Conversion from extracorporeal membrane oxygenation to total cardiopulmonary bypass: a simplified method

Pediatric patients who have preoperative hemodynamic instability or postoperative cardiac decompensation may frequently require the use of extracorporeal membrane oxygenation (ECMO) for stabilization of cardiac and respiratory function. While ECMO can be a therapeutic treatment for the congenital pediatric patient, it does not allow the additional functions of a complete cardiopulmonary bypass (CPB) circuit should subsequent surgical revision in the operating room be required. This paper will discuss our approach to converting the ECMO circuit to total cardiopulmonary bypass allowing the use of cardioplegia, cardiotomy suction, and modified ultrafiltration. This technique allows the conversion to CPB without ceasing support to the critically ill patient or exposing them to additional blood products or surface area in the priming of a new extracorporeal circuit. In addition, this circuit design allows for the resumption of ECMO support utilizing the same circuit if the patient necessitates it.     

Extracorporeal membrane oxygenation for perioperative support in neonatal and pediatric cardiac transplantation

Currently there is a lack of consensus on guidelines in the clinical application of extracorporeal membrane oxygenation (ECMO) in neonatal and pediatric cardiac transplantation patients. In this context, given the limited data presently available through the Extracorporeal Life Support Organization (ELSO) Registry, we conducted a preliminary survey to specifically evaluate the practice of using ECMO as a bridge to cardiac transplantation or as posttransplantation therapy for failure to wean from cardiopulmonary bypass or graft failure. We received responses to our questionnaire from 95 of 118 (81%) centers located in the U.S.A. and abroad. Of the 95 centers that responded, 36 were performing neonatal/pediatric cardiac transplants, with 29 centers reporting the concomitant use of ECMO to support cardiac transplant patients. There was wide variability in the responses from the 29 centers to a selected list of relative ECMO contraindications. However, only 7 centers had specific ECMO entry criteria for cardiac transplant patients. Fifteen of the 29 centers provided relevant data on cardiac transplant patients including the proportions of neonatal (11 of 37) and pediatric (63 of 217) patients requiring ECMO; neonatal (2 of 5) and pediatric (16 of 27) patients surviving to transplant; and neonatal (1 of 5) and pediatric (12 of 27) patients surviving to hospital discharge. These findings confirm the important role of ECMO in providing perioperative support in neonatal and pediatric cardiac transplantation patients. However, the lack of consensus among centers contributes to uncertainty in the decision making process to offer ECMO and to utilize ECMO effectively in this high risk population. We recommend that institution-specific information be collected, either using the ELSO Registry (or by a similar multicentric database) to develop specific guidelines for ECMO applications in cardiac transplant patients, and to carefully monitor and follow up EMCO treated patients to further evaluate the efficacy of this limited resource.     

A review of a newly established ECMO program in a university affiliated cardiac center

Extracorporeal membrane oxygenation (ECMO) is an established rescue treatment option for severe respiratory and cardiac failure in infants and neonates and has recently become widely utilised in adults. ECMO support can be initiated rapidly in an emergency setting both by percutanous implantation and surgically; it allows transportation of patients in cardio-pulmonary collapse and bridging of critically ill patients to be recovered, other support measures or transplantation. The aim of this study was to report authors' initial experience after starting an ECMO program in a university-based cardiac center. The institutionally approved ECMO team bears responsibility for adjudication regarding indication and implementation of ECMO in all patients. Since the establishment of the ECMO team in October 2007, one elective and nine urgent patients in deep cardiogenic and/or ventilatory collapse were treated by ECMO support up to December 2008. Three patients suffered severe acute right heart dysfunction, two patients suffered postcardiotomy refractory cardiogenic shock, two patients had a cardiogenic shock due to postinfarction interventricular septal rupture, two patients experienced severe respiratory failure and one had elective ECMO implantation as a back-up support during high-risk percutaneous coronary intervention. Veno-arterial ECMO was used in eight cases and veno-venous in two cases of isolated respiratory failure. In nine patients, ECMO circuit was instituted by peripheral cannulation, in eight out of nine cases by percutaneous puncture. On one occasion central surgical cannulation was used. In urgent patients, immediate hemodynamic and oxygenation improvement was observed. Average support duration was 6.8 days (range 1-16 days). Five (50 %) patients were successfully weaned from ECMO and survived to hospital discharge. The illness severity in urgent patients defined by SOFA score ranged from 10 to 17, patients dying while on ECMO had higher SOFA scores (14.8±1.6 vs. 10.8±1.5; P=0.0065). Complications included mainly bleeding. ECMO support allows treatment of severely ill patients in imminent cardiovascular and/or ventilatory collapse. Therefore, establishment of an ECMO program in university affiliated cardiac center is fully justified. A multidisciplinary approach is essential. Despite adequate training and education of ECMO team members, this highly invasive therapeutic modality bears an inherent risk of complications.     

