The effect of intravenous dopamine and dobutamine on blood circulation during a microvascular TRAM flap operation.

A study was conducted to assess the effect of intraoperatively administered inotropic agents on blood flow in the recipient and donor vessels, during breast reconstruction with a muscle sparing free TRAM flap. Twenty-one consecutive patients were randomized into 3 groups receiving either dopamine, dobutamine, or placebo. When the flap and all vessels had been fully dissected but not yet divided, the study drug was administered intravenously for 15 minutes. Hemodynamic parameters and transit-time flow of the thoracodorsal and inferior epigastric arteries were monitored. Both dobutamine and dopamine infusions resulted in significant raises in cardiac output and mean arterial pressure. However, while dobutamine resulted in a higher cardiac output (P = 0.001) and a decrease in systemic vascular resistance (P = 0.028), the increase in mean arterial pressure was greater with dopamine (P = 0.002). Only the dobutamine group showed increased blood flow, in both the thoracodorsal (P = 0.043) and the inferior epigastric (P = 0.043) arteries. If vasoactive agents are needed during microvascular anesthesia, dobutamine seems to be more advantageous than dopamine.