Early CDH repair on ECMO: Improved survival but no decrease in ECMO duration (A CDH Study Group Investigation)

Purpose“Early on-ECMO” repair of CDH entails repair within 48–72 h of cannulation in an effort to optimize pulmonary physiology, shorten ECMO duration, and, ultimately, improve survival. This study evaluated the effect of early on-ECMO repair as compared to leaving patients unrepaired during ECMO.MethodsThe CDH Study Group database was queried for CDH patients requiring ECMO who either underwent repair within the first 72 h after cannulation or remained unrepaired on ECMO. Primary outcomes were survival to decannulation and ECMO duration.ResultsA total of 248 patients underwent early repair and 922 remained unrepaired on ECMO. The early repair group had increased risk factors for poor outcomes, including higher odds of cardiac defects and thoracic liver location, and lower odds of hernia sac presence. Nonetheless, ECMO survival for the early repair group was 87.1% compared to 78.4% in the unrepaired group (p = 0.002). However, the early repair group had a longer median ECMO duration than the unrepaired group (240.6 vs 196.8 h, p = 0.001).ConclusionWhile early ECMO repair does not shorten ECMO duration, it results in increased survival to decannulation as compared to those unrepaired on ECMO. This suggests that there may be a physiologic benefit leading to increased ECMO survival in a subset of patients undergoing on-ECMO repair over those designated to undergo post-ECMO repair.Level of evidenceLevel III.     

Cardiac arrest in the ECMO candidate

Extracorporeal membrane oxygenation (ECMO) improves survival in appropriately selected full-term neonates with severe respiratory failure. The clinical course and outcome of infants placed on ECMO after sustaining a cardiac arrest is not known. This study reviews the characteristics and outcome of 10 neonates, identified by retrospective review, placed on ECMO at Children's Hospital Medical Center (CHMC), Cincinnati, OH, after sustaining a cardiac arrest. Long-term survival in this group was 60%, significantly less than the 87% overall ECMO survival in infants at CHMC (P less than .01). Survivors and nonsurvivors in the cardiac arrest group were similar with regard to gestational age, birth weight, Apgar scores, and arterial PO2 prior to cannulation. Nonsurvivors had an ECMO course complicated by progressive multisystem organ failure. Head computed tomography obtained at the time of discharge demonstrated right-sided brain lesions in three of six survivors. Despite these radiographic findings, early clinical follow-up suggests adequate growth and development with no individuals demonstrating a severe neurological deficit. Thus, ECMO can play a role in the resuscitation of neonatal ECMO candidates sustaining cardiac arrest prior to or at the time of cannulation. Early clinical follow-up suggests adequate preservation of neurological function in this extremely high-risk group.     

Extracorporeal membrane oxygenation (ECMO) as lung or heart assist

Extracorporeal membrane oxygenation (ECMO) may serve as extracorporeal lung assist (ECLA) in patients with acute respiratory failure (ARF) or as extracorporeal heart assist (ECHA) in patients with low output syndrome (LOS) after open heart surgery. From 1988 to 1992 seven patients underwent ECMO in our hospital; four suffered from ARF and three from LOS. Various bypass techniques were employed. Two ARF patients, aged 58 and 18 years, had veno-venous bypass; in the latter, ECMO was reinstituted as a veno-arterial bypass one week after weaning. In a three-year-old boy, the ECMO outflow tubing was primarily connected to the pulmonary artery, and shortly afterwards relocated to the common carotid artery. In a 31-year-old man with ARF, and three LOS patients, a 56-year-old woman, and two men aged 68 and 70 years, ECMO was veno-arterial with direct access to the ascending aorta. A heparin-coated system was used, and all but one patient, who was treated with warfarin, received a daily low dose of heparin, which was withdrawn after from one to nine days.
Six patients were weaned off ECMO after 4.5 to 21 days. Three ARF patients recovered completely; the child died. In one LOS patient, ECMO was withdrawn due to a poor general condition. Two others were weaned off ECMO and the intra-aortic balloon pump, and the inotropic support was significantly reduced, but both died of multiple system organ failure. Although no firm conclusions can be drawn from these few case reports, the heparin-coated system used as ECLA appears promising, whereas ECHA seems to imply a poor prognosis in patients who are not candidates for cardiac transplantation.     

Long-term survival after pediatric cardiac transplantation and postoperative ECMO support

BACKGROUND: Graft failure after cardiac transplantation in children can be managed acutely with mechanical support, most commonly extracorporeal membrane oxygenation (ECMO). The purpose of this study was to evaluation the long-term outcome of ECMO support early and late after pediatric cardiac transplantation. METHODS: From February 1982 through October 2002, 168 patients underwent isolated cardiac transplantation. Twenty patients (11.9%) required mechanical support early or late after transplantation. Inpatient and outpatient records of these were reviewed. RESULTS: Indication for transplantation was complex congenital heart disease in 12, cardiomyopathy in 7, and graft failure (retransplant) in 1. One patient was also on ECMO preoperatively. Fifteen patients required circulatory support immediately or shortly (less than 6 weeks) after transplantation. The remaining 5 patients were placed on ECMO for ventricular dysfunction late (3 months to 7 years) after transplantation. In the perioperative ECMO group, 8 (53%) were successfully decannulated and subsequently discharged. Three of 5 (60%) patients placed on ECMO late were successfully decannulated, 1 of whom died in hospital 10 days later and 2 of whom are still alive. CONCLUSIONS: Mechanical circulatory support using ECMO can be a useful strategy is the management of graft dysfunction after pediatric cardiac transplantation both early and late postoperatively. The mortality rate is acceptable in this very high risk group of patients and long-term outcome is good.     

体外膜肺氧合在临床肺移植中的应用

目的 总结体外膜肺氧合(ECMO)技术在临床肺移植中应用的经验.方法 45例肺移植受者,年龄(50.5±8.6)岁(16～74)岁.原发病为肺纤维化合并肺动脉高压32例,慢性阻塞性肺病4例,矽肺2例,肺结核2例,弥漫性细支气管炎1例,支气管扩张2例,以及原发性肺动脉高压2例.其中3例受者在术前经股动、静脉切开置ECMO管道,分别维持13、19和6d后,在ECMO支持下接受了肺移植手术;40例受者在术中应用了ECMO辅助;2例未在体外循环下接受肺移植的受者,因原发性移植物功能丧失(PGD)于术后行ECMO辅助支持.结果 40例术中应用ECMO者,37例于术毕顺利撤除ECMO,术中辅助流量为(2.8±0.6)L/min,辅助持续时间为(7.7±0.9)h,存活31例;3例术后继续使用ECMO,直至血流动力学稳定,其中2例分别于术后36 h和7d时顺利撤除,另1例术后使用ECMO维持5d后出现急性肾功能衰竭,术后2周时死于多器官功能衰竭.2例术中无体外循环辅助受者和其余3例术中辅助受者因术后发生PGD或急性心力衰竭,而初次或再次使用ECMO,辅助流量分别为(2.5±0.3)L/min和(2.6±0.4)L/min,辅助持续时间分别为(53.5±21.9)h和(88.7±45.9)h,其中3例治愈出院,2例因多器官功能衰竭而死亡.所有受者均未发生明确与ECMO相关的并发症.结论 ECMO是肺移植围手术期支持的重要辅助工具,对于降低等待肺移植过程中的死亡率、稳定术中血流动力学、改善术后严重呼吸功能障碍以及原发性移植物功能不良,可以提供良好的辅助功能.     

Measuring left ventricular function after heart transplantation via digitization of M-mode echocardiograms

Abstract The aim of the study was to assess the usefulness of M-mode echocardiography for noninvasive diagnosis of cardiac rejection. For this purpose, 292 M-mode images of 26 heart transplant recipients were analyzed. The echocardiographic images were digitized into an image analysis system. The curves of left ventricular diameter changes were obtained and its first differential calculated. A total of 23 parameters were measured. The most important parameters were: peak velocity of systolic diameter change, peak velocity of diastolic diameter change, time to peak velocity of systolic diameter change, time to peak velocity of diastolic diameter change (TPEAK-D), isovolumetric relaxation time (IVRT), rapid filling time (RFT), shortening fraction (SF), and mean velocity of circumferential fiber shortening (MVCF). The echocardiographic parameters were compared to biopsy results. In 18 patients, 23 biopsy-proven moderate rejections occurred. When rejection occurred, IVRT decreased 23%± 6% ( P <0.05), SF decreased 13%± 14% ( P <0.05), MVCF decreased 18%±18% ( P < 0.05, and TPEAK-D increased 27%± 27% ( P <0.05). We concluded that the analysis of digitized M-mode images can identify heart transplant rejection.     

ECMO without heparin: laboratory and clinical experience

To evaluate the feasibility of long-term extracorporeal membrane oxygenation (ECMO) without heparin, we placed six lambs on standard venoarterial ECMO for 71 to 96 hours. Group 1 (3 animals) was given doses of heparin to maintain activated clotting times (ACT) greater than 400 seconds. No form of anticoagulant was used for the three animals in group 2. Blood flow was maintained at 60 mL/kg/min. No histological evidence of thrombosis was noted at necropsy. ACT, prothrombin time, and partial thromboplastin time were higher in group 1, and much lower, although still above normal in group 2. Fibrinogen was significantly lower in group 2 (75 +/- 35 v 219 +/- 64 mg/dL group 1), and, although the platelet count was lower in group 2 (142 +/- 76 x 10(3)/mm3 v 225 +/- 167 x 10(3)/mm3), it was clinically acceptable. These results encouraged us to discontinue heparin when faced with severe hemorrhage in four patients on ECMO, rather than withdraw support at a time when there was little chance of survival. Heparin was discontinued for 10.5 +/- 6 hours. The mean ACT was reduced from 220 +/- 23 seconds to 144 +/- 22 seconds. One patient, who required repair of gastric necrosis while on ECMO following repair of a congenital diaphragmatic hernia, survived and had a decrease in blood loss from 2 to 0 mL/kg/h after the heparin was discontinued. One of the three patients who died had an autopsy with no evidence of thrombosis. We conclude that it may be reasonable to discontinue heparin in the face of life-threatening hemorrhage while on ECMO.     

Neonatal presentation of cystic fibrosis requiring ECMO

This is a case of cystic fibrosis causing respiratory distress in a newborn who was treated successfully with extracorporeal membrane oxygenation (ECMO). To date, this is the only such case reported to the Neonatal ECMO Registry at the University of Michigan. ECMO can be a life-saving intervention in these neonates. Advances in the total care of these patients make them acceptable candidates for neonatal ECMO, but the patholophysiology of cystic fibrosis raises many questions about their suitability for ECMO at older ages, as the associated pulmonary disease becomes less reversible.     

Studies on ECMO. (III)--Study on pumpless A-V ECMO

Silicon hollow fiber membrane oxygenator is considered to be useful for long term extracorporeal membrane oxygenation (ECMO) and blood usually flows inside of the fiber (inside flow type). But if it flows outside of the fiber (outside flow type), the pressure drop is supposed to be less than that of inside flow type. In this study the oxygenator of an outside flow type was used. At first, the pilot study was done to evaluate the capability of this oxygenator as an outside flow type. The pressure drop was 50 mmHg at the blood flow of 400 ml.min-1. At this blood flow and same gas flow, CO2 transfer rate was 22.3 ml.min-1. In the second study, the effects of pumpless arterio-venous ECMO (pumpless A-V ECMO) were studied in 8 dogs under mechanical hypoventilation. During ECMO, there were no significant changes in hemodynamics when the blood flow rate was 15% of cardiac output. PaO2 and PaCO2 recovered considerably. In conclusion, pumpless A-V ECMO using this membrane oxygenator of outside flow type is effective for CO2 removal and considered to be clinically useful.     

Long-term follow-up of infants and children treated with extracorporeal membrane oxygenation (ECMO): a preliminary report

Extracorporeal Membrane Oxygenation (ECMO) has been used clinically as a life-saving treatment modality in infants and children who are dying of respiratory insufficiency. From 1973 to 1980 47 children less than 10 years of age were treated in a study to determine the feasibility and effectiveness of ECMO in the pediatric population. Despite a predicted mortality of 90% or greater, 24 patients survived. Eighteen of those patients have been seen in long-term follow-up. Thirteen patients (72%) demonstrate basically normal growth and development. Five patients (28%) have definite handicaps which are severe in two. Despite ligation of one common carotid artery and systemic heparinization, the risk of intracranial hemorrhage and/or neurodevelopmental problems appears to be no higher in this ECMO group and may even be lower than in the high-risk population treated with conventional therapy. The incidence of chronic respiratory problems, especially bronchopulmonary dysplasia, is zero in this group of patients. Only one patient (4%) has a defect that lateralizes to the right hemisphere which may have been affected by ligation of the carotid artery. Further study is required; however, it appears that ECMO offers life-saving intervention without increasing morbidity in select children with severe respiratory insufficiency.     

ECMO in ARDS: a long-term follow-up study regarding pulmonary morphology and function and health-related quality of life

Background: A high survival rate can be achieved in patients with severe acute respiratory distress syndrome (ARDS) using extracorporeal membrane oxygenation (ECMO). The technique and the costs are, however, debated and follow-up studies in survivors are few. The aim of this study was to evaluate long-term pulmonary health after ECMO and severe ARDS.
Methods: Twenty-one long-term survivors of severe ARDS and ECMO were studied in a follow-up program including high-resolution computed tomography (HRCT) of the lungs, extensive pulmonary function tests, pulmonary scintigraphy and the pulmonary disease-specific St George's Respiratory Questionnaire (SGRQ).
Results: The majority of patients had residual lung parenchymal changes on HRCT suggestive of fibrosis, but the extension of morphologic abnormalities was limited and without the typical anterior localization presumed to indicate ventilator-associated lung injury. Pulmonary function tests revealed good restitution with mean values in the lower normal range, while T½ for outwash of inhaled isotope was abnormal in all patients consistent with subclinical obstructivity. Most patients had reduced health-related quality of life (HRQoL), according to the SGRQ, but were stating less respiratory symptoms than conventionally treated ARDS patients in previous studies. The majority were integrated in normal work.
Conclusion: The majority of ECMO-treated ARDS patients have good physical and social functioning. However, lung parenchymal changes on HRCT suggestive of fibrosis and minor pulmonary function abnormalities remain common and can be detected more than 1 year after ECMO. Furthermore, most patients experience a reduction in HRQoL due to the pulmonary sequelae.     

A complication of ECMO cannula placement resulting in hemodynamic and oxygenation alterations: A case report

Veno-veno extracorporeal membrane oxygenation (VV ECMO) is used as a bridge to recovery in acute respiratory distress syndrome (ARDS) patients who have reversible lung failure. We present a complication of ECMO cannula placement/position resulting in hemodynamic and oxygenation alterations. These demonstrate principles related to the interaction of the VV ECMO circuit and patient cardio-pulmonary physiology. Consideration and comprehension of pulmonary shunt fraction, ECMO cannula recirculation ratio and ECMO blood flow to cardiac output (CO) ratio are central to continuous assessment and diagnosis of cardio-pulmonary changes encountered during management of VV ECMO.     

Pulmonary hypertension in neonatal cystic lung disease: survival following lobectomy and ECMO in two cases

Extracorporeal membrane oxygenation (ECMO) is an accepted form of therapy in the treatment of neonates with otherwise lethal persistent pulmonary hypertension related to meconium aspiration, congenital diaphragmatic hernia, and sepsis. This report concerns two neonates with congenital cystic lesions of the lung who developed severe pulmonary hypertension and were salvaged with lobectomy and ECMO. These cases present an additional group of patients in whom ECMO may be a life-saving measure.     

Surgical complications and procedures in neonates on extracorporeal membrane oxygenation.

We report our experience from May 1985 to January 1991 with surgical complications and procedures performed in neonates on extracorporeal membrane oxygenation (ECMO) (218 venoarterial and 7 venovenous bypass). Eleven children older than 1 month were excluded. Total complications were 96 in 67 patients and included: bleeding (37), problems with initial cannula placement (17), thrombus formation (15), hemothorax, pneumothorax, or effusions (11), mechanical problems (11), and miscellaneous (5). Forty-eight procedures were performed in 37 patients while on ECMO. These were recannulation or reposition of cannulas (14), tube thoracostomy (11), cardiac surgery (6), cardiac catheterization (4), repair of congenital diaphragmatic hernia (5), thoracotomy (4), and others. Twenty-eight complications occurred in 15 of the 27 patients who died. Mortality rate was 12% for the entire group. Primary causes of death were hypoplastic lung (11), cardiac (8), sepsis (4), intraventricular hemorrhage (2), and pulmonary hypertension (2). No deaths were due solely to complications except for the two patients with intraventricular hemorrhage. Mortality in neonates who had complications while on ECMO was significantly higher (P less than .005) than in patients without complications. Hemorrhagic and thoracic complications were associated with higher mortality (P less than .001). Mortality was not affected by mechanical problems, thrombus formation, or catheter-related problems. While on ECMO cardiac defects, diaphragmatic hernia, lobar emphysema, and other conditions can be safely corrected. The use of echocardiography to position the cannulas, better control of coagulation factors and improvement in equipment may ultimately decrease complications.     

Reversal of mortality for congenital diaphragmatic hernia with ECMO.

Extracorporeal Membrane Oxygenation (ECMO) has been available to neonates with respiratory failure at the University of Michigan School of Medicine since June 1981. In order to evaluate the impact of this type of pulmonary support, a retrospective analysis of 50 neonates with posterolateral congenital diaphragmatic hernia (CDH) who were symptomatic during the first hour of life and were treated between June 1974 and December 1987 was carried out. The patients were divided into two groups, those treated before June 1981 (16 patients) and those treated after June 1981 (34 patients). Overall survival improved from 50% (eight of 16 patients) during the pre-ECMO era to 76% (26 of 34 patients) during the post-ECMO period (p = 0.06). During the period after June 1981, 21 neonates were unresponsive to conventional therapy and were therefore considered for ECMO. Failure of conventional therapy was defined as acute clinical deterioration with an expected mortality of greater than 80% based on an objective formula previously reported. Six patients were excluded on the basis of specific contraindications to ECMO. Thirteen of 15 infants (87%) supported with ECMO survived. Three patients treated before 1981 met criteria for ECMO; all three died while receiving treatment using conventional therapy. These survival differences are significant (p less than 0.01). In addition, the survival of 87% for the infants treated with ECMO versus the expected mortality of greater than 80% for these same patients when treated with conventional therapy is highly significant (p less than 0.005). Based on this data, ECMO appears to be a successful, reliable, and safe method of respiratory support for selected, critically ill infants with CDH.     

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.     

Effect of burns on cardiac performance in the dog

Changes in cardiac performance after a third-degree 50% burn were studied using seventeen mongrel dogs divided into three groups: A, sham burn (n = 6); B, burn (n = 5); C, burn + fluid therapy (n = 6). From the measurements of local ventricular dimension and left ventricular pressure (P), end-systolic pressure-length ratio (Emax) mean velocity of circumferential fiber shortening (mean Vcf), peak dp/dt, and percent shortening (% delta L) as indices of myocardial contractility were calculated. Cardiac output (CO), aortic pressure (Aop) and heart rate (HR) were also measured. All measurements were repeated every 30 minutes until 360 minutes after burning. In group B and C, CO as well as left ventricular end-diastolic pressure (LVEDP) and length (EDL) as indices of the preload were significantly decreased as compared with group A. All indices of myocardial contractility in B and C were significantly lower than those in A. These results indicate that, in severe thermal burns, cardiac pump function is depressed by the fall of myocardial contractility in addition to the decrease in the preload.     

Open lung biopsy in neonatal and paediatric patients referred for extracorporeal membrane oxygenation (ECMO)

BACKGROUND: This study was undertaken to determine the usefulness, safety, and most appropriate timing of open lung biopsy in infants and children considered for and on extracorporeal membrane oxygenation (ECMO) for respiratory failure. METHODS: A retrospective review of children referred for consideration of and placed on ECMO in our institution in the period 1996-2002. RESULTS: 506 patients were referred, 15 (3%) of whom underwent antemortem open lung biopsy (eight neonatal, four paediatric, and three cardiac patients). In the neonatal group open lung biopsy contributed to clinical decision making in all patients. Four neonates had a fatal lung dysplasia (three alveolar capillary dysplasia and one surfactant protein B deficiency) and treatment was withdrawn. Of the other four neonates, two had pulmonary hypoplasia, one had pulmonary lymphangiectasia, and one had meconium aspiration with mild barotrauma. Treatment was continued in these four patients and two survived. In the paediatric group the biopsies were of clinical relevance in two infants with pertussis who had lung infarction on biopsy in whom treatment was withdrawn. In the other two paediatric patients the biopsies were equivocal, treatment was continued, but both patients died. In the cardiac group, who presented perioperatively with pulmonary hypertension, the biopsies excluded a fatal lung dysplasia and severe pulmonary vascular disease but all three infants died. One patient had non-fatal bleeding complications. CONCLUSION: Open lung biopsy is clinically most useful when performed to diagnose fatal lung dysplasias in neonates and to confirm the presence of viable lung tissue in patients with acute lung injury due to pertussis infection.     

Incidence,Risk Factors,and Outcomes of Hyperbilirubinemia in Adult Cardiac Patients Supported by Veno‐Arterial ECMO

The aims of this study were to evaluate the incidence, risk factors, and outcomes of hyperbilirubinemia in cardiac patients with veno‐arterial (VA) ECMO. Data on 89 adult patients with cardiac diseases who received VA ECMO implantation in our hospital were retrospectively reviewed. All patients were divided into the following three groups: 24 in normal group (N, total bilirubin [TBIL] ≤3 mg/dL), 30 in high bilirubin group (HB, 6 mg/dL ≥ TBIL > 3 mg/dL), and 35 in severe high bilirubin group (SHB, TBIL > 6 mg/dL). lg(variables + 1) was performed for nonnormally distributed variables. The incidence of hyperbilirubinemia (>3 mg/dL) was 73%. In a multiple linear regression analysis, lg(peak TBIL + 1) was significantly associated with lg(peak AST + 1) (b‐coefficient 0.188, P = 0.001), lg(peak pFHb + 1) (b‐coefficient 0.201, P = 0.003), and basic TBIL (b‐coefficient 0.006, P = 0.009). Repeated measurement analysis of variance revealed that the main effect for three groups in pFHb and lg(AST + 1) was significant at first 3 days during ECMO. The patients in SHB had low platelets during ECMO and low in‐hospital survival rate. Hyperbilirubinemia remains common in patients with VA ECMO and is associated with low platelets and high in‐hospital mortality. Hemolysis and liver dysfunction during ECMO and basic high bilirubin levels are risk factors of hyperbilirubinemia.     

Temporary ECMO support following lung and heart-lung transplantation.

7 days) failure. Seven (78%) patients in the early group were weaned off ECMO and 5 (56%) survived to hospital discharge. In the late group, none of the patients could be weaned off ECMO, yielding 100% mortality. ECMO support instituted for pulmonary graft failure that occurred within 24 hours of transplantation may improve patient survival.