Contrast-induced nephropathy—prevention and risk reduction

Contrast-induced nephropathy (CIN) is a serious, but potentially preventable adverse event associated with the use of iodinated contrast media (CM). Studies suggest that the occurrence of CIN is directly related to the number of pre-existing patient risk factors such as pre-existing renal insufficiency (RI) with or without diabetes, advanced age, congestive heart failure and dehydration. Because the risk factors for CIN are common and the consequences serious or even life-threatening, it is important for physicians to implement preventive strategies. Although the optimal strategy for preventing CIN has not been fully established, it is important to first identify patients at risk. The commonly used methods for identifying patients at risk include use of patient questionnaires, review of medical history and measurement of serum creatinine levels prior to the administration of CM. Estimation of the glomerular filtration rate (GFR) before CM administration should be encouraged. To prevent the development of CIN, patients should be well-hydrated and nephrotoxic medications should be withdrawn at least 24 h prior to CM. Use of the minimal necessary CM dose is recommended, as the nephrotoxic effect of CM is dose-dependent. Furthermore, appropriate selection of CM is important. The incidence of CIN has been shown to be lower when an iso-osmolar CM rather than a low-osmolar CM (iohexol) is used in patients with RI and diabetes. Pharmacological intervention with calcium channel blockers, dopamine and N-acetylcysteine have not consistently been shown to reduce the incidence of CIN. This article will review the risk factors for the development of CIN and discuss practical strategies for its prevention in at-risk patients.