There are two types of ECMO:
Venous Arterial (VA) ECMO
Venous Venous (VV) ECMO
In VA ECMO, a catheter is placed in the vein on the right side of the neck which removes un-oxygenated blood from the body. A second catheter is placed in the artery on the right side of the neck which returns oxygenated blood from the ECMO circuit to the body.
In VV ECMO, a single catheter is placed in a vein. VV ECMO only provides support for the lungs, whereas VA provides support to the heart and the lung.
ECMO blood flow is maintained at a sufficient rate to adequately perfuse the patient and allow "rest" of the heart and lungs. In most infants, this can be achieved at flows of 80% of the required cardiac output.
ECMO is also maintained at a level such that adequate oxygen delivery is achieved for patient needs. These oxygenation needs may change from time to time, depending on the patient's condition.