Neonatal intensive care

Background: Extracorporeal membrane oxygenation (ECMO), originally developed as an artificial replacement for respiratory assistance, is decreasingly used in neonates with respiratory failure. Nevertheless, there is a constant need for this invasive and expensive neonatal treatment modality. Intervention: Review of our experience (80 recent ECMO performances because of circulatory failure) and the literature. Results: In contrary to reduced ECMO performances out of respiratory insufficiency in neonates, ECMO as circulatory support is increasingly used. Neonatal sepsis, preand postoperative cardiac failure, combined circulatory and respiratory failure after resuscitation and with congenital diaphragmatic hernia result in a permanent need for ECMO, whenever there are fewer ECMO treatments per year. Nonocclusive pumps, portable devices, small priming volumes and tapered anticoagulation protocols enable survival through ECMO even in virtually hopeless hernodynamic conditions. Special efforts in investigation and prevention of permanent neurological impairment, esspecially after severe pre-ECMO hypoxia seem to be mandatory. Conclusion: ECMO remains an important tool in neonatal and pediatric intensive care. However, the number of ECMO therapies was reduced due to respiratory therapeutic progress, but indications and ECMO technology have changed. Background and technical remarks Indications, techniques and outcome of ECMO therapy, originally developed as replacement for respiratory assistance by Bartlett (l), have changed a lot during the past years. In the beginning of ECMO an occlusive roller pump drained blood from right ventricle. The roller pump was servocontrolled by means of a collapsible bladder positioned at the venous line. Thus, excessive suction and negative pressure, with the risk of cannular collapse and air embolism was avoided. Blood was pumped into the oxygenator, which was used as heat exchanger as well, or a heat exchanger was connected distally. It was possible to combine a hemofilter with the oxygenator, if necessary. Blood was returned mostly via filter into arteria carotis communis. Obstruction of backleading cannula produces high pressures in tubing system with the risk of rupture. Mechanical stress in centrifugal blood pump also enlarges the risk of rupture. The advantage of an occlusive system is the possibility of stable management of blood flow and therefore sure oxygenation. Arteria carotis communis was necessary for reinfusion of blood. To minimize adverse effects the artery was restored after ECMO was finished, or venovenous ECMO was promoted to avoid arterial cannulation. Following that strategy Chevalier, in Paris, developed a "single needle tidal flow ECMO (he named it AREC assistance respiratoire extracorporeal membrane oxygenation corporelle) (2). Only one venous cannulation is necessary, and the risk of rupture and air embolism is therefore diminished by using a nonocclusive roller pump. Necessary anticoagulation is applied to a lower degree (Antithrombin Clotting Time 150-180 seconds). Using a blood flow of only 50% of cardiac output combined with a kind of intratracheal ventilation he was able to treat neonates with respiratory failure effectively.