RESUMO
BACKGROUND: An increase in total body water and the systemic inflammatory response occurs during cardiopulmonary bypass (CPB) which has resulted in the release of inflammatory mediators, including tumor necrosis factor-alpha (TNFalpha), interleukin-1beta, interleukin-6,and interleukin-8. These substances were suggested to be responsible for postoperative organ dysfunction and morbidity. Conventional ultrafiltration (cUF) and modified ultrafiltration (mUF) were used in cardiac operations to reduce volume overload and total body water. The purpose of this study was to estimate the value of these techniques in removing inflammatory mediators during CPB. METHODS: Serial plasma samples were taken before CPB,after 1 hour of CPB, just before cUF, after cUF, after mUF and 24 hrs after bypass. Cytokines were detected using highly specific double-ligand enzyme-linked immunosorbent assays. The data were analyzed using the repeated measurement ANOVA. RESULTS: TNFalpha, interleukin-1beta, interleukin-6, and interleukin-8 were increased during CPB and peaked just before cUF. After cUF, all four cytokines had been significantly decreased. After mUF,interleukin-6 and interleukin-8 had significantly been decreased, but TNFalpha and interleukin-1beta did not change significantly. After 24 hours of CPB , TNFalpha and interleukin-8 returned to preCPB values, but interleukin-1beta and interleukin-6 did not. CONCLUSIONS: We conclude that ultrafiltration has the potential to remove cytokines from the circulation. The ultrafiltration technique may be a useful technique in the management of patients undergoing bypass, particularly in patients at high risk of accumulating fluids and inflammatory reactions.