Centrifugal pumps and hemolysis in pediatric extracorporeal membrane oxygenation (ECMO) patients: An analysis of Extracorporeal Life Support Organization (ELSO) registry data

Use of Extracorporeal Membrane Oxygenation for Patients with Coronavirus Disease 2019 Infection

The coronavirus disease 2019 (COVID-19) pandemic was a cataclysmic event that infected over 772 million and killed over 6.9 million people worldwide. The pandemic pushed hospitals and society to their limits and resulted in incredibly severe respiratory disease in millions of people. This severe respiratory disease often necessitated maximum medical therapy, including the use of extracorporeal membrane oxygenation. While our understanding of COVID-19 and its treatment continue to evolve, we review the current evidence to guide the care of patients with severe COVID-19 infection.

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.

Impact of Blood Sampling Methods on Blood Loss and Transfusion After Pediatric Cardiac Surgery: An Observational Study

OBJECTIVES

The aims of this study were to assess the impact of the closed-loop sampling method on blood loss and the need for blood transfusion in pediatric patients following cardiac surgery.

DESIGN

Retrospective observational study.

SETTING

A single tertiary center.

PARTICIPANTS

All pediatric patients younger than 4 years old who were admitted to the pediatric intensive care unit (PICU) after cardiac surgery were enrolled. The study included 100 pediatric patients in the conservative (postimplementation) group and 43 pediatric patients in the nonconservative group (preimplementation).

INTERVENTIONS

Observational.

MEASUREMENTS

The primary outcome was the volume of blood loss during the PICU follow-up period. The secondary outcomes were the requirement for blood transfusion in each group, duration of mechanical ventilation, length of intensive care unit (ICU) stay, length of hospital stay, and mortality.

MAIN RESULTS

In the conservative (postimplementation) group, blood loss during the follow-up period was 0.67 (0.33-1.16) mL/kg/d, while it was 0.95 (0.50-2.30) mL/kg/d in the nonconservative (preimplementation) group, demonstrating a significant reduction in blood loss in the conservative group (p = 0.012). The groups showed no significant differences in terms of the required blood transfusion volume postoperatively during the first 24 hours, first 48 hours, or after 48 hours (p = 0.061, 0.536, 0.442, respectively). The frequency of blood transfusion was comparable between the groups during the first 24 hours, first 48 hours, or after 48 hours postoperatively (p = 0.277, 0.639, 0.075, respectively). In addition, the groups did not show significant differences in the duration of mechanical ventilation, length of ICU stay, length of hospital stay, or mortality.

CONCLUSIONS

The closed-loop sampling method can be efficient in decreasing blood loss during postoperative PICU follow-up for pediatric patients after cardiac surgeries. However, its application did not reduce the frequency or the volume of blood transfusion in these patients.

Standardized Definitions for Cardiogenic Shock Research and Mechanical Circulatory Support Devices: Scientific Expert Panel From the Shock Academic Research Consortium (SHARC)

The Shock Academic Research Consortium is a multi-stakeholder group, including representatives from the US Food and Drug Administration and other government agencies, industry, and payers, convened to develop pragmatic consensus definitions useful for the evaluation of clinical trials enrolling patients with cardiogenic shock, including trials evaluating mechanical circulatory support devices. Several in-person and virtual meetings were convened between 2020 and 2022 to discuss the need for developing the standardized definitions required for evaluation of mechanical circulatory support devices in clinical trials for cardiogenic shock patients. The expert panel identified key concepts and topics by performing literature reviews, including previous clinical trials, while recognizing current challenges and the need to advance evidence-based practice and statistical analysis to support future clinical trials. For each category, a lead (primary) author was assigned to perform a literature search and draft a proposed definition, which was presented to the subgroup. These definitions were further modified after feedback from the expert panel meetings until a consensus was reached. This manuscript summarizes the expert panel recommendations focused on outcome definitions, including efficacy and safety.

Evolution of Carboxyhemoglobin in Children Supported by Extracorporeal Membrane Oxygenation: An Observational Single-Center Study

Carboxyhemoglobin (COHb) is potentially a novel marker of hemolysis on extracorporeal membrane oxygenation (ECMO) and may be useful as an indicator for circuit-related complication in adults, but little is known about COHb levels in children. An observational single-center study was performed between January 2018 and December 2021. Fifty-eight children were included and COHb levels were obtained along with routine blood gas analysis before, during, and after ECMO support. From the 6th hour of ECMO support, the COHb level increased relative to the pre-ECMO level, with an adjusted mean difference of 0.44 (95% confidence interval [CI], 0.26-0.62; p < 0.001) and remained higher during ECMO run and within 6 hours after weaning ( p < 0.001). Among the 18 children (31%) who experienced at least one circuit-related complication leading to a circuit change, we observed a significant decrease in COHb levels within 24 hours after the circuit change, compared with the 24 hours before (adjusted mean difference, 0.54%; 95% CI, 0.27-0.80; p < 0.001). The maximal daily COHb level was able to predict circuit-related complications within 24 hours following COHb measurement with an area under the receiver operating characteristic (ROC) curve of 0.85 (95% CI, 0.77-0.92; p < 0.001).

Extracorporeal life support in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the most common indication for ECLS in neonatal respiratory failure. The ultimate purpose of ECLS is to grant cardiopulmonary support, allowing time for operative intervention and optimization of cardiopulmonary function as the pathophysiologic processes of pulmonary hypertension, pulmonary hypoplasia, and ventricular dysfunction either improve or resolve. In CDH, ECLS plays a crucial role in the management of the most challenging patients, facilitating postnatal stabilization, allowing a ventilation strategy which minimizes barotrauma and volutrauma, and permitting treatment of and recovery from pulmonary hypertension and/or cardiac dysfunction. Understanding the nuances of CDH patients, which differ from other forms of neonatal respiratory failure, and the benefits of ECLS for these infants, is crucial for effective management. CDH patients present distinct challenges. Every aspect of ECLS, from mode of support and anticoagulation medication to pump selection, ventilation strategy, pulmonary hypertension management, and the weaning process, requires meticulous consideration. ECLS for CDH serves as a bridge to making informed decisions, granting clinicians stability and time to manage / recover from specific pathophysiologic consequences, and it offers the potential for survival among even the most challenging and complex patients. As overall care and management for infants with CDH receiving ECLS continue to improve, the focus has shifted toward managing survivor morbidity. Given the multisystem nature of the disease, this requires significant experience, expertise, and multidisciplinary teamwork to optimize long-term outcomes for these patients.

