Extracorporeal membrane oxygenation for intraoperative cardiac support in children with congenital heart disease☆☆☆

Bridging with Veno-Arterial Extracorporeal Membrane Oxygenation in Children: A 10-Year Single-Center Experience

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is frequently used in children with and without congenital heart disease (CHD). This study, of a single-center and retrospective design, evaluated the use and timing of V-A ECMO in a pediatric cohort who underwent V-A ECMO implantation between January 2009 and December 2019. The patients were divided into a pre-/non-surgical group and a post-surgical group. Among the investigated variables were age, gender, weight, duration of ECMO, ECMO indication, and ventricular physiology, with only the latter being statistically relevant between the two groups. A total of 111 children (58 male/53 female), with a median age of 87 days (IQR: 7–623) were supported using V-A ECMO. The pre-/non-surgical group consisted of 59 patients and the post-surgical group of 52 patients. Survival at discharge was 49% for the pre-/non-surgical group and 21% for the surgical group (p = 0.04). Single-ventricle physiology was significant for a worse outcome (p = 0.0193). Heart anatomy still has the biggest role in the outcomes of children on ECMO. Nevertheless, children with CHD can be successfully bridged with ECMO to cardiac operation.

Use of Extracorporeal Membrane Oxygenation After Congenital Heart Disease Repair: A Systematic Review and Meta-Analysis

Introduction: Extracorporeal membrane oxygenation (ECMO) has been widely used to treat cardiopulmonary failure in patients with congenital heart defects (CHD) postoperatively. A meta-analysis is performed for outcomes of postoperative CHD patients on ECMO. Methods: Electronic databases, including PubMed, EMbase, and Cochrane Library CENTRAL were searched systematically from January 1990 to June 2020 for literature which reported the outcomes of postoperative CHD cases on ECMO. The scope of this search was restricted to articles published in English. Results: Forty-three studies were included in this study, involving 3,585 subjects. Postoperative ventricular failure with low cardiac output was the most common indication of ECMO initiation. The pooled estimated incidence of in-hospital mortality was 56.8% (95% CI, 52.5-61.0%). Bleeding was the most common complication with ECMO with an incidence of 47.1% (95% CI, 38.5-55.8%). Multivariate meta-regression analysis revealed that single ventricular physiology (coefficient 0.213, 95% CI 0.099-0.327, P = 0.001) and renal failure (coefficient 0.315, 95% CI 0.091-0.540, P = 0.008) were two independent risk factors for in-hospital mortality. Conclusions: There is an overall high in-hospital mortality of 56.8% in postoperative CHD patients on ECMO. Bleeding is the most common complication during ECMO running with an incidence of 47.1%. Single ventricular physiology and renal failure, as two independent risk factors, may potentially increase in-hospital mortality. Further studies exploring the differences in outcomes between ECMO and other extracorporeal life support strategies are warranted.

Extracorporeal Membrane Oxygenation Support for Failure to Wean From Cardiopulmonary Bypass After Pediatric Cardiac Surgery: Analysis of Extracorporeal Life Support Organization Registry Data

Supplemental Digital Content is available in the text.

Objectives:

Extracorporeal membrane oxygenation has been used to support children who fail to wean from cardiopulmonary bypass after pediatric cardiac surgery, but little is known about outcomes. We aimed to describe epidemiology and extracorporeal membrane oxygenation factors associated with inhospital mortality in these patients.

Design:

Retrospective multicenter registry-based cohort study.

Setting:

International pediatric extracorporeal membrane oxygenation centers.

Patients:

Children less than 18 years old supported with extracorporeal membrane oxygenation for failure to wean from cardiopulmonary bypass after cardiac surgery during 2000–2016 and reported to Extracorporeal Life Support Organization’s registry.

Intervention:

None.

Measurements and Main Results:

The primary outcome measure was inhospital mortality. Cardiac surgical procedural complexity was assigned using risk adjustment in congenital heart surgery-1. Multivariable logistic regression was used to identify factors independently associated with the primary outcome. We included 2,322 patients, with a median age of 26 days (interquartile range, 7–159); 47% underwent complex surgical procedures (risk adjustment in congenital heart surgery 4–6 categories). Inhospital mortality was 55%. The multivariable model evaluating associations with inhospital mortality showed noncardiac congenital anomalies (odds ratio, 1.78; CI, 1.36–2.32), comorbidities (odds ratio, 1.59; CI, 1.30–1.94), preoperative cardiac arrest (odds ratio, 1.67; CI, 1.20–2.34), preoperative mechanical ventilation greater than 24 hours (odds ratio, 1.49; CI, 1.21–1.84), preoperative bicarbonate administration (odds ratio, 1.42; CI, 1.08–1.86), longer cardiopulmonary bypass time (> 251 min; odds ratio, 1.50; CI, 1.13–1.99), complex surgical procedures (odds ratio, 1.43; CI, 1.13–1.81), longer extracorporeal membrane oxygenation duration (> 104 hr, odds ratio, 1.54; CI, 1.17–2.02), and extracorporeal membrane oxygenation complications increased the odds of inhospital mortality. Age greater than 26 days (odds ratio, 0.56; CI, 0.42–0.75) reduced the odds of mortality.

Conclusions:

Children supported with extracorporeal membrane oxygenation for failure to wean from cardiopulmonary bypass after cardiac surgery are at high risk of mortality (55%). Younger patients, those with congenital abnormalities and comorbidities, undergoing complex procedures, requiring longer cardiopulmonary bypass, and experiencing extracorporeal membrane oxygenation complications and longer extracorporeal membrane oxygenation duration have higher mortality risk. These data can help assessing prognosis in this high-risk population.

