Nephropathy induced by contrast media: pathogenesis, risk factors and preventive strategies

Abstract

With the increasing use of contrast media in diagnostic and interventional procedures, nephropathy induced by contrast media has become the third leading cause of hospital-acquired acute renal failure. It is also associated with a significant risk of morbidity and death. The current understanding of the pathogenesis indicates that contrast-medium nephropathy is caused by a combination of renal ischemia and direct toxic effects on renal tubular cells. Patients with pre-existing renal insufficiency, diabetes mellitus and congestive heart failure are at highest risk. Risk factors also include the type and amount of contrast medium administered. Therapeutic prevention strategies are being extensively investigated, but there is still no definitive answer. In this article, we review the current evidence on the causes, pathogenesis and clinical course of contrast-medium nephropathy as well as therapeutic approaches to its prevention evaluated in clinical trials.

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Box 1

Fig. 1: Suggested management of patients scheduled to undergo diagnostic procedures involving use of a contrast medium. *Major risk factors are listed in Table 1. †A standard hydration protocol should include 45% saline administered intravenously at 1 mL/kg hourly, 12 hours before and after exposure to the contrast medium. ‡Large prospective studies are required to validate the efficacy of these therapies in specific subgroups of high-risk patients. §An abbreviated protocol with N-acetylcysteine may be required if full hydration is not feasible owing to severe unstable congestive heart failure or the need for an emergency procedure.