Effects of dopexamine on creatinine clearance, systemic inflammation, and splanchnic oxygenation in patients undergoing coronary artery bypass grafting

Impairment of splanchnic and peripheral tissue perfusion during cardiopulmonary bypass (CPB) may be responsible for endotoxin-mediated systemic inflammation and acute phase responses. We examined the effects of dopexamine on hemodynamic parameters, creatinine clearance, systemic and splanchnic oxygenation, gastric mucosal pH (pHi), and mixed and hepatic venous plasma levels of endotoxin, interleukin-6 (IL-6), serum amyloid A (SAA), and C-reactive protein (CRP) in 44 patients scheduled for coronary artery bypass grafting. Patients were randomized to receive continuous infusions of 0.5, 1.0, or 2 mu g.kg(-1) min(-1) dopexamine (n = 10 per group) or placebo (n = 14) prior to surgery, intraoperatively, and postoperatively. Dopexamine infusion increased systemic oxygen delivery (P less than or equal to 0.01). Hepatic venous oxygen saturation did not change, and pi-Ii decreased during and after CPB in all patients (P less than or equal to 0.01). Postoperative increases in IL-6 were smallest in patients who received 2.0 mu g.kg(-1).min(-1) dopexamine (P less than or equal to 0.02). SAA and CRP increases during the postoperative period were less pronounced with dopexamine throughout the study. Creatinine clearance was elevated in all dopexamine groups (P less than or equal to 0.025). This elevation was higher with lower dopexamine doses (P less than or equal to 0.025). We conclude that dopexamine improves creatinine clearance and reduces systemic inflammation without affecting splanchnic oxygenation.