Factors affecting the outcome of extracorporeal membrane oxygenation following paediatric cardiac surgery

BACKGROUND

Extracorporeal membrane oxygenation has been widely used after paediatric cardiac surgery due to increasing complex surgical repairs in neonates and infants having complex CHDs.

MATERIALS AND METHODS

We reviewed retrospectively the medical records of all patients with CHD requiring corrective or palliative cardiac surgery at King Abdulaziz University Hospital that needed extracorporeal membrane oxygenation support between November 2015 and November 2018.

RESULTS

The extracorporeal membrane oxygenation population was 30 patients, which represented 4% of 746 children who had cardiac surgery during this period. The patients' age range was from 1 day to 20.33 years, with a median age of 6.5 months. Median weight was 5 kg (range from 2 to 53 kg). Twenty patients were successfully decannulated (66.67%), and 12 patients (40%) were survived to hospital discharge. Patients with biventricular repair tended to have better survival rate compared with those with single ventricle palliation (55.55 versus 16.66%, p-value 0.058). During the first 24 hours of extracorporeal membrane oxygenation support, the flow rate was significantly reduced after 4 hours of extracorporeal membrane oxygenation connection in successfully decannulated patients.

CONCLUSION

Survival to hospital discharge in patients requiring extracorporeal membrane oxygenation support after paediatric cardiac surgery was better in those who underwent biventricular repair than in those who had univentricular palliation. Capillary leak on extracorporeal membrane oxygenation could be a risk of mortality in patients after paediatric cardiac surgery.

Pediatric ventricular assist devices: what are the key considerations and requirements?

Introduction: The development of ventricular assist devices (VADs) have enabled myocardial recovery and improved patient survival until heart transplantation. However, device options remain limited for children and lag in development.Areas covered: This review focuses on the evolution of pediatric VADs in becoming to be an accepted treatment option in advanced heart failure, discusses the classification of VADs available for children, i.e. types of pumps and duration of support, and defines implantation indications and explantation criteria, describes attendant complications and long-term outcome of VAD support. Furthermore, we emphasize the key considerations and requirements in the application of these devices in infants, children and adolescents.Expert opinion: Increasing use of VADs has facilitated a leading edge in management of advanced heart failure either as a bridge to transplantation or as a bridge to myocardial recovery. In newborns and small children, the EXCOR Pediatric VAD remains the only reliable option. In some patients ventricular unloading may lead to complete myocardial recovery. There is a strong need for pumps that are fully implantable, suitable for single ventricle physiology, such as the right ventricle.

Structured review of post-cardiotomy extracorporeal membrane oxygenation: Part 2-pediatric patients

Veno-arterial extracorporeal membrane oxygenation (ECMO) is established therapy for short-term circulatory support for children with life-treating cardiorespiratory dysfunction. In children with congenital heart disease (CHD), ECMO is commonly used to support patients with post-cardiotomy shock or complications including intractable arrhythmias, cardiac arrest, and acute respiratory failure. Cannulation configurations include central, when the right atrium and aorta are utilized in patients with recent sternotomy, or peripheral, when cannulation of the neck or femoral vessels are used in non-operative patients. ECMO can be used to support any form of cardiac disease, including univentricular palliated circulation. Although veno-arterial ECMO is commonly used to support children with CHD, veno-venous ECMO has been used in selected patients with hypoxemia or ventilatory failure in the presence of good cardiac function. ECMO use and outcomes in the CHD population are mainly informed by single-center studies and reports from collated registry data. Significant knowledge gaps remain, including optimal patient selection, timing of ECMO deployment, duration of support, anti-coagulation, complications, and the impact of these factors on short- and long-term outcomes. This report, therefore, aims to present a comprehensive overview of the available literature informing patient selection, ECMO management, and in-hospital and early post-discharge outcomes in pediatric patients treated with ECMO for post-cardiotomy cardiorespiratory failure.

Risk factors for mortality in paediatric cardiac ICU patients managed with extracorporeal membrane oxygenation

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation is frequently used in patients with cardiac disease. We evaluated short-term outcomes and identified factors associated with hospital mortality in cardiac patients supported with veno-arterial extracorporeal membrane oxygenation.

METHODS

A retrospective review of patients supported with veno-arterial extracorporeal membrane oxygenation at a university-affiliated children's hospital was performed.

RESULTS

A total of 253 patients with cardiac disease managed with extracorporeal membrane oxygenation were identified; survival to discharge was 48%, which significantly improved from 39% in an earlier era (1995-2001) (p=0.01). Patients were categorised into surgical versus non-surgical groups on the basis of whether they had undergone cardiac surgery before or not, respectively. The most common indication for extracorporeal membrane oxygenation was extracorporeal cardiopulmonary resuscitation: 96 (51%) in the surgical group and 45 (68%) in the non-surgical group. In a multiple covariate analysis, single-ventricle physiology (p=0.01), duration of extracorporeal membrane oxygenation (p<0.01), and length of hospital stay (p=0.03) were associated with hospital mortality. Weekend or night shift cannulation was associated with mortality in non-surgical patients (p=0.05).

CONCLUSION

We report improvement in survival compared with an earlier era in cardiac patients supported with extracorporeal membrane oxygenation. Single-ventricle physiology continues to negatively impact survival, along with evidence of organ dysfunction during extracorporeal membrane oxygenation, duration of extracorporeal membrane oxygenation, and length of stay.

Late-Term Gestation Is Associated With Improved Survival in Neonates With Congenital Heart Disease Following Postoperative Extracorporeal Life Support

OBJECTIVE

Several population-based studies have shown that gestational age 39-40 weeks at birth is associated with superior outcomes in various pediatric settings. A high proportion of births for neonates with congenital heart disease occur before 39 weeks. We aimed to assess the influence of late-term gestation (39-40 wk) on survival in neonates requiring extracorporeal life support following surgery for congenital heart disease.

