The Effects of Anesthetic Management on Oxidative Injuries After Cardiopulmonary Bypass

Ischemia- reperfusion ( IR ) injuries were not only seen in the transplanted organs but also the remote organs such as lungs that brings major postoperative complications. Severe complications such as pulmonary infiltration and pulmonary edema following reperfusion were frequently associated with liver transplantation. Cardiac surgery performed with the use of cardiopulmonary bypass ( CPB ) provokes a systemic inflammatory response syndrome that affects postoperative pulmonary, myocardiac and renal functions. Previous study about the reperfusion injuries was focused on the leukocyte and endothelial activation and the following oxidative injuries, however, the alteration on pulmonary function such as dynamic compliance and the oxidative/antioxidative balance in erythrocytes and the following effects in CPB have not been fully studied. Erythrocytes' reaction to oxidative stress including cytoplasma and cell membrane should be studied because RBCs are the major circulating blood cells having different types of antioxidant system to capture reactive oxygen species ( ROS ) thus RBC may be severely injured by ROS or protected ROS injuries during CPB. In these three-year study, we plan to explore the extent and pattern of remote oxidative injuries in lungs by massive ROS production and the following products released from reperfused organs. In the first year, the remote pulmonary injuries from hepatic IR will be focused. We plan to establish an animal model for pulmonary function and pulmonary injury assessments including dynamic compliance (Cdyn), pulmonary edema wet-to-dry ratio (W/D), malondialdehyde (MDA) and histopathological findings under hepatic IR challenge. In the second year, the IR effects during and after CPB on circulating blood cells will be fully studied. We plan to investigate the magnitude, subtypes and timing on ROS production, the changes of oxidative and antioxidant activities of erythrocytes including cytoplasma and cell membrane, the changes on leukocytes and plasma to explore the roles of circulating erythrocytes on oxidative stress in CPB. In the third year, we plan to try propofol, stated having antioxidant in vivo and in vitro, on the remote pulmonary injuries following hepatic IR and CPB.