Centrifugal or Roller Blood Pumps for Neonatal Venovenous Extracorporeal Membrane Oxygenation: Extracorporeal Life Support Organization Database Comparison of Mortality and Morbidity

OBJECTIVES

To investigate outcomes associated with conventional roller or centrifugal pumps during neonatal venovenous extracorporeal membrane oxygenation (ECMO). Our primary hypothesis is that in comparison with conventional roller-pump support, centrifugal pump use is associated with greater odds of survival. Our secondary hypothesis is that centrifugal pump use is associated with lesser odds of complications.

DESIGN

Retrospective cohort identified using the Extracorporeal Life Support Organization (ELSO) registry 2016 to 2020 dataset.

SETTING

All ECMO centers reporting to the ELSO registry.

PATIENTS

All neonates (≤ 28 d) supported with venovenous ECMO and cannulated via right internal jugular vein using dual-lumen venovenous cannulas and polymethyl pentene membrane oxygenators.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 612 neonates (centrifugal, n = 340; conventional roller, n = 272) were included in the analysis. Using a multivariable logistic regression model, centrifugal pump use-as opposed to roller pump use-was associated with lesser odds of survival (odds ratio [OR], 0.53; 95% CI, 0.33-0.84; p < 0.008). Thrombosis and clots in the circuit components were also associated with lesser odds of survival (OR, 0.28; 95% CI, 0.16-0.60; p < 0.001). We failed to show that hemolysis was an independent variable for survival (OR, 0.60; 95% CI, 0.31-1.19; p = 0.14). The primary diagnosis of neonatal aspiration/meconium aspiration is associated with more than seven-fold greater odds of survival (OR, 7.57; 95% CI, 4.02-15.74; p < 0.001).

CONCLUSIONS

Contrary to our hypotheses, conventional roller pump use was associated with greater odds of survival. While thrombosis and clots in circuit components were independent variables for lesser odds of survival, further research is needed better to understand the use of centrifugal pumps in neonatal practice.

Hemolysis performance analysis and a novel estimation model of roller pump system

OBJECTIVE

Hemolysis performance is a crucial criterion for roller pumps utilized in life supporting system. In this study, the factor of hemolysis for roller pumps was selected as the target, and an estimation formulation was built to evaluate its hemolysis.

METHODS

Several models were proposed and then simulated with the assistant of Computational fluid dynamics (CFD) framework. The hemolysis performance was calculated using the power law model based on CFD and the estimation model in accordance with geometry parameters proposed in this study. The results of the in vitro experiments were compared with the simulation results. Power law model with the lowest error was utilized in following analysis.

RESULTS

As indicated by the simulation result, the rotary speed most significantly affected the hemolysis performance of roller blood pumps, followed by roller number and diameter of tube. The index of hemolysis (IH) for roller blood pumps at a rotary speed of 20-100 rpm ranged from 8.73E-7 to 8.07E-5. The relative error of the estimation model (4.93%) was lower than of the power law model (6.78%).

CONCLUSION

The IH led by pumps shows a significant, nonlinear relationship with the rotary speed. The design of multiple rollers design is harmful for hemolysis performance and larger diameter of tube exhibits decreased hemolysis at constant flow rate. An estimation formula was proposed with lower relative error for roller pump with the same shell set, which exhibited reduced computation and elevated convenience. And it can be utilized in hemolysis estimation of roller pumps potentially.

The Evolution of Extracorporeal Membrane Oxygenation Circuitry and Impact on Clinical Outcomes in Children: A Systematic Review

This systematic review summarizes the major developments in extracorporeal membrane oxygenation (ECMO) circuitry in pediatrics over the past 20 years and demonstrates the impacts of those developments on clinical outcomes. This systematic review followed structured Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 1987 studies were retrieved, of which 82 were included in the final analysis. Over the past 20 years, ECMO pumps have shifted from roller pumps to centrifugal pumps. Silicone and polypropylene hollow fiber membrane oxygenators were initially used but have been replaced by polymethylpentene hollow fiber membrane oxygenators, with other ECMO components poorly reported. Considerable variability in mortality was found across studies and there was no statistical difference in mortality rates across different periods. The duration of ECMO and other outcome measures were inconsistently reported across studies. This systematic review demonstrated technological developments in pumps and oxygenators over the last two decades, although patient mortality rates remained unchanged. This could be because of ECMO support applied to patients in more critical conditions over the years. We also highlighted the limitations of methodology information disclosure and outcome measures in current ECMO studies, showing the need of reporting standardization for future ECMO studies.

Optimization of a Screw Centrifugal Blood Pump Based on Random Forest and Multi-Objective Gray Wolf Optimization Algorithm

The centrifugal blood pump is a commonly used ventricular assist device. It can replace part of the heart function, pumping blood throughout the body in order to maintain normal function. However, the high shear stress caused by the impeller rotating at high speeds can lead to hemolysis and, as a consequence, to stroke and other syndromes. Therefore, reducing the hemolysis level while ensuring adequate pressure generation is key to the optimization of centrifugal blood pumps. In this study, a screw centrifugal blood pump was used as the research object. In addition, pressure generation and the hemolysis level were optimized simultaneously using a coupled algorithm composed of random forest (RF) and multi-objective gray wolf optimization (MOGWO). After verifying the prediction accuracy of the algorithm, three optimized models were selected and compared with the baseline model in terms of pressure cloud, 2D streamline, SSS distribution, HI distribution, and vortex distribution. Finally, via a comprehensive evaluation, the optimized model was selected as the final optimization design, in which the pressure generation increased by 24% and the hemolysis value decreased by 48%.