DESIGN

Retrospective cohort study.

SETTING

The Royal Children's Hospital, Melbourne, Australia.

PATIENTS

Neonates requiring extracorporeal life support after cardiac surgery for congenital heart disease.

MEASUREMENTS AND MAIN RESULTS

From 2005 to 2014, 110 neonates (10.5% of neonates undergoing cardiac surgery) required extracorporeal life support after cardiac surgery. Indications were failure to separate from cardiopulmonary bypass in 40 (36%), extracorporeal cardiopulmonary resuscitation in 48 (44%), progressive low cardiac output in 15 (14%), and other reasons in seven (6%). Extracorporeal life support duration was 94 hours (interquartile range, 53-135), and 54 (49%) underwent single ventricle repair. Gestation at birth (n [%]) was as follows: less than 37 weeks, 19 (17%); 37-38 weeks, 38 (35%); 39-40 weeks, 50 (45%); 41 weeks or more, 3 (3%). By multivariable analysis (controlling for age, era of extracorporeal life support 2005-2009 vs 2010-2014, single ventricle status and acute renal failure), gestational age of 39-40 weeks was associated with the lowest odds for intensive care mortality: using less than 37 weeks as referent, the adjusted odds ratio (95% CI) for 37-38 weeks was 0.41 (0.12-1.33); for 39-40 weeks, 0.27 (0.08-0.84); and for 41 weeks or more, 1.06 (0.07-14.7). Similar association was also seen in a subcohort of study neonates (n = 66) who were commenced on extracorporeal life support after admission to intensive care: using less than 37 weeks as referent, the adjusted odds ratio (95% CI) for 37-38 weeks was 0.52 (0.10-2.80) and for 39-40 weeks, 0.15 (0.03-0.81).

CONCLUSIONS

In this cohort of neonates requiring extracorporeal life support following cardiac surgery, 39-40 weeks of gestation at birth is associated with the best survival. The additional maturity gained by reaching a gestation of at least 39 weeks is likely to confer a survival advantage in this high-risk cohort.

Extracorporeal Life Support: Four Decades and Counting

Extracorporeal membrane oxygenation (ECMO) or extracorporeal life support (ECLS) is a form of heart lung bypass that is used to support neonates, pediatrics, and adult patients with cardiorespiratory failure for days or weeks till organ recovery or transplantation. Venoarterial (VA) and venovenous (VV) ECLS are the most common modes of support. ECLS circuit components and monitoring have been evolving over the last 40 years. The technology is safer, simpler, and more durable with fewer complications. The use of neonatal respiratory ECLS use has been declining over the last two decades, while adult respiratory ECLS is growing especially since the H1N1 influenza pandemic in 2009. This review provides an overview of ECLS evolution over the last four decades, its use in neonatal, pediatric and adults, description of basic principles, circuit components, complications, and outcomes as well as a quick look into the future.

Institution of Veno-arterial Extracorporeal Membrane Oxygenation Does Not Lead to Increased Wall Stress in Patients with Impaired Myocardial Function

The effect of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on wall stress in patients with cardiomyopathy, myocarditis, or other cardiac conditions is unknown. We set out to determine the circumferential and meridional wall stress (WS) in patients with systemic left ventricles before and during VA ECMO. We established a cohort of patients with impaired myocardial function who underwent VA ECMO therapy from January 2000 to November 2013. Demographic and clinical data were collected and inotropic score calculated. Measurements were taken on echocardiograms prior to the initiation of VA ECMO and while on full-flow VA ECMO, in order to derive wall stress (circumferential and meridional), VCFc, ejection fraction, and fractional shortening. A post hoc sub-analysis was conducted, separating those with pulmonary hypertension (PH) and those with impaired systemic output. Thirty-three patients met inclusion criteria. The patients' median age was 0.06 years (range 0-18.7). Eleven (33%) patients constituted the organ failure group (Gr2), while the remaining 22 (66%) patients survived to discharge (Gr1). WS and all other echocardiographic measures were not different when comparing patients before and during VA ECMO. Ejection and shortening fraction, WS, and VCFc were not statistically different comparing the survival and organ failure groups. The patients' position on the VCFc-WS curve did not change after the initiation of VA ECMO. Those with PH had decreased WS as well as increased EF after ECMO initiation, while those with impaired systemic output showed no difference in those parameters with initiation of ECMO. The external workload on the myocardium as indicated by WS is unchanged by the institution of VA ECMO support. Furthermore, echocardiographic measures of cardiac function do not reflect the changes in ventricular performance inherent to VA ECMO support. These findings are informative for the interpretation of echocardiograms in the setting of VA ECMO. ECMO may improve ventricular mechanics in those with PH as the primary diagnosis.

Use of Therapeutic Plasma Exchange during Extracorporeal Life Support in Critically Ill Cardiac Children with Thrombocytopenia-Associated Multi-Organ Failure

BACKGROUND

Thrombocytopenia-associated multi-organ failure (TAMOF) in children is a well-described factor for increased hospital mortality. Low cardiac output syndrome (LCOS) and the effects of cardiopulmonary bypass may manifest with several adverse physiologic and immunologic effects, with varying degrees of thrombocytopenia and multi-organ dysfunction, sometimes very similar to TAMOF. LCOS is a common occurrence in children with critical heart disease, presenting in as much as 23.8% of infants postoperative of congenital heart surgery. Therapeutic plasma exchange (TPE) has been offered as a promising therapy for TAMOF; however, the therapeutic implications of this modality in children with critical heart disease and a clinical diagnosis of TAMOF are unknown.

