 days of ECMO that coincided with improving renal creatinine clearance during that same time period. Establishing an initial starting dose of bivalirudin contingent upon eGFR is essential for the rapid achievement of target anticoagulation intensity. Further dose adjustments guided by laboratory monitoring is necessary given the dynamic changes in creatinine clearance following ECMO initiation.

Impact of Continuous Renal Replacement Therapy on Bivalirudin Dosing in Pediatric Extracorporeal Membrane Oxygenation

There is an increasing interest in the use of bivalirudin for pediatric extracorporeal membrane oxygenation (ECMO) anticoagulation. However, dosing is not well described in those requiring continuous renal replacement therapy (CRRT). We aimed to determine whether CRRT affects bivalirudin dosing in pediatric ECMO patients. Children ≤18 years of age placed on ECMO and anticoagulated with bivalirudin for ≥24 hours from January 2019 to May 2020 were included. Bivalirudin doses were collected for 144 hours from initiation of bivalirudin or CRRT. Analysis was performed to determine whether CRRT, age, or weight affected bivalirudin dosing. Thirty-one children were included, and 11 (35%) required concomitant CRRT. There was no difference in age (median 9.1 versus 3.2 months, p = 0.15) or days on ECMO (median 11 versus 9, p = 0.7) between those who did or did not receive CRRT. The mean bivalirudin dosing was similar in patients who did or did not require CRRT (median and IQR: 0.13 mg/kg/hour [0.08-0.26] versus 0.15 mg/kg/hour [0.11-0.22], respectively, p = 0.13). Younger age ( p < 0.001) and lower weight ( p < 0.001) were associated with higher bivalirudin dosing. In our study, bivalirudin dosing did not differ if the patient required CRRT while on ECMO.

Comparison of Bivalirudin Versus Heparin for Anticoagulation During Extracorporeal Membrane Oxygenation

The effect and safety of bivalirudin compared with heparin in patients undergoing extracorporeal membrane oxygenation (ECMO) remains unclear. Therefore, we conducted a systematic review and meta-analysis to compare the effectiveness and safety of heparin and bivalirudin in patients who underwent ECMO. We searched Embase, the Cochrane Central Register of Controlled Trials, and MEDLINE. Inclusion criteria included patients (1) undergoing ECMO and (2) receiving bivalirudin or heparin. We excluded studies where the majority of patients switched heparin to bivalirudin or vice versa during the clinical course. The primary outcome was short-term mortality. We presented the results of all analyses with the use of random-effects models. Eleven studies reported short-term mortality. The use of bivalirudin was associated with significantly lower short-term mortality, compared with heparin (odds ratio: 0.71, 95% confidence interval, 0.55-0.92; p = 0.01, I2 = 7%). In this meta-analysis of observational studies, the use of bivalirudin was associated with significantly lower short-term mortality, compared with heparin. Further prospective studies are warranted to clarify this finding.

Bivalirudin or Unfractionated Heparin for Anticoagulation in Pediatric Patients on Continuous Flow Ventricular Assist Device Support: Single-Center Retrospective Cohort Study

OBJECTIVES

Bivalirudin is a direct thrombin inhibitor that is being increasingly used for anticoagulation in children after ventricular assist device (VAD) implantation. While the data on bivalirudin use in pulsatile flow VADs are growing, reports on its use in patients on continuous flow (CF) VAD as well as comparisons of associated outcomes with unfractionated heparin (UFH) remain limited.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary-quaternary referral center.

