Effective hepatic blood flow during cardiopulmonary bypass

Hepatic dysfunction following cardiopulmonary bypass (CPB) is a relatively frequent finding, and jaundice occurring after CPB is associated with an increased mortality rate. Post-CPB jaundice may be a consequence of inadequate liver perfusion during CPB. To evaluate the potential impact of CPB on effective hepatic blood flow, 10 patients undergoing CPB for cardiac procedures were studied. Effective hepatic blood flow was measured in each patient during the operative procedure but before institution of CPB and during CPB as well. Effective hepatic blood flow was measured by the galactose clearance technique. Blood lactate and pyruvate levels were also measured before and during CPB. During CPB, effective hepatic blood flow was consistently reduced by an average of 19%. Although for most patients this reduction seems well tolerated, in a minority of patients it may contribute to postoperative hepatic dysfunction.