Prevention of contrast-induced nephropathy: a critical review.

Although contrast-induced nephropathy (CIN) is common and portends a significant morbidity and mortality, only few large and well designed trials have assessed the available prophylactic measures and there are no clear evidence-based guidelines that can easily be adopted by the clinician. We critically discuss the evidence for periprocedural hydration, pharmacological agents, periprocedural withdrawal of medication, application of renal replacement therapy and the use of contrast media. Pending confirmation of the superiority of sodium bicarbonate, NaCl 0.9% remains the fluid of choice for periprocedural hydration. A recent trial found a dose-dependent beneficial effect of acetylcysteine on CIN and mortality, adding to the controversy on the prophylactic use of this agent. Publication bias of acetylcysteine trials may have confounded the results of the meta-analyses, since negative results were more likely to be published as an abstract only. Periprocedural haemofiltration protected against CIN in a high-risk population, but the results require confirmation before the technique can be recommended. Pending randomized controlled trials with rigorous scientific design, we propose practical mixed evidence-based and opinion-based guidelines for the prevention of CIN, using a stratification of patients into three risk groups, based on their renal function and a risk-prediction model.