Nephroprotection and iodinate contrast medias.

The incidence of post-contrast acute kidney injury (PC-AKI) is low with the new low- or iso-osmolar non-ionic iodinated contrast agents. The only proven form of prophylaxis for PC-AKI is hydration, preferably intravenous, although oral hydration is equally effective. In this article we define PC-AKI and its risk factors, propose a prophylaxis protocol and respond to the most common doubts that arise around prophylaxis. We also update the fasting guidelines to be followed prior to contrast testing. In general, fasting of solids is not necessary before injecting iodinated contrast or gadolinium except in tests in which it is necessary to specifically study the upper digestive tract and bile duct. Even in these cases, fasting clear liquids is not required, which is of great help for oral hydration and for reducing the incidence of PC-AKI.