Transient renal insufficiency is frequently observed in the course of cardiovascular arrest. Although elevation of creatinine is reversible in a large majority of cases, severe renal insufficiency is sometimes observed and is associated with a dark prognosis. Any intervention that may limit the worsening of renal function may have an impact on patient mortality. There is currently no validated pharmacological treatment to limit the progression of ARI or to accelerate its recovery. A major challenge then concerns the detection of the reversible character of renal damage.