In a randomized , double-blinded , placebo-controlled study , 40 patients referred for radical prostatectomy received either 6 % HES 130/0 .4 or saline 0.9 % ; 7.5 mL/kg during the first hour of surgery and 5 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 .