PATIENTS

All patients less than 21 years old on CF-VAD support who received bivalirudin or UFH for anticoagulation between the years 2016 and 2020.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

Clinical characteristics compared between the cohorts included time to target range of anticoagulation, markers of hemolysis, and prevalence of hemocompatibility-related adverse events such as major hemorrhagic complications, ischemic stroke, and pump thrombosis. In 42 unique patients (41 HeartWare HVAD [Medtronic, Minneapolis, MN], one HeartMate 3 LVAD [Abbott Laboratories, Abbott Park, IL]) during the study period, a total of 67 encounters of IV anticoagulation infusions (29 UFH and 38 bivalirudin) were retrospectively reviewed. In comparison with use of UFH, bivalirudin was associated with lesser odds of major bleeding complications (odds ratio [OR], 0.29; 95% CI, 0.09-0.97; p = 0.038). We failed to identify any difference in odds of major thrombotic complications (OR, 2.53; 95% CI, 0.47-13.59; p = 0.450). Eight of the patients (28%) on UFH were switched to bivalirudin due to hemorrhagic or thrombotic complications or inability to achieve therapeutic anticoagulation, while two of the patients (5%) on bivalirudin were switched to UFH due to hemorrhagic complications. Bivalirudin was used for a "washout" in eight cases with concern for pump thrombosis-six had resolution of the pump thrombosis, while two needed pump exchange.

CONCLUSIONS

Use of bivalirudin for anticoagulation in patients on CF-VAD support was associated with lesser odds of hemorrhagic complications compared with use of UFH. Bivalirudin "washout" was successful in medical management of six of eight cases of possible pump thrombosis.

Comparison of Extracorporeal Life Support Anticoagulation Using Activated Clotting Time Only to a Multimodal Approach in Pediatric Patients

OBJECTIVE

To evaluate an institutional practice change from an extracorporeal life support (ECLS) anticoagulation monitoring strategy of activated clotting time (ACT) alone to a multimodal strategy including ACT, activated partial thrombin time, heparin anti-factor-Xa, and thromboelastography.

METHODS

This was a retrospective review of patients younger than 18 years on ECLS and heparin between January 2014 and June 2020 at a single institution.

RESULTS

Twenty-seven patients used an ACT-directed strategy and 25 used a multimodal strategy. The ACT-directed group was on ECLS for a shorter median duration than the multimodal group (136 versus 164 hours; p = 0.046). There was a non-significant increase in major hemorrhage (85.1% versus 60%; p = 0.061) and a significantly higher incidence of central nervous system (CNS) hemorrhage in the ACT-directed group (29.6% versus 0%; p = 0.004). Rates of thrombosis were similar, with a median of 3 circuit changes per group (p = 0.921). The ACT-directed group had larger median heparin doses (55 versus 34 units/kg/hr; p < 0.001), required more dose adjustments per day (3.8 versus 1.7; p < 0.001), and had higher rates of heparin doses >50 units/kg/hr (62.9% versus 16%; p = 0.001). More anticoagulation parameters were supratherapeutic (p = 0.015) and fewer were therapeutic (p < 0.001) in the ACT-directed group.

CONCLUSIONS

Patients with a multimodal strategy for monitoring anticoagulation during ECLS had lower rates of CNS hemorrhage and decreased need for large heparin doses of >50 units/kg/hr without an increase in clotting complications, compared with ACT-directed anticoagulation. Multimodal anticoagulation monitoring appears superior to ACT-only strategies and may reduce heparin exposure and risk of hemorrhagic complications for pediatric patients on ECLS.

Evaluation of clinical outcomes in patients treated with heparin or direct thrombin inhibitors during extracorporeal membrane oxygenation: a systematic review and meta-analysis

BACKGROUND

The number of patients treated with extracorporeal membrane oxygenation (ECMO) devices is increasing. Anticoagulation therapy is crucial to prevent thrombosis during ECMO therapy. Predominantly, heparin has been used as primary anticoagulant but direct thrombin inhibitors (DTI) have been established as alternatives. The aim of this systematic review and meta-analysis was to evaluate clinical outcomes in patients treated with heparin compared to different DTI during ECMO.