Coagulation and hemolysis complications in neonatal ECLS: Role of devices

Neonatal extracorporeal life support (ECLS) has enjoyed a long history of successful patient support for both cardiac and respiratory failure. The small size of this patient population has provided many technical challenges from cannulation to pumps and oxygenators. This is further complicated by the relatively meager commercial options for equipment owing to the relatively low utilization of neonatal ECLS compared to adults, which has exploded following the H1N1 epidemic and the availability of the polymethylpentene oxygenator. This paper focuses on the impact of equipment choices on thrombosis and hemolysis in neonatal ECLS and the underlying mechanisms behind them. Based upon the available evidence, it is clear neonatal ECLS requires careful attention to the selection and operation of all parts of the ECLS system. Practitioners should also be aware of the factors that increase blood cell fragility, which can impact decisions around equipment and subsequent operation.

Computational fluid dynamics analysis and experimental hemolytic performance of three clinical centrifugal blood pumps: Revolution, Rotaflow and CentriMag

Centrifugal blood pumps have become popular for adult extracorporeal membrane oxygenation (ECMO) due to their superior blood handling and reduced thrombosis risk featured by their secondary flow paths that avoid stagnant areas. However, the high rotational speed within a centrifugal blood pump can introduce high shear stress, causing a significant shear-induced hemolysis rate. The Revolution pump, the Rotaflow pump, and the CentriMag pump are three of the leading centrifugal blood pumps on the market. Although many experimental and computational studies have focused on evaluating the hydraulic and hemolytic performances of the Rotaflow and CentriMag pumps, there are few on the Revolution pump. Furthermore, a thorough direct comparison of these three pumps' flow characteristics and hemolysis is not available. In this study, we conducted a computational and experimental analysis to compare the hemolytic performances of the Revolution, Rotaflow, and CentriMag pumps operating under a clinically relevant condition, i.e., the blood flow rate of 5 L/min and pump pressure head of 350 mmHg, for adult ECMO support. In silico simulations were used to characterize the shear stress distributions and predict the hemolysis index, while in vitro blood loop studies experimentally determined hemolysis performance. Comparative simulation results and experimental data demonstrated that the CentriMag pump caused the lowest hemolysis while the Revolution pump generated the highest hemolysis.

Extracorporeal Membrane Oxygenation in Critically Ill Children

Neonatal and pediatric extracorporeal membrane oxygenation (ECMO) has evolved over the past 50 years. Advances in technology, expertise, and application have increased the number of centers providing ECMO with expanded indications for use. However, increasing the use of ECMO in recent years to more medically complex critically ill children has not changed overall survival despite increased experience and improvements in technology. This review focuses on ECMO history, circuits, indications and contraindications, management, complications, and outcome data. The authors highlight important areas of progress, including unintubated and awake patients on ECMO, application during the COVID-19 pandemic, and future directions.

Premature and Extracorporeal Life Support: Is it Time? A Systematic Review

Early preterm birth < 34 gestational weeks (GA) and birth weight (BW) <2 kg are relative contraindications for extracorporeal membrane oxygenation (ECMO). However, with improved technology, ECMO is presently managed more safely and with decreasing complications. Thus, these relative contraindications may no longer apply. We performed a systematic review to evaluate the existing literature on ECMO in early and late (34-37 GA) prematurity focusing on survival to hospital discharge and the complication intracranial hemorrhage (ICH). Data sources: MEDLINE, PubMed, Web of Science, Embase, and the Cochrane Database. Only publications in the English language were evaluated. Of the 36 included studies, 23 were related to ECMO support for respiratory failure, 10 for cardiac causes, and four for congenital diaphragmatic hernia (CDH). Over the past decades, the frequency of ICH has declined (89-21%); survival has increased in both early prematurity (25-76%), and in CDH (33-75%), with outcome similar to late prematurity (48%). The study was limited by an inherent risk of bias from overlapping single-center and registry data. Both the risk of ICH and death have decreased in prematurely born treated with ECMO. We challenge the 34 week GA time limit for ECMO and propose an international task force to revise current guidelines. At present, gestational age < 34 weeks might no longer be considered a contraindication for ECMO in premature neonates.

Risk factors for hemolysis with centrifugal pumps in pediatric extracorporeal membrane oxygenation: Is pump replacement an answer?

INTRODUCTION

Hemolysis during pediatric extracorporeal membrane oxygenation (ECMO) is associated with increased risk for renal failure and mortality.

OBJECTIVES

We aim to describe risk factors for hemolysis in pediatric ECMO supported by centrifugal pumps.

METHODS

We conducted an analysis of retrospective data collected at an academic children's hospital from January 2017 to December 2019.

MEASUREMENTS AND RESULTS

Plasma-free hemoglobin (PFH) levels were measured daily, and hemolysis was defined as PFH>50 mg/dL. Of 46 ECMO runs over 528 ECMO days, hemolysis occurred in 23 (58%) patients over a total of 40 (8%) ECMO days. In multivariable logistic regression models, VA-ECMO (aOR=4.69, 95% CI: 1.01-21.83) and higher hemoglobin (aOR = 1.38, 95% CI: 1.06-1.81) were independently associated with hemolysis. There were also non-significant trends toward increased risk for hemolysis with higher rotational pump speed (aOR=2.39, 95% CI: 0.75-7.65), higher packed red blood cell transfusions (aOR=1.15, 95% CI: 0.99-1.34), and higher cryoprecipitate transfusions (aOR=2.01, 95% CI: 0.83-4.86). Isolated pump exchanges that were performed in 12 patients with hemolysis led to significant decreases in PFH levels within 24 h (89 vs 11 mg/dL, p<0.01).

CONCLUSIONS

Hemolysis is common in pediatric ECMO using centrifugal pumps. Avoidance of high pump speeds and conservative administration of blood products may help to mitigate the risk for hemolysis. Furthermore, pump exchange may be an effective first-line treatment for hemolysis.

