Dobutamine restores intestinal mucosal blood flow in a porcine model of intra-abdominal hyperpressure

Objective: To assess the effects of dopamine and dobutamine administration on the systemic and mesenteric (macro- and microvascular) circulatory distu rbances 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 i nserted 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 int estinal mucosal blood flows, respectively, CO2 was insufflated into the per itoneal cavity to reach an intra-abdominal pressure of 15 mm Hg, and 60 min s later, animals received dopamine (5 mu g/kg/min; n = 10), dobutamine (5 m u g/kg/min; n = 10), or saline (n = 5) for 30 mins. Measurements and Main Results: Peritoneal CO2 insufflation induced signific ant increases in heart rate, arterial pressure, and systemic vascular resis tance with concomitant decreases in cardiac output and superior mesenteric arterial and intestinal mucosal blood flows. Although dobutamine infusion r eversed the decrease in cardiac output, it failed to restore superior mesen teric 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 th e intestinal mucosal perfusion impairment induced by moderate increases in intra-abdominal pressure.