METHODS

A systematic search was conducted. Full scientific articles were sought for inclusion if heparin anticoagulation was compared to DTI (argatroban/bivalirudin) in ECMO patients. Risk of bias was assessed by Newcastle Ottawa scale. Primary endpoint was in-hospital mortality. Bleeding events, thrombotic events, hours of ECMO support, days of hospital stay, percentage of time within therapeutic range and time to therapeutic range were extracted from full texts as secondary endpoints. Results were presented as Forrest-plots. GRADE was used for confidence assessment in outcomes.

RESULTS

Systematic search identified 4.385 records, thereof 18 retrospective studies for a total of 1942 patients, complied with the predefined eligibility criteria:15 studies investigated bivalirudin and 3 studies investigated argatroban versus heparin. Risk of bias was high for most studies. In-hospital mortality, major bleeding events and pump-related thrombosis were less frequent in DTI group as compared to heparin [mortality-OR 0.69, 95% CI 0.54-0.86; major bleeding-OR 0.48, 95% CI 0.29-0.81; pump thrombosis-OR 0.55, 95% CI 0.40-0.76]. Additionally, percentage of time within therapeutic range was higher for DTI [SMD 0.54, 95% CI 0.14-0.94]. GRADE approach revealed a very low level of certainty for each outcome.

CONCLUSION

In this meta-analysis, DTI and especially bivalirudin showed beneficial effects on clinical outcomes in ECMO patients as compared to heparin. However, due to the lack of randomized trials, certainty of evidence is low.

TRIAL REGISTRATION

This systematic review and meta-analysis was prospectively registered at PROSPERO data base (reference number CRD42021237252 ).

Anticoagulation with nafamostat mesilate during extracorporeal life support

Nafamostat mesylate (NM) affects coagulation and fibrinolysis and impedes obesity-associated protein demethylase activity, which regulates Na⁺/K⁺ transport properties and the NF-κB signaling pathway. NM significantly decreases macrophage, neutrophil, and T lymphocyte infiltration, thereby reducing inflammation and apoptosis after reperfusion and promoting recovery in patients with severe conditions such as near-fatal asthma and cardiac arrest. Extracorporeal life support (ECLS) devices are used for cardiac and/or pulmonary support as a bridge to recovery, decision, surgery, or transplant in patients with refractory cardio-circulatory or respiratory diseases and provide essential opportunities for organ support and patient survival. However, they can lead to some potential adverse events such as hemorrhage and thrombosis. NM provides a sustained innate immune response of coagulation and anti-inflammation in extracorporeal circuits, principally due to its activation of the contact and complement systems. Heparin is the main anticoagulant used in extracorporeal circuits; however, it may cause massive bleeding and heparin-induced thrombocytopenia. Although no antidote is available, NM has a very short half-life of approximately 8-10 min and might have positive effects on patients who require coagulation and anti-inflammation. NM has been used for anticoagulation in continuous renal replacement therapy, extracorporeal membrane oxygenation, hemodialysis, and left ventricular assist devices. In this review, we focused on the pharmacology, monitoring parameters, and considerations for the special use of NM in patients receiving ECLS. Our findings suggest that systemic anticoagulation with NM during ECLS might be a feasible and safe alternative with several advantages for critically ill patients with high-risk bleeding and might improve their prognosis.

The Changing Landscape of Anticoagulation in Pediatric Extracorporeal Membrane Oxygenation: Use of the Direct Thrombin Inhibitors

Bleeding and thrombosis frequently occur in pediatric patients with extracorporeal membrane oxygenation (ECMO) therapy. Until now, most patients are anticoagulated with unfractionated heparin (UFH). However, heparin has many disadvantages, such as binding to other plasma proteins and endothelial cells in addition to antithrombin, causing an unpredictable response, challenging monitoring, development of heparin resistance, and risk of heparin-induced thrombocytopenia (HIT). Direct thrombin inhibitors (DTIs), such as bivalirudin and argatroban, might be a good alternative. This review will discuss the use of both UFH and DTIs in pediatric patients with ECMO therapy.

