Antioxidant and antiprotease status in peripheral blood and BAL fluid after cardiopulmonary bypass

Objective: Cardiopulmonary bypass (CPB) triggers systemic inflammation. Rec ent evidence suggests that metabolic and oxygenation management can affect the outcome of patients after cardiac surgery. We investigated the influenc e of oxidant/antioxidant and protease/antiprotease imbalance during the cou rse of systemic and pulmonary inflammation. Methods: In a study of 61 patients, we measured the intracellular thiol con centration, the intracellular activity of cathepsins and elastase, and the concentrations of secreted elastase, soluble as-proteinase inhibitor (alpha (1)-Pl), and secretory leukoprotease inhibitor (SLPI). Peripheral blood an d BAL fluid (BALE) were obtained preoperatively and 2 h after CPB. Results: A post-CPB depletion of thiol was found in blood granulocytes, lym phocytes, and monocytes, as well as BALF lymphocytes and macrophages. The d egree of postoperative depletion correlated with Po-2 and blood glucose lev els during CPB. Concomitant reduction of FEV1 showed positive correlation w ith thiol depletion of blood monocytes and granulocytes. Elastase and cathe psin activities were increased in blood cells but not in lymphocytes or mac rophages from BALF. The concentrations of secreted elastase were significan tly increased in blood plasma but not in BALE. Enhanced antiprotease (alpha (1)-PI, SLPI) concentrations were measured in BALF but not in peripheral b lood. Conclusions: The inflammatory response of the intra-alveolar compartment is clearly distinguishable from systemic inflammation. CPB causes a different iated impairment of the antioxidant defense system as well as a protease/an tiprotease imbalance in blood and BALE Oxygenation under circumstances of C PB and concomitant pulmonary disease, as well as blood glucose metabolism, influence the antioxidative defense. Individual perioperative management of blood glucose and oxygenation could improve cellular defense systems in th e peripheral blood and BALF and therefore result in a more favorable patien t outcome.