PREdiction of succeSSful weanING From Continuous Renal Replacement Theraphy: the Possible Role of Delta C-cistatin

Inclusion Criteria: * age ≥ 18 years; * diagnosis of acute kidney injury (defined according to KDIGO 2012 criteria) * need for support with CRRT according to the indications of the nephrologist consultants and Clinical Practice * Obtaining informed consent Exclusion Criteria: * CRRT already ongoing (in another department not participating in the study) at the time of transfer/admission to intensive care; * need for RRT (any type and modality) in the 14 days prior to enrolment; * diagnosis of AKD/CKD/ESRF on admission; * Discontinuation of CRRT under conditions that do not comply with the criteria established by the study; * Need for CRRT not associated with AKI condition (e.g. elimination of toxicants); * pregnant women; * presence of known thyreopathy * Continuous use of corticosteroids * patient with known neoplastic disease.