Bivalirudin in pediatric extracorporeal membrane oxygenation

PURPOSE OF REVIEW

This review summarizes the current literature surrounding the use of bivalirudin as an alternative anticoagulant for pediatric extracorporeal membrane oxygenation (ECMO) patients.

RECENT FINDINGS

Recent single center studies describe that bivalirudin may be associated with decreased blood product transfusion, decreased cost and similar clinical outcomes for pediatric ECMO patients who have failed unfractionated heparin (UFH) anticoagulation. aPTT is the most common test to monitor bivalirudin but has several limitations. Other tests including dilute thrombin time (dTT) and viscoelastic assays are promising but more study is needed. Current evidence suggests that bivalirudin is a well tolerated and effective alternative anticoagulant for pediatric ECMO patients who have failed UFH anticoagulation but prospective studies are needed to confirm these results.

SUMMARY

Bivalirudin is a promising alternative anticoagulant for pediatric ECMO patients who have failed UFH. Large prospective, multicenter studies are needed to confirm safety and efficacy.

Hospital and Professional Charges and Reimbursement Patterns in Pediatric Extracorporeal Membrane Oxygenation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is an expensive therapeutic modality. We sought to identify the main charge contributors to patient bills and analyze their patterns of reimbursement. We additionally sought to evaluate the impact of 2015 Current Procedural Terminology (CPT) code changes in professional billing for pediatric surgeons.

METHODS

A retrospective review of ECMO cases at a standalone quaternary children's hospital between 2008-2017 was performed. Itemized hospital and professional bills were analyzed.

RESULTS

Top charges included room rates, nitric oxide, medications, invasive support and monitoring, and laboratory testing. Average reimbursement was ∼60% for hospital and ∼36% for professional bills. CPT code changes in 2015 represented a 65% reduction in RVUs and 46% reduction in professional charges. Medicaid reimbursement for professional billing remained stable at 9%, and commercial reimbursement fell from 70% to 59% during the study period.

CONCLUSIONS

The main drivers of ECMO charges are unrelated to ECMO supplies or surgery. Evidence-based guidelines for ECMO management could make a difference in healthcare expenditure. Modern CPT codes depreciate RVUs and professional charges, compromising revenue. As the infrastructure required to provide this service is costly, diminishing returns may limit access to this therapy.

Viscoelastic Testing in Pediatric Mechanical Circulatory Support

Pediatric mechanical circulatory support can be lifesaving. However, managing anticoagulation is one of the most challenging aspects of care in patients requiring mechanical circulatory support. Effective anticoagulation is even more difficult in pediatric patients due to the smaller size of their blood vessels, increased turbulent flow, and developmental hemostasis. Recently, viscoelastic testing (VET) has been used as a qualitative measure of anticoagulation efficacy in patients receiving extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VAD). Thromboelastography (TEG®) and thromboelastometry (ROTEM®) provide a global qualitative assessment of hemostatic function from initiation of clot formation with the platelet-fibrin interaction, platelet aggregation, clot strength, and clot lysis. This review focuses on the TEG®/ROTEM® and important laboratory and patient considerations for interpretation in the ECMO and VAD population. We summarize the adult and pediatric ECMO/VAD literature regarding VET values, VET-platelet mapping, utility over standard laboratory monitoring, and association with outcome measures such as blood product utilization, bleeding, and thrombosis.

The Efficacy and Safety of Bivalirudin Versus Heparin in the Anticoagulation Therapy of Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

