Oxidative stress and inflammatory response increase during coronary artery bypass grafting with extracorporeal circulation

introduction: thiobarbituric acid-reactive substance is a marker of oxidative stress and has cytotoxic and genotoxic actions. c- reactive protein is used to evaluate the acute phase of inflammatory response. objectives: to assess the thiobarbituric acid-reactive substance and c-reactive protein levels during extracorporeal circulation in patients submitted to cardiopulmonary bypass. methods: twenty-five consecutive surgical patients (16 men and nine women; mean age 61.2 ± 9.7 years) with severe coronary artery disease diagnosed by angiography scheduled for myocardial revascularization surgery with extracorporeal circulation were selected. blood samples were collected immediately before initializing extracorporeal circulation, t0; in 10 minutes, t10; and in 30 minutes, t30. results: the thiobarbituric acid-reactive substance levels increased after extracorporeal circulation (p=0.001), with average values in t0=1.5 ± 0.07; in t10=5.54 ± 0.35; and in t30=3.36 ± 0.29 mmoles/mg of serum protein. the c-reactive protein levels in t0 were negative in all samples; in t10 average was 0.96 ± 0.7 mg/dl; and in t30 average was 0.99 ± 0.76 mg/dl. there were no significant differences between the dosages in t10 and t30 (p=0.83). conclusions: c-reactive protein and thiobarbituric acid-reactive substance plasma levels progressively increased during extracorporeal circulation, with maximum values of thiobarbituric acid-reactive substance at 10 min and of creactive protein at 30 min. it suggests that there are an inflammatory response and oxidative stress during extracorporeal circulation.