Extracorporeal membrane oxygenation for cardiac failure after congenital heart 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.

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.

Extracorporeal Life Support in Pediatric and Neonatal Critical Care: A Review

Extracorporeal life support (ECLS) is a modified form of cardiopulmonary bypass used to provide prolonged tissue oxygen delivery in patients with respiratory and/or cardiac failure. The first large-scale success of ECLS was achieved in the management of term newborns with respiratory failure. ECLS has become an accepted therapeutic modality for neonates, children, and adults who have failed conventional therapy and in whom cardiac and/or respiratory insufficiency is potentially reversible. The use of ECLS allows one to reduce other cardiopulmonary supports and apply a gentle ventilation strategy in a population of severely compromised critical care patients. ECLS has now been employed in more than 26,000 neonatal and pediatric patients with an overall survival rate of 68%. ECLS has evolved significantly over 25 years of clinical practice; patient selection for this complex and highly invasive therapy, as well as how ECLS is employed in different patient groups, is constantly changing. Generally, ECLS is used more liberally now than in the past. The number of patients requiring this support, however, is declining yearly, and those patients who receive ECLS compose a more severe subset of an intensive care population. This review provides an overview of the development of ECLS and the equipment and techniques employed. The use of ECLS for neonatal respiratory failure, pediatric respiratory failure, and cardiac support are outlined. Management of the ECLS patient is discussed in detail, and outcome of these patients is reviewed. Finally, current trends and future implications of ECLS in neonatal and pediatric critical care are addressed.

Extracorporeal membrane oxygenation support after the Fontan operation

OBJECTIVE

Extracorporeal membrane oxygenation has been used to support children with cardiac failure after the Fontan operation. Mortality is high, and causes of mortality remain unclear. We evaluated the in-hospital mortality and factors associated with mortality in these patients.

METHODS

Extracorporeal Life Support Organization registry data on patients requiring extracorporeal membrane oxygenation after the Fontan operation from 1987 to 2009 were retrospectively analyzed. Demographics and extracorporeal membrane oxygenation data were compared for survivors and nonsurvivors. A multivariable logistic regression model was used to identify factors associated with mortality.

RESULTS

Of 230 patients, 81 (35%) survived to hospital discharge. Cardiopulmonary resuscitation was more frequent (34% vs 17%, P = .04), and median fraction of inspired oxygen concentration was higher (1 [confidence interval, 0.9-1.0] vs 0.9 [confidence interval, 0.8-1.0], P = .03) before extracorporeal membrane oxygenation in nonsurvivors compared with survivors. Extracorporeal membrane oxygenation duration and incidence of complications, including surgical bleeding, neurologic injury, renal failure, inotrope use on extracorporeal membrane oxygenation, and bloodstream infection, were higher in nonsurvivors compared with survivors (P < .05 for all). In a multivariable model, neurologic injury (odds ratio, 5.18; 95% confidence interval, 1.97-13.61), surgical bleeding (odds ratio, 2.36; 95% confidence interval, 1.22-4.56), and renal failure (odds ratio, 2.81; 95% confidence interval, 1.41-5.59) increased mortality. Extracorporeal membrane oxygenation duration of more than 65 hours to 119 hours (odds ratio, 0.33; 95% confidence interval, 0.14-0.76) was associated with decreased mortality.

CONCLUSIONS

Cardiac failure requiring extracorporeal membrane oxygenation after the Fontan operation is associated with high mortality. Complications during extracorporeal membrane oxygenation support increase mortality odds. Prompt correction of surgical bleeding when possible may improve survival.

Successful support and separation from veno-venous extracorporeal membrane oxygenation support in a three-month-old patient following bidirectional Glenn procedure

While extracorporeal membrane oxygenation (ECMO) is a useful mechanism of providing support in pediatric patients with cardiopulmonary dysfunction following surgery for congenital heart disease, outcomes have varied dramatically between distinct cardiac diagnoses. Reported outcomes of ECMO support following a bidirectional Glenn procedure in patients with single ventricle physiology are uniformly poor due in part to physiological and anatomical challenges inherent to cannulation in this population. We describe a unique veno-venous cannulation that can be applied to this patient population and has allowed for successful decannulation in our practice.

Lung physiology during ECS resuscitation of DCD donors followed by in situ assessment of lung function

Extracorporeal cardiopulmonary support (ECS) of donors after cardiac death (DCD) has been shown to improve abdominal organs for transplantation. This study assesses whether pulmonary congestion occurs during ECS with the heart arrested and describes an in vivo method to assess if lungs are suitable for transplantation from DCD donors after ECS resuscitation. Cardiac arrest was induced in 30 kg pigs, followed by 10 min of warm ischemia. Cannulae were placed into the right atrium (RA) and iliac artery, and veno-arterial ECS was initiated for 90 min with lungs inflated, group 1 (n = 5) or deflated, group 2 (n = 3). Left atrial pressures were measured as a marker for pulmonary congestion. After 90 min of ECS, lung function was evaluated. Cannulae were placed into the pulmonary artery (PA) and left ventricle (LV). A second pump was included, and ECS was converted to a bi-ventricular (bi-VAD) system. The RVAD drained from the RA and pumped into the PA, and the LVAD drained the LV and pumped into the iliac. This brought the lungs back into circulation for a 1-hr assessment period. The oxygenator was turned off, and ventilation was restarted. Flows, blood gases, PA and left atrial pressures, and compliance were recorded. In both the groups, LA pressure was <15 mm Hg during ECS. During the lung assessment period, PA flows were 1.4-2.2 L/min. PO2 was >300 mm Hg, with normal PCO2. Extracorporeal cardiopulmonary support resuscitation of DCD donors is feasible and allows for assessment of function before procurement. Extracorporeal cardiopulmonary support does not cause pulmonary congestion, and the lungs retain adequate function for transplantation. Compliance correlated with lung function.

Intraoperative extracorporeal membrane oxygenation and survival of pediatric patients undergoing repair of congenital heart disease

BACKGROUND

We studied the association between the introduction of extracorporeal membrane oxygenation (ECMO) into routine practice and the survival of children who failed weaning from cardiopulmonary bypass (CPB). We compare two periods, before formal introduction of ECMO in our institution (1993-1999, pre-ECMO era) and after ECMO became a formalized program (2000-2006, ECMO era).

METHODS

Retrospective review of Mayo Clinic Database between 1993 and 2006 for outcomes of patients <18 years old who required ECMO during repair of congenital heart malformations.

