Definition
“ECMO” stands for extracorporeal membrane oxygenation and is a cardiological and intensive care medical procedure for the relief or replacement of lung and possibly also heart function. The reason for the use of ECMO is serious lung dysfunction, such as ARDS (acute respiratory distress syndrome) in adults or respiratory distress syndrome in newborns. In ECMO, blood is drained from a vein (a blood vessel with a low oxygen content), transported through a tube system into a device, where it is filtered through a kind of membrane, enriched and then returned to the human circulation through another tube system.
Indications for an ECMO
Causes for the application of extracorporeal membrane oxygenation are all diseases or changes that restrict the lung in its function to such an extent that there is no longer sufficient gas exchange and thus the risk of oxygen deficiency in the body (hypoxia). The most common indication for ECMO is the so-called ARDS (acute respiratory distress syndrome). ARDS can be triggered by a variety of factors, such as blood poisoning, shock, burns or injuries and manifests itself through a kind of inflammatory reaction within the lung tissue.
Oedema formation (water retention) occurs, resulting in limited gas exchange. Other common causes for the use of an ECMO are resuscitations, lung transplantation, hypothermia or severe pneumonia. ECMO is also frequently used for newborns.
The main causes are neonatal respiratory distress syndrome (IRDS), meconium aspiration (penetration of stool into the lungs) and blood poisoning. In contrast to adults, significantly higher survival rates (approx. 80%) are achieved in the newborn. For the application of ECMO the affected persons are put into an artificial coma.
How does the therapy with ECMO work?
In the most common type of cannula system used in extracorporeal membrane oxygenation, the great inguinal vein (vena femoralis) is used as the outflow vessel and the deep cervical vein (vena jugularis interna) as the inflow vessel. When creating ECMO, the respective vein is first punctured with a larger needle. Once the vessel has been hit, a thin wire is inserted and advanced sufficiently far.
After the skin has expanded, if necessary, a tube is inserted into the vessel along the wire and then sutured to the skin. In the case of the deep jugular vein, this tube usually extends into the right atrium of the heart. In addition to the veno-venous ECMO system, there is also veno-arterial (VA) and the somewhat rarer arterial-venous (AV) extracorporeal membrane oxygenation. In the context of resuscitations, the placement of cannulas in the periphery (area away from the body), for example in the groin, has proven to be particularly effective, as this does not interrupt or hinder resuscitation.
