The pharmacological protection of renal function in patients undergoing cardiac surgery.

OBJECTIVES: To compare the effects of different routes and timings of administration of dopamine and mannitol used to alleviate the adverse effects of prolonged cardiopulmonary bypass (CPB) on renal functions in coronary artery surgery.

METHODS: Group I (n: 25 patients): Mannitol 1 g/kg was added into the priming solution for CPB. Group II (n: 25 patients): IV dopamine was administered at a dose of 2 μg/kg/min during the time period between anesthesia induction and end of surgery. Group III (n: 25 patients): IV dopamine was administered at a dose of 2 μg/kg/min during the time period between anesthesia induction and end of surgery and mannitol 1 g/kg was added into the priming solution for CPB. Group IV (n: 25 patients) (Controls): Furosemide was given when the urine output was low.

RESULTS: There was a significant increase in post operative urine microalbumin/creatinine ratio in all groups (p < 0.05), even increase of cystatin-c in Groups I, II and III (p < 0.01).

CONCLUSIONS: We believe that concurrent use of dopamine infusion (2 μg/kg/min) with mannitol (1 g/kg) during CPB may represent a more effective strategy for the prevention of the untoward effects of CPB on renal functions.