Veno-arterial extracorporeal membrane oxygenation (VA ECMO) in postcardiotomy cardiogenic shock: how much pump flow is enough?

Post-cardiotomy cardiogenic shock (PCCS) is a complication of heart surgery associated with a poor prognosis: veno-arterial extracorporeal membrane oxygenation (VA ECMO) ensures end-organ perfusion while fully replacing heart and lung function, though it is associated with unsatisfactory results. Few studies have identified reliable predictors of poor prognosis early in the course of extracorporeal support. A recent study showed the strong prognostic power of urine output in the first 24 hours of VA ECMO in predicting early and late mortality of PCCS. Urine output is a commonly collected parameter in all intensive care units (ICU) and has a defined role in the diagnosis of acute kidney injury (AKI) and is inexpensive. These findings offer the possibility to summarize some aspects regarding the adequacy of extracorporeal support early in the course of cardiogenic shock and to shed light about cardio-renal interactions in ECMO patients. Finally, it is our opinion that a timely implantation of mechanical circulatory support in post cardiotomy shock should be considered if systemic perfusion is not ensured by low or medium dose inotropic support and intra-aortic balloon counterpulsation.