Optimization of Fluid Balance Guided by Bioelectrical Impedance Analysis in Patients Undergoing Continuous Renal Replacement Therapy in Critical Care

Inclusion Criteria: * Age \> 18 years * The patient was hospitalized in the intensive care unit of Amiens-Picardie University Hospital. * Patient with an increase in fluid balance (TBW \> 5%) * Patient receiving continuous veno-venous hemofiltration (CVVH) on a PrismaFlexR or PrisMaxR machine, initiated due to oliguria, potassium level \> 6.5 mmol/L, urea level \> 25 mmol/L, or creatinine \> 300 µmol/L and severe metabolic acidosis (pH \< 7.2). * Hemodynamically stable patient with a mean arterial pressure (MAP) \> 65 mmHg for more than 4 hours with norepinephrine. * Signed consent to participate in the study by the patient or, if unconscious, their legal representative/next of kin. Exclusion Criteria: * Invalid BIA measurements * Internal device powered by an electrical current (pacemaker, implantable cardioverter-defibrillator, neurostimulator) * Cardiac arrhythmia (atrial fibrillation, atrial flutter) present at the inclusion * Chronic dialysis patient * Moribund patient * The patient is on extracorporeal mechanical support * Hemorrhagic shock * Pregnant woman * Patient under guardianship or conservators.