Differential effects of dopamine, dopexamine, and dobutamine on jejunal mucosal perfusion early after cardiac surgery

Objective: To evaluate the potential differential effects of dopamine, dope xamine, and dobutamine on jejunal mucosal perfusion, assessed by endolumina l laser Doppler flowmetry in uncomplicated postcardiac surgical patients. Design: A prospective, blinded, randomized, crossover study. Setting: A cardiothoracic intensive care unit in a tertiary care center. Patients: A total of ten postoperative cardiac surgical patients were studi ed. Interventions: Each patient received sequentially, randomly, and in a blind ed fashion 2.7 +/- 0.2 mu g.kg(-1).min(-1) dopamine, 0.7 +/- 0.1 mu g.kg(-1 ).min(-1) dopexamine, and 2.7 +/- 0.1 mu g.kg(-1).min(-1) dobutamine. Each inotropic agent was titrated to increase cardiac output by 25% from baselin e. Data on jejunal mucosal perfusion, splanchnic lactate, and oxygen extrac tion were obtained during a 1-min control period and a B-min drug infusion period after the target cardiac output was reached. The procedure was seque ntially repeated for each agent, and there was a 20- to 30-min washout peri od between each agent. Measurements and Main Results: Dopamine, dopexamine, and dobutamine increas ed jejunal mucosal perfusion by 27% (p < .01), 20% (p < .001), and 7% (p < .001), respectively. The increase in jejunal mucosal perfusion by dopamine and dopexamine were significantly more pronounced compared with dobutamine (p < .05 and p < .01, respectively), whereas there was no difference betwee n dopamine and dopexamine. Splanchnic oxygen extraction decreased to the sa me extent with all three drugs. Splanchnic lactate extraction did not chang e for any of the drugs. The effects on central hemodynamics were similar fo r the three inotropic agents. Conclusions: Endoluminal laser Doppler flowmetry is a new tool for the dete ction of perfusion changes at the local intestinal mucosal level. Dopamine, dopexamine, and dobutamine have differential effects on jejunal mucosal pe rfusion probably because of their different receptor stimulating properties . These findings may be of clinical importance when the therapeutic goal is to improve gut mucosal perfusion.