In a randomized , double-blinded , placebo-controlled study , @ patients referred for radical prostatectomy received either @ % HES @/@ @ or saline @ % ; @ mL/kg during the first hour of surgery and @ mL/kg in the following hours ; u-NGAL , urine albumin , C ( crea ) , UO , arterial blood pressure , and plasma concentrations of creatinine , renin , angiotensin II , aldosterone , and vasopressin were measured before , during , and after surgery .