ICU patients without Acute Kidney Injury

Intensive care unit (ICU) patients who do not develop acute kidney injury (AKI) during their stay.~AKI will be defined by KDIGO stage 1.~The baseline serum creatinine (sCr) measurement will be defined as the sCr at admission if the corresponding estimation of glomerular filtration rate (GFR) by CKD-EPI formula is at least 90ml/min/1.73m2. Otherwise, the most recent sCr measured from 7-365 days prior to admission will be used. If there is no sCr measurement available from this period, it will be estimated using a reverse CKD-EPI formula for a GFR of 75 ml/min/1.73m2.~No intervention is foreseen out of the observation of data relative to kidney function during ICU stay, at 3 month and 12 month of ICU admission.~There will be no biological sample collection.

ICU patients with transient Acute kidney injury

Transient AKI will be defined as a complete renal recovery within 48 hours after the start of AKI.~Complete renal recovery will be defined as a return to within 25% of the baseline serum creatinine measurement. TIf several AKI episodes occur during the patient's ICU stay, only the longest episode will be considered.~No intervention is foreseen out of the observation of data relative to kidney function during ICU stay, at 3 month and 12 month of AKI start.~There will be no biological sample collection.

ICU patients with persistent Acute kidney injury

If the AKI episode lasts longer than 48 hours, it will be classified as persistent AKI. If several AKI episodes occur during the patient's ICU stay, only the longest episode will be considered.~No intervention is foreseen out of the observation of data relative to kidney function during ICU stay, at 3 month and 12 month of AKI start.~There will be no biological sample collection.