Lack of renoprotective effects of dopamine and furosemide during cardiac surgery

Because development of acute renal failure is one of the most potent predic tors of outcome in cardiac surgery patients, the prevention of renal dysfun ction is of utmost importance in perioperative care. In a double-blind rand omized controlled trial, the effectiveness of dopamine or furosemide in pre vention of renal impairment after cardiac surgery was evaluated. A total of 126 patients with preoperatively normal renal function undergoing elective cardiac surgery received a continuous infusion of either "renal-dose" dopa mine (2 mu g/kg per min) (group D), furosemide (0.5 mu g/kg per min) (group F), or isotonic sodium chloride as placebo (group P), starting at the begi nning of surgery and continuing for 48 h or until discharge from the intens ive care unit, whichever came first. Renal function parameters and the maxi mal increase of serum creatinine above baseline value within 48 h (Delta Cr ea(max)) were determined. The increase in plasma creatinine was twice as hi gh in group F as in groups D and P (P < 0.01). Acute renal injury (defined as Delta Crea(max) > 0.5 mg/dl) occurred more frequently in group F (six of 41 patients) than in group D (one of 42) and group P (zero of 40) (P < 0.0 1). (The difference between group D and group P was not significant.) Creat inine clearance was lower in group F (P < 0.05). Two patients in group F re quired renal replacement therapy. The mean Volume of in fused fluids, blood urea nitrogen, serum sodium, serum potassium, and osmolar- and free-water clearance was similar in all groups. It was shown that continuous infusion of dopamine for renal protection was ineffective and was not superior to pl acebo in preventing postoperative dysfunction after cardiac surgery. In con trast, continuous infusion of furosemide was associated with the highest ra te of renal impairment. Thus, renal-dose dopamine is ineffective and furose mide is even detrimental in the protection of renal dysfunction after cardi ac surgery.