Great question! You are referring to ECMO. The main limitations of ECMO come from the serious complications that can occur, which can include life-threatening bleeding, blood clots, infections, strokes, and brain damage. The number of hospitals in the US offering ECMO is in the low hundreds. It takes an experienced team to use it safely, and if used in the wrong patients, it can artificially prolong suffering rather than saving a life. However, it is still an amazing technology for some patients.