Blood Damaging Effects in Cardiotomy Suction Return

(J. Extra-Corpor. Technol. 20[1]: p. 40–45, 44 references, Spring Issue) Over the past three decades improvements have been made to many of the components of the extracorporeal circulation system resulting in decreased blood damage. However, the cardiotomy suction return sub-circuit, recognized as one of the most injurious components of heart-lung bypass, has remained relatively unchanged. The purpose of this study was to investigate the amount of blood damage that occurred with different cardiotomy suction designs. The five test designs compared two different suction tips with various air-mixing techniques, in vitro. Significant blood damage was observed in the air-containing designs as compared to the airless and control circuits. A minimal flow rate capable of excluding air was demonstrated as being the most important factor for blood protection, irrespective of aspirator tip design.