RESULTS

Thirty-five children during ECMO era received intraoperative ECMO, and 17 (54%) survived to hospital discharge. The frequency of ECMO use was the highest in neonates, therefore, this was the only subcohort of pediatric patients that allowed comparison of survival between the pre-ECMO and ECMO eras. When compared to pre-ECMO era, neonatal survival increased during ECMO era (P = 0.043). ECMO was mostly used in neonates with higher complexity of cardiac defects undergoing more complex repairs, and the overall improvement of survival was primarily due to better survival of these patients. During pre-ECMO era, survival was lower in patients with higher risk (P = 0.001). However, during ECMO era, no difference in survival was observed across assigned risk groups (P = 0.658).

CONCLUSIONS

The availability of ECMO for neonates failing to wean from CPB was associated with improved survival, especially in children undergoing repair of the most complex congenital heart malformations. After introduction of ECMO, survival improved and no longer depended upon the complexity of surgical repair.

Factors influencing the outcome of paediatric cardiac surgical patients during extracorporeal circulatory support

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (ECMO) is a common modality of circulatory assist device used in children. We assessed the outcome of children who had ECMO following repair of congenital cardiac defects (CCD) and identified the risk factors associated with hospital mortality.

METHODS

From April 1990 to December 2003, 53 patients required ECMO following surgical correction of CCD. Retrospectively collected data was analyzed with univariate and multivariate logistic regression analysis.

RESULTS

Median age and weight of the patients were 150 days and 5.4 kgs respectively. The indications for ECMO were low cardiac output in 16, failure to wean cardiopulmonary bypass in 13, cardiac arrest in 10 and cardio-respiratory failure in 14 patients. The mean duration of ECMO was 143 hours. Weaning off from ECMO was successful in 66% and of these 83% were survival to hospital-discharge. 37.7% of patients were alive for the mean follow-up period of 75 months. On univariate analysis, arrhythmias, ECMO duration >168 hours, bleeding complications, renal replacement therapy on ECMO, arrhythmias and cardiac arrest after ECMO were associated with hospital mortality.On multivariate analysis, abnormal neurology, bleeding complications and arrhythmias after ECMO were associated with hospital mortality. Extra and intra-thoracic cannulations were used in 79% and 21% of patients respectively and extra-thoracic cannulation had significantly less bleeding complications (p = 0.031).

CONCLUSION

ECMO provides an effective circulatory support following surgical repair of CCD in children. Extra-thoracic cannulation is associated with less bleeding complications. Abnormal neurology, bleeding complications on ECMO and arrhythmias after ECMO are poor prognostic indicators for hospital survival.

Mechanical cardiac support in the young. Short-term support: ECMO

Although based on technology developed several decades ago, extracorporeal membrane oxygenation (ECMO) retains great clinical relevance in the management of advanced pediatric cardiorespiratory disease. Largely because of its widespread use in pediatric patients with respiratory failure, familiarity with this technology has established ECMO as the most commonly used form of mechanical circulatory support in children. Clinical applications and technical aspects of ECMO support continue to evolve, ensuring the ongoing importance of this modality for pediatric circulatory support.

Early experience with low-prime (99 ml) extracorporeal membrane oxygenation support in children

Quick setup is mandatory for cardiopulmonary resuscitation using an extracorporeal membrane oxygenation (ECMO) assist device. Our conventional ECMO circuit for pediatric patients consists of a centrifugal pump (CX-HP) and membrane oxygenator (CX10H). Because of the large priming volume (260 ml), the circuit had to be primed with donor blood and required 30 minutes for setup. We started to use a low-prime ECMO with small centrifugal pump (HPM-15) and membrane oxygenator (MENOX Alpha Cube) for induction of ECMO beginning in 2000. The priming volume of this low-prime circuit is only 99 ml. The circuit can be primed without donor blood, even in the small patient, and requires only 10 minutes to set up. We review our experiences with cardiopulmonary resuscitation for sudden cardiopulmonary collapse in pediatric patients, including postcardiotomy patients. From 1997 to 2000, 23 patients underwent ECMO support with a conventional circuit (group A). From 2000 to 2004, we used low-prime circuit for induction of ECMO in 12 patients (group B). After the induction of ECMO with low-prime circuit, ECMO was converted to conventional heparin-bonded circuit for the longer support. The results suggested that the quick induction of ECMO with low-prime circuit has significant advantages in cardiopulmonary support in pediatric patients.

Pediatric Mechanical Circulatory Support

Extracorporeal membrane oxygenation (ECMO) is based on technology that has been used clinically for decades. Largely because of its widespread use in pediatric patients with respiratory failure, familiarity with this technology has established ECMO as the most commonly used form of circulatory support for children. However, clinical applications and technical aspects of ECMO support continue to evolve, ensuring the ongoing importance of this modality for pediatric circulatory support. Although traditionally lagging behind development for adult applications, the use of ventricular assist devices (VADs) is expanding in pediatrics. Of particular interest, a number of new VADs designed specifically for children are becoming available, while early development of some innovative devices for pediatric circulatory support is currently underway.

Pulsatile ECMO in Neonates and Infants: First European Clinical Experience with a New Device

This study presents the first European clinical experience with the Medos DeltaStream DP1, a new pulsatile flow pump, in neonates and infants. Between January 2002 and December 2004, 420 patients at our institution underwent congenital heart surgery on cardiopulmonary bypass. During this period, 10 patients required extracorporeal membrane oxygenation (ECMO) support for acute postcardiotomy heart failure. Seven patients (median age 7 days, range 1-70 days), were supported by a nonpulsatile Biomedicus centrifugal pump, whereas three patients (aged 1 month, 1 year, and 12 years) were supported by a pulsatile Medos DP1. The DP1 is an extracorporeal rotary blood pump. The pump features a diagonal-flow impeller, and can be used for both continuous and pulsatile output. Special characteristics include a small priming volume of approximately 30 ml and a high pumping capacity. A temperature sensor and speed sensors are integrated in the pump. The pump has a delivery rate of up to 8 l/min and a speed range of 100-10,000 rpm. Overall mortality was 40% (4 of 10 patients), and all four deaths were in the nonpulsatile Biomedicus group. In the nonpulsatile group, the median support duration was 95 hours with a range of 48-140 hours. Two patients assisted with the pulsatile pump system were successfully weaned after 36 and 53 hours, respectively; the 12-year-old patient was successfully transplanted on the eighth postimplant day and discharged from the hospital on the 32nd posttransplant day. Although this preliminary experience doesn't allow for statistical analysis, clinically it was possible to observe a better performance in pulsatile flow recipients with faster lactate recovery, reduced need for inotropic support, reduced assistance duration in bridge-to-recovery settings, and smoother intensive care management. ECMO for postcardiotomy heart failure in neonates and infants still carries high mortality and morbidity rates. Pulsatile flow with the Medos DeltaStream DP1 pump system improves results by producing more physiologic hemodynamics, reducing the duration of support in the case of bridge to recovery, and improving end-organ function.

