Dopamine and renal blood flow in radiocontrast-induced nephropathy in humans

Previous studies suggest a role for renal vasoconstriction in the pathogenesis of radiocontrast-induced nephropathy (RCIN). A renal vasodilator such as dopamine may be protective. However, the effect of dopamine on renal blood flow (RBF) in patients with chronic renal failure (CRF) is controversial. Patients with CRF of diabetic (DM) or nondiabetic (NDM) origin were hydrated with 0.45% NaCl intravenously at 100 mL/h for 12 h and then randomized to either 0.45% NaCl IV at 100 mL/h (Group 1) or dopamine IV at 2 micrograms/kg/min in 0.45% NaCl at 100 mL/h for 2 h during and after cardiac catheterization. Mean arterial pressure (MAP), cardiac output (CO), and RBF were measured at baseline (t = 0), after 5 min of vehicle (Group 1) or dopamine (Group 2) but before ionic radiocontrast (t = 5 min), after ventriculogram (t = 15 min), and after coronary angiography (t = 65 min). Serum creatinine (SCr) was measured at baseline and 24 and 48 h after cardiac catheterization. RCIN was defined as a 25% increase of SCr above baseline 48 h after cardiac catheterization. Baseline characteristics demonstrated the groups to be equivalent in age, SCr, creatinine clearance, CO, MAP, RBF, and radiocontrast dose administered. The incidence of RCIN was not different between Group 1 and Group 2 (Group 1, 6 of 15 patients; Group 2, 5 of 15 patients). Dopamine infusion was associated with a significant increase in RBF at 5 min (Group 1, 110 +/- 13%; Group 2, 193 +/- 40% at t = 5, p < .05). RBF remained elevated throughout the catheterization in Group 2.(ABSTRACT TRUNCATED AT 250 WORDS)