Combined Use of Subnormothermic Extracorporeal Support and Hypothermic Oxygenated Machine Perfusion for Liver Graft After Cardiac Death in Pigs

BackgroundThe use of grafts from donors after cardiac death (DCD) would greatly contribute to the expansion of the donor organ pool. This study aims to determine the benefits of extracorporeal membrane oxygenation (ECMO) and hypothermic oxygenated machine perfusion (HOPE) in a large animal model of DCD liver.MethodsAfter cardiac arrest, the abdominal aorta and the inferior vena cava were cannulated and connected to an ECMO circuit. Porcine livers were perfused in situ with ECMO at 22°C for 60 minutes after 45 minutes of cardiac death. Then, the livers were perfused for 4 hours by cold storage (CS) or HOPE. In group 1, non-in situ ECMO and grafts were preserved by HOPE. In group 2, in situ ECMO and grafts were preserved by HOPE. In group 3, in situ ECMO and grafts were preserved by CS. After preservation, all grafts were evaluated using an isolated reperfusion model (IRM) with autologous blood for 2 hours.ResultsDuring HOPE, aspartate aminotransferase (AST) levels and hepatic arterial pressure in group 2 tended to be lower than in group 1. Hematoxylin–eosin staining findings after HOPE showed more massive sinusoidal congestion and hepatocyte cytoplasmic vacuolization in group 1 than in group 2. The AST and LDH levels in group 2 at the start-up of IRM tended to be lower than in group 1.ConclusionsThe combined use of in situ subnormothermic ECMO and HOPE is essential for the functional recovery of DCD liver grafts.     

Extracorporeal membrane oxygenation in pediatric cardiac transplantation

Background

We reviewed a single institution experience with extracorporeal membrane oxygenation (ECMO) in the perioperative management of cardiac transplantation.

Methods

Of all pediatric cardiac transplant candidates (1984-2003), patients requiring ECMO pretransplantation/posttransplantation were identified, with particular attention to use of ECMO as a bridge to transplantation. Parameters reviewed included proportionate survival, incidence of pre-ECMO cardiac arrest, ECMO duration, and United Network for Organ Sharing list time.

Results

Three hundred patients were listed for transplantation. Twenty-nine required ECMO: 18 pretransplant, 3 pretransplant and posttransplant, 6 posttransplant, and 2 for delayed acute rejection. There were 21 bridge-to-transplant candidates, of which 10 eventually transplanted with 60% survival; 11 not transplanted had no survivors (P = .004). Thirteen of 21 had cardiac arrest pre-ECMO with 1 (8%) survivor; 8 of 21 had no arrest with 5 (63%) survivors (P = .014). Mean ECMO duration and United Network for Organ Sharing list times between transplanted and not transplanted were not significant. Nine received ECMO posttransplantation for cardiopulmonary support; 5 (56%) of 9 survived. Two patients supported with ECMO for rejection-related cardiovascular collapse survived.

