The role of N-acetylcysteine in radiocontrast nephropathy

Oh, Dong Jin

Abstract

Radiocontrast nephropathy (RCN) is one of the most common etiologies of hospital-acquired acute kidney injury (AKI), accounting for more than 10% of cases. Although most patients who develop RCN have mild and transient decrement in renal function and do not require renal replacement therapy, RCN is associated with significant prolongation of hospitalization and increased morbidity and mortality. Volume expansion with isotonic saline or isotonic sodium bicarbonate before and after radiocontrast administration has been shown to decrease the risk of RCN in high-risk patients. The infusion of isotonic saline or sodium bicarbonate has significant clinical limits, requiring the need for overnight hospitalization and causing volume overload in patients with renal dysfunction. On the contrary, N-acetylcysteine (NAC) is inexpensive, convenient and free of significant complications. It is therefore reasonable to employ this agent, albeit with recognition that its benefit may be limited in published trials. In this issue of the Journal, Seo and Kim compare the efficacy of oral NAC alone with half saline hydration for preventing radiocontrast nephropathy in patients with renal dysfunction. They found that there was no significant difference in the incidence of RCN in the two groups. In addition, although there was no statistical difference between both groups, they stressed the role of nitric oxide (NO) in the prevention of RCN. Consequently, they conclude that oral NAC alone may be effective to prevent RCN in patients with the risk of volume overload after bolus hydration. However, this is a single-center study and requires validation across additional clinical settings including the group of more rapid infusion rate than 12 h pre- and postprocedure used in this study. Therefore, additional large, multicenter, randomized, controlled trials will be required to define the true role of NAC in preventing RCN.