Files
Abstract
In order for vacuum assisted venous return to be used safely and efficiently, a full understanding of venous return is necessary. Through the use of the concepts of conservation of energy and viscous energy dissipation, a theoretical model of venous return utilizing vacuum assist has been developed in this work. The effectiveness and accuracy of this model has been verified through in vitro laboratory investigations and statistical analysis. In summary, the developed model accurately predicts flow rates given cannula size, amount of vacuum applied, and circuit dimensions. Although vacuum assisted venous return can provide higher flows through smaller cannula, vacuum assist can lead to increased levels of shear stress that the blood is exposed to as well as an increased likelihood of cavitation in the venous line. Both of which may lead to an exacerbation of the detrimental effects of cardiopulmonary bypass.