Conclusion

ECMO can bridge children to cardiac transplantation. Survival is significantly impaired in bridge-to-transplant candidates stratified by pre-ECMO cardiac arrest. ECMO can also help transition from cardiopulmonary bypass after transplantation and provide effective support during acute rejection.     

Extracorporeal Membrane Oxygenation Can Save Lives in Children With Heart or Lung Failure After Liver Transplantation

The risk of cardiac or lung failure after liver transplantation (LT) is significant. In rare cases, the usual intensive care techniques fail to maintain organ oxygenation with a risk of multiorgan dysfunction. Although extracorporeal membrane oxygenation (ECMO) is a difficult and risky procedure, it can be proposed as life‐saving. Four children with either acute pulmonary (three) or cardiac (one) failure after LT, and the criteria that decided the use of ECMO (level of ventilation and results, dosage of inotropic drugs, cardiac ultrasound, blood lactate) were retrospectively reported. These patients, 1–11 years old, were treated with either veno‐arterial (three) or veno‐venous (one) ECMO. Two experienced a full recovery, with 3 and 6 years of follow‐up. Two died of systemic inflammatory response syndrome (SIRS) due to ECMO, and relapse of heart failure due to the underlying disease. Although our patients' survival was only 50%, we showed that ECMO can be useful in children after LT. It should be considered before the development of irreversible multiorgan failure.     

Effect of the Pulsatile Extracorporeal Membrane Oxygenation on Hemodynamic Energy and Systemic Microcirculation in a Piglet Model of Acute Cardiac Failure

The objective of this study was to compare the effects of pulsatile and nonpulsatile extracorporeal membrane oxygenation (ECMO) on hemodynamic energy and systemic microcirculation in an acute cardiac failure model in piglets. Fourteen piglets with a mean body weight of 6.08 ± 0.86 kg were divided into pulsatile (N = 7) and nonpulsatile (N = 7) ECMO groups. The experimental ECMO circuit consisted of a centrifugal pump, a membrane oxygenator, and a pneumatic pulsatile flow generator system developed in‐house. Nonpulsatile ECMO was initiated at a flow rate of 140 mL/kg/min for the first 30 min with normal heart beating, with rectal temperature maintained at 36°C. Ventricular fibrillation was then induced with a 3.5‐V alternating current to generate a cardiac dysfunction model. Using this model, we collected the data on pulsatile and nonpulsatile groups. The piglets were weaned off ECMO at the end of the experiment (180 min after ECMO was initiated). The animals did not receive blood transfusions, inotropic drugs, or vasoactive drugs. Blood samples were collected to measure hemoglobin, methemoglobin, blood gases, electrolytes, and lactic acid levels. Hemodynamic energy was calculated using the Shepard's energy equivalent pressure. Near‐infrared spectroscopy was used to monitor brain and kidney perfusion. The pulsatile ECMO group had a higher atrial pressure (systolic and mean), and significantly higher regional saturation at the brain level, than the nonpulsatile group (for both, P < 0.05). Additionally, the pulsatile ECMO group had higher methemoglobin levels within the normal range than the nonpulsatile group. Our study demonstrated that pulsatile ECMO produces significantly higher hemodynamic energy and improves systemic microcirculation, compared with nonpulsatile ECMO in acute cardiac failure.     

Predictors of Acute Renal Failure During Extracorporeal Membrane Oxygenation in Pediatric Patients After Cardiac Surgery