Respiratory indications for ECMO: focus on COVID-19

Extracorporeal membrane oxygenation (ECMO) is increasingly being used for patients with severe respiratory failure and has received particular attention during the coronavirus disease 2019 (COVID-19) pandemic. Evidence from two key randomized controlled trials, a subsequent post hoc Bayesian analysis, and meta-analyses support the interpretation of a benefit of ECMO in combination with ultra-lung-protective ventilation for select patients with very severe forms of acute respiratory distress syndrome (ARDS). During the pandemic, new evidence has emerged helping to better define the role of ECMO for patients with COVID-19. Results from large cohorts suggest outcomes during the first wave of the pandemic were similar to those in non-COVID-19 cohorts. As the pandemic continued, mortality of patients supported with ECMO has increased. However, the precise reasons for this observation are unclear. Known risk factors for mortality in COVID-19 and non-COVID-19 patients are higher patient age, concomitant extra-pulmonary organ failures or malignancies, prolonged mechanical ventilation before ECMO, less experienced treatment teams and lower ECMO caseloads in the treating center. ECMO is a high resource-dependent support option; therefore, it should be used judiciously, and its availability may need to be constrained when resources are scarce. More evidence from high-quality research is required to better define the role and limitations of ECMO in patients with severe COVID-19.

Miniaturized soft centrifugal pumps with magnetic levitation for fluid handling

Centrifugal pumps are essential mechanical components for liquid delivery in many biomedical systems whose miniaturization can promote innovative disease treatment approaches. However, centrifugal pumps are predominately constructed by rigid and bulky components. Here, we combine the soft materials and flexible electronics to achieve soft magnetic levitation micropumps (SMLMs) that are only 1.9 to 12.8 grams in weight. The SMLMs that rotate at a rotation speed of 1000 revolutions per min to pump liquids with various viscosities ranging from 1 to 6 centipoise can be used in assisting dialysis, blood circulation, and skin temperature control because of excellent biocompatibility with no organ damage. The development of SMLMs not only demonstrates the possibility to replace rigid rotating structures with soft materials for handling large volumes of fluids but also indicates the potential for fully flexible artificial organs that may revolutionize health care and improve the well-being of patients.

Three-dimensional membranes for artificial lungs: Comparison of flow-induced hemolysis

BACKGROUND

Membranes based on triply periodic minimal surfaces (TPMS) have proven a superior gas transfer compared to the contemporary hollow fiber membrane (HFM) design in artificial lungs. The improved oxygen transfer is attributed to disrupting the laminar boundary layer adjacent to the membrane surface known as main limiting factor to mass transport. However, it requires experimental proof that this improvement is not at the expense of greater damage to the blood. Hence, the aim of this work is a valid statement regarding the structure-dependent hemolytic behavior of TPMS structures compared to the current HFM design.

METHODS

Hemolysis tests were performed on structure samples of three different kind of TPMS-based designs (Schwarz-P, Schwarz-D and Schoen's Gyroid) in direct comparison to a hollow fiber structure as reference.

RESULTS

The results of this study suggest that the difference in hemolysis between TPMS membranes compared to HFMs is small although slightly increased for the TPMS membranes. There is no significant difference between the TPMS structures and the hollow fiber design. Nevertheless, the ratio between the achieved additional oxygen transfer and the additional hemolysis favors the TPMS-based membrane shapes.

CONCLUSION

TPMS-shaped membranes offer a safe way to improve gas transfer in artificial lungs.

Acute Myocarditis in Children: An Overview of Treatment and Recent Patents

BACKGROUND

Pediatric myocarditis is rare but challenging. This overview summarized the current knowledge and recent patents on childhood myocarditis.

METHODS

Clinical queries and keywords of "myocarditis" and "childhood" were used as search engine.

RESULTS

Viral infections are the most common causes of acute myocarditis. Affected children often have a prodrome of fever, malaise, and myalgia. Clinical manifestations of acute myocarditis in children can be nonspecific. Some children may present with easy fatigability, poor appetite, vomiting, abdominal pain, exercise intolerance, respiratory distress/tachypnea, dyspnea at rest, orthopnea, chronic cough with wheezing, chest pain, unexplained tachycardia, hypotension, syncope, and hepatomegaly. Supraventricular arrhythmias, ventricular arrhythmias, and heart block may be present. A subset of patients have fulminant myocarditis and present with cardiovascular collapse, which may progress to severe cardiogenic shock, and even death. A high index of suspicion is crucial to its diagnosis and timely management. Cardiac magnetic resonance imaging is important in aiding clinical diagnosis while, endomyocardial biopsy remains the gold standard. The treatment consists of supportive therapy, ranging from supplemental oxygen and fluid restriction to mechanical circulatory support. Angiotensinconverting enzyme inhibitors, angio-tensin II receptor blockers, β-blockers, and aldosterone antagonists might be used for the treatment of heart failure while, immunosuppression treatments remain controversial. There are a few recent patents targeting prevention or treatment of viral myocarditis, including an immunogenic composition comprising a PCV-2 antigen, glutathione-S-transferase P1, neuregulins, NF-[kappa] B inhibitor, a pharmaceutical composition which contains 2-amino-2- (2- (4-octyl phenyl) - ethyl) propane 1,3-diol, a composition containing pycnojenol, Chinese herbal concoctions, and a Korean oral rapamycin. Evidence of their efficacy is still lacking.

CONCLUSION

This article reviews the current literature regarding etiology, clinical manifestations, diagnosis, and management of acute myocarditis in children.

Coagulation complications after conversion from roller to centrifugal pump in neonatal and pediatric extracorporeal membrane oxygenation

BACKGROUND/PURPOSE

Coagulation complications are frequent, unwanted occurrences in extracorporeal membrane oxygenation (ECMO) treatment, possibly influenced by the pump in the ECMO-circuit. We hypothesized that fewer complications would occur with a smaller, heparin-coated ECMO system with a centrifugal pump (CP) than with one with a roller pump (RP) and that after conversion, complication rates would decrease over time.

METHODS

This single-center, retrospective chart study included all first neonatal and pediatric ECMO runs between 2009 and 2015. Differences between groups were assessed with Mann-Whitney U tests and Kruskal-Wallis tests. Determinants of complication rates were evaluated through Poisson regression models. The CP group was divided into three consecutive groups to assess whether complication rates decreased over time.

RESULTS

The RP group comprised 90 ECMO runs and the CP group 82. Hemorrhagic complication rates were significantly higher with the CP than with the RP, without serious therapeutic consequences, while thrombotic complications rates were unaffected. Intracranial hemorrhage rates and coagulation-related mortality rates were similar. Gained experience with the CP did not improve complication rates or survival over time.