Background: Bivalirudin is a direct thrombin inhibitor (DTI) that can be an alternative to unfractionated heparin (UFH). The efficacy and safety of bivalirudin in anticoagulation therapy in extracorporeal membrane oxygenation (ECMO) remain unknown. Methods: This study followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A systematic literature search was performed in PubMed, EMBASE, and The Cochrane Library databases to identify all relevant original studies estimating bivalirudin's efficacy and safety versus UFH as anticoagulation therapy in ECMO. The time limit for searching is from the search beginning to June 2021. Two researchers independently screened the literature, extracted data and evaluated the risk of bias of the included studies. The meta-analysis (CRD42020214713) was performed via the RevMan version 5.3.5 Software and STATA version 15.1 Software. Results: Ten articles with 847 patients were included for the quantitative analysis. Bivalirudin can significantly reduce the incidence of major bleeding in children (I 2 = 48%, p = 0.01, odd ratio (OR) = 0.17, 95% confidence interval (CI): 0.04-0.66), patient thrombosis (I 2 = 0%, p = 0.02, OR = 0.58, 95% CI: 0.37-0.93), in-circuit thrombosis/interventions (I 2 = 0%, p = 0.0005, OR = 0.40, 95% CI: 0.24-0.68), and in-hospital mortality (I 2 = 0%, p = 0.007, OR = 0.64, 95% CI: 0.46-0.88). Also, comparable clinical outcomes were observed in the incidence of major bleeding in adults (I 2 = 48%, p = 0.65, OR = 0.87, 95% CI: 0.46-1.62), 30-day mortality (I 2 = 0%, p = 0.61, OR = 0.83, 95% CI: 0.41-1.68), and ECMO duration in adults (I 2 = 41%, p = 0.75, mean difference (MD) = -3.19, 95% CI: -23.01-16.63) and children (I 2 = 76%, p = 0.65, MD = 40.33, 95% CI:-135.45-216.12). Conclusions: Compared with UFH, bivalirudin can be a safe and feasible alternative anticoagulant option to UFH as anticoagulation therapy in ECMO, especially for heparin resistance (HR) and heparin-induced thrombocytopenia (HIT) cases.

Direct Thrombin Inhibition in Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is a widely used technique to provide circulatory and/or respiratory support in critically ill patients. ECMO treatment usually necessitates systemic anticoagulation. Unfractionated Heparin (UFH) is a commonly used anticoagulant in patients on ECMO support. In situations where UFH is contraindicated, alternative anticoagulation strategies can be applied, such as the use of direct thrombin inhibitors (DTI). Bivalirudin and argatroban are the most widely used DTIs. In this report we give account of the current evidence regarding dosing, monitoring and complications associated with the use of these agents in ECMO dependent patients.

Extracorporeal Membrane Oxygenation in Congenital Heart Disease

Mechanical circulatory support (MCS) is a key therapy in the management of patients with severe cardiac disease or respiratory failure. There are two major forms of MCS commonly employed in the pediatric population—extracorporeal membrane oxygenation (ECMO) and ventricular assist device (VAD). These modalities have overlapping but distinct roles in the management of pediatric patients with severe cardiopulmonary compromise. The use of ECMO to provide circulatory support arose from the development of the first membrane oxygenator by George Clowes in 1957, and subsequent incorporation into pediatric cardiopulmonary bypass (CPB) by Dorson and colleagues. The first successful application of ECMO in children with congenital heart disease undergoing cardiac surgery was reported by Baffes et al. in 1970. For the ensuing nearly two decades, ECMO was performed sparingly and only in specialized centers with varying degrees of success. The formation of the Extracorporeal Life Support Organization (ELSO) in 1989 allowed for the collation of ECMO-related data across multiple centers for the first time. This facilitated development of consensus guidelines for the use of ECMO in various populations. Coupled with improving ECMO technology, these advances resulted in significant improvements in ECMO utilization, morbidity, and mortality. This article will review the use of ECMO in children with congenital heart disease.

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.

Bivalirudin versus Heparin in Pediatric and Adult Patients on Extracorporeal Membrane Oxygenation: A Meta-analysis

AIMS

Unfractionated heparin (UFH) has been the primary anticoagulant of choice on extracorporeal membrane oxygenation (ECMO). However, it is debatable whether bivalirudin (BIV), a direct thrombin inhibitor, may be considered a better alternative anticoagulant option.