OBJECTIVES

We describe our institutional experience with TPE as an adjuvant rescue therapy for children with critical heart disease and a clinical diagnosis of TAMOF, while supported by extracorporeal membrane oxygenation (ECMO).

METHODS

Single-center retrospective analysis of children with critical heart disease admitted to the CICU and supported by ECMO, undergoing TPE for a clinical diagnosis of TAMOF between January 2006 and June 2015.

RESULTS

Forty-one patients were included for analysis. Median age and weight of patients was 0.6 years (range 0.0-17.2) and 8.5 kg (range 1.5-80.0). TPE was initiated at a median of 1 day (0-13) after initiation of ECMO. Modified organ failure index (MOFI) and platelet count improved after TPE start (p < 0.001). Patients with early TPE initiation after ECMO cannulation (<1 day) showed more improvement in MOFI and platelet counts than patients with late TPE initiation (p < 0.001 for each). Overall survival to hospital discharge was 53.7%. The within-groups hospital survival was 73.3% for patients with heart failure, 34.8% for patients with congenital heart disease, and 100% for those with other cardiac disease (p = 0.016).

CONCLUSION

In children with critical cardiac disease and clinical diagnosis of TAMOF necessitating ECMO for hemodynamic support, concurrent TPE may be associated with an improvement in organ failure and platelet count, particularly when started early. Further studies are warranted to establish the most effective use of TPE and its effect on survival in this population.

Extracorporeal Membrane Oxygenation in a 1,360-g Premature Neonate after Repairing Total Anomalous Pulmonary Venous Return

With advancements in complex repairs in neonates with complicated congenital heart diseases, extracorporeal membrane oxygenation (ECMO) has been increasingly used as cardiac support. ECMO has also been increasingly used for low birth weight (LBW) or very low birth weight (VLBW) neonates. However, since prematurity and LBW are risk factors for ECMO, the appropriate indications for neonates with LBW, especially VLBW, are under dispute. We report a case of ECMO performed in a 1,360-g premature infant with VLBW due to cardiopulmonary bypass weaning failure after repairing infracardiac total anomalous pulmonary venous return.

Modern Outcomes of Mechanical Circulatory Support as a Bridge to Pediatric Heart Transplantation

BACKGROUND

Pediatric patients awaiting orthotopic heart transplantation frequently require bridge to transplantation (BTT) with mechanical circulatory support. Posttransplant survival outcomes and predictors of mortality have not been thoroughly described in the modern era using a large-scale analysis.

METHODS

The United Network for Organ Sharing database was reviewed to identify pediatric heart transplant recipients from 2005 through 2012. Patients were stratified into three groups: extracorporeal membrane oxygenation (ECMO), ventricular assist device (VAD), and direct transplantation (DTXP). The primary outcome was posttransplant survival.

RESULTS

Two thousand seven hundred seventy-seven pediatric patients underwent orthotopic heart transplantation. There were 617 patients who required BTT with mechanical circulatory support (22.2%), of whom there were 428 VAD BTT (69.4%) and 189 ECMO BTT (30.6%). An increase in VAD use was observed during the study period (p < 0.0001). Compared with DTXP, patients in the ECMO BTT group had a lower median age (<1 versus 5 years; p < 0.0001) and were significantly smaller (8 versus 14 kg; p < 0.001), whereas patients in the VAD BTT group were older (8 versus 5 years; p = 0.0002) and larger (24 versus 14 kg; p < 0.001). Actuarial survival was greater in the DTXP group compared with ECMO BTT, but similar to VAD BTT at 30 days and 1, 3, and 5 years. However, this survival difference was lost after censoring the first 4 months after transplant. In multivariable analysis, when restricted to the first 4 months of survival, independent predictors for mortality were ECMO BTT, age, diagnosis, and functional status, whereas VAD BTT was not.

CONCLUSIONS

Pediatric patients with DTXP or VAD BTT have equivalent posttransplant survival. However, those requiring ECMO BTT have inferior early posttransplant survival compared with those receiving DTXP.

Prophylactic milrinone for the prevention of low cardiac output syndrome and mortality in children undergoing surgery for congenital heart disease

BACKGROUND

Children with congenital heart disease often undergo heart surgery at a young age. They are at risk for postoperative low cardiac output syndrome (LCOS) or death. Milrinone may be used to provide inotropic and vasodilatory support during the immediate postoperative period.

OBJECTIVES

This review examines the effectiveness of prophylactic postoperative use of milrinone to prevent LCOS or death in children having undergone surgery for congenital heart disease.

SEARCH METHODS

Electronic and manual literature searches were performed to identify randomised controlled trials. We searched CENTRAL, MEDLINE, EMBASE and Web of Science in February 2014 and conducted a top-up search in September 2014 as well as clinical trial registries and reference lists of published studies. We did not apply any language restrictions.

SELECTION CRITERIA

Only randomised controlled trials were selected for analysis. We considered studies with newborn infants, infants, toddlers, and children up to 12 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data according to a pre-defined protocol. We obtained additional information from all study authors.

