IRA will be defined according to the new proposal of AKIN (Acute Kidney Injury Network) (awaiting publication): abrupt elevation (48 hours) of serum creatinine in value greater than or equal to 0.3 mg / dL or an increase of 50% compared to baseline or reduction of urinary volume to 0.5 ml / kg / h for more than 6 hours (Annex 1).