Objective: The purpose of this study was to evaluate the renoprotective effects of fenoldopam in patients at high risk of postoperative acute kidney injury undergoing elective cardiac surgery requiring cardiopulmonary bypass.
Design: A double-blind randomized clinical trial.
Setting: Hospital.
Participants: One hundred ninety-three patients.
Interventions: Patients undergoing cardiac surgery were randomly assigned to receive a continuous infusion of fenoldopam, 0.1 microg/kg/min (95 patients), or placebo (98 patients) for 24 hours. Patients were included if at least 1 of the following risk factors was present: preoperative serum creatinine > or =1.5 mg/dL, age >70 years, diabetes mellitus, or prior cardiac surgery. Serum creatinine and urinary output were measured at baseline (T1), 24 hours (T2), and 48 hours after surgery (T3). Acute kidney injury was defined as a postoperative serum creatinine level of > or =2 mg/dL with an increase in serum creatinine level of 0.7 mg/dL or greater from preoperative to maximum postoperative values.
Measurements and main results: Acute kidney injury developed in 12 of 95 (12.6%) patients receiving fenoldopam and in 27 of 98 (27.6%) patients receiving placebo (p = 0.02), whereas renal replacement therapy was started in 0 of 95 and 8 of 98 (8.2%) patients, respectively (p = 0.004). Serum creatinine was similar at baseline (1.8 +/- 0.4 mg/dL v 1.9 +/- 0.3 mg/dL) in the fenoldopam and placebo groups but differed significantly (p < 0.001 and p < 0.001) 24 hours (1.6 +/- 0.2 mg/dL v 2.5 +/- 0.6 mg/dL) and 48 hours (1.5 +/- 0.3 mg/dL v 2.8 +/- 0.4 mg/dL) after the operation.
Conclusions: A 24-hour infusion of 0.1 mug/kg/min of fenoldopam prevented acute kidney injury in a high-risk population undergoing cardiac surgery.