Inclusion criteria:  Diagnosis of acute kidney injury Being started on continuous renal replacement therapy  Exclusion criteria:  Diagnosis of chronic kidney disease stage 5 or end-stage renal disease Having received a kidney transplant Moribund patients (who are expected to die within 1 day of CRRT initiation) Presence of an intoxication requiring extracorporeal removal RRT within the previous 1 month Rapidly progressive glomerulonephritis