The study aims to develop and validate a prediction score of chronic renal disease occurrence within 3 years after ICU discharge in patients who suffered an acute kidney failure during ICU stay and recovered normal renal function at 90 days following their discharge.

The primary study outcome is the incidence of chronic renal disease within the first 3 years after ICU discharge, defined by a lower glomerular filtration rate (GFR) under 60 mL/minute/1.73m2.

As second objectives, the study aims to:

• Evaluate the GFR decline in patients who had an underlying chronic kidney disease.
• Evaluate factors associated with a persistent decreased GFR at day-90.
• Characterization the clinical and biological phenotype of chronic renal disease in these patients.
• Evaluate treatments provided to these patients according to CKD occurence.
• Evaluate the rate of cardiovascular and thrombo-embolic morbidity-mortality.
• Assess the quality of life every year for 3 years.
• Evaluate the medico-economic burden of CKD.

Inclusion Criteria:

• Patient ⩾ 18 years;
• Patient suffering an acute kidney injury (defined by AKIN score ⩾1) during ICU stay;
• Patient discharged alive from the ICU;
• Patient's signed consent obtained;
• Patient covered by a healthcare insurance.

Exclusion Criteria:

• Pregnant or breastfeeding woman;
• SOFA score < 1 (except for kidney assessment) at time of ICU admission;
• End-stage of renal failure or dialysis treatment or renal transplantation prior to ICU admission;
• Patient treated with dialysis at ICU discharge;
• Immunosuppressive treatment prior to ICU admission;
• Patient under legal incapacity (tutor or guardian protection);
• Being unable to follow-up of the study;
• Life expectancy expected shorter than 90 days;
• Refusal to participate in the study;
• Patient's main address is outside of Il de France region for the centers in this region;
• Patient < 18 years;
• Patient not affiliated to national social security scheme;
• Patient deprived of liberty by judicial measure.

Patient with acute kidney injury during ICU stay