CONCLUSIONS

Although the CP seems safe, it does not seem beneficial over the RP. Further research is warranted on how pump type affects coagulation, taking into account the severity and implications of coagulation complications.

LEVEL OF EVIDENCE

Level III.

Carboxyhemoglobin levels in children during extracorporeal membrane oxygenation support: a retrospective study

INTRODUCTION

Hemolysis is a common complication of extracorporeal membrane oxygenation (ECMO). There are few data on whether carboxyhemoglobin (COHb), a potential marker of hemolysis, are elevated during ECMO support.

METHODS

We conducted a single-center, retrospective study comparing peak COHb levels of children pre-, during, and post-ECMO from January 2017 to August 2020.

RESULTS

There were 154 ECMO runs in 147 children (154 PICU admissions) included in the study. The median age was 3.5 (IQR 0.2, 39.2) months. Veno-arterial ECMO was the predominant mode: 146/154 (94.8%). Eighty-seven children (56.5%) underwent cardiac surgery. Peak COHb levels during ECMO were statistically significantly higher compared to pre ECMO (COHb 1.8% (IQR 1.4, 2.6) vs COHb 1.2% (IQR 0.7, 1.7), p < 0.001) and post ECMO (COHb 1.6% (IQR 1.3, 2.2), p = 0.009). Children with COHb ⩾2% were younger and had longer duration of ECMO support. Plasma hemoglobin weakly correlated with COHb level (r = 0.14; p = 0.04).

CONCLUSIONS

Carboxyhemoglobin levels increased during ECMO support compared to the pre and post ECMO period. Younger age and longer ECMO duration were associated with COHb levels ⩾2%. Plasma hemoglobin weakly correlated with COHb level.

Analysis of the 2020 EACTS/ELSO/STS/AATS Expert Guidelines on the Management of Adult Postcardiotomy Extracorporeal Life Support

Extracorporeal life support (ECLS), also known as extracorporeal membrane oxygenation (ECMO), increasingly is used in postcardiotomy (PC) shock to facilitate a bridge to sustained recovery, long-term mechanical support, or heart transplantation. Given increasing prevalence and complexity of PC-ECLS, a joint expert consensus guideline was created in 2020 for management of adult PC-ECLS by the European Association for Cardio-Thoracic Surgery (EACTS), the Extracorporeal Life Support Organization (ELSO), the Society of Thoracic Surgeons (STS), and the American Association of Thoracic Surgery (AATS). The aim of this analysis was to comprehensively review the expert consensus guidelines, with particular emphasis on PC-ECLS candidacy, timing, cannula configuration, left ventricular distention, anticoagulation, ECLS weaning, and intensive care unit complications. This analysis finds the expert consensus guideline to be timely, pertinent, and clinically valuable, although there remains the need for larger clinical trials to codify best practices.

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

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

Risk Factors for Hemolysis During Extracorporeal Life Support for Congenital Diaphragmatic Hernia

BACKGROUND

Neonates receiving extracorporeal life support (ECLS) for congenital diaphragmatic hernia (CDH) require prolonged support compared with neonates with other forms of respiratory failure. Hemolysis is a complication that can be seen during ECLS and can lead to renal failure and potentially to worse outcomes. The purpose of this study was to identify risk factors for the development of hemolysis in CDH patients treated with ECLS.

METHODS

The Extracorporeal Life Support Organization database was used to identify infants with CDH (2000-2015). The primary outcome was hemolysis (plasma-free hemoglobin >50 mg/dL). Potentially associated variables were identified in the data set. Descriptive statistics and a series of nested multivariable logistic regression models were used to identify associations between hemolysis and demographic, pre-ECLS, and on-ECLS factors.

RESULTS

There were 4576 infants with a mortality of 52.5%. The overall mean rate of hemolysis was 10.5% during the study period. In earlier years (2000-2005), the hemolysis rates were 6.3% and 52.7% for roller versus centrifugal pumps, whereas in later years (2010-2015), they were 2.9% and 26.5%, respectively. The fully adjusted model demonstrated that the use of centrifugal pumps was a strong predictor of hemolysis (odds ratio: 6.67, 95% confidence interval: 5.14-8.67). In addition, other risk factors for hemolysis included low 5-min Apgar score, on-ECLS complications (renal, metabolic, and cardiovascular), and duration of ECLS.

CONCLUSIONS

In our cohort of CDH patients receiving ECLS over 15 y, the use of centrifugal pumps increased over time, along with the rate of hemolysis. Patient- and treatment-level risk factors were identified contributing to the development of hemolysis.

ABO incompatibility and mild factor VIII deficiency in the neonate: Not too much of a problem but a challenge on ECMO

Coagulopathy and bleeding on extracorporeal membrane oxygenation (ECMO) contribute to a worse outcome, and hyperbilirubinemia is an additional threat for newborn babies. We report a case of a newborn boy with congenital diaphragmatic hernia (CDH) associated with ABO incompatibility and an inherited mild hemophilia A. Due to respiratory failure he needed ECMO on his first day of life. During ECMO an exchange transfusion was performed after an extensive hyperbilirubinemia had evolved. Thereafter severe bleeding occurred, and a very low factor VIII level was found causative for that. After factor VIII substitution bleeding was under control and the baby eventually could be weaned from ECMO, underwent corrective surgery, and recovered.

Platelet count reduction during in vitro membrane oxygenation affects platelet activation, neutrophil extracellular trap formation and clot stability, but does not prevent clotting

Introduction:

Due to improved technology and increased application the mortality during extracorporeal membrane oxygenation (ECMO) is constantly declining. Nevertheless, complications including haemorrhage or thrombus formation remain frequent. Local mitigation of coagulation within an ECMO system to prevent thrombus formation on ECMO components and optimizing systemic anticoagulation is an approach to reduce clotting and bleeding complications at once. Foreign surfaces of ECMO systems, activate platelets (PLTs), which besides their major role in coagulation, can trigger the formation of neutrophil extracellular traps (NETs) contributing to robust thrombus formation. The impact of a reduced PLT count on PLT activation and NET formation is of paramount importance and worth investigating.

