[Acute kidney injury: from concept to practice].

Definition and classification of acute renal failure evolved in recent years. The acronym "Acute Kidney Injury" replaces "Acute Renal Failure". The RIFLE classification spreads the AKI in three degrees of severity, and two degrees of disease duration. The group Acute Kidney Injury Network refines this classification into three stages, to improve the sensitivity in detecting moderate forms. The epidemiology of AKI remains imprecise. In the ICU, more than 30% of patients suffered from AKI, often in a context of multiple organs failure. In addition to serum creatinine and urine output, new biomarkers can be assessed. Their early detection should enable a clearer distinction between "acute tubular necrosis" and other causes of AKI, but also to distinguish patients at risk for pejorative evolution of renal function. The management of AKI based on an optimal resuscitation. The administration of loop diuretics or low dose dopamine showed no benefit. Hydration in prevention of the contrast-induced nephropathy is confirmed. The role of acetylcysteine must be determined. The ideal time to initiate a renal replacement therapy and the choice of the technique remain unresolved. The same goes for the dose of dialysis administered. A systematic application of an algorithm, such as proposed by Bagshow would make comparisons easier and the realisation of multicenter studies will help to clarify these points.