IS IT TRUE THAT CARDIAC OPERATIONS WITH CARDIOPULMONARY BYPASS IMPAIRTHE RETICULOENDOTHELIAL SYSTEM

Reticuloendothelial system (RES) function after cardiac operations is a controversial issue. Sequential changes in plasma fibronectin levels and RES phagocytic function were studied after a cardiac operation an d a lung operation (control). In the cardiac operation group, the plas ma fibronectin level decreased until the third postoperative day and i ncreased thereafter. Reticuloendothelial system phagocytic function re mained unchanged on the third postoperative day and then it increased. However, in the control group it increased significantly after operat ion. In the past, investigators have demonstrated a decline in plasma fibronectin levels following cardiac operation and have assumed that R ES function was impaired. However, this sequential study showed that p hagocytic function was not impaired, but its enhanced phase was delaye d. Moreover, our previous morphologic studies demonstrated that RES fu nction was potentially activated after cardiopulmonary bypass. It appe ars that the delay of the enhanced phase is caused by the overloading of substances which must be processed by the RES during cardiopulmonar y bypass. Thus, we conclude that cardiac operation produces hyperactiv e, yet oversaturated RES function. There is no impairment of RES funct ion after cardiac operations.