Extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is prolonged cardiopulmonary bypass used to treat critically ill patients with severe but reversible cardiac and/or respiratory failure. The severity of their symptoms, the rapid deterioration in their conditions, the difficulty in mechanical transportation, and the risks of traveling with an ECMO circuit often prohibit cannulation in an operating room. Cannulation for and decannulation after ECMO therapy can be safely accomplished in the intensive care unit by utilizing experienced perioperative nurses.     

Extracorporeal membrane oxygenation in myocardial failure after pediatric heart surgery

In spite of progressive improvement not only in myocardial protection but also in anesthetic and surgical techniques, the repair of complex congenital heart defects can still lead to cardiopulmonary compromise refractory to conventional treatment. We describe two patients in whom successful surgical repair of congenital heart defects was followed by severe heart failure refractory to medical treatment. Both patients were managed by extracorporeal membrane oxygenation (ECMO). We discuss the indications, contraindications and use of ECMO in the postoperative intensive care unit.     

Extracorporeal membrane oxygenation for cardiac support in children

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) support for cardiac failure has been used in children since 1981 at the Children's Hospital in Pittsburgh. Most children required support after cardiac operations. Recently, however, a larger number of patients with decompensated cardiomyopathy or myocarditis have been supported with ECMO, which was used as a bridge to transplantation in most. METHODS: From 1981 to 1994, 68 children were placed on ECMO for cardiac support. RESULTS: The overall survival for the entire time period was 38%, with the more recent experience survival increased to 47%. In 14 children, ECMO was used as a bridge to transplantation, with 9 children receiving a heart transplant and 7 long-term survivors. Extracorporeal membrane oxygenation has also been used to resuscitate 11 children after sudden cardiac arrest, with a long-term survival of 53%. CONCLUSIONS: We conclude that ECMO support for severe cardiac failure is effective. Patient selection and the use of heart transplantation for intractable heart failure have improved the overall survival.     

Extracorporeal membrane oxygenation for acute respiratory failure induced by Legionella pneumoniae. (Case report)

We report a case of severe legionella pneumonia with acute respiratory failure, successfully managed with veno-venous extracorporeal membrane oxygenation (VV-ECMO). The patient presented with 4-day history of fever and cough. He was in critical condition, with exacerbated respiratory failure. Mechanical ventilation, volume replacement and antibiotic therapy were initiated. Despite increasing mechanical ventilatory support (FiO2 100%, TV 10 ml/kg, f 30/min, PEEP 5 cmH20), PaO2 fell below 40Torr and life sustaining measures were undertaken. VV-ECMO (flow 30 ml/kg/min) was commenced, and the patient responded well, with an elevation of PaO2. Erythromycin therapy was effective against the pneumonia. VV-ECMO was maintained for 92 hours, mechanical ventilation was successfully discontinued 11 days after and the patient was discharged 82 days after cessation of ventilator support. Serum antibody examination proved legionella infection. VV-ECMO may have a role in the management of patients with acute respiratory failure caused by bacterial pneumonia.     

Extra-corporeal membrane oxygenation for paediatric respiratory failure

Extracorporeal membrane oxygenation (ECMO) uses modified cardiopulmonary bypass technology to provide prolonged respiratory or cardiorespiratory support for patients of all ages who have failed conventional intensive care management. The use of ECMO for neonatal respiratory failure is now evidence-based following the publication of the randomised UK Collaborative Trial. ECMO use in children remains more controversial, but overall survival of 71% is possible in a group of moribund patients whose mean PaO2/FIO2 ratio of 61 mmHg accurately predicts death in studies of conventional ventilation. Common diagnoses for children requiring ECMO support are pneumonia and the acute respiratory distress syndrome (ARDS).     

Extracorporeal membrane oxygenation. Controversies in selection of patients and management

Laser tissue welding is a technologic innovation that is beginning to move from the theoretical laboratory environment to the reality of clinical application. This article reviews the concepts, potential advantages, and techniques involved in laser tissue welding as they apply to urology.     

Extracorporeal support of oxygenation and ventilation

The management of the patient with respiratory failure is instituted in step-wise fashion. Each successive step requires higher levels of intervention. The final level of support when all conventional means fail is the use of ECMO. The specific method of extracorporeal support may or may not be important in determining ultimate outcome. However, the means of ventilator support during extracorporeal support is controversial. No study has shown a beneficial effect of one method over another. The avoidance of further barotrauma and high oxygen concentration is the keystone to individual ventilator management. The method of introducing extracorporeal devices on to a patient's cardiovascular circuit varies. The technical aspects differ from institution to institution and may reflect surgeon preference. However, all methods are relatively quick and efficient. The amount of personnel needed to manage an extracorporeal circuit varies from institution to institution but nonetheless requires extra people and equipment. The cost of instituting this type of therapy is high. And, although the cost efficiency of ECMO has not been closely analyzed, it is hoped that the judicious use of this technology will produce a favorable result.     

Extracorporeal membrane oxygenator support for cardiopulmonary failure. Experience in 28 cases

We have used extracorporeal membrane oxygenation (ECMO) for 28 patients (14 children and 14 adults) over a 5 year period. Nine patients improved on ECMO and 5 were long-term survivors. ECMO was used for pulmonary insufficiency in 24 patients. Initially, only moribund patients were treated, but recently the combination of open lung biopsy and pulmonary insufficiency index (PII) has been used to select patients. The best results have been obtained in newborn cases and the adult capillary leak syndromes; the major problem has been progression to fibrosis despite ECMO support. ECMO was used for cardiac failure in 4 patients. Children with postoperative cardiac failure did the best; profound shock was not reversed with venoarterial bypass. ECMO support is lifesaving in selected cases of pulmonary insufficiency. Initial trials in cardiac failure and the infant age group in this series suggest that ECMO will have an even greater role in those applications.     

Extracorporeal membrane oxygenation in neonatology: review of the use of the method

Extracorporeal life support and extracorporeal membrane oxygenation characterize the use of mechanical devices for temporary support of heart and lung function. The mechanical circuit consists of a blood pump (heart), membrane oxygenator (lung: which accomplishes both carbon dioxide removal and oxygen delivery), heat exchanger and a servo-control module. Venous blood is drained from the right atrium through the right internal jugular vein, and returned oxygenated through either the right common carotid artery (venoarterial bypass), or into a large vein (venovenous bypass). All patients treated must be free of coagulopathies, as all patients are anticoagulated. Neonatal candidates should be older than 34 weeks gestational age and weigh more than 2000 grams. As of March, 1997 twenty six patients have been treated with extracorporeal life support at Tulane Medical Center with an overall survival rate of 62%. Twelve neonates with either meconium aspiration or pneumonia have been treated with a 100% survival. Six children with congenital diaphragmatic hernia have been unsuccessfully treated.     

Extracorporeal membrane oxygenation with heparin-coated systems in a 13-month-old infant with acute hypoxic respiratory failure after correction of tetralogy of Fallot

Hemorrhagic disorders due to systemic heparinization are frequent during extracorporeal lung support (veno-venous extracorporeal membrane oxygenation: vv-ECMO). The development of heparin-coated systems has reduced the need for high-dose heparinization. Whereas the use of these heparin-coated membrane lungs and tubings has been described in former studies in adults, only few reports exist in children. This case report describes the application of a heparin-coated extracorporeal system for long-term vv-ECMO in a 13-month-old infant suffering from acute hypoxic respiratory failure after correction of tetralogy of Fallot. Only moderately elevated levels of activated clotting time (ACT, 120-160 s) and activated partial thromboplastin time (aPTT, 40-60 s) were necessary to avoid thrombotic events in the extracorporeal system. Thoracotomies were performed twice without bleeding complications by discontinuation of the systemic heparinization. We conclude that the use of heparin-coated membrane lungs in infants may improve the safety of extracorporeal lung support and permits surgical intervention without major risk of bleeding.     

Extracorporeal membrane oxygenation. Will this therapy continue to be as efficacious in the future?

The efficacy of ECMO has been discussed. If only a dichotomous live/die outcome is used as a measure of utility, ECMO is efficacious for infants with a greater than 20% mortality rate. Using a Bayesian approach and neonatal follow-up data, one concludes that ECMO, as used at present, is effective. Future measures of efficacy will vary depending on utility measures used, the populations studied, and the relative efficacy of alternative therapies.