Methods:

In this study platelet poor (PLT^–) and native (PLT⁺) heparinized human blood was circulated in two identical in vitro test circuits for ECMO devices for 6 hours. PLT reduction was achieved by a centrifugation protocol prior to the experiments. To achieve native coagulation characteristics within the test circuits, the initial heparin dose was antagonized by continuous protamine administration.

Results:

The PLT^– group showed significantly lower platelet activation, basal NET formation and limited clot stability measured via thromboelastometry. Fluorescent and scanning electron microscope imaging showed differences in clot composition. Both groups showed equal clot formation within the circuit.

Conclusions:

This study demonstrated that the reduction of PLTs within an ECMO system is associated with limited PLT activation and NET formation, which reduces clot stability but is not sufficient to inhibit clot formation per se.

Switching to centrifugal pumps may decrease hemolysis rates among pediatric ECMO patients

Recent advances in ECLS technology have led to the adoption of centrifugal pumps for the majority of patients worldwide. Despite several advantages of centrifugal pumps, they remain controversial because a number of studies have shown increased rates of hemolysis. The aim of this study was to assess the impact of transitioning from roller to centrifugal pumps on hemolysis rates at our center. A retrospective analysis of all pediatric ECMO patients at a single center between 2005 and 2017 was undertaken. Hemolysis was defined as a plasma free hemoglobin >50 mg/dL. Multivariable logistic regression was performed correcting for several factors to determine risk factors for hemolysis and analyze outcomes among patients with hemolysis. Significant findings were those with p < 0.05. A total of 590 patients were identified during the study period. Multivariable logistic regression for risk factors for hemolysis showed roller pumps (OR 1.92, CI 1.11–3.33) and ECMO duration (OR 1.002 per hour, CI 1.00–1.01) to be significant factors. Rates of hemolysis significantly improved following conversion from roller to centrifugal pumps, with significantly lower rates of hemolysis in 2012, 2015, 2016, and 2017 when compared to the historical average with roller pumps from 2005 to 2009 (34.7%). Additionally, hemolysis was associated with an increased risk of death (OR 3.59, CI 2.05–6.29) when correcting for other factors. These data suggest decreasing rates of hemolysis with centrifugal pumps compared to roller pumps. Since hemolysis was also associated with increased risk of death, these data support the switch from roller to centrifugal pumps at ECMO centers.

Intravascular Hemolysis and Complications During Extracorporeal Membrane Oxygenation

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

Is there a "safe" suction pressure in the venous line of extracorporeal circulation system?

Successes of extracorporeal life support increased the use of centrifugal pumps. However, reports of hemolysis call for caution in using these pumps, especially in neonatology and in pediatric intensive care. Cavitation can be a cause of blood damage. The aim of our study was to obtain information about the cavitation conditions and to provide the safest operating range of centrifugal pumps. A series of tests were undertaken to determine the points at which pump performance decreases 3% and gas bubbles start to appear downstream of the pump. Two pumps were tested; pump R with a closed impeller and pump S with a semiopen impeller. The performance tests demonstrated that pump S has an optimal region narrower than pump R and it is shifted to the higher flows. When the pump performance started to decrease, the inlet pressure varies but close to −150 mmHg in the test with low gas content and higher than −100 mmHg in the tests with increased gas content. The same trend was observed at the points of development of massive gas emboli. Importantly, small packages of bubbles downstream of the pump were registered at relatively high inlet pressures. The gaseous cavitation in centrifugal pumps is a phenomenon that appears with decreasing inlet pump pressures. There are a few ways to increase inlet pump pressures: (1) positioning the pump as low as possible in relation to the patient; (2) selecting appropriate sized venous cannulas and their careful positioning; and (3) controlling patient’s volume status.

Overview of the bicaval dual lumen cannula

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a form of extracorporeal life support that provides total gas exchange (CO2 and O2) within the central venous circulation. The bicaval dual lumen cannula (DLC) is an option for patients requiring respiratory support with VV-ECMO. The catheter is inserted via the internal jugular vein into the superior and inferior vena cava, drains blood into the ECMO circuit for gas exchange, and then returns arterialized blood to the right heart for circulation. The DLC facilitates physical therapy, ambulation, and early extubation. This chapter will review the uses, advantages, and unique complications of the DLC.

Bivalirudin Dosing Requirements in Adult Patients on Extracorporeal Life Support With or Without Continuous Renal Replacement Therapy

Systemic anticoagulation with unfractionated heparin is standard of care for patients receiving extracorporeal life support (ECLS); however, an alternative anticoagulant may be necessary when challenges with heparin therapy arise. Evidence for alternative anticoagulation in ECLS patients is limited. This retrospective analysis evaluated the dosing and outcomes associated with bivalirudin use in 14 adult ECLS patients. Indications for bivalirudin included heparin-induced thrombocytopenia, heparin resistance, or persistent clotting or bleeding while on heparin. The median initial bivalirudin dose to achieve target activated partial thromboplastin time was 0.15 mg/kg/h (range 0.04-0.26 mg/kg/h). Dosing requirements increased by 75-125% when renal replacement was included. Median time on bivalirudin was 5.2 days (range 0.9-28 days). Five patients (36%) required a circuit change while on bivalirudin because of clotting or failing oxygenation, and four (28.6%) had bleeding significant enough to require either reduction in activated partial thromboplastin time goals or temporary holding of anticoagulation. Bivalirudin appears to be a potential option for adult patients on ECLS who are unable to receive or fail heparin therapy; however, the wide variation in dosing suggests the need for careful management.