METHODS

We searched Embase, Pubmed, Cochrane library, Clinicaltrials.gov, CNKI, and Wanfang databases up to June 15, 2021. Randomized controlled trials (RCTs) and observational studies were considered eligible for inclusion. Random-effects meta-analyses, including subgroup analyses, were conducted.

RESULTS

A total of 9 studies containing 994 patients were enrolled. All articles were retrospective cohort studies. Compared with UFH, BIV was associated with lower risks of major bleeding (risk ratio [RR]: 0.32, 95% confidence interval [CI] 0.22-0.49), ECMO in-circuit thrombosis (RR: 0.57, 95% CI 0.43-0.74), stroke (RR: 0.52, 95% CI 0.29-0.95), in-hospital mortality (RR: 0.82, 95% CI 0.69-0.99) and higher rates of survival to ECMO decannulation (RR: 1.18, 95% CI 1.03-1.34). Pooled risk estimates did not show a significant association with clinical thrombotic events (RR: 0.69, 95% CI 0.45-1.07). Moreover, BIV was associated with a lower risk of ECMO in-circuit thrombosis and in-hospital mortality in the adult subgroup but not in the pediatric subgroup. However, leave-one-out sensitivity analyses indicated that the results of stroke, survival to ECMO decannulation and in-hospital mortality should be interpreted with caution.

CONCLUSIONS

BIV appears to be a potential alternative to UFH in pediatric and adult patients requiring ECMO.

Bivalirudin versus heparin in adult and pediatric patients with extracorporeal membrane oxygenation therapy: a systematic review and meta-analysis

BACKGROUND

Our study sought to investigate the efficacy and safety of bivalirudin versus those of unfractionated heparin (UFH) in patients undergoing extracorporeal membrane oxygenation (ECMO).

METHODS

PubMed, EMBASE and Cochrane Library were searched for studies enrolling ECMO patients on bivalirudin and UFH (from inception till July 2021). Meta-analysis was conducted. The I² statistic and p value were used in measuring heterogeneity, and random effects or fixed-effect model was adopted. The Newcastle-Ottawa Scale was used for the risk of bias assessment. Sensitivity and subgroup analyses were undertaken. We performed Egger's test to evaluate publication bias.

RESULTS

Fourteen eligible retrospective observational studies with 1501 subjects were identified. Compared with UFH, bivalirudin significantly reduced the risk of in-circuit thrombosis (OR = 0.44, 95% CI [0.31-0.61], p = 0.000), thrombosis (OR = 0.61, 95% CI [0.45-0.83], p = 0.002) and hospital mortality (OR = 0.78, 95% CI [0.61-0.99], p = 0.04) and had a positive impact on survival ECMO (OR = 1.50, 95% CI [1.04-2.16], p = 0.032). Decrease in risk of bleeding (OR = 0.36, 95% CI [0.14-0.91], p = 0.031) associated with bivalirudin was observed. Sources of heterogeneity were identified, and sensitivity analysis revealed similar results.

CONCLUSION

Our meta-analysis suggested that bivalirudin was associated with the decreased risk of in-circuit thrombosis, thrombosis, hospital mortality and bleeding in patients on ECMO and improved survival ECMO, indicating the superiority of bivalirudin to UFH in terms of efficacy and safety.

Antimicrobial Prophylaxis and Anticoagulation Therapy in Pediatric ECMO: A Survey Study

OBJECTIVE

The purpose was to characterize antimicrobial and anticoagulation therapies used in health systems with children receiving extracorporeal membrane oxygenation (ECMO).

METHODS

An anonymous electronic survey assessing health system demographics and antimicrobial and anticoagulation therapies during ECMO was distributed to the American College of Clinical Pharmacy Pediatric Practice and Research Network and the Pediatric Pharmacy Association Critical Care Special Interest Group. The primary objective was to identify the number of respondents using antimicrobial prophylaxis for ECMO cannulation and ECMO runs. Secondary objectives included the first- and second-line anticoagulants and anticoagulation laboratory parameters. Additionally, the antimicrobial regimens and the dosing and administration of antithrombin III (AT III) with systemic anticoagulation were collected. Descriptive statistics were employed.

