Compared with placebo , low-dose dopamine had no significant effect on @-hour cumulative urine volume ( dopamine , @ mL ; @ % CI , @-@ vs placebo , @ mL ; @ % CI , @-@ ; difference , @ mL ; @ % CI , -@ to @ mL ; P = @ ) or on the change in cystatin C level ( dopamine , @ mg/L ; @ % CI , @-@ @ vs placebo , @ mg/L ; @ % CI , @-@ @ ; difference , @ ; @ % CI , -@ to @ ; P = @ ) .