We read with interest this succinct review by Keller (1), published in the recent issue of Critical Care Medicine, on the application of peripheral venoarterial extracorporeal membrane oxygenation (ECMO) in cardiogenic shock, the intricate physiologic challenges which arise with its institution, and its lack of definitive guidelines. We note that areas of concern include how to “dose” mechanical circulatory support appropriately, and agree that its titration is difficult. Each patient with cardiogenic shock being supported with venoarterial ECMO is unique, which is why an individualized, patient-centered approach is inevitable, and guidelines are difficult to prescribe.