Cardiac failure in hemolytic uremic syndrome and rescue with extracorporeal life support

Extrarenal involvement manifesting in the cardiovascular system is a rare but potentially fatal complication of hemolytic uremic syndrome (HUS). Current treatment is aimed at cardiovascular supportive measures while awaiting organ recovery. However, there are cases in which this recovery never occurs, and patients succumb secondary to heart failure. We report two cases of severe cardiac failure in children in the acute phase of HUS and the use of extracorporeal membrane oxygenation (ECMO) to support one patient to cardiac recovery. Clinicians should be aware of this potentially life-threatening cardiac involvement and should consider the use of ECMO for potentially salvageable children with HUS.

Extracorporeal membrane oxygenation support of the Fontan and bidirectional Glenn circulations

BACKGROUND

Extracorporeal membrane oxygenation can provide effective mechanical circulatory support for the failing circulation in children. Patients with failing Fontan and bidirectional Glenn physiology present additional challenges both for extracorporeal membrane oxygenation cannulation and support. We report our institutional experience in patients with cavopulmonary connections who received extracorporeal membrane oxygenation.

METHODS

We performed a retrospective review of 20 patients with cavopulmonary connections (14 Fontan and 6 bidirectional Glenn) who were supported with extracorporeal membrane oxygenation from a single, large pediatric tertiary care center.

RESULTS

Of the 20 patients, ten were supported and decannulated successfully (50%) (two after cardiac transplantation), but only six (30%) are alive at follow-up. Of the 14 Fontan patients, seven (50%) were withdrawn from extracorporeal membrane oxygenation or died within 48 hours of decannulation due to lack of myocardial recovery or severe neurologic injury. All four adult-sized (> 40 kg) Fontan patients were withdrawn from extracorporeal support. The seven Fontan patients who were successfully decannulated survived to discharge, and five (35.7%) are alive at follow-up (median 35 months; range, 7 to 140 months). Of the six bidirectional Glenn patients, five died before hospital discharge and the lone survivor has neurologic injury at follow-up.

CONCLUSIONS

Patients with failing Fontan and bidirectional Glenn physiology present significant challenges to successful extracorporeal membrane oxygenation support. While the morbidity and mortality rates are high, there are select patients for whom extracorporeal support can be effective and lifesaving as a short-term resuscitative intervention.

Cardiac ECMO for biventricular hearts after paediatric open heart surgery

OBJECTIVE

To delineate predictors of hospital survival in a large series of children with biventricular physiology supported with extracorporeal membrane oxygenation (ECMO) after open heart surgery.

RESULTS

81 children were placed on ECMO after open heart surgery. 58% (47 of 81) were transferred directly from cardiopulmonary bypass to ECMO. Hospital survival was 49% (40 of 81) but there were seven late deaths among these survivors (18%). Factors that improved the odds of survival were initiation of ECMO in theatre (64% survival (30 of 47)) rather than the cardiac intensive care unit (29% survival (10 of 34)) and initiation of ECMO for reactive pulmonary hypertension. Important adverse factors for hospital survival were serious mechanical ECMO circuit problems, renal support, residual lesions, and duration of ECMO.

CONCLUSIONS

Hospital survival of children with biventricular physiology who require cardiac ECMO is similar to that found in series that include univentricular hearts, suggesting that successful cardiac ECMO is critically dependent on the identification of hearts with reversible ventricular dysfunction. In our experience of postoperative cardiac ECMO, the higher survival of patients cannulated in the operating room than in the cardiac intensive care unit is due to early effective support preventing prolonged hypoperfusion and the avoidance of a catastrophic cardiac arrest.

Use of routine ventricular assist following the first stage Norwood procedure

Surgical treatment of hypoplastic left heart syndrome has generated substantial interest and attention amongst cardiac surgeons since the initial reports from Norwood and his colleagues in 1980.1,2 Initial efforts at most programmes were to create reproducible results, and mortality rates remained high at several institutions throughout the 1980s and 1990s. A recent multi-institutional review demonstrates that the hospital mortality still remains high in numerous centers at the current time.3 Nevertheless, several advances over recent years have led to improved outcomes, and in the best centers, hospital survival now approaches 90%. Survival in successful centers is claimed to relate to the ability of the team to help the patient balance the systemic and pulmonary flows of blood. This ability to balance flow has been enhanced, over recent years, by numerous contributions, including decreasing the size of shunt ordinarily used,4 the use of alpha blockade,5 the rapid deployment of extracorporeal membrane oxygenation,6–8 and various forms of ventilatory manipulation.

Routine mechanical ventricular assist following the Norwood procedure—improved neurologic outcome and excellent hospital survival

BACKGROUND

Although excellent survival following the Norwood procedure for palliation of hypoplastic left heart syndrome (HLHS) is being achieved by some, most centers, especially the ones with small surgical volume and limited experience, continue to struggle with initial results. Survivors often showed evidence of significant neurologic injury. The early postoperative care is labor-intensive as attempts are made to balance the systemic and pulmonary circulation for these infants. We report our experience with routine use of mechanical circulatory assist to support the increased cardiac output requirements present following Norwood procedure.

METHODS

Eighteen consecutive infants undergoing Norwood operation for HLHS (Oregon Health & Science University [OHSU] 13; University of Louisville [UL] 5) were placed on a ventricular assist device (VAD) immediately following modified ultrafiltration in the operating room using the cardiopulmonary bypass (CPB) cannulas that were in the right atrium and the neoaorta. VAD flows were maintained at approximately 200 mL x kg(-1) x min(-1) and the patients were transported to the intensive care unit (ICU). Patients operated at OHSU also received neurodevelopmental testing before their Glenn procedure, approximately 4 to 6 months following their Norwood operation.

RESULTS

All patients were stable on VAD support and no attempt was made to balance the systemic and pulmonary circulation. The ventilator was manipulated to achieve systemic Pa0(2) between 30 and 45 mm Hg and PaC0(2) between 35 and 45 mm Hg. Evidence of hypoperfusion (increasing lactates) was managed by increasing the VAD flow. Lactates normalized [< 2 mmol/L]) by 1.8 +/- 1.1 days following surgery. Average time of VAD support was 3.1 +/- 1.0 (range, 2 to 5 days) and average time until chest closure was 3.4 +/- 1.5 (range, 2 to 8 days). There were two cases of postoperative bleeding (11.1%) requiring reexploration and one case of mediastinitis (5.5%) in a patient who has now gone on to successful Glenn. Sixteen of the eighteen patients survived (hospital survival mean 89% with a 95% confidence interval of 63.9% to 98.1%; 12/13 OHSU [92.3%]; 4/5 UL [80%]). Neurodevelopmental testing using the Mullen Scales of Early Learning and the Vineland Adaptive Behavior Scale were normal for all infants tested.

