The protective roles of low-dose dopamine and mannitol infusion in the renal function of patients undergoing cardiovascular surgery were compared in 36 patients by measuring urine N-acetyl-b-D- glucosaminidase activity, serum and urinary creatinine, blood urea nitrogen (BUN) levels and urine output. The patients were randomly selected and received a continuous infusion of dopamine, 3 µg/kg/min (Group I), mannitol, 1 mg/kg/h (Group II), no medication (Group III) before the induction of anaesthesia. Urine N- acetyl-b-D-glucosaminidase activities, serum and urinary creatinine and BUN were determined preoperatively after aortic cross- clamping, and on the first and second postoperative days. Changes in urine N-acetyl- b-D-glucosaminidase activity or serum and urinary creatinine, and BUN levels were not statistically significant (p>0.05) between different groups. Our results revealed that, for the protection of renal function during cardiopulmonary bypass, on comparison, the prophylactic use of "low-dose" dopamine or mannitol did not display any marked superiority.

The protective roles of low-dose dopamine and mannitol infusion in the renal function of patients undergoing cardiovascular surgery were compared in 36 patients by measuring urine N-acetyl-b-D- glucosaminidase activity, serum and urinary creatinine, blood urea nitrogen (BUN) levels and urine output. The patients were randomly selected and received a continuous infusion of dopamine, 3 µg/kg/min (Group I), mannitol, 1 mg/kg/h (Group II), no medication (Group III) before the induction of anaesthesia. Urine N- acetyl-b-D-glucosaminidase activities, serum and urinary creatinine and BUN were determined preoperatively after aortic cross- clamping, and on the first and second postoperative days. Changes in urine N-acetyl- b-D-glucosaminidase activity or serum and urinary creatinine, and BUN levels were not statistically significant (p>0.05) between different groups. Our results revealed that, for the protection of renal function during cardiopulmonary bypass, on comparison, the prophylactic use of "low-dose" dopamine or mannitol did not display any marked superiority.