Low dose dopamine is widely used during the perioperative period to preserve renal perfusion. Low dose dopamine (3-5 µg/kg/min) was administrated to partial hepatectomy patients and BUN, creatinine in serum were measured to determine the effects of low dose dopamine on renal function.

Liver group (n = 28) were administered low dose dopamine (3-5 µg/kg/min) and the stomach group (n = 23) were not administered any vasoactive drugs during the operation. Perioperative plasma BUN, and creatinine, creatinine clearance, BUN/creatinine ratio, serum Na+ and K+, and central venous pressure (CVP) were checked 3 times, just after starting operation, 4 hours after starting the operation, and at PACU for both groups. We also evaluated intravascular volume status using the CVP and the BUN/creatinine ratio. Changes in BUN, and creatinine level during the operation in both group were compared. All the patients in this study were confirmed as having euvolemia by CVP and BUN/creatinine ratio.

Urine volume increased significantly in the liver group with low dose dopamine compared to the stomach group (P < 0.05). The BUN level in the liver group increased significantly versus the stomach group (P < 0.05). In both groups, the creatinine level increased significantly (P < 0.05) and the plasma Na+ level decreased significantly (P < 0.05).

We confirmed that low dose dopamine significantly increases urine volume in euvolemia status cases during liver surgery. But we were unable to determine why increased diuresis by the administration of low dose dopamine during operation and has a renal protective effect.