The effects of dopamine infusion on the postoperative energy expenditure, metabolism, and catecholamine levels of patients after esophagectomy.

Although dopamine is one of the most widely used vasoactive agents, its postoperative thermogenic and metabolic effects have not been studied. In this study, the effects of low-dose dopamine, given at 5 microgram/kg/min, on resting energy expenditure (REE), metabolism, and plasma catecholamine levels were examined in eight postsurgical patients. Dopamine infusion increased REE from 1,839 +/- 171 kcal/day to 2,071 +/- 170 kcal/day, and it decreased to 1,867 +/- 141 kcal/day after cessation of the infusion. Dopamine also increased the plasma levels of glucagon from 109.4 +/- 8.7 pg/ml to 132.5 +/- 8.0 pg/ml, and it decreased to 102.9 +/- 11.1 pg/ml after cessation of the infusion. The plasma levels of dopamine before, during, and after the infusion were 116.1 +/- 18.3, 161.1 +/- 25.6 and 121.4 +/- 17.2 ng/ml, respectively. Insulin and glucose were affected by dopamine, but changes in their plasma levels did not parallel the dopamine levels. Epinephrine and norepinephrine were increased by the infusion of dopamine and continued to increase even after its cessation. The results of this study revealed that low-dose dopamine increased REE in postsurgical patients and that this might be associated with the concomitant increase in plasma glucagon.