Prediction of chronic kidney disease after acute kidney injury in ICU patients: study protocol for the PREDICT multicenter prospective observational study.

BACKGROUND: Acute kidney injury (AKI) is frequent and associated with poor outcome in intensive care unit (ICU) patients. Besides the association with short- and long-term mortality, the increased risk of chronic kidney disease (CKD) has been recently highlighted in non-ICU patients. This study aims to describe the incidence and determinants of CKD after AKI and to develop a prediction score for CKD in ICU patients.

METHODS: Prospective multicenter (n = 17) observational study included 1200 ICU patients who suffered from AKI (defined by an AKIN stage ≥ 1) during their ICU stay and were discharged alive from ICU. Preexisting end-stage renal disease (ESRD) and immunosuppressant treatments are the main exclusion criteria. Patients will be monitored by a nephrologist at day 90 and every year for 3 years. The main outcome is the occurrence of CKD defined by a creatinine-based estimated glomerular filtration rate (eGFR) lower than 60 mL/min/1.73 m2 or renal replacement therapy for ESRD in patients whose eGFR will be normalized (≥ 60 mL/min/1.73 m2 ) at day 90. Secondary outcomes include albuminuria changes, eGFR decline slope and ESRD risk in patients with preexisting CKD, cardiovascular and thromboembolic events and health-related quality of life.

DISCUSSION: This is the first study prospectively investigating kidney function evolution in ICU patients who suffered from AKI. Albuminuria and eGFR monitoring will allow to identify ICU patients at risk of CKD who may benefit from close surveillance after recovering from AKI. Major patient and AKI-related determinants will be tested to develop a prediction score for CKD in this population. Trial registration ClinicalTrials.gov, NCT03282409. Registered on September 14, 2017.