Critical illness with severe pulmonary or cardiac failure is associated with high mortality. Advances in lung-protective strategies and cardiac assist devices have helped to improve survival for patients with lung or heart failure. Mortality rates can be as high as 30 to 40% for patients with ARDS (adult respiratory distress syndrome) and 50% for patients with cardiac failure. In patients who do not respond to traditional treatment algorithms, few options exist for rescue therapy.
Extracorporeal membrane oxygenation (ECMO) is a mechanical support system that provides life support through the use of a modified heart-lung machine to support gas exchange; this allows time for damaged heart or lungs to heal while "resting" the damaged organs from the effects of mechanical ventilation and inotropic drugs. ECMO is an intensive treatment that is currently used in many specialized centers to support patients with respiratory or cardiac failure who are unresponsive to conventional therapeutic interventions
Most children and adults treated with ECMO are very ill and at risk of death. Some causes of respiratory failure in neonates include respiratory distress syndrome (hyaline membrane disease), meconium aspiration syndrome, and congenital diaphragmatic hernia. Some causes of respiratory and cardiac failure in post-neonatal children (at least one month old) and adults include pneumonia, septic shock, congenital heart disease, cardiomyopathy, severe burns, and pulmonary hemorrhage. Contraindications to ECMO include overt central nervous system damage, sepsis, or other profoundly debilitating conditions that are considered incompatible with a normal life. Conventional methods of treating respiratory failure include pharmacologic treatment, supplemental oxygen and mechanical ventilation, which may further damage the lung and contribute to the increased morbidity and mortality associated with chronic pulmonary disease.
Severe pulmonary graft failure (PGF) is the most common cause of death within the first 30 days after lung transplantation. ECMO may provide lifesaving temporary support after lung transplantation. When cardiopulmonary bypass is discontinued the transplanted lungs are exposed to the cardiac output, which can lead to a negative effect on early allograft function, and the need for aggressive mechanical ventilation with high tidal volumes and pressures. All these factors can be avoided by the use of intra- and post-operative ECMO support.