Cardiac surgery elicits a cascade of stress responses mediated by the release of various cytokines and stress hormones (Roth-Isigkeit 1998). Apart from the stress induced by the surgical process, cardiopulmonary bypass (CPB) has been documented to play a major role in the perioperative stress response seen following cardiac surgery (Butler 1993, McBirde 1995, Hall 1997). The imbalance in pro- and anti-inflammatory responses may affect outcome in cardiac surgery patients (Casey 1993, McBride 1995, Menasche 1995). The deleterious effects of CPB were secondary to the exposure of blood to abnormal surfaces in the bypass circuit which initiated a "Whole body inflammatory response" (Kirklin 1983).