RESULTS

The questionnaire was completed by 38 respondents from 33 health systems; respondents practiced in the pediatric ICU (n = 20; 52.6%), cardiovascular ICU (n = 14; 36.8%), and neonatal ICU (n = 4; 10.5%). Twenty-eight (73.6%) respondents use antimicrobial prophylaxis during ECMO cannulation or ECMO runs, with most units using cefazolin monotherapy. Thirty-five (92.1%) respondents use heparin as the first-line anticoagulant and used a variety of laboratory tests including anti-factor Xa, activated clotting time, and activated partial thromboplastin time. The most common second-line anticoagulant was bivalirudin (n = 24; 63.2%). Thirty-six (94.7%) respondents use AT III with heparin, with most patients receiving AT III dosing calculated based on a formula for the desired AT III concentration.

CONCLUSIONS

The majority of respondents use antimicrobial prophylaxis, but variations in the regimens were noted. Heparin was the most common anticoagulant, but variations in laboratory monitoring and concomitant use of AT III were found.

The horizon of pediatric cardiac critical care

Pediatric Cardiac Critical Care (PCCC) is a challenging discipline where decisions require a high degree of preparation and clinical expertise. In the modern era, outcomes of neonates and children with congenital heart defects have dramatically improved, largely by transformative technologies and an expanding collection of pharmacotherapies. Exponential advances in science and technology are occurring at a breathtaking rate, and applying these advances to the PCCC patient is essential to further advancing the science and practice of the field. In this article, we identified and elaborate on seven key elements within the PCCC that will pave the way for the future.

Is bivalirudin an alternative anticoagulant for extracorporeal membrane oxygenation (ECMO) patients? A systematic review and meta-analysis

BACKGROUND

Anticoagulation is important for extracorporeal membrane oxygenation (ECMO). Heparin is widely used; however, in some cases, it is not suitable for patients. Bivalirudin has been recently proposed for ECMO patients, and there is no evidence regarding its effectiveness and safety.

OBJECTIVE

We aimed to systematically review the effectiveness and safety of bivalirudin in ECMO patients.

STUDY DESIGN AND METHODS

PubMed, Web of Science, Cochrane Library, and EMBASE were searched to find relevant research on the use of bivalirudin versus heparin for anticoagulation in ECMO patients. Outcomes included in-hospital mortality, ECMO duration, major bleeding events, thrombosis events and circuit intervention events. Types of studies included randomized control trials (RCTs), cohort studies, and case-control studies. Case reports, studies lacking comparison with heparin, and where patients transitioned between heparin and bivalirudin, were excluded. Publication bias was evaluated when the number of included studies was more than ten. Sensitivity analysis was performed to examine the stability of the results.

RESULTS

Ten articles were selected, and nine articles were included in the meta-analysis. The results of the meta-analysis showed hospital mortality [OR = 0.65, 95%CI (0.44, 0.95), P = 0.03] and thrombosis events decreased (OR = 0.55, 95%CI [0.37, 0.83], P = 0.004) in bivalirudin group compared with heparin in adult patients. Major bleeding events (OR = 0.66, 95%CI [0.17, 2.55], P = 0.55), ECMO duration (MD = 18.92, 95%CI [-29.33, 67.17], P = 0.44) and circuit intervention events (OR = 1.67, 95%CI [0.54, 5.18], P = 0.37) in the bivalirudin group was not statistically significant compared with the heparin group.

CONCLUSION

Bivalirudin may provide survival benefits and reduce thrombosis in adult patients on ECMO compared with heparin. There is no difference in treating major bleeding events between bivalirudin and heparin group. However, because all included studies were retrospective observational studies, the evidence level of this systematic review is low and heterogeneity could not be avoided. More high-quality clinical studies are urgently needed to confirm these benefits.