Experimental study on the hemodynamic effects of veno-arterial extracorporeal membrane oxygenation with an automatically driven blood pump on puppies.

Hemodynamics, mainly the pressure of the heart, was studied while performing veno-arterial extra-corporeal membrane oxygenation (VA-ECMO) on 16 puppies between the right atrium and the right carotid artery with a unique ECMO circuit using an automatically driven blood pump. The resulting decrease in the mean pulmonary arterial pressure indicated a definite support of VA-ECMO on the volume work of the right heart. The right and left ventricular end-diastolic pressures decreased during the low flow bypass, but increased significantly with flow over 50 ml/min/kg. The results indicated biventricular pressure strain due to the increase in afterload. The left ventricular systolic pressure gradually increased despite the steady decrease in the systemic arterial systolic pressure when bypass flow exceeded 60 ml/min/kg. The findings were similar to those in peripheral circulatory insufficiency. The authors concluded that VA-ECMO flow should be kept as low as possible, in view of undesirable hemodynamic effects on both ventricles.