MAIN RESULTS

Three of the five included studies compared milrinone versus levosimendan, one study compared milrinone with placebo, and one compared milrinone verus dobutamine, with 101, 242, and 50 participants, respectively. Three trials were at low risk of bias while two were at higher risk of bias. The number and definitions of outcomes were non-uniform as well. In one study comparing two doses of milrinone and placebo, there was some evidence in an overall comparison of milrinone versus placebo that milrinone lowered risk for LCOS (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.28 to 0.96; 227 participants). The results from two small studies do not provide enough information to determine whether milrinone increases the risk of LCOS when compared to levosimendan (RR 1.22, 95% CI 0.32 to 4.65; 59 participants). Mortality rates in the studies were low, and there was insufficient evidence to draw conclusions on the effect of milrinone compared to placebo or levosimendan or dobutamine regarding mortality, the duration of intensive care stay, hospital stay, mechanical ventilation, or maximum inotrope score (where available). Numbers of patients requiring mechanical cardiac support were also low and did not allow a comparison between studies, and none of the participants of any study received a heart transplantation up to the end of the respective follow-up period. Time to death within three months was not reported in any of the included studies. A number of adverse events was examined, but differences between the treatment groups could not be proven for hypotension, intraventricular haemorrhage, hypokalaemia, bronchospasm, elevated serum levels of liver enzymes, or a reduced left ventricular ejection fraction < 50% or reduced left ventricular fraction of shortening < 28%. Our analysis did not prove an increased risk of arrhythmias in patients treated prophylactically with milrinone compared with placebo (RR 3.59, 95% CI 0.83 to 15.42; 238 participants), a decreased risk of pleural effusions (RR 1.78, 95% CI 0.92 to 3.42; 231 participants), or a difference in risk of thrombocytopenia on milrinone compared with placebo (RR 0.86, 95% CI 0.39 to 1.88; 238 participants). Comparisons of milrinone with levosimendan or with dobutamine, respectively, did not clarify the risk of arrhythmia and were not possible for pleural effusions or thrombocytopenia.

AUTHORS' CONCLUSIONS

There is insufficient evidence of the effectiveness of prophylactic milrinone in preventing death or low cardiac output syndrome in children undergoing surgery for congenital heart disease, compared to placebo. So far, no differences have been shown between milrinone and other inodilators, such as levosimendan or dobutamine, in the immediate postoperative period, in reducing the risk of LCOS or death. The existing data on the prophylactic use of milrinone has to be viewed cautiously due to the small number of small trials and their risk of bias.

Delayed extracorporeal membrane oxygenation in children after cardiac surgery: two-institution experience

OBJECTIVE

There are limited data on the outcomes of children receiving delayed (≥7 days) extracorporeal membrane oxygenation after cardiac surgery. The primary aim of this project is to identify the aetiology and outcomes of extracorporeal membrane oxygenation in children receiving delayed (≥7 days) extracorporeal membrane oxygenation after cardiac surgery.

PATIENTS AND METHODS

We conducted a retrospective review of all children ≤18 years supported with delayed extracorporeal membrane oxygenation after cardiac surgery between the period January, 2001 and March, 2012 at the Arkansas Children's Hospital, United States of America, and Royal Children's Hospital, Australia. The data collected in our study included patient demographic information, diagnoses, extracorporeal membrane oxygenation indication, extracorporeal membrane oxygenation support details, medical and surgical history, laboratory, microbiological, and radiographic data, information on organ dysfunction, complications, and patient outcomes. The outcome variables evaluated in this report included: survival to hospital discharge and current survival with emphasis on neurological, renal, pulmonary, and other end-organ function.

RESULTS

During the study period, 423 patients undergoing cardiac surgery were supported with extracorporeal membrane oxygenation at two institutions, with a survival of 232 patients (55%). Of these, 371 patients received extracorporeal membrane oxygenation <7 days after cardiac surgery, with a survival of 205 (55%) patients, and 52 patients received extracorporeal membrane oxygenation ≥7 days after cardiac surgery, with a survival of 27 (52%) patients. The median duration of extracorporeal membrane oxygenation run for the study cohort was 5 days (interquartile range: 3, 10). In all, 14 patients (25%) received extracorporeal membrane oxygenation during active cardiopulmonary resuscitation with chest compressions. There were 24 patients (44%) who received dialysis while being on extracorporeal membrane oxygenation. There were eight patients (15%) who had positive blood cultures and four patients (7%) who had positive urine cultures while being on extracorporeal membrane oxygenation. There were nine patients (16%) who had bleeding complications associated with extracorporeal membrane oxygenation runs. There were 10 patients (18%) who had cerebrovascular thromboembolic events associated with extracorporeal membrane oxygenation runs. Of these, 19 patients are still alive with significant comorbidities.

CONCLUSIONS

This study demonstrates that mortality outcomes are comparable among children receiving extracorporeal membrane oxygenation ≥7 days and <7 days after cardiac surgery. The proportion of patients receiving extracorporeal membrane oxygenation ≥7 days is small and the aetiology diverse.

Predictors of mortality in pediatric patients on venoarterial extracorporeal membrane oxygenation

OBJECTIVES

Currently, there are no established echocardiographic or hemodynamic predictors of mortality after weaning venoarterial extracorporeal membrane oxygenation in children. We wished to determine which measurements predict mortality.

DESIGN

Over 3 years, we prospectively assessed six echo and six hemodynamic variables at 3-5 circuit rates while weaning extracorporeal membrane oxygenation flow. Hemodynamic measurements were heart rate, inotropic score, arteriovenous oxygen difference, pulse pressure, oxygenation index, and lactate. Echo variables included shortening/ejection fraction, outflow tract Doppler-derived stroke distance (velocity-time integral), degree of atrioventricular valve regurgitation, longitudinal strain (global longitudinal strain), and circumferential strain (global circumferential strain).

SETTING

Cardiovascular ICU at Lucille Packard Children's Hospital Stanford, CA.

SUBJECTS

Patients were stratified into those who died or required heart transplant (Gr1) and those who did not (Gr2). For each patient, we compared the change for each variable between full versus minimum extracorporeal membrane oxygenation flow for each group.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We enrolled 21 patients ranging in age from 0.02 to 15 years. Five had dilated cardiomyopathy, and 16 had structural heart disease with severe ventricular dysfunction. Thirteen of 21 patients (62%) comprised Gr1, including two patients with heart transplants. Eight patients constituted Gr2. Gr1 patients had a significantly greater increase in oxygenation index (35% mean increase; p < 0.01) off extracorporeal membrane oxygenation compared to full flow, but no change in velocity-time integral or arteriovenous oxygen difference. In Gr2, velocity-time integral increased (31% mean increase; p < 0.01), with no change in arteriovenous oxygen difference or oxygenation index. Pulse pressure increased modestly with flow reduction only in Gr1 (p < 0.01).

CONCLUSION

Failure to augment velocity-time integral or an increase in oxygenation index during the extracorporeal membrane oxygenation weaning is associated with poor outcomes in children. We propose that these measurements should be performed during extracorporeal membrane oxygenation wean, as they may discriminate who will require alternative methods of circulatory support for survival.

Mechanical circulatory support for infants and small children

The number of children in need of mechanical circulatory support has increased substantially over the last two decades, due to the technological progress made in surgery and intensive care, leading to improved survival of patients with congenital heart disease. In addition, primary myocardial dysfunction related to myocarditis or dilated cardiomyopathy may cause end-stage cardiac failure in children or infants, although not as frequently as in adults. The need for mechanical circulatory support may be either temporary until spontaneous myocardial recovery, as in postcardiotomy cardiac failure, or prolonged until heart transplantation in the absence of recovery. Two types of mechanical circulatory devices are suitable for the paediatric population: extracorporeal membrane oxygenation for short-term support; and ventricular assist devices for long-term support as a bridge to transplantation. The aim of this review is to describe the specific issues related to paediatric mechanical circulatory support and the different types of devices available, to report on their rapidly growing use worldwide and on the outcomes for each indication and type of device, and to provide a perspective on the future developments and remaining challenges in this field.

Perioperative mechanical circulatory support in children: an analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database

OBJECTIVES

Analyses of mechanical circulatory support (MCS) in pediatric heart surgery have primarily focused on single-center outcomes or narrow applications. We describe the patterns of use, patient characteristics, and MCS-associated outcomes across a large multicenter cohort.

METHODS

Patients (aged <18 years) in the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database (2000-2010) were included. The characteristics and outcomes of those receiving postoperative MCS were described, and bayesian hierarchical models were used to examine variations in the adjusted MCS rates across institutions.

RESULTS

Of 96,596 operations (80 centers), MCS was used in 2.4%. The MCS patients were younger (13 vs 195 days, P < .0001) and more often had STS-defined preoperative risk factors (57.2% vs 32.7%, P < .0001). The operations with the greatest MCS rates included the Norwood procedure (17%) and complex biventricular repairs (arterial switch, ventricular septal defect, and arch repair [14%]). More than one half of the MCS patients did not survive to hospital discharge (53.2% vs 2.9% of non-MCS patients; P < .0001). MCS-associated mortality was greatest for truncus arteriosus and Ross-Konno operations (both 71%). The hospital-level MCS rates adjusted for patient characteristics and case mix varied by 15-fold across institutions, with both high- and low-volume hospitals having substantial variation in MCS rates.

CONCLUSIONS

Perioperative MCS use varied widely across centers. The MCS rates were greatest overall for the Norwood procedure and complex biventricular repairs. Although MCS can be a life-saving therapy, more than one half of MCS patients will not survive to hospital discharge, with mortality >70% for some operations. Future studies aimed at better understanding the appropriate indications, optimal timing, and management of MCS could help to reduce the variation in MCS use across hospitals and improve outcomes.

Extracorporeal life support after cardiac surgery in children: outcomes from a single institution

Extracorporeal life support (ECLS) is used after congenital heart surgery for several indications, including failure to separate from cardiopulmonary bypass, postoperative low cardiac output syndrome, and extracorporeal cardiopulmonary resuscitation. Here, we assessed the outcomes of ECLS in children after cardiac surgery at our institution. Medical records of all children who required postoperative ECLS at our institution were reviewed. Between 2003 and 2011, 36 (1.4%) of 2541 pediatric cardiac surgical cases required postoperative ECLS. Median age of patients was 64 days (range: 0 days-4.1 years). ECLS was in the form of either extracorporeal membrane oxygenation (ECMO; n = 24) or ventricular assist system (VAS; n = 12). Mean duration of ECLS was 4.9 ± 4.2 days. Overall, 21 patients (58%) were weaned off ECLS, and 17 patients (47%) were successfully discharged from the hospital. Patients with biventricular heart (BVH) had higher survival-to-hospital discharge rates compared with those with univentricular heart (UVH) (P = 0.019). Regarding ECLS type, UVH patients who received VAS showed higher rates of device discontinuation than UVH patients who received ECMO (P = 0.012). However, rates of hospital discharge were not significantly different between UVH patients who received VAS or ECMO. Surgical interventions, such as banding of Blalock-Taussig shunt to reduce pulmonary blood flow or placing bidirectional cavopulmonary shunt to minimize ventricular volume overload, were effective for weaning off ECLS in patients with UVH. ECLS is beneficial to children with low cardiac output after cardiac surgery. Rates of survival-to-hospital discharge were higher in BVH patients than UVH patients. Additional interventions to reduce ventricular volume load may be effective for discontinuing ECLS in patients with UVH.

Early clinical outcomes of new pediatric extracorporeal life support system (Endumo (2000) in neonates and infants

We investigated early clinical outcomes of a new extracorporeal life support (ECLS) system (Endumo 2000, Heiwa Bussan, Tokyo, Japan), which consists of a ROTAFLOW centrifugal pump, a BIOCUBE oxygenator with plasma-leakage-tight polymer fibers, and a biocompatible coating (T-NCVC coating), in pediatric patients <1 year old. From 2008 to 2011, 31 patients required ECLS. Except for 1 patient who was instituted with a transitional ECLS device, a conventional ECLS system (pediatric Emersave, TERUMO, Saitama, Japan) was initiated in 14 patients before December 2009 (6 boys, 63.4 ± 87.1 days old, 3.1 ± 1.0 kg), and the Endumo 2000 was initiated in 16 patients after December 2009 (8 boys, 43.9 ± 78.5 days old, 3.2 ± 0.7 kg). Primary reasons for the institution of ECLS were intraoperative low output syndrome in 11 patients, post-cardiotomy cardiopulmonary collapse in 9 patients, and other reasons in 10 patients. The median support period was 21.7 ± 20.7 days and the total number of circuit exchanges was 83. The median first circuit durability was significantly longer in the Endumo group [8.0 days (range 5.9-13.2) vs. 4.4 days (1.9-8.3)] (p = 0.020). Significant cranial hemorrhage occurred in only 1 patient, who received the Emersave system. The success rate for weaning from ECLS was 14.3% in the Emersave group and 56.3% in the Endumo group. Univariate analysis showed that usage of the Endumo 2000 was a predictor for successful weaning from the ECLS (p = 0.017) as well as survival at discharge (p = 0.032). The Endumo 2000 system provided safe and effective cardiopulmonary support without complications.

Short- and intermediate-term survival after extracorporeal membrane oxygenation in children with cardiac disease

OBJECTIVES

In children with cardiac disease, common indications for extracorporeal membrane oxygenation (ECMO) include refractory cardiopulmonary resuscitation (E-CPR), failure to separate from cardiopulmonary bypass (OR-ECMO), and low cardiac output syndrome (LCOS-ECMO). Despite established acceptance, ECMO outcomes are suboptimal with a survival between 38% and 55%. We evaluated factors associated with significantly increased survival in cardiac patients requiring ECMO.

METHODS

We conducted a retrospective investigation of consecutive patients undergoing ECMO between 2006 and 2010. Demographic, pre-ECMO, ECMO, and post-ECMO parameters were analyzed. Neurologic outcomes were assessed with the pediatric overall performance category scale at the latest follow-up.

RESULTS

There were 3524 admissions, 95 (3%) of which necessitated ECMO; 40 (42%) E-CPR, 31 (33%) OR-ECMO, and 24 (25%) LCOS-ECMO. The overall hospital survival was 73%. The within-groups hospital survival was 75% in E-CPR, 77% OR-ECMO and 62% LCOS-ECMO. In the multivariable logistic regression analysis, chromosomal anomalies (odds ratio [OR], 8; 95% confidence interval [CI], 2-35), single ventricle (OR ,6; 95% CI, 3-33), multiple ECMO runs (OR, 15; 95% CI, 4-42), higher 24-hour ECMO flows (OR, 8; 95% CI, 4-22), decreased lung compliance (OR, 5; 95% CI, 2-16), and need for plasma exchange (OR, 5; 95% CI, 3-18) were all significant factors associated with mortality. From the univariate analysis, a common parameter associated with mortality within all groups was intracranial hemorrhage. At 1.9 years (0.9, 2.9) of follow-up, 66% were still alive, and 89% of survivors had normal function or only mild neurodevelopmental disability.

CONCLUSIONS

ECMO was successfully used in children with cardiac disease with 73% and 66% short- and intermediate-term survival, respectively. The majority of the survivors had normal function or only a minimal neurodevelopmental deficit.

Use of volatile anesthetics in extracorporeal circulation

BACKGROUND AND OBJECTIVES

The use of volatile anesthetics in cardiac surgery is not recent. Since the introduction of halothane in clinical practice, several cardiac surgery centers started to use these anesthetics constantly.

CONTENT

In the last years a great number of studies have shown that the volatile anesthetics have a protecting effect against myocardial ischemic dysfunction. Experimental evidences have shown that the halogenated anesthetics have cardioprotective effects that cannot be only explained by coronary flow alterations or by the balance between myocardium available and consumed oxygen. In addition to that, the use of volatile anesthetics during extracorporeal circulation (ECC) in cardiac surgery plays an important role. Recent studies have proven that these agents have cardioprotective properties and produce better results when the volatile anesthetic is used during the whole surgery procedure, including ECC. The use of halogenated anesthetics through calibrated vaporizers adapted to the ECC circuit via oxygenator membranes has become popular. Therefore, the professionals involved such as anesthesiologists and perfusionists should learn specifics in order to solve possible doubts.

The impact of extracorporeal membrane oxygenation on survival in pediatric patients with respiratory and heart failure: review of our experience

Extracorporeal membrane oxygenation (ECMO) is widely used for circulatory support in pediatric cardiac patients with low cardiac output and hypoxemia. We retrospectively evaluated the efficacy of ECMO support for respiratory and heart failure in infants and children. From April 2002 to February 2011, 14 patients aged 19 days to 20 years old (average 44 months), with body weight 2.6 kg to 71 kg (median 14.1 kg), underwent ECMO support for failing cardiac function, hypoxemia, and low cardiac output syndrome. In 12 patients, ECMO was introduced after operation for congenital heart disease (four with complete repair including Fontan circulation, and eight with palliative repair). In one patient, ECMO was introduced after partial pulmonary resection for congenital cystic adenomatoid malformation because of respiratory failure. ECMO was introduced in a patient with severe heart failure caused by fulminant myocarditis. Patients' demographics, duration of extracorporeal membrane oxygenation, additional support, and outcomes were analyzed. Ten patients (71%) were successfully weaned from ECMO, and eight patients (57%) were discharged from the hospital. The mean duration of ECMO support was 332 h (range 11-2030 h). Although management of the ECMO circuit, including anticoagulation (activated clotting time: 150-250), was conducted following the institutional practice guidelines, it was difficult to control the bleeding. Seven patients required renal replacement therapy during ECMO support using peritoneal dialysis or continuous hemodiafiltration. Five patients had additional operative procedures: systemic-pulmonary shunt in two, bidirectional Glenn takedown with right modified Blalock-Taussig shunt, total cavopulmonary connection takedown, and redo ECMO in one patient each. The patient who had the longest ECMO support for respiratory failure due to acute respiratory distress syndrome after lung surgery was successfully weaned from ECMO because high-frequency oscillation (HFO) improved respiratory function. ECMO for heart and respiratory failure in infants and children is effective and allows time for recovery of cardiac dysfunction and acute hypoxic insult. The long-term ECMO support for over 2000 h was very rare, but it was possible to wean this patient from ECMO using HFO.

Extracorporeal membrane oxygenation following pediatric cardiac surgery: development and outcomes from a single-center experience

Extracorporeal membrane oxygenation (ECMO) has emerged as an effective mechanical support following cardiac surgery with respiratory and cardiac failure. However, there are no clear indications for ECMO use after pediatric cardiac surgery. We retrospectively reviewed medical records of 76 pediatric patients [mean age, 10.8 months (0–86); mean weight, 5.16 kg (1.16–16.5)] with congenital heart disease who received ECMO following cardiac surgery between January 1997 and October 2010. Forty-five patients were treated with an aggressive ECMO approach (aggressive ECMO group, April 2005–October 2010) and 31 with a delayed ECMO approach (delayed ECMO group, January 1997–March 2005). Demographics, diagnosis, operative variables, ECMO indication, and duration of survivors and non-survivors were compared. Thirty-four patients (75.5%) were successfully weaned from ECMO in the aggressive ECMO group and 26 (57.7%) were discharged. Conversely, eight patients (25.8%) were successfully weaned from ECMO in the delayed ECMO group and two (6.5%) were discharged. Forty-five patients with shunted single ventricle physiology (aggressive: 29 patients, delayed: 16 patients) received ECMO, but only 15 (33.3%) survived and were discharged. The survival rate of the aggressive ECMO group was significantly better when compared with the delayed ECMO group (p<0.01). Also, ECMO duration was significantly shorter among the aggressive ECMO group survivors (96.5 ± 62.9 h, p<0.01). Thus, the aggressive ECMO approach is a superior strategy compared to the delayed ECMO approach in pediatric cardiac patients. The aggressive ECMO approach improved our outcomes of neonatal and pediatric ECMO.

Rescue extracorporeal membrane oxygenation in children with refractory cardiac arrest

We describe our experience with extracorporeal cardiopulmonary resuscitation (CPR) using extracorporeal membrane oxygenation (ECMO) in children with refractory cardiac arrest, and determine predictors for mortality. ECMO support was instituted on 42 children, median age 0.7 years (1 day-17.8 years), median weight 7.05 (range 2.7-80) kg who suffered refractory cardiac arrest (1992-2008). Patients were postcardiotomy (n=27), or had uncorrected congenital heart diseases (n=3), cardiomyopathy (n=3), myocarditis (n=2), respiratory failure (n=3), or had trauma (n=4). Cannulation site was the chest in all except for three neonates who were cannulated through the neck vessels and two children who had femoral cannulation. ECMO was successfully discontinued in 17 patients. Primary cause of mortality was neurological injury. Pre-ECMO CPR duration for survivors against those who died was a mean of 35±1.3 min vs. a mean of 46±4.2 min. Age, weight, sex, anatomic diagnosis, etiology (surgical vs. medical) were not significant predictors of poor outcome. Prolonged CPR and high-dose inotropes are significant predictors of mortality. Rescue ECMO support in children with refractory cardiac arrest can achieve acceptable survival and neurological outcomes.

Current status of pediatric/neonatal extracorporeal life support: clinical outcomes, circuit evolution, and translational research

Extracorporeal life support (ECLS) offers lifesaving mechanical circulatory support for patients afflicted with respiratory and/or cardiac failure. Neonatal respiratory patients have higher survival rates compared to pediatric patients, while, for cardiac cases, pediatric patients are more likely to survive. The indications for ECLS have been expanded due to the improved technology and favorable outcomes. However, the rate of mortality and morbidity for ECLS patients remains significant. Mechanical complications still comprise a large percentage of ECLS complications, leaving definite room for improvement in ECLS circuit technology in the future. As a pre-clinical evaluating tool, translational research will provide more useful information for the selection of ECLS devices, encourage further development of ECLS technology, and, ultimately, benefit the patients.

Veno-arterial extracorporeal membrane oxygenation for high-risk cardiac catheterisation procedures

Extracorporeal membrane oxygenation (ECMO) provides circulatory or respiratory support, or both, to patients with severe but potentially reversible cardiac or respiratory failure refractory to standard therapy. The use of ECMO in the paediatric cardiac surgical population is established. Likewise, the use of ECMO for severe adult respiratory failure has recently been established and has been the subject of recent clinical trials. However, its use as a means of cardiac support in the adult population is not routine in clinical practice. We herein review the indications, technical procedure, complications and outcomes of extracorporeal membrane oxygenation as pertinent to cardiac disease in general, and specifically, to catheter-based interventions. We describe two cases of high-risk cardiac catheterisation laboratory procedures performed with veno-arterial ECMO support in adult patients who were deemed to be at unacceptably high risk for conventional open-heart surgery and cardiopulmonary bypass.