A comparison between fenoldopam and low-dose dopamine in early renal dysfunction of critically ill patients

Abstract

Objective: Fenoldopam mesylate is a selective dopamine-1 agonist, with no effect on dopamine-2 and alpha1 receptors, producing a selective renal vasodilation. This may favor the kidney oxygen supply/demand ratio and prevent acute renal failure. The aim of the study was to investigate if fenoldopam can provide greater benefit than low-dose dopamine in early renal dysfunction of critically ill patients.

Design: Prospective, multiple-center, randomized, controlled trial.

Setting: University and city hospital intensive care units.

Patients: One hundred adult critically ill patients with early renal dysfunction (intensive care unit stay<1 wk, hemodynamic stability, and urine output<or=0.5 mL/kg over a 6-hr period and/or serum creatinine concentration>or=1.5 mg/dL and<or= 3.5 mg/dL).

Interventions: Patients were randomized to receive 2 microg/kg/min dopamine (group D) or 0.1 microg/kg/min fenoldopam mesylate (group F). Drugs were administered as continuous infusion over a 4-day period.

Measurements and main results: Systemic hemodynamic and renal function variables were recorded daily. The two groups were well matched at enrollment for illness severity and hemodynamic and renal dysfunction. No differences in heart rate or systolic, diastolic, or mean arterial pressure were observed between groups. Fenoldopam produced a more significant reduction in creatinine values compared with dopamine after 2, 3, and 4 days of infusion (change from baseline at time 2, -0.32 vs. -0.03 mg/dL, p=.047; at time 3, -0.45 vs. -0.09 mg/dL, p=.047; and at time 4, -.041 vs. -0.09 mg/dL, p=.02, in groups F and D, respectively). The maximum decrease in creatinine compared with baseline was significantly greater in group F than group D (-0.53+/-0.47 vs. -0.34+/-0.38 mg/dL, p=.027). Moreover, 66% of patients in group F had a creatinine decrease>10% of the baseline value at the end of infusion, compared with only 46% in dopamine group (chi-square=4.06, p=.04). Total urinary output during drug infusion was not significantly different between groups. After 1 day, urinary output was lower in group F compared with group D (p<.05).

Conclusions: In critically ill patients, a continuous infusion of fenoldopam at 0.1 microg/kg/min does not cause any clinically significant hemodynamic impairment and improves renal function compared with renal dose dopamine. In the setting of acute early renal dysfunction, before severe renal failure has occurred, the attempt to reverse renal hypoperfusion with fenoldopam is more effective than with low-dose dopamine.