Factors associated with hemolysis during extracorporeal membrane oxygenation (ECMO)-Comparison of VA- versus VV ECMO

Venovenous (VV) and venoarterial (VA) extracorporeal membrane oxygenation (ECMO) are effective support modalities to treat critically ill patients. ECMO-associated hemolysis remains a serious complication. The aim was to disclose similarities and differences in VA- and VV ECMO-associated hemolysis. This is a retrospective single-center analysis (January 2012 to September 2018) including 1,063 adult consecutive patients (VA, n = 606; VV, n = 457). Severe hemolysis (free plasma hemoglobin, fHb > 500 mg/l) during therapy occurred in 4% (VA) and 2% (VV) (p≤0.001). VV ECMO showed significantly more hemolysis by pump head thrombosis (PHT) compared to VA ECMO (9% vs. 2%; p≤0.001). Pretreatments (ECPR, cardiac surgery) of patients who required VA ECMO caused high fHb pre levels which aggravates the proof of ECMO-induced hemolysis (median (interquartile range), VA: fHb pre: 225.0 (89.3–458.0); VV: fHb pre: 72.0 (42.0–138.0); p≤0.001). The survival rate to discharge from hospital differed depending on ECMO type (40% (VA) vs. 63% (VV); p≤0.001). Hemolysis was dominant in VA ECMO patients, mainly caused by different indications and not by the ECMO support itself. PHT was the most severe form of ECMO-induced hemolysis that occurs in both therapies with low frequency, but more commonly in VV ECMO due to prolonged support time.

Outcomes of Infants Supported With Extracorporeal Membrane Oxygenation Using Centrifugal Versus Roller Pumps: An Analysis From the Extracorporeal Life Support Organization Registry

OBJECTIVES

To determine whether mortality differs between roller and centrifugal pumps used during extracorporeal membrane oxygenation in infants weighing less than 10 kg.

DESIGN

Retrospective propensity-matched cohort study.

SETTING

All extracorporeal membrane oxygenation centers reporting to the Extracorporeal Life Support Organization.

PATIENTS

All patients less than 10 kg supported on extracorporeal membrane oxygenation during 2011-2016 within Extracorporeal Life Support Organization Registry.

INTERVENTIONS

Centrifugal and roller pump recipients were propensity matched (1:1) based on predicted probability of receiving a centrifugal pump using demographic variables, indication for extracorporeal membrane oxygenation, central versus peripheral cannulation, and pre-extracorporeal membrane oxygenation patient management.

MEASUREMENTS AND MAIN RESULTS

A total of 12,890 patients less than 10 kg were supported with extracorporeal membrane oxygenation within the Extracorporeal Life Support Organization registry during 2011-2016. Patients were propensity matched into a cohort of 8,366. Venoarterial and venovenous extracorporeal membrane oxygenation runs were propensity matched separately. The propensity-matched cohorts were similar except earlier year of extracorporeal membrane oxygenation (standardized mean difference, 0.49) in the roller pump group. Within the propensity-matched cohort, survival to discharge was lower in the centrifugal pump group (57% vs 59%; odds ratio, 0.91; 95% CI, 0.83-0.99; p = 0.04). Hemolytic, infectious, limb injury, mechanical, metabolic, neurologic, pulmonary, and renal complications were more frequent in the centrifugal pump group. Hemorrhagic complications were similar between groups. Hemolysis mediated the relationship between centrifugal pumps and mortality (indirect effect, 0.023; p < 0.001).

CONCLUSIONS

In this propensity score-matched cohort study of 8,366 extracorporeal membrane oxygenation recipients weighing less than 10 kg, those supported with centrifugal pumps had increased mortality and extracorporeal membrane oxygenation complications. Hemolysis was evaluated as a potential mediator of the relationship between centrifugal pump use and mortality and met criteria for full mediation.

Updates in Pediatric Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation is an increasingly used mode of life support for patients with cardiac and/or respiratory failure refractory to conventional therapy. This review provides a synopsis of the evolution of extracorporeal life support in neonates, infants, and children and offers a framework for areas in need of research. Specific aspects addressed are the changing epidemiology; technologic advancements in extracorporeal membrane oxygenation circuitry; the current status and future direction of anticoagulation management; sedative and analgesic strategies; and outcomes, with special attention to the lessons learned from neonatal survivors.

Neonatal Cardiac ECMO in 2019 and Beyond

Worldwide, the use of Extracorporeal Membrane Oxygenation (ECMO) for cardiac failure has been steadily increasing in the neonatal population and has become a widely accepted modality. Especially in centers caring for children with (congenital) heart disease, ECMO is now an essential part of care available for those with severe heart failure as a bridge to recovery, long term mechanical support, or transplantation. Short-term outcomes depend very much on indication. Hospital survival is ~40% for all neonatal cardiac ECMO patients combined. ECMO is being used for pre- and/or post-operative stabilization in neonates with congenital heart disease and in neonates with medical heart disease such as myocarditis, cardiomyopathy or refractory arrhythmias. ECMO use during resuscitation (ECPR) or for sepsis is summarized elsewhere in this special edition of Frontiers in Pediatrics. In this review article, we will discuss the indications for neonatal cardiac ECMO, the difficult process of patients' selection and identifying the right timing to initiate ECMO, as well as outline pros and cons for peripheral vs. central cannulation. We will present predictors of mortality and, very importantly, predictors of survival: what can be done to improve the outcomes for your patients. Furthermore, an overview of current insights regarding supportive care in neonatal cardiac ECMO is given. Additionally, we will address issues specific to neonates with single ventricle physiology on ECMO, for example cannulation strategies and the influence of shunt type (Blalock-Taussig shunt vs. "right ventricle to pulmonary artery" shunt). We will not only focus on short term outcomes, such as hospital survival, but also on the importance of long-term neuro-developmental outcomes, and we will end this review with suggestions for future research.

Hemolysis During Pediatric Extracorporeal Membrane Oxygenation: Associations With Circuitry, Complications, and Mortality

OBJECTIVES

To describe factors associated with hemolysis during pediatric extracorporeal membrane oxygenation and the relationships between hemolysis, complications, and mortality.

DESIGN

Secondary analysis of data collected prospectively by the Collaborative Pediatric Critical Care Research Network between December 2012 and September 2014.

SETTING

Three Collaborative Pediatric Critical Care Research Network-affiliated hospitals.

