Should we give prophylactic "renal-dose" dopamine after coronary artery bypass surgery?

Objective: A prospective double-blind randomized study undertaken to assess the effect of postoperative prophylactic "renal-dose" dopamine on post-coronary artery bypass grafting surgery's clinical outcome. Methods: Eighty-five consecutive patients undergoing CABG operation were randomized to receive either 3-5 μg/kg/min dopamine (group D, n = 41) or saline as placebo (group P, n = 45) for 48 postoperative hours. Clinical outcome parameters were collected for four postoperative days. Results: Preoperative and operative parameters were similar in both groups. Four patients from group P and none from group D reached an end-point of the study (oliguria, renal dysfunction) and received dopamine. Two patients from group P and none from group D needed an additional inotropic support. Mean arterial pressure values were similar during the first 24 hours after operation, but left atrial pressure values tended to be higher in group P (10 ± 4 vs 7 ± 3 mmH₂O, p = 0.18). The mean pH was higher in group D at 8 hours after operation (7.38 ± 0.2 vs 7.36 ± 0.3, p = NS), due to higher bicarbonate levels (23 ± 2 mmol/l vs 21 ± 2, p = 0.49). The incidence of lung congestion in chest X-rays and CT scans was significantly higher in group P (50% vs 29%, p = 0.073 at 48 hours postoperatively). Room air blood O ₂ saturation and maximal expiratory volume tended to be higher in group D (at 72 hours after operation- 92 ± 4 vs 90% ± 5, p = 0.29 and 646 ± 276 vs 485 ml ± 206, p = 0.16, respectively). There was no statistical difference in urine output but the amount of furosemide given to patients in group P was significantly higher (during the first 8 hours 2.5 ± 0.5 vs. 0.3 mg ± 1.6, p = 0.07). Plasma creatinine levels were significantly lower in group D (at 24 hours 0.93 ± 0.02 vs 1.05 mg/dL ± 0.02, p = 0.02). Mobilization after surgery was faster in group D. Conclusions: Prophylactic dopamine administration after coronary artery bypass grafting surgery improves patient hemodynamic and renal status, reduces the need for additional medical support (inotropes and furosemide) and thus, provides stable postoperative course.