Other than saline hydration, measures that were believed to reduce the risk of contrast-induced AKI have been found to be neutral, to have deleterious effects, or to be characterized by heteroge- neous and conflicting data. Studies of hydration to reduce the risk of contrast-induced AKI suggest that isotonic saline is preferable to half isotonic saline, intravenous (IV) hydration is preferable to oral hydra- tion, hydration for hours before and after exposure to contrast media is preferable to a bolus administration of saline immedi- ately before or during contrast media exposure, and administra- tion of isotonic saline alone is preferable to administration of isotonic saline plus mannitol or furosemide.272 275,320 On the basis of these studies, a reasonable hydration regimen would be isotonic crystalloid (1.0 to 1.5 mL/kg per hour) for 3 to 12 hours before the procedure and continuing for 6 to 24 hours after the Prior studies of N-acetyl-L-cysteine and sodium bicarbon- ate have produced conflicting results. Some, often small, earlier studies suggested benefit, but many other more con- temporary studies and meta-analyses found no clear evidence of benefit, and there are potential issues of publication bias and poor methodology issues in several analyses.279 282,322 332 The recently completed largest randomized study on N-acetyl-L-cysteine and contrast nephropathy in patients undergoing angiographic procedures, ACT (Acetylcysteine for Contrast-Induced Nephropathy Trial), demonstrated no benefit in primary or secondary endpoints. An updated meta-analysis using only high-quality trials similarly demon- strated no benefit.283 Taken as a whole, these studies do not support any recommendation for the use of N-acetyl-L- cysteine, they do, however, provide sufficient data to con- clude that N-acetyl-L-cysteine does not prevent contrast- induced AKI in patients undergoing angiographic procedures. 