The effect of dopexamine on regional tissue oxygenation, systemic inflammation and amino acid exchange in major abdominal surgery

Background: Beta-adrenergic agents are frequently used to improve cardiac p erformance in surgical and intensive care patients. Beta-adrenergic agents have metabolic and anti-inflammatory effects in addition to their cardiovas cular effects. Splanchnic metabolic activity increases in response to surge ry and inflammation. Dopexamine is believed to favor blood flow distributio n to the splanchnic region. Methods: We investigated the effect of dopexamine, started before major abd ominal surgery, on postoperative patterns of systemic and regional blood fl ow, metabolic response, and markers of inflammation. Twenty-one patients un dergoing major abdominal surgery were studied. All patients were stabilized preoperatively to predefined hemodynamic endpoints with fluids. After preo perative measurement of systemic and splanchnic oxygen transport and splanc hnic lactate, glutamine and alanine exchange and blood levels of tumor necr osis factor (TNF) and interleukin-6 (IL-6), the patients were randomized to receive an infusion of dopexamine at 0.5 mu g kg(-1) min(-1) (group 1) or 2.0 mu g kg(-1) min(-1) (group 2) or placebo. Measurements were repeated at 6 h and 24 h after the end of the operation and the blood levels of cytoki nes also at 36 h postoperatively. Results: Dopexamine evoked an increase in cardiac index pre- operatively. P ostoperatively, there was no difference between the groups in systemic and regional hemodynamics or oxygen transport: cardiac index, splanchnic blood flow and oxygen delivery increased similarly in each group. Accordingly, sy stemic oxygen extraction decreased. Glutamine, alanine and lactate exchange did not differ between the groups. The only metabolic change was an increa sed splanchnic uptake of alanine, which also was unaffected by dopexamine. There was no difference between the groups in TNF and IL-6 levels; TNF leve l did not change, while IL-6 level increased in response to surgery. Conclusions: Dopexamine, when added to a preoperative stabilization protoco l with fluids, did not augment the postoperative hemodynamic response, and had no effect on postoperative metabolic and inflammatory responses. (C) Ac ts Anaesthesiologica Scandinavica 44 (2000).