Prevention of radiocontrast nephropathy

The vast numbers of radiocontrast procedures performed yearly paired with the increasing prevalence of renal insufficiency in the aging population has focused recent attention on radiocontrast nephropathy. No effective treatment exists for this iatrogenic disease: therefore prevention remains the key strategy. Several clinical investigations have been published over the past 2 years that address potential prophylaxis against contrast nephropathy.

Iso-osmolar non-ionic contrast media appear to have the least nephrotoxicity. Pooled data of published randomized controlled trials of pre-procedural intravenous hydration plus N-acetylcysteine versus placebo demonstrate that acute renal failure from contrast nephropathy is rare when these therapies are given several hours in advance. Strategies that employ fenoldopam and theophylline, however, do not appear to be effective. Urine alkalinization with intravenous sodium bicarbonate may be useful, especially in high-risk patients, but further investigation is needed.

Available evidence indicates that several hours of intravenous pre-hydration is protective against contrast nephropathy and some studies suggest that oral N-acetylcysteine administration adds to this protection. Further research is needed, however, with agents that can be administered immediately prior to contrast administration. This is particularly important for diabetics with baseline kidney disease who require emergent contrast studies and are at high risk for acute renal failure.