Furosemide Stress Test Guiding Initiation of Renal Replacement Therapy

Inclusion Criteria: * Age older than 18 years old and admission in an ICU * Acute kidney injury (defined by serum creatinine increