Extracorporeal membrane oxygenation (ECMO), also known as extracorporeal lung support (ECLA), is an intensive care therapy procedure that can support or take over cardiac and pulmonary function in children and adults.
The procedure is used as a temporary cardiac support (temporary support of cardiac function), in severe hypoxemic lung failure and as a low-flow system in leading hypercapnic respiratory failure (e.g. due to acute exacerbated chronic obstructive pulmonary disease (COPD), i.e. significant worsening of the symptoms of the disease).
Note: A distinction is made between acute hypoxemic respiratory failure as acute respiratory insufficiency type I and hypercapnic failure as acute respiratory insufficiency type II.
Respiratory insufficiency is a disorder of oxygenation (saturation of tissues with oxygen) in which the partial pressure of oxygen in arterial blood decreases, but the partial pressure of carbon dioxide can still be compensated. In hypercapnic respiratory insufficiency, both the partial pressure of oxygen and the partial pressure of carbon dioxide are pathologically (abnormally) altered.
Indications (areas of application)
- Early use of veno-venous ECMO (VV-ECMO: see procedure below) in severe ARDS (“acute respiratory distress syndrome”; adult respiratory distress syndrome).
- Low-flow ECMO/ECCO2R in hypercapnic respiratory failure (due to acute exacerbated chronic obstructive pulmonary disease (COPD)).
In severe ARDS with a PaO2/FiO 2 below 80 mmHg, contact should be made with a treatment center.
Conditions that may require extracorporeal membrane oxygenation are ARDS, COVID-19, and cardiogenic shock.
The procedure
The main forms of ECMO are venovenous ECMO (VV-ECMO), venoarterial ECMO (VA-ECMO), and pumpless arterio-venous ECLA (pECLA).
In the first two forms, blood is drawn from the major veins (e.g., femoral vein or internal jugular vein).
In VV-ECMO, the oxygenated blood (enriched with oxygen) is returned to a vein. There are now also double lumen cannulas with which blood is simultaneously withdrawn from the vein and returned. In this case, only a single puncture of the right internal jugular vein (“internal jugular vein”; vein of the neck) is necessary. This form of therapy is used in severe lung failure with still sufficient pumping function of the heart.
In patients with heart failure (cardiac insufficiency) with reduced ejection fraction (ejection fraction), venoarterial ECMO (VA-ECMO) is used to relieve the heart. This drainage is performed via a venous cannula inserted from the right atrium. The oxygenated blood is then returned retrogradely (“retrograde”) to the circulation via the aorta through an arterial cannula. VA-ECMO is thus a cardiac support system, which is used in cardiology as well as in patients with severe cardiogenic shock (e.g., infarct-related cardiogenic shock (ICS))
Pumpless arteriovenous ECLA (pECLA) is used in patients with adequate cardiac function when they require less gas exchange support. The procedure results in less blood damage because no pump is used.
ECMO systems from a rotary blood pump and an oxygenator (device that oxygenates blood). The oxygenator is equipped with a polymethylpentene membrane that allows gas exchange without transfer of corpuscular (“blood cell”) or fluid components of the blood.
Note: Early indication should always be made with an experienced treatment center!