Acute renal failure (ARF) is associated with increased mortality in pediatric extracorporeal membrane oxygenation (ECMO). The aim of this study was to identify predictors of ARF during ECMO in pediatric patients after cardiac surgery. A retrospective study analyzed 42 children (≤15 years) after cardiac surgery requiring venous‐arterial ECMO between December 2008 and December 2014 at Fuwai Hospital. ARF was defined as ≥300% rise in serum creatinine (SCr) concentration from baseline or application of dialysis. Multivariate logistic regression was performed to identify the predictors of ARF during ECMO. A total of 42 children (age, interquartile range [IQR], 13.0 [7.2–29.8] months; weight, IQR, 8.5 [6.7–11.0] kg) after cardiac surgery requiring ECMO were included in this study. The total survival rate was 52.4%, and the incidence of ARF was 40.5%. As the result of univariate analysis, ECMO duration, cardiopulmonary resuscitation, maximum free hemoglobin (FHB) during ECMO, lactate level, and mean blood pressure before initiation of ECMO were entered in multiple logistic regression analysis. In multiple logistic regression analysis, FHB during ECMO (OR 1.136, 95% CI 1.023–1.261) and lactate level before initiation of ECMO (OR 1.602, 95% CI 1.025–2.502) were risk factors for ARF during ECMO after pediatric cardiac surgery. There was a linear correlation between maximum SCr and maximum FHB (Pearson's r = 0.535, P = 0.001). Maximum SCr during ECMO has also a linear correlation with lactate level before initiation of ECMO (Pearson's r = 0.342, P = 0.044). Increased FHB during ECMO and high lactate level before initiation of ECMO were risk factors for ARF during ECMO in pediatric patients after cardiac surgery.     

Cardiac stun in infants undergoing extracorporeal membrane oxygenation

Previous studies have shown that cardiac performance decreases in infants undergoing extracorporeal membrane oxygenation (ECMO). Some infants have an exaggerated decrease in cardiac performance during ECMO. This syndrome has been called cardiac stun. To better understand this phenomenon, we reviewed the records of infants with cardiac stun and compared them with infants who did not have the syndrome. Cardiac stun was detected in 12 of 240 infants (5.0%) undergoing ECMO. The diagnoses were congenital diaphragmatic hernia (7/12), meconium aspiration syndrome (3/12), respiratory distress syndrome (1/12), and persistent pulmonary hypertension of the newborn (1/12). The weight, gestational age, inotropic support, and time to start of ECMO were similar to infants without cardiac stun. Arterial oxygen tension was lower, carbon dioxide tension was higher, and pH was lower before ECMO in infants in whom cardiac stun developed (p less than or equal to 0.03). Cardiac arrests were more common, before ECMO, in infants in whom cardiac stun developed (6/12; p less than or equal to 0.01). Cardiac stun began at an average 2 1/2 hours after beginning ECMO (range 0.1 to 7 hours). Pulse pressure decreased from 20 mm Hg (range 10 to 45 mm Hg) before stun to 8 mm Hg (range 4 to 12 mm Hg) after stun. Heart rate did not change. Cardiac stun lasted for 33 hours (range 1 to 64 hours) on ECMO and recurred in three infants. Decreases in pump flow and increases in preload, afterload reduction, and inotropic agents did not improve cardiac performance. Survival was lower in the infants in whom cardiac stun developed (p less than or equal to 0.001). Only 5 of 12 infants (42%) survived ECMO when cardiac stun occurred. Our findings show that cardiac stun occurs infrequently during ECMO and is transient in most infants. Infants in whom cardiac stun develops appear to be more ill before ECMO and have a higher mortality after ECMO.     

Extracorporeal Membrane Oxygenation as a Bridge to Organ Donation: A Case Report

Hemodynamic instability is a frequent complication in potential organ donors. Despite maximal medical therapy, it can lead to cardiac arrest with consequent loss of organs. In this study we present the use of extracorporeal membrane oxygenation circulation (ECMO) as a bridge to organ procurement in a potential donor with hemodynamic instability. A 14-year-old girl who drowned in a pool experienced cardiorespiratory arrest with prolonged resuscitation. In the intensive care unit (ICU), she displayed hemodynamic instability requiring high doses of inotropis agents. After 60 hours for ICU admission clinical diagnosis of brain death, was established and consent for organ donation obtained. During the observation period, the hemodynamic instability worsened, requiring ECMO which was continued during transport to the operating room and during organ retrieval, totaling 3 hours. We retrieved liver, kidneys, heart valves and cornea. Liver and kidney transplantations were successfully performed in 3 recipients, all of whom displayed appropriate organ functions after 15 months. In conclusion, ECMO support of potential donors can be used to prevent cardiac arrest, preserve organs, and thus increase the number of potential donors.     

Ecmo-assisted carinal resection and reconstruction after left pneumonectomy

Extracorporeal Membrane Oxygenation (ECMO) has become an increasingly important technique for patients with respiratory or cardiac failure for a variety of causes. In addition, there are many reports about the use of ECMO in surgical operation on neonates and children patients with tracheal obstruction. In this report we present a case about an adult patient who underwent a carinal resection and reconstruction after left pneumonectomy with ECMO assistance successfully. To our knowledge, this case is the first of its kind to use ECMO in adult carinal resection and reconstruction after pneumonectomy. In this report, we try to illustrate that ECMO is effective in operations of this kind.     

Single Needle Venovenous Extracorporeal Membrane Oxygenation Using a Nonocclusive Roller Pump for Rescue in Infants and Children

Abstract: In 1993, J.Y. Chevalier described a single needle venovenous extracorporeal membrane oxygenation (ECMO) system using a nonocclusive roller pump and alternating clamps for pulmonary support in neonates. We modified this system to use it in older children as well and for additional indications. Introducing a double raceway and 2 different sizes of tubing sets and performing percutaneous approach, we treated 21 children (age 1 day to 49 months) using this system. Indications for treatment were hypoxia and hypoxic induced myocardial dysfunction resulting from pulmonary failure, sepsis, and congenital defects. Of the chiIdren treated for neonatal indications. 7/9 survived. For 2 children ECMO was terminated because of intraventricular hemorrhage (TVH). In the pediatric group 5/7 of the children could be weaned from ECMO, and 2 children died after more than 30 days on ECMO. Two of the children who had been almost completely weaned died later because of therapy withdrawal following a brain death diagnosis. In the cardiac group, 3/5 of the children survived. We conclude that the described system is an effective venovenous ECMO system that reduces invasivity and expenditure.     

Ventricular function determination during extracorporeal membrane oxygenation (ECMO) following Norwood operation: a case report

Extracorporeal membrane oxygenation has been used successfully to support both cardiac and pulmonary function following Stage I Norwood operation. Determination of the return of native cardiac function and pulmonary function can be easily accomplished because of the single ventricle physiology. The pulmonary function can be assessed while on full flow ECMO by isolating the membrane oxygenator gas compartment, allowing evaluation of native pulmonary gas exchange through the modified Blalock-Taussig shunt. Cardiac output can be calculated by using the following oxygen delivery equation: Total O2 delivery = ECMO oxygen delivery + ventricular oxygen delivery. The ventricular O2 saturation used in the formula for oxygen delivery is same as the mixed venous O2 saturation returning to the ECMO pump because of the large atrial communication following the Norwood operation. A 3.2 kilogram patient was placed on a pediatric ECMO circuit utilizing a heparin-coated centrifugal pump and a microporous membrane oxygenate after failure to wean from bypass because of a low oxygen saturation and poor ventricular function. On day 1 of support, the systemic arterial oxygen saturation was 100% and matched the ECMO arterial saturation. On day 2 of the support, the patient's arterial saturation decreased to 96%, and the ECMO mixed venous saturation was 87%. Using the oxygen delivery formula, the ventricular cardiac output was calculated to be 175 mL/min, with an ECMO flow of 400 mL/min for a total cardiac output of 575 mL/min. The native ventricular contribution was, therefore, 30% of total cardiac output. Calculation of cardiac output would normally require a left ventricular sample in a patient with biventricular physiology. The single ventricle physiology in the post-operative Norwood patient makes this calculation a useful tool for assessing return of ventricular function in these patients.     

The Feasibility of Extracorporeal Membrane Oxygenation in the Variant Airway Problems

Introduction: Extracorporeal membrane oxygenation (ECMO) is widely used to treat respiratory distress during cardiac or respiratory arrest; moreover, its use is being extended to a wide variety of clinical fields. In this study we assess the utility of ECMO in the management of airway obstruction.Patients and Methods: 15 patients underwent ECMO for airway obstruction. We retrospectively analyzed and evaluated the feasibility of ECMO in the treatment of airway problems.Results: Seven patients received ECMO to facilitate respiration and promote stability during trachea surgery. In six cases ECMO ceased immediately following the operation; in the remaining case ECMO cessation was delayed due to post-operative ARDS. In three cases emergency ECMO was used in response to respiratory arrest; two patients died. In five cases ECMO was emergently inserted to prevent death, following airway blockade by massive hemoptysis. One patient was not discharged from the intensive care unit. Another patient was transferred to a general ward but died from other causes.Conclusion: ECMO is useful during anesthesia in patients at high risk of airway blockade, for example due to endobronchial bleeding, and during complex thoracic surgery. ECMO confers a safer environment during airway surgery, and its complication rate is acceptable.     

Ethical Issues in the Use of Extracorporeal Membrane Oxygenation in Controlled Donation After Circulatory Determination of Death

The use of donor extracorporeal membrane oxygenation (ECMO) to improve graft outcomes by some controlled donation after circulatory determination of death (cDCDD) programs raises ethical issues. We reviewed cDCDD protocols using ECMO and the relevant ethics literature to analyze these issues. It is not obvious that ECMO in cDCDD improves graft outcomes. In our opinion, ECMO implemented before death can interfere with end‐of‐life care and damage bodily integrity. By restoring systemic circulation, ECMO risks invalidating the preceding declaration of death if brain and cardiac perfusion is not adequately excluded because of malfunction or misplacement of the supradiaphragmatic aortic occlusion balloon. The use of ECMO is not compatible with the acronym DCDD because circulation is restored after the determination of death. Because of these deficiencies, we concluded that other techniques are preferable, such as rapid recovery or in situ cold infusion. If ECMO is performed, it requires a specific informed consent and transparency.     

Assessment of liver function during extracorporeal membrane oxygenation in the non-heart beating donor swine

INTRODUCTION: Although the use of non-heart beating donors (NHBD) could bridge the widening gap between organ demand and supply, its application to liver transplantation is limited due to warm ischemia (WI), biliary tree injury, and inadequate organ assessment. Warm blood reperfusion using extracorporeal membrane oxygenation (ECMO) can be a suitable option to reduce WI in organs from NHBD, allowing one to determine hepatic flow characteristics and bile production and facilitating assessment of organ viability. METHODS: This work evaluates the use of warm blood veno-arterial ECMO reperfusion in NHBD swine. Systemic and hepatic hemodynamics, bile, urine, and mixed venous blood were measured. After baseline data collection, 10 kU heparin was given intravenously followed by 1 g KCl to elicit cardiac arrest (CA). ECMO was started after 30 or 60 minutes of CA and kept running for 120 minutes. RESULTS: One-way repeated measures analysis of variance (ANOVA) with Tukey test analysis was used within a group. Two-way ANOVA was used between groups. ECMO can restore venous SO2 and pH in both groups; the values were close to baseline in the 30-minute CA group. Also, in this group, bile production was > 65% from baseline early during reperfusion and its value was lower in the longer CA group < 55% (P < .001). Aspartate aminotransferase (AST) was doubled at the end of ECMO support in the 60-minute CA group (P < .05). CONCLUSION: In this preheparinized NHBD swine model, ECMO support restores liver perfusion, oxygenation, and bile production after 60 minutes of CA. Quantification and analysis of bile production could be a determinant of liver function during ECMO resuscitation, and it may be a predictor of graft viability before transplantation.     

