Interactions between veno-venous extracorporeal membrane oxygenation and cardiac function: an echocardiographic study upon weaning

Head-to-toe bedside ultrasound for adult patients on extracorporeal membrane oxygenation

Bedside ultrasound represents a well-suited diagnostic and monitoring tool for patients on extracorporeal membrane oxygenation (ECMO) who may be too unstable for transport to other hospital areas for diagnostic tests. The role of ultrasound, however, starts even before ECMO initiation. Every patient considered for ECMO should have a thorough ultrasonographic assessment of cardiac and valvular function, as well as vascular anatomy without delaying ECMO cannulation. The role of pre-ECMO ultrasound is to confirm the indication for ECMO, identify clinical situations for which ECMO is not indicated, rule out contraindications, and inform the choice of ECMO configuration. During ECMO cannulation, the use of vascular and cardiac ultrasound reduces the risk of complications and ensures adequate cannula positioning. Ultrasound remains key for monitoring during ECMO support and troubleshooting ECMO complications. For instance, ultrasound is helpful in the assessment of drainage insufficiency, hemodynamic instability, biventricular function, persistent hypoxemia, and recirculation on venovenous (VV) ECMO. Lung ultrasound can be used to monitor signs of recovery on VV ECMO. Brain ultrasound provides valuable diagnostic and prognostic information on ECMO. Echocardiography is essential in the assessment of readiness for liberation from venoarterial (VA) ECMO. Lastly, post decannulation ultrasound mainly aims at identifying post decannulation thrombosis and vascular complications. This review will cover the role of head-to-toe ultrasound for the management of adult ECMO patients from decision to initiate ECMO to the post decannulation phase.

Weaning from veno-venous extracorporeal membrane oxygenation: how I do it

Veno-venous extracorporeal membrane oxygenation (VV ECMO) is a rescue treatment for acute respiratory distress syndrome (ARDS) failing protective mechanical ventilation. It temporarily provides proper gas exchange: hypoxia is treated by adjusting the blood flow rate and fraction in spired oxygen over the ventilator (FiO2) on the extracorporeal membrane oxygenation (ECMO) circuit while CO2 removal is regulated by the ECMO fresh gas flow. Therefore, ventilator settings can be gradually reduced allowing the lungs to rest and recover. Nowadays, indications for ECMO referral and implantation are clearly formulated; on the contrary, little evidence currently exists to guide the process of weaning from ECMO support, especially concerning the timing during the course of lung healing. Therefore, indications to stop ECMO are less well standardized so that in clinical trials extracorporeal assistance is generally continued until lung recovery, with neither specific nor homogenous criteria for withdrawal. Notably, in almost all papers dealing with data on VV ECMO support, the management of weaning and the weaning procedure itself are not described. The aim of this paper is to make a picture of VV ECMO weaning, as it is performed in three European large volume intensive care units (ICUs) which represent referral centers for VV ECMO treatment. We focused on data concerning the timing of VV ECMO weaning and parameters at the time of weaning, in order to assess adequacy and safety of VV ECMO removal.