PATIENTS

Age less than 19 years and treated with extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Hemolysis was defined based on peak plasma free hemoglobin levels during extracorporeal membrane oxygenation and categorized as none (< 0.001 g/L), mild (0.001 to < 0.5 g/L), moderate (0.5 to < 1.0 g/L), or severe (≥ 1.0 g/L). Of 216 patients, four (1.9%) had no hemolysis, 67 (31.0%) had mild, 51 (23.6%) had moderate, and 94 (43.5%) had severe. On multivariable analysis, variables independently associated with higher daily plasma free hemoglobin concentration included the use of in-line hemofiltration or other continuous renal replacement therapy, higher hemoglobin concentration, higher total bilirubin concentration, lower mean heparin infusion dose, lower body weight, and lower platelet count. Using multivariable Cox modeling, daily plasma free hemoglobin was independently associated with development of renal failure during extracorporeal membrane oxygenation (defined as creatinine > 2 mg/dL [> 176.8 μmol/L] or use of in-line hemofiltration or continuous renal replacement therapy) (hazard ratio, 1.04; 95% CI, 1.02-1.06; p < 0.001), but not mortality (hazard ratio, 1.01; 95% CI, 0.99-1.04; p = 0.389).

CONCLUSIONS

Hemolysis is common during pediatric extracorporeal membrane oxygenation. Hemolysis may contribute to the development of renal failure, and therapies used to manage renal failure such as in-line hemofiltration and other forms of continuous renal replacement therapy may contribute to hemolysis. Hemolysis was not associated with mortality after controlling for other factors. Monitoring for hemolysis should be a routine part of extracorporeal membrane oxygenation practice, and efforts to reduce hemolysis may improve patient care.

Effect of pump type on outcomes in neonates with congenital diaphragmatic hernia requiring ECMO

PURPOSE

With the exception of neonatal respiratory failure, most centers are now using centrifugal over roller-type pumps for the delivery of extracorporeal membrane oxygenation (ECMO). Evidence supporting the use of centrifugal pumps specifically in infants with congenital diaphragmatic hernia (CDH) remains lacking. We hypothesized that the use of centrifugal pumps in infants with CDH would not affect mortality or rates of severe neurologic injury (SNI).

METHODS

Infants with CDH were identified within the ELSO registry (2000-2016). Patients were then divided into those undergoing ECMO with rollertype pumps or centrifugal pumps. Patients were matched based on propensity score (PS) for the ECMO pump type based on pre-ECMO covariates. This was done for all infants and separately for each ECMO mode, venovenous (VV) and venoarterial (VA) ECMO.

RESULTS

We identified 4,367 infants who were treated with either roller or centrifugal pumps from 2000-2016. There was no difference in mortality or SNI between the two pump types in any of the groups (all infants, VA-ECMO infants, VV-ECMO infants). However, there was at least a six-fold increase in the odds of hemolysis for centrifugal pumps in all groups: all infants (odds ratio [OR] 6.99, p<0.001), VA-ECMO infants (OR 8.11, p<0.001 and VV-ECMO infants (OR 9.66, p<0.001).

CONCLUSION

For neonates with CDH requiring ECMO, there is no survival advantage or difference in severe neurologic injury between those receiving roller or centrifugal pump ECMO. However, there is a significant increase in red blood cell hemolysis associated with centrifugal ECMO support.

Hematological complications in children subjected to extracorporeal membrane oxygenation

OBJECTIVES

To analyze the hematological complications and need for transfusions in children receiving extracorporeal life support (ECLS).

DESIGN

A retrospective study was carried out.

SETTING

A pediatric intensive care unit.

PATIENTS

Children under 18 years of age subjected to ECLS between September 2006 and November 2015.

INTERVENTIONS

None.

VARIABLES OF INTEREST

Patient and ECLS characteristics, anticoagulation, hematological and coagulation parameters, transfusions and clinical course.

RESULTS

A total of 100 patients (94 with heart disease) with a median age of 11 months were studied. Seventy-six patients presented bleeding. The most frequent bleeding point was the mediastinum and 39 patients required revision surgery. In the first 3days, 97% of the patients required blood transfusion (34.4ml/kg per day), 94% platelets (21.1ml/kg per day) and 90% plasma (26.6ml/kg per day). Patients who were in the postoperative period, those who were bleeding at the start of ECLS, those requiring revision surgery, those who could not suspend extracorporeal circulation, and those subjected to transthoracic cannulation required a greater volume of transfusions than the rest of the patients. Thromboembolism occurred in 14 patients and hemolysis in 33 patients. Mortality among the children who were bleeding at the start of ECLS (57.6%) was significantly higher than in the rest of the patients (37.5%) (P=.048).

CONCLUSIONS

Children subjected to ECLS present high blood product needs. The main factors related to transfusions were the postoperative period, bleeding at the start of ECLS, revision surgery, transthoracic cannulation, and the impossibility of suspending extracorporeal circulation. Children with bleeding suffered greater mortality than the rest of the patients.

Special equipment considerations for neonatal ECMO

Extracorporeal membrane oxygenation (ECMO) for neonates is applied routinely at major children's hospitals around the world. While the practice seems routine, the peculiar physiology of the small human imposes particular constraints on selection of equipment, performance of the circuit, and risks to the child. The physiology of small patients and physics of circuit elements leave many areas opaque and far from optimal, but still allow assembly of a set of useful heuristics for good practice. Here, we examine individual mechanical components of the ECMO circuit with attention to selection, pitfalls, and peculiarities of each when applied to the neonate.

Improving Long-Term Outcomes After Extracorporeal Membrane Oxygenation: From Observational Follow-Up Programs Toward Risk Stratification

Since the introduction of extracorporeal membrane oxygenation (ECMO), more neonates and children with cardiorespiratory failure survive. Interest has therefore shifted from reduction of mortality toward evaluation of long-term outcomes and prevention of morbidity. This review addresses the changes in ECMO population and the ECMO-treatment that may affect long-term outcomes, the diagnostic modalities to evaluate neurological morbidities and their contributions to prognostication of long-term outcomes. Most follow-up data have only become available from observational follow-up programs in neonatal ECMO-survivors. The main topics are discussed in this review. Recommendations for long-term follow up depend on the presence of neurological comorbidity, the nature and extent of the underlying disease, and the indication for ECMO. Follow up should preferably be offered as standard of care, and in an interdisciplinary, structured and standardized way. This permits evaluation of outcome data and effect of interventions. We propose a standardized approach and recommend that multiple domains should be evaluated during long-term follow up of neonates and children who needed extracorporeal life support.