CONCLUSIONS

Routine postoperative use of VAD can support the increased cardiac output demands of infants following Norwood operation and results in a stable postoperative convalescence that does not require aggressive ventilator or inotrope manipulation. Although not a panacea, this strategy can simplify postoperative management, lead to excellent hospital survival, and possibly augment cerebral oxygen delivery, resulting in improved neurologic outcomes for this challenging group of patients.

Routine use of mechanical ventricular assist following the Norwood procedure

Conventional postoperative management after the Norwood procedure in patients with hypoplastic left heart syndrome suffers from three main shortfalls. First, the early postoperative care is often labor-intensive and ironically (despite sometimes heroic efforts), when babies die, health care providers often feel like failures, and in the worst scenarios, surgeons or other physicians create cultures of blame. Second, hospital survival is inconsistent in most centers, especially the ones with small surgical volume and limited experience. Third, survivors often show evidence of significant neurologic impairment. To address these postoperative problems, we have adopted the strategy of routinely placing all our patients with hypoplastic left heart syndrome on mechanical circulatory support immediately after their Norwood procedure. No attempt was made to balance the systemic and pulmonary circulation. Because an oxygenator was not used in the circuit, a much lower level of anticoagulation was used. Once the lactate level normalized, the amount of mechanical circulatory support was weaned. Since January of 2001, 23 patients have been managed using this strategy. The average time of mechanical circulatory support was approximately 3 days and has decreased to 2 days in more recent experience. The overall incidence of complications was 22%, and overall hospital survival was 87%. Neurodevelopmental testing before the Glenn procedure was normal for all patients tested. Routine postoperative use of mechanical ventricular assist device can support the increased cardiac output demands of infants following Norwood procedure and results in a stable postoperative convalescence. This strategy can simplify postoperative management, lead to excellent hospital survival, and possibly augment cerebral oxygen delivery resulting in improved neurologic outcomes for these patients.

Outcome of pediatric patients treated with extracorporeal life support after cardiac surgery

BACKGROUND

Extracorporeal life support (ECLS) has been used for over two decades in select patients after cardiac surgery. We previously described factors associated with death in this population. We now review our recent experience to reassess factors related to mortality.

METHODS

All pediatric patients who received ECLS support within 7 days after surgery between July 1995 and June 2001 were examined to describe clinical features associated with survival. We compared the results with our prior report to assess changes in practice and outcome.

RESULTS

Seventy-four patients were followed. Fifty percent survived to discharge. Hospital survival was not significantly related to patient age, cannulation site, or indication. Thirty-five percent of patients required hemofiltration while on ECLS and were significantly less likely to survive (23% vs 65%). A multivariate analysis combining all children from our prior report with the present cohort revealed that patients who received hemofiltration were five times more likely to die (odds ratio 5.01, 95% confidence interval 2.11-11.88). Children with an adequate two-ventricular repair had lower risk of death (odds ratio 0.42, 95% confidence interval 0.19-0.91) after adjusting for patient age, study period, and hours elapsed before initiation of ECLS after surgery.

CONCLUSIONS

Patients with an adequate two-ventricle repair have significantly higher hospital survival, whereas those with single ventricle physiology or need for dialysis have decreased survival.

After repair, atrioventricular valve regurgitation during cardiac extracorporeal membrane oxygenation predicts survival

BACKGROUND

When echocardiography is used to follow up cardiac patients on extracorporeal membrane oxygenation (ECMO), ejection fraction as a measure of ventricular function has been used to determine likelihood of survival after decannulation. We hypothesized that systemic atrioventricular (AV) valve regurgitation while on ECMO may be a better predictor of survival.

METHODS

From February 1995 to March 2001, 64 patients required ECMO postoperatively. Three were removed from ECMO owing to brain death, so 61 patients formed our study group. Retrospective chart review was performed with systemic AV valve regurgitation and ejection fraction while on ECMO recorded from echocardiography reports. Patients alive 1 month after decannulation were considered survivors.

RESULTS

There were 29 survivors (47.5%). Ejection fraction in survivors (mean 41% +/- 0.13%) was not significantly different from that of nonsurvivors (41% +/- 0.18%; p < or = 0.839) but severity of systemic AV valve regurgitation was significantly different. Only 2 survivors (6.8%) had at least moderate AV valve regurgitation compared with 17 of the 32 nonsurvivors (53%). Patients with moderate to severe regurgitation while on ECMO were less likely to survive for 1 month after decannulation, with an odds ratio of 16.63 (95% confidence interval 3.08, 89.70; p = 0.001). Also female sex increased the odds of death by a factor of 5.43 (95% confidence interval 1.45, 20.36; p = 0.012).

CONCLUSIONS

Severity of systemic AV valve regurgitation on ECMO is a more reliable predictor than ejection fraction for survival at 1 month after decannulation. Patients with less than moderate AV valve regurgitation have a significantly better chance of survival.

Pediatric arteriovenous extracorporeal membrane oxygenation (ECMO) as a bridge to cardiac transplantation

BACKGROUND

Since 1990, extracorporeal membrane oxygenation (ECMO) has been used as a bridge to cardiac transplantation in 47 patients.

METHODS

A review of the ECMO database, approved by the Arkansas Children's Hospital institutional review board, forms the basis of this report. We made statistical comparison using Fisher's exact probability testing. The ECMO circuitry was a roller occlusion pump with computer-assisted perfusion system technology.

RESULTS

Thirty-two (68%) patients underwent transcatheter septostomy for cardiac decompression. Diagnosis at presentation was either congenital heart disease (CHD, n = 15) or cardiomyopathy (n = 32). Ages ranged from 1 day to 22 years old (median, 18 months old), and weight ranged from 2.9 to 100 kg (median, 10 kg). The average duration of support was 242 hours (range, 22-1078 hours). Overall long-term survival was 47%, with 16 (34%) patients successfully bridged to cardiac transplantation (of which 9 [56%] survived) and 13 (28%) successfully weaned from ECMO. Patients undergoing ECMO after cardiotomy had 31% survival. Survival was improved significantly (p < 0.02) in patients with cardiomyopathy (59%) vs those with CHD (20%). Patients with cardiomyopathy underwent 8 transplantations with 7 survivors (88%), whereas in the CHD group, there were 8 transplantations with only 2 survivors (25%), p < 0.05. Sub-analysis of the cardiomyopathy group revealed that patients with acute cardiomyopathy in association with documented viral illness had a 75% chance of being weaned from ECMO without undergoing transplantation. Complications during ECMO occurred in 45% of survivors and were more frequent in non-survivors. Infectious complications were most frequent, followed by neurologic complications, technical ECMO problems, and renal insufficiency.

CONCLUSIONS

Patients with cardiomyopathy has a better prognosis than did those with CHD when using ECMO as a bridge to transplantation or survival. Complications are significant and increase with the duration of support. Extracorporeal membrane oxygenation for salvage and subsequent transplantation in this high-risk group of patients requires critical review. Alternative support options must be developed in the pediatric population that will allow improved outcomes, comparable with outcomes achieved in the adult population.

