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Adult ECMO Simulator

The effect of afterload on pump flow during VA ECMO.

Effect Of Afterload

The data above were acquired from a virtual patient on stable VA ECMO. The patient is being perfused through a 21 F return cannula at 3200 rpm. During the course of the simulation, the supervisor has manipulated the patient's SVR so that the mean arterial pressure varies between 60 and 130 mm Hg.

As mean pressure ('Afterload') increases, so delivered flow decreases. This is an illustration of the 'Afterload Dependence' of (non-occlusive)centrifugal pumping systems and can be contrasted with the behaviour of (volumetric) roller pumps.

Unless obstruction to outflow occurs, afterload dependence is usually not an issue in patients being treated with VV ECMO.