Effect of combined dopamine and diltiazem on renal function after cardiac surgery

In order to evaluate the effect of the combined use of dopamine and diltiazem on renal function in patients undergoing coronary artery bypass grafting (CABG), we conducted a prospective randomized study.

Sixty patients (8F, 52M) with normal preoperative renal function undergoing CABG were divided randomly into four groups, including control (n=15), use of dopamine-only (n=15), use of diltiazem-only (n=15), and combined use of dopamine and diltiazem (n=15). The patients ranged in age from 38 to 74 years (mean 59.3). Drug administration (diltiazem: intravenous infusion of 2 microg x kg(-1) x min(-1), dopamine: 2 microg x kg(-1) x min(-1)) was initiated 24 hours before surgery and was continued for 72 hours.

Creatinine and osmotic clearances were found to be significantly higher in the combined group compared with the other groups 24 hours after surgery (p<0.05). There was no significant difference in respect to creatinine clearance, osmotic clearance, and free water clearance in the dopamine-only and diltiazem-only groups compared to the control group. The free water clearance at 24 and 72 hours after surgery were significantly higher in the combined group compared with the other groups (p<0.05). In the control group, dopamine-only, and diltiazem-only groups beta(2)-microglobulin was statistically higher 72 hours postoperative than preoperatively (p<0.05). There were no significant changes in beta(2)-microglobulin levels in the combined group.

The combined use of dopamine and diltiazem may provide a positive contribution and sufficient protection for early postoperative renal function in patients undergoing CABG.