Hemodynamics and Extracorporeal Circulation

Abstract

Peripheral veno-arterial membrane oxygenation (PVA-ECMO) is increasingly used as first-line therapy during refractory cardiogenic shock. It is responsible for striking changes in patient’s hemodynamics. They are mostly related to the retrograde direction of the ECMO blood flow in the aorta, responsible for a massive increase in cardiac afterload and a massive reduction in the residual stroke volume of the native heart. Both effects put the patient at risk for pulmonary edema and blood stagnation in the heart, which can be lowered by setting the lowest possible ECMO blood flow, maintaining inotropes and diuretics, and eventually combining an intra-aortic balloon pump to ECMO support. Compared to PVA-ECMO, central cannulation has a more physiological blood flow direction, responsible for less increase in cardiac afterload, and better left ventricular unloading. Restoring a normal pulsatility under ECMO remains debated, both for its effects on systemic vascular resistances and on microcirculation.