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 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 oxygenation for nonneonatal pulmonary and multiple-organ failure

PURPOSE: Extracorporeal membrane oxygenation (ECMO) is an accepted therapy for neonatal pulmonary failure, but its use in older children has been controversial. METHODS: Over 13 years, 55 children (ages, 3 months to 16 years) were treated with venoarterial or venovenous ECMO. The diagnoses were viral, bacterial, or fungal pneumonia (24 patients); hydrocarbon or gastric aspiration (n = 10); adult respiratory distress syndrome (ARDS), sepsis, near drowning (n = 15); pulmonary contusion (n = 2); airway obstruction (n = 3); pulmonary artery foreign body (n = 1). Pre-ECMO blood gas ranges (and means) were PO2, 21 to 100 (n = 44); PCO2, 23 to 125 (n = 72); pH, 6.81 to 7.55 (n = 7.11). RESULTS: All patients received inotropes, and 38 required dialysis or hemofiltration. ECMO was used for 20 to 613 hours (mean, 196 hours). Patient complications included cannulation site hemorrhage (n = 40), renal failure (n = 10), seizures (n = 8), stroke (n = 3), and cerebral hemorrhage (n = 2). Twenty-five patients (45%) survived ECMO, with 21 long-term survivors (10 pneumonia, five aspiration, five ARDS, one pulmonary contusion), five of whom have mild to moderate neurological deficit. Patients with combinations of pulmonary, cardiac, and renal failure, or sepsis did not survive. CONCLUSIONS: ECMO is an invasive technique that can be life saving in the child with isolated respiratory failure, but its usefulness in children with multiorgan failure is less certain.     

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. 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 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 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.     

Successful extracorporeal membrane oxygenation (ECMO) support for fulminant community-acquired pneumococcal pneumonia

A case is described of fulminant community-acquired pneumococcal pneumonia in a 16 year old girl with no previous history of respiratory disease or any predisposing factors. She required extracorporeal membrane oxygenation (ECMO) until the diagnosis could be made and appropriate antibiotic therapy established.     

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.     

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).     

Cardiac oxygenation by extracorporeal membrane oxygenation in exteriorized fetal lambs

Inhibitors of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase, such as Simvastatin and Lovastatin, reduce the rate of DNA synthesis and proliferation of a wide variety of cell types in vitro, by inducing a cell cycle arrest in G1. In estrogen-free medium, DNA synthesis is reduced by more that 90% following exposure of normal and transformed human breast epithelia] cells to 20 microM Simvastatin or Lovastatin for 24 to 42 hrs. We show here that stimulation of estrogen responsive MCF-7 cells with nanomolar concentrations of 17beta-estradiol (E2) prevents inhibition of DNA synthesis by these compounds. The effect of the hormone is antagonized by both steroidal and non steroidal antiestrogens, and it is not detectable in estrogen receptor-negative MCF-10a cells. Cell cycle analysis demonstrates that HMG-CoA reductase inhibitors are unable to induce G1 arrest of MCF-7 cells in the presence of E2.     

Extracorporeal shock wave lithotripsy in children

An experience with 103 children treated with extracorporeal shock wave lithotripsy (ESWL) is reviewed in this report. The success rate was 63%. The stone volume was of major importance for the result. There was a continuous decrease in success rate with increasing stone size. It was also shown that stone-free rates decreased with an increasing number of stones. Short-term complications were minor and hospitalization times were short. It is concluded that ESWL is a first-choice treatment in children with urinary calculi smaller than 200 mm2 in size.     

Extracorporeal support for intractable cardiorespiratory failure due to meningococcal disease

BACKGROUND: Meningococcal disease is still associated with considerable mortality, despite the use of early antibiotics and management in specialised intensive care units, due principally to early refractory myocardial depression and hypotension as well as severe acute respiratory distress syndrome. Extracorporeal membrane oxygenation (ECMO) is a complex technology that uses a modified "heart-lung" machine to provide temporary cardiac and respiratory support. We reviewed the UK and Australian experience of the use of ECMO in patients with refractory cardiorespiratory failure due to meningococcal disease. METHODS: The records from all 12 known patients supported with ECMO for meningococcal disease in the UK and Australia since 1989 were reviewed. FINDINGS: 12 patients (aged 4 months to 18 years, median 26 months) with meningococcal disease received ECMO over 8 years. In seven patients, ECMO was required early for cardiac support for intractable shock within 36 h of admission to intensive care. In the other five patients, ECMO was indicated for respiratory failure due to severe adult respiratory distress syndrome, which tended to occur later in the disease. The paediatric risk of mortality score ranged from 13 to 40 (median 29, median predicted risk of mortality 72%). Six of the 12 patients required cardiopulmonary resuscitation before ECMO and the other six were deteriorating despite maximal conventional therapy. Overall, eight of the 12 patients survived, with six leading functionally normal lives at a median of 1 year (range 4 months to 4 years) of follow-up. INTERPRETATION: ECMO might be considered to support patients with intractable cardiorespiratory failure due to meningococcal disease who are not responding to conventional treatment.