PROVOCATION Trial - PROphylactic intraVenOus Hydration for Contrast Agent Toxicity PreventION

"control group: preventive hydration with 154mEq/l saline at 1ml/kg per hour of 12 hours prior and after the procedure.~7h-sodium bicarbonate: before contrast 3ml/kg NaHCO3 166mEq/l for one hour, followed by NaHCO3 166mEq/l (1ml/kg per hour until 6h after contrast).~short-term sodium bicarbonate: NaHCO3 166mEq/l (3ml/kg) as a bolus 20 minutes before contrast; ingestion of Nephrotrans® (500mg NaHCO3/capsule: 1 capsule/10kg) with 1-2 dl non-sparkling mineral water at the start of the infusion. Ingestion of non-sparkling mineral water in the first 6 hours after contrast."