Dopamine-induced changes in renal blood flow in normals and in patients with renal dysfunction^†

Background: Despite their controversial effect, “renal” doses of dopamine (3–5 μg · kg⁻¹ · min⁻¹) are often used in intensive care units to preserve renal function and to improve final outcome. Aim: To assess the effects of different doses of dopamine on renal blood flow in patients with normal renal function and in patients with renal dysfunction. Methods and Results: In 17 patients with normal renal function and in 12 patients with moderate renal dysfunction, mean arterial pressure (MAP), heart rate (HR), and average peak renal flow velocities (FlowWire APV) were continuously recorded at baseline and during IV administration of increasing dopamine doses (3, 5, 10, 20, and 30 μg · kg⁻¹ · min⁻¹). MAP and HR did not change during infusion of 3–5 μg · kg⁻¹ · min⁻¹ but increased to the same extent in both groups during infusion of >10 μg · kg⁻¹ · min⁻¹. Baseline APV was similar in both groups. Infusion of 3–5 μg · kg⁻¹ · min⁻¹ induced a significant change in APV only in patients with normal renal function. In patients with renal dysfunction, APV increased only during infusion of >10 μg · kg⁻¹ · min⁻¹ in parallel with MAP and HR. Conclusion: “Renal” doses of dopamine increase renal blood flow in normals but not in patients with moderate renal dysfunction. © 2008 Wiley-Liss, Inc.