Extracorporeal Membrane Oxygenator Support in a Case of Severe Status Asthmaticus

Support with extracorporeal membrane oxygenation (ECMO) can sustain life for a substantial period of time, but the role of long-term ECMO support is limited. The National Institutes of Health ECMO collaborative study revealed no significant reduction in mortality in adults with severe respiratory distress syndrome treated with ECMO. The value of ECMO in the treatment of transient, severe acute respiratory insufficiency has been demonstrated in patients after cardiac operations, in patients with Pneumocystis carinii pneumonia, and in patients following trauma. We present an example of refractory respiratory failure in a young asthmatic with massive atelectasis in whom the institution of ECMO allowed us to perform adequate pulmonary lavage. It resulted in improvement in gas exchange and the patient's survival.     

Use of a ventricular assist device as a bridge to transplantation in a patient with single ventricle physiology and total cavopulmonary anastomosis

Mechanical circulatory support can be used to manage acute and chronic cardiac failure in both adult and pediatric patients. Traditionally, extracorporeal membrane oxygenation (ECMO) has been the most common form of mechanical circulatory support in children. However, more recently, in cases of pure ventricular dysfunction, ventricular assist devices (VADs) have offered specific advantages over ECMO, including better ventricular recovery, reduced anticoagulation requirements, decreased use of blood products and decreased cost. We present the use of a VAD in an adolescent with single-ventricle physiology, who could not be weaned from cardiopulmonary bypass (CPB) after undergoing a revision of a modified Fontan operation. Gas exchange was provided by the patient's lungs while the centrifugal VAD was used successfully to support the circulation as a bridge, first to a totally implantable pulsatile VAD and subsequently to heart transplantation.     

The role of extracorporeal membrane oxygenation (ECMO) therapy in acute heart failure

ECMO is a reliable and useful treatment for patient with acute cardiac failure. However, outcomes of cardiac ECMO are not yet as successful as case of ECMO support for respiratory failure. To improve the results of cardiac ECMO, proper patient selection, management, and weaning strategy are crucial. Other options, including LVADs and heart transplant, should be considered when patients do not show any improvements under ECMO therapy. A multidisciplinary approach is required to provide the maximum chance of survival after ECMO treatment.     

Extracorporeal membrane oxygenation in children after repair of congenital cardiac lesions

Background. The purpose of this study was to review our experience in the early application of extracorporeal membrane oxygenation (ECMO) in patients requiring mechanical assistance after cardiac surgical procedures.

Methods. The hospital records of all children requiring ECMO after cardiac operation were retrospectively reviewed, and an analysis of variables affecting survival was performed.

Results. Fifty pediatric patients between May 1997 and October 2000 required ECMO for cardiopulmonary support after cardiac operation. Patients ranged in age from 1 day to 11 years (median age, 40 days). Forty-eight patients underwent repair of congenital cardiac lesions and 2 were included after receiving a heart transplant. Twenty-two children could not be weaned from cardiopulmonary bypass and were placed on ECMO in the operating room for circulatory support. Of the 28 children who required ECMO in the intensive care unit, 10 had ECMO instituted after cardiopulmonary arrest (mean cardiopulmonary resuscitation time, 42 minutes; range, 5 to 110 minutes). In infants with single-ventricle physiology, survival to discharge was 61% (11 of 18 patients) as compared with 43% (14 of 32 patients) in those with biventricular physiology. Thirty of the 50 patients (60%) were successfully weaned from ECMO, of which 25 (83%) were discharged home. Overall survival to discharge in the entire cohort was 50%. Extracorporeal membrane oxygenation support greater than 72 hours was a grave prognostic indicator. Overall survival in this group was 36% (9 of 25 patients) compared with 56% (14 of 25 patients) in those with ECMO support less than 72 hours (p < 0.05). Univariate analysis revealed the presence of renal failure, extended periods of circulatory support, and a prolonged period of cardiopulmonary resuscitation as risk factors for mortality. The presence of shunt-dependent flow, operative procedure, and institution of ECMO in the intensive care unit did not alter survival.

Conclusions. Extracorporeal membrane oxygenation provides effective support for postoperative cardiac and pulmonary failure refractory to medical management. Early institution of ECMO may decrease the incidence of cardiac arrest and end-organ damage, thus increasing survival in these critically ill patients.