These days, some studies have shown that hydration with sodium bicarbonate plus N-Acetylcysteine was effective and safe in the prevention of CIAKI. In these studies, bicarbonate was used for both alkalinizing renal tubular fluid and hydration. However, if we want to do hydration, we can use saline and if we want to alkalinize renal tubular fluid, we might use bicarbonate by bolus injection.