Objective: Cardiopulmonary bypass (CPB) triggers
systemic inflammation. Recent evidence suggests that metabolic and
oxygenation management can affect the outcome of patients after cardiac
surgery. We investigated the influence of oxidant/antioxidant and
protease/antiprotease imbalance during the course of systemic and
Methods: In a study of 61
patients, we measured the intracellular thiol concentration, the
intracellular activity of cathepsins and elastase, and the
concentrations of secreted elastase, solubleα
1-proteinase inhibitor (α1-PI), and
secretory leukoprotease inhibitor (SLPI). Peripheral blood and BAL
fluid (BALF) were obtained preoperatively and 2 h after CPB.
Results: A post-CPB depletion of thiol was found in blood
granulocytes, lymphocytes, and monocytes, as well as BALF lymphocytes
and macrophages. The degree of postoperative depletion correlated with
Po2 and blood glucose levels during CPB.
Concomitant reduction of FEV1 showed positive correlation
with thiol depletion of blood monocytes and granulocytes. Elastase and
cathepsin activities were increased in blood cells but not in
lymphocytes or macrophages from BALF. The concentrations of secreted
elastase were significantly increased in blood plasma but not in BALF.
Enhanced antiprotease (α1-PI, SLPI) concentrations were
measured in BALF but not in peripheral blood.
Conclusions: The inflammatory response of the
intra-alveolar compartment is clearly distinguishable from
systemic inflammation. CPB causes a differentiated impairment of the
antioxidant defense system as well as a protease/antiprotease imbalance
in blood and BALF. Oxygenation under circumstances of CPB 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 the peripheral blood and BALF and therefore result
in a more favorable patient outcome.