Venous reservoirs are interposed between the patient and the arterial pump and serve to remove air bubbles and provide compliance that accommodates variations in the volume of blood circulating in the extracorporeal circuit during cardiopulmonary bypass (CPB). The invention is a reservoir that incorporates automated means to remove air bubbles from the venous line prior to the blood entering the arterial blood pump. In another form, the reservoir includes means that handles foam prior to the blood entering the blood pump. In yet another form, the invention is means that improve air removal in a soft shell venous reservoir. These features are applicable to CPB circuits using gravity drainage or vacuum assisted venous drainage.