Contrast Nephropathy. Definition, Risk Factors, Prophylaxis

Abstract

Contrast induced nephropathy (CIN) is one of the most frequent cause of acute kidney injury in recovered patients. CIN incidence depends on patient's risk factors (i.e. chronic kidney disease, diabetes, cardiovascular diseases and older age) and procedure's related factors (i.e. high contrast dose, intra arterial administration). Chronic kidney disease, especially if associated with diabetes, is the main risk factor of CIN. Hydration before and after contrast administration is the only preventive therapy strongly recommended in guidelines in patients at risk for CIN. CIN prevention studies have focused mainly on cardiological patients with moderate renal risk (GFR 60–40 mL/min) who underwent intra arterial contrast administration. Many clinical trials have evaluated efficacy of hydration associated with sodium bicarbonate and of N acetylcysteine (NAC) in CIN prevention. Sodium bicarbonate infusion has demonstrated better efficacy than saline infusion, particularly when short infusion times are needed, such as in emergency procedures. NAC hasn't shown clear effect, in fact some positive studies results haven't been confirmed in other trials yet. The discussion is still opened on the efficacy of renal replacement therapies in CIN prevention in high renal risk subjects (GFR<30 mL/min) in which CIN could associate to beginning of chronic dialysis.