Objective: To assess the effects of dopamine and dobutamine administration on the systemic and mesenteric (macro- and microvascular) circulatory disturbances induced by intra-abdominal hyperpressure.
Design: Prospective, randomized study.
Setting: Animal research laboratory in a university hospital.
Subjects: Twenty-five pigs of either gender, weighing 30-35 kg.
Interventions: Animals were anesthetized, and their lungs were mechanically ventilated. Pulmonary artery flotation and carotid artery catheters were inserted for hemodynamic monitoring and blood sampling. A perivascular flow probe was placed around the superior mesenteric artery, and a laser Doppler probe was positioned in the lumen of the ileum to measure arterial and intestinal mucosal blood flows, respectively. CO2 was insufflated into the peritoneal cavity to reach an intra-abdominal pressure of 15 mm Hg, and 60 mins later, animals received dopamine (5 microg/kg/min; n = 10), dobutamine (5 microg/kg/min; n = 10), or saline (n = 5) for 30 mins.
Measurements and main results: Peritoneal CO2 insufflation induced significant increases in heart rate, arterial pressure, and systemic vascular resistance with concomitant decreases in cardiac output and superior mesenteric arterial and intestinal mucosal blood flows. Although dobutamine infusion reversed the decrease in cardiac output, it failed to restore superior mesenteric artery blood flow; however, intestinal mucosal blood flow returned to baseline levels. Dopamine also attenuated the decrease in cardiac output, but it had no beneficial effect on splanchnic hemodynamic variables.
Conclusions: Low-dose infusion of dobutamine, but not dopamine, corrects the intestinal mucosal perfusion impairment induced by moderate increases in intra-abdominal pressure.