Evaluation of dopamine, prostaglandin E₁ and olprinone on renal blood flow velocity following coronary arterial bypass grafting by 2-D Doppler echographic measurement

Abstract

We investigated the effects of dopamine, prostaglandin E₁ and olprinone on renal blood flow in the early postoperative period following coronary artery bypass grafting (CABG) by means of 2-D Doppler echographic measurement. Twenty-four patients scheduled for elective CABG surgery were randomly assigned to one of three groups: dopamine group (n=8) (Group D), prostaglandin E₁ group (n=8) (Group P) and olprinone group (n=8) (Group O). We assessed renal blood flow in the interlobular arteries along the right renal pyramid, which were identified under color Doppler guidance four hours after the end of surgery. We measured the maximum systolic blood flow velocity (V_max) and the minimum diastolic blood flow velocity (V_min) as baseline data with the pulse doppler system (Aloka SSD-2000 Tokyo). We calculated the V_max/V_min ratio (V_max/V_min) and the resistance index (RI=(V_max-V_min)/V_max). After baseline measurement, the dopamine loading dosage was increased through the central venous catheter from 3 to 5μg·kg^-1·min^-1 in group D, prostaglandin E₁ from 0.02 to 0.05μg·kg^-1·min^-1 in group P and olprinone from 0.1 to 0.2μg·kg^-1·min^-1 in group O every 60 minutes. Renal blood flow was measured at each point.
V_max and V_min did not significantly increase but V_max/V_min and RI significantly decreased compared to baseline in all groups after the loading with each drug. The decreases of the V_max/V_min ratio and RI indicate increases of renal blood flow when constant blood flow velocity is constant. We demonstrated that dopamine, prostaglandin E₁ and olprinone in the early postoperative period following CABG led to an increase of renal blood flow.