Neurodevelopmental outcome of infants supported with extracorporeal membrane oxygenation after cardiac surgery

OBJECTIVES

To evaluate the long-term neurodevelopmental outcome of infants who underwent cardiac surgery and required extracorporeal membrane oxygenation (ECMO) support, and to examine variables that predict death or disability in these patients.

METHODS

We studied all infants who had congenital heart disease and were supported postoperatively with ECMO from 1990 to 2001 at our institution (n = 53). Medical records were reviewed retrospectively to obtain clinical variables. Neurologic and age-appropriate developmental examinations occurred at ages 1, 1.5, 2.5, and 4.5 years. Median age at follow-up was 55 months (9-101). Cognitive outcome was defined as suspect when scores were between 1 and 2 SD below the mean for age and abnormal when scores were >2 SD below mean for age. Neuromotor outcome was defined as suspect when the patient manifested clumsiness, tremor, or mild tone and reflex changes without functional limitations, and abnormal when there were functional limitations.

RESULTS

In-hospital survival was 17 (32%) of 53. Of survivors, 14 (88%) of 16 are living and 1 patient was lost to follow-up. Of the 53 patients, 7 survived completely intact (13%). Seven (50%) of 14 patients had a normal cognitive outcome, 3 (21%) had a suspect cognitive outcome, and 4 (29%) were abnormal. Ten (72%) of 14 patients had a normal neuromotor outcome, 1 (7%) patient had a suspect neuromotor outcome, and 3 (21%) were abnormal. No survivor with an aortic cross-clamp time >40 minutes had a normal cognitive outcome. Nonsurvivors were more likely than survivors to have had cardiac arrest as an indication for ECMO (31% vs 6%), to have had a longer aortic cross-clamp time (mean 73 minutes vs 32 minutes), and to have required continuous arteriovenous hemofiltration (78% vs 35%). The age and weight at cannulation, gender, cardiac diagnosis, interval from surgery to ECMO, cardiopulmonary bypass time, diagnosis of sepsis or mediastinitis, and duration of ECMO were not significantly associated with survival.

CONCLUSIONS

Although mortality was 68% in infants who had congenital heart disease and were treated with ECMO postoperatively, of those who survive to hospital discharge, 75% have a normal neuromotor outcome and 50% have a normal cognitive outcome. These high rates of mortality and disability suggest that increased attention be paid to neuroprotection in these complex disorders.

The intraaortic balloon pump in cardiac surgery

The intraaortic balloon pump (IABP) has been used in cardiac operations since the late 1960s. Over the years, with refinements in technology, its use has expanded; the IABP is now the most commonly used mechanical assist device in cardiac operative procedures. This review provides an evaluation of evidence for the efficacy of IABP use in different clinical scenarios, using the American College of Cardiology/American Heart Association classification of evidence where appropriate. We evaluated complications and outcomes associated with IABP use, and attempted to draw conclusions regarding the use of the IABP in different clinical situations. We examined the trends and variation in utilization over time and across centers. We discussed the IABP in light of new cardiac assist devices and the changing patient population and management strategies. Lastly, we identified areas of future research.

Pediatric circulatory support systems

Ventricular assist devices (VADs) are a valid option for long term circulatory support in pediatric patients with postoperative myocardial failure or debilitating heart defects. Most clinical experience to date has involved the short-term support of patients weighing 6 kg and larger. For cases of VAD implementation in pediatric patients, the assist device showed tremendous promise in reversing cardiac failure and providing adequate support as a bridge to cardiac transplantation. The Medos-HIA system, Berlin Heart, Medtronic Bio-Medicus Pump, Abiomed BVS 5000, Toyobo-Zeon pumps, and Hemopumps have proven successful for short-term circulatory support for the pediatric population. The Jarvik 2000 and Pierce-Donachy pediatric system further demonstrate the potential to be used for pediatric circulatory support. The clinical and experimental success of these support systems provide encouragement to believe that long-term support is possible.

Left ventricular dysfunction during extracorporeal membrane oxygenation in a hypoxemic swine model

BACKGROUND

Perfusion of the coronary circulation with hypoxemic blood from the left ventricle has been postulated to cause myocardial dysfunction during venoarterial extracorporeal membrane oxygenation for respiratory support.

METHODS

We investigated this hypothesis in 10 anesthetized open-chest piglets (7 to 9 kg) undergoing venoarterial extracorporeal membrane oxygenation after placement of minor-axis sonomicrometry crystals and left ventricular micromanometer. The left atrial partial pressure of oxygen was made hypoxemic (25 to 40 mm Hg) after initiation of extracorporeal membrane oxygenation by ventilation with a hypoxic gas mixture. Left ventricular contractile function, including peak LV pressure, shortening fraction, maximum rate of increase of left ventricular pressure, velocity of circumferential fiber shortening, end-systolic pressure-minor axis dimension relationship, and preload recruitable dimensional stroke work, was measured or calculated on extracorporeal membrane oxygenation before (baseline) and at 4 and 6 hours after rendering the left atrial blood hypoxemic.

RESULTS

Left ventricular shortening fraction and velocity of circumferential fiber shortening were significantly lower (p < 0.05) at 4 and 6 hours when compared with baseline. The slope of the end-systolic pressure-minor axis dimension relationship decreased but was not significantly different at 4 and 6 hours when compared with baseline owing to poor linear correlation (r = 0.30 to 0.93). The preload recruitable dimensional stroke work was more linear (r = 0.87 to 0.99), and the slope was significantly lower (p < 0.01) at 4 and 6 hours when compared with baseline.

CONCLUSIONS

Hypoxemic cardiac output from the left ventricle during venoarterial extracorporeal membrane oxygenation is associated with depression of left ventricular systolic function in this animal model. Current use of venoarterial extracorporeal membrane oxygenation for respiratory support may not provide adequate oxygen supply to the myocardium.

Essentials of Nitric Oxide for the Pediatric (Cardiac) Anesthesiologist

Short- and long-term survival rates for the operative treat ment of congenital heart disease (CHD) have improved significantly in the past 2 decades. The increasing sophisti cation of the pediatric cardiologist's diagnostic armamen tarium has led to more pervasive use of fetal screening with echocardiography. Early diagnosis and pre-emptive care of the neonate with complex CHD have allowed interventional strategies in the catheterization suite or the operating room to be optimized in both the timing and the quality of pallia tive or corrective procedures. Medications such as prosta glandin E and ventilator strategies using hypoxic and hyper carbic inspired gases exemplify therapies benefitting the contemporary neonate with CHD, often allowing stabiliza tion of the patient before surgery. Surgical care of neonates, infants, and children with CHD has also improved. Insights into maturational differences in myocardial and autonomic function have led to more appropriate myocardial protection strategies and pharmacologic support of the circulation. Recognition of those anomalies in which total correction in the neonate is desirable has stimulated improvements in the technical and cognitive skills of pediatric cardiovascular sur geons and pediatric cardiac anesthesiologists to meet these challenges. The goal of this article is to provide the pediatric anesthesiologist with an overview of inhaled nitric oxide and its relevance to clinical practice.

Effect of extracorporeal membrane oxygenation on left ventricular function of swine

BACKGROUND

Previous clinical and experimental investigations have produced inconsistent data describing the effects of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on intrinsic left ventricular (LV) function. We report an animal model that allows investigation of the effects of VA ECMO on the mechanics of the LV using two load-insensitive indices: end-systolic pressure-minor axis dimension relationship (ESPDR) and preload recruitable dimensional stroke work (PRDSW).

METHODS

Eight piglets (5 to 11 kg) were anesthetized, instrumented, and placed on VA ECMO. Throughout the experiment, systemic and left atrial partial pressure of oxygen were maintained between 100 to 200 mm Hg. At ECMO flow rate of 50% of baseline cardiac output, data were collected prior to ECMO, at 4 and 6 hours during ECMO, and after weaning from ECMO. Data measured or calculated for each time point included heart rate, LV pressures and minor axis dimensions at different pre-loads, first derivative of LV pressure with respect to time, velocity of circumferential fiber length shortening (VCF), LV shortening fraction (LVSF), ESPDR, and PRDSW.

RESULTS

A significant (p < 0.05) decrease in LVSF and VCF was seen at 4 and 6 hours during ECMO when compared to baseline, but the ESPDR and PRDSW did not change during ECMO.

CONCLUSIONS

VA ECMO alone changes some of the load-dependent parameters of contractility, but intrinsic function of the heart is not significantly affected as measured by load-insensitive indices of LV performance.

Is there a role for extracorporeal life support after stage I Norwood?

OBJECTIVES

Controversy still surrounds the use of extracorporeal life support (ECLS) in patients with single ventricle physiology. An analysis of the experience with a group of neonates who underwent stage I Norwood palliation and received ECLS is reported.

METHODS

A retrospective review of hospital records, operative notes and perfusion data was performed in a group of 12 consecutive patients undergoing ECLS in the perioperative period after stage I. An analysis to identify risk factors for poor outcome was performed.

RESULTS

The mean age and weight were 3.9 days (1-14) and 2.6 kg (1.4-3.8), respectively. There were 3/12 patients under 2.5 kg and four patients were under 35 weeks of gestation. The most common diagnosis (7/12) was hypoplastic left heart syndrome with aortic atresia. Associated extracardiac anomalies were present in four patients. Three patients had an additional cardiac defect and two of these required an additional surgical procedure besides the stage I Norwood. The mean circulatory arrest was 56 min (46-63). ECLS was initiated preoperatively in one, intraoperatively in nine, and postoperatively in two patients. The indication for support was: arrhythmia (one), low output (six), cardiac arrest (three), unbalanced circulation (one), and hypoxemia (two). The mean duration of support was 68 h (24-192). Eight patients were weaned off support, and six were discharged home in good condition. Morbidity included sepsis in five, renal failure in five, neurologic sequelae in three, and bleeding in two. Prematurity, renal dysfunction and the initiation of ECLS outside the operating room were significantly associated with poor outcome. Residual hemodynamic effect, low birth weight and neurologic event showed a tendency towards poor outcome, but did not reach statistical significance.

CONCLUSIONS

Although the use of ECLS in patients with single ventricle physiology still carries a significant risk, prompt initiation of support can improve the outcome in a group of patients with impaired cardiopulmonary function after stage I palliation.

Extracorporeal membrane oxygenation for infant postcardiotomy support: significance of shunt management

BACKGROUND

After repair of complex congenital heart defects in infants and children, postcardiotomy cardiac failure requiring temporary circulatory support can occur. This is usually accomplished with the use of extracorporeal membrane oxygenation (ECMO). ECMO management of patients with single-ventricle physiology and aorto-pulmonary shunts can be particularly challenging. We retrospectively reviewed our experience with postcardiotomy support with particular attention to those children with single-ventricle palliation.

METHODS

Thirty-five consecutive children (age 1 to 820 days, median 19 days) out of 1,020 patients (3.4%) required mechanical support (ECMO) after repair of congenital cardiac lesions from February 1994 to April 1999. Twenty-five patients underwent two ventricle repairs and 10 patients had single-ventricle palliation. Various parameters analyzed included strategies of shunt management, presence of presupport cardiac arrest, and timing of support initiation.

RESULTS

Overall hospital survival for these 35 patients was 61%. There were four additional late deaths. Hospital survival was the same for those patients in whom support was initiated for failure to wean from cardiopulmonary bypass in the operating room versus those patients in whom support was initiated after successful separation from cardiopulmonary bypass (6 of 10 vs 15 of 25 or 60% survival). In those patients with shunt-dependent pulmonary circulation, survival was significantly improved in those patients in which the aorto-pulmonary shunt was left open (4 of 5 with open shunt vs 0 of 4 with occluded shunt (p = 0.048).

CONCLUSIONS

The ability to readily implement postcardiotomy support is vital to the management of children with complex congenital cardiac disease. Overall survival can be quite satisfactory if support is employed in a rational and expedient manner. In patients with single-ventricle physiology and aorto-pulmonary shunts, leaving the shunt open during the period of support can result in markedly improved outcomes.

Impact of multiple organ system dysfunction and nosocomial infections on survival of children treated with extracorporeal membrane oxygenation after heart surgery

OBJECTIVES

To evaluate whether cardiac and noncardiac variables may be used to predict survival in children treated with extracorporeal membrane oxygenation (ECMO) after cardiopulmonary bypass and to determine when to discontinue ECMO support.

DESIGN

Retrospective review.

SETTING

Neonatal and pediatric intensive care units of Kosair Children's Hospital.

PATIENTS

Fifty-nine children treated with ECMO after cardiopulmonary bypass from 1987 through 1996.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical, nursing, operative, and perfusion records for each patient were reviewed. The primary outcome measure was survival to hospital discharge. Cardiac and noncardiac variables were recorded at serial times. Nineteen of 59 patients (32%) survived. No cardiac variable was a clinically useful predictor of survival or marker for when to discontinue ECMO. Among the noncardiac variables, progressive multiple organ system dysfunction and development of a nosocomial infection were significantly associated with nonsurvival. No patient with a positive blood culture (n = 3) within the first 24 hrs of ECMO survived, and 21 of 24 children with a positive culture from any site during ECMO died (p = .007). Despite their higher mortality, children with positive cultures were supported with ECMO significantly longer than those with negative cultures (275+/-168 vs. 135+/-108 hrs, respectively; p = .0004). For all patients, the longest duration of ECMO that resulted in survival was 256 hrs. For children with a positive culture, the longest duration of support that resulted in survival was 200 hrs.

CONCLUSIONS

Support with ECMO beyond 256 hrs was not associated with survival. Progressive multiple organ system dysfunction and nosocomial infections have a negative impact on survival. Serious consideration should be given to discontinuing ECMO support whenever there is a progressive increase in the number of abnormally functioning organ systems, a nosocomial infection occurs, or native cardiac function has not improved significantly by 250 hrs of ECMO support.

Proposed entry criteria for postoperative cardiac extracorporeal membrane oxygenation after pediatric open heart surgery

While extracorporeal membrane oxygenation (ECMO) is being used increasingly after pediatric cardiac surgery, criteria are lacking for initiating ECMO after bypass weaning. To develop clinically useful ECMO entry criteria based on parameters readily available, children were examined at postoperative pediatric intensive care unit (PICU) admission. Using hospital mortality as the primary outcome, univariate and multiple logistic regressions were performed to estimate the predictive value of clinical (age, weight, and diagnosis) and laboratory (arterial blood pressure, pH, lactate, creatine kinase, and arterial and central venous oxygen saturation [ScvO2]) variables. Data from 218 children over a 2 year period were analyzed retrospectively. Univariate regression demonstrated that age, weight, diagnosis, blood pressure, venous and arterial saturation, and lactate were significantly associated with postoperative mortality (p < 0.05). In multiple regression, ScvO2 and lactate level were found to be independent predictors and were used in a predictive model (ScvO2 odds ratio: 2.03-828.6, p = 0.016) (lactate odds ratio: 1.58 -4.20, p = 0.0002) (R2 = 0.70). Applying an 80% risk of mortality to establish entry criteria as in neonatal ECMO, PICU admission values of lactate > 70 mg/dl if ScvO2 < 60% or lactate >163 mg/dl if ScvO2 > 60% are proposed to serve as postoperative ECMO entry criteria if bypass weaning has been possible but is followed by low cardiac output.

Pathophysiology of cardiac extracorporeal membrane oxygenation

The treatment of cardiogenic shock using inotropic agents and vascular volume expansion places an added burden on the heart. The resultant increase in cardiac work may cause myocardial ischemia and lead to cardiac arrest. Extracorporeal membrane oxygenation (ECMO) may be used to treat cardiogenic shock. It supports systemic circulation, assures diastolic perfusion of the myocardium, and reduces cardiac workload. The rise in blood pressure associated with restoring systemic circulation afterloads the heart and can cause left atrial hypertension and pulmonary edema. ECMO does not automatically reduce cardiac work, especially in the presence of residual shunts. Left atrial drainage or decompression may be essential in certain patients both to avert pulmonary edema and to reduce cardiac work.

Surgical aspects of pediatric cardiac extracorporeal membrane oxygenation

Because children with severe myocardial dysfunction have limited therapeutic options, mechanical support of a failing heart is a matter of great interest. In the setting of cardiogenic shock or severe low cardiac output and hypoperfusion, extracorporeal membrane oxygenation (ECMO) can produce decisive improvements. The criteria for successful treatment include appropriate patient selection, improved surgical techniques and experience, higher recognition and anticipation of complications, and minimized delay in initiation of ECMO. Because the need for mechanical circulatory support may arise pre-, intra-, and postoperatively, every pediatric cardiac surgeon must be familiar with the principles and the surgical aspects of ECMO.

Intraaortic balloon pumping in children

BACKGROUND

Intraaortic balloon pump (IABP) usage in young children remains a rarity because, first, there is a widespread misconception that the greater elasticity of the aorta in children may prevent effective augmentation, and second, children in low cardiac output states are more likely to have associated right ventricular failure and pulmonary problems. We report our experience with the use of IABP in children undergoing cardiac surgery in whom mechanical support was necessary for the treatment of refractory cardiac failure.

METHODS

Over a 3-year period, 14 children were identified as requiring IABP support after cardiac surgery. Their median age was 3 years (range 7 days to 13 years) and their median weight was 13.3 kg (range 3.5-51 kg). Indications for IABP use were: failure to wean from cardiopulmonary bypass (5 patients), sudden deterioration in intensive therapy unit (ITU) (3 patients), progressive deterioration in ITU (4 patients), and prophylactic therapy for known poor preoperative ventricular function (2 patients).

RESULTS

Ten of 14 patients (71%) were successfully weaned from the IABP, of whom 8 became long-term survivors (57%). Among the survivors, the mean duration of IABP usage was 127 h (range 12-260 h), while for those who died while on IABP, the mean duration was 15 h (range 8-24 h). The most major IABP-related complication encountered was mesenteric ischemia, which had a fatal outcome.

CONCLUSIONS

IABP therapy, used as an adjunct to conventional medical treatment, can give properly selected young children in refractory low cardiac output states after heart surgery a greater than 50% chance of long-term survival.

Utility of cardiac catheterization in pediatric cardiac patients on ECMO

Cardiac catheterization has been utilized rarely in children on extracorporeal membrane oxygenation (ECMO). We performed a retrospective review of 15 children with congenital heart disease who had undergone catheterization while on ECMO from December 1990-December 1995. The procedures, including four interventions, were successful in all patients with adequate evaluation of clinical questions. Unexpected diagnostic information of clinical importance was obtained in 40%, and clinical management of patients was significantly altered in 73%. All patients tolerated the procedure and transport well. The only significant complication was a retroperitoneal hemorrhage in one patient after approximately 12 hr. Although no patients died at catheterization, overall survival was poor, with 50% weaning from ECMO, 29% surviving to discharge, and 14% surviving at follow-up. We conclude that diagnostic and interventional catheterization may be performed in patients on ECMO with acceptable morbidity and mortality; however, long-term survival in this population is poor.

Inhaled nitric oxide in the neonate with cardiac disease

As a selective pulmonary vasodilator, inhaled nitric oxide is an important diagnostic and therapeutic agent for the treatment of pulmonary hypertension in patients with congenital heart disease. Among 400 patients treated in our center with nitric oxide, 37% were newborns. Hemodynamic benefit was shown in newborns with total anomalous pulmonary venous connection, in those with congenital mitral stenosis, and in postoperative patients with preexisting left to right shunts and other lesions. It can be used to help discriminate anatomic obstruction to pulmonary blood flow from pulmonary vasoconstriction, and it may be used in the treatment or prevention of pulmonary hypertensive crises after cardiopulmonary bypass. However, none of the purported benefits of inhaled nitric oxide in children with congenital heart disease have been studied in a randomized, placebo-controlled manner.

Preoperative versus postoperative extracorporeal life support in neonatal cardiac patients

The aim of this study is to document our experience with the use of extracorporeal life support (ECLS) in the neonatal cardiac patient, to detect differences in the morbidity and mortality between patients who required ECLS preoperatively and those who required ECLS postoperatively, and to determine the long-term effects of these morbidities. A chart review was undertaken of all neonatal cardiac patients who required ECLS between May 1985 and July 1994 at Kosair Children's Hospital, Louisville, Kentucky. Twenty-three neonatal cardiac patients had received preoperative or postoperative ECLS with an overall survival rate of 35%. Our preoperative and postoperative patients had similar demographics, diagnoses, decannulation rates and survival rates. However, patients receiving postoperative ECLS more frequently required more than two inotropes (p < 0.001), had an increased incidence of renal failure (p < 0.02), had more central nervous system abnormalities on brain imaging studies (p < 0.004), and had a longer hospital stay (p < 0.05). Follow-up testing of survivors yielded normal Bayley Scale of Infant Development (BSID) scores in half of the patients. Survival in the two groups was similar, but a significant difference in morbidity was found. Except for severe intracranial abnormalities, the morbidity was shown to be reversible on follow-up examination. We recommend the continued use of ECLS for neonatal cardiac patients who require preoperative or postoperative support even when severe renal failure ensues or minor abnormalities are detected on brain imaging studies.

Myocardial recovery through ECMO after repair of total anomalous pulmonary venous connection: the importance of left heart unloading

A 7-day-old boy who had been placed on extracorporeal membrane oxygenation on his second day of life developed biventricular failure after undergoing surgical repair of a supracardiac variant of total anomalous pulmonary venous connection. Extracorporeal membrane oxygenation was again necessary for postoperative cardiopulmonary support. However, severe left ventricular failure made it imperative to leave the vertical vein open during support in order to decrease pressure on the left ventricle. The patient was successfully weaned from extracorporeal membrane oxygenation on day 8 after surgery and discharged from the hospital on day 23.

Nitric oxide might reduce the need for extracorporeal support in children with critical postoperative pulmonary hypertension

BACKGROUND

Postoperative pulmonary hypertension is a life-threatening, yet reversible complication of congenital heart operations. Although inhaled nitric oxide (iNO), a selective pulmonary vasodilator, has been shown extensively to improve short-term oxygenation and hemodynamic indices in these patients, its influence on patient outcome has not been evaluated. The purpose of this study was to assess retrospectively whether patients who fulfilled our criteria for extracorporeal life support (ECLS) for critical postoperative pulmonary hypertension still required ECLS after the administration of iNO therapy.

METHODS

Since January 1992, 10 patients (age 3 days to 10 months) fulfilled the criteria at our institution for ECLS for postoperative pulmonary hypertension. Of these, 5 could not be separated from cardiopulmonary bypass because of pulmonary hypertension, and 5 had critical pulmonary hypertension (pulmonary arterial pressure approaching systemic arterial pressure) causing severe cardiopulmonary compromise.

RESULTS

Six of the 10 ECLS candidates had a sustained response to iNO and survived to discharge from the hospital, without the need for rescue ECLS. Three patients still required ECLS after 30 minutes, 4 hours, and 8 hours of beginning iNO because of failing cardiac output, and 2 survived. The remaining patient died after 5 days of iNO therapy, but was no longer a candidate for ECLS because of sepsis and multiorgan system failure.

CONCLUSIONS

Children with critical pulmonary hypertension unresponsive to maximal conventional treatment may be managed successfully with iNO without the need for rescue ECLS. A trial of iNO should therefore be given before the use of ECLS in these patients.

Mechanical circulatory assistance in paediatric patients with cardiac failure

Extracorporeal membrane oxygenation (ECMO) was initially developed for respiratory failure. Its use, however, has evolved into an excellent method of preoperative and postoperative support in the treatment of infants and children with acquired and congenital heart disease. Along with ECMO, the left ventricular assist device (LVAD) and the intraaortic balloon pump (IABP) have also found a place in the management of paediatric patients with heart failure. This report documents 15 patients who were treated with one or a combination of these mechanical devices, either preoperatively or postoperatively. There is a 74% survival rate and the long-term outcome has been excellent in most cases. The use of heparin-coated devices and tight regulation of heparin has allowed the transfer of infants and children from standard cardiopulmonary bypass to assist devices in the operating room. Mechanical devices are an essential adjunct for the preoperative and postoperative treatment of infants and children with cardiac disease.

Pediatric cardiac surgical ECMO: multivariate analysis of risk factors for hospital death

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has emerged as an effective technique for the mechanical support of many pediatric postcardiotomy patients with medically refractory cardiac failure.

METHODS

We retrospectively reviewed the records of 73 pediatric patients with congenital heart disease who were placed on ECMO support between August 1984 and February 1994. The patients were divided into groups defined by the timing of ECMO cannulation relative to the time of operation. Group 1 patients (n = 7, 9.6%) were placed on ECMO preoperatively. Group 2 patients (n = 66, 90.4%) were a heterogeneous population placed on ECMO at any interval after cardiac repair. Subgroup 2A consisted of patients (n = 17, 25.8%) who could not be weaned from cardiopulmonary bypass and were converted directly to ECMO support immediately after repair. Subgroup 2B patients (n = 49, 74.2%) were cannulated postoperatively after an initial period of clinical stability.

RESULTS

Hospital survival for all study patients (42/73) and for group 2 patients (38/66) was 58%. Only 4 group 2A patients (23.5%) survived their hospitalization compared with 34 group 2B patients (69.4%) (p = 0.001). Multivariate analysis identified elevated right atrial pressure after ECMO decannulation (p = 0.049) and, possibly, membership in group 2A (p = 0.061) as independent risk factors for hospital death.

CONCLUSIONS

Extracorporeal membrane oxygenation is most effective in salvaging pediatric cardiac surgical patients who demonstrate medically refractory hemodynamic deterioration at some interval after being successfully weaned from cardiopulmonary bypass. The right atrial pressure after extracorporeal membrane oxygenation decannulation is an independent predictor of hospital death.

Successful use of transesophageal echocardiography during extracorporeal membrane oxygenation in infants after cardiac operations

We report the use of transesophageal echocardiography in infants after cardiac operations while supported on extracorporeal membrane oxygenation. In all patients transesophageal echocardiography provided valuable information when standard transthoracic echocardiographic evaluation was limited by poor acoustic windows. This report describes the application of transesophageal echocardiography during extracorporeal membrane oxygenation after cardiac operations.

Extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation has now evolved into standard therapy for patients unresponsive to conventional ventilatory and pharmacological support. This article presents a clinical review of extracorporeal life support and its application to neonatal and pediatric patients as well as children requiring circulatory support after open heart surgery.