Weaning from veno-arterial extra-corporeal membrane oxygenation: which strategy to use?

Abstract

Refractory cardiogenic shock patients may be rescued by veno-arterial extracorporeal membrane oxygenation (VA ECMO). After a few days of mechanical assistance, the device can sometimes be successfully removed if the patient has partially or fully recovered from the condition that required the use of ECMO. The percentage of patients with refractory cardiogenic shock who are successfully weaned from ECMO varies from 31% to 76%. Weaning does not mean survival, because 20% to 65% of patients weaned from VA ECMO support do not survive to hospital discharge. The high death rate after successful weaning shows that many questions remain unresolved in this field. In this review, we will discuss the various factors influencing survival and a successful weaning from VA ECMO, in addition to weaning approaches proposed in the literature. Based on this information, we will propose a strategy to optimize the weaning process.

Keywords: Veno-arterial extracorporeal membrane oxygenation (VA ECMO); echocardiography; weaning.

Figure 1

Useful echocardiographic parameters. LV, left ventricle; RV, right ventricle; RA, right atrium.

Figure 2

Proposed algorithm for successful weaning from VA ECMO. MAP, mean arterial pressure; VTI, velocity-time integration; LVEF, left ventricular ejection fraction; TDSa, Tissue Doppler lateral mitral annulus peak systolic velocity; RV, right ventricle; CI, cardiac index; PCWP, pulmonary capillary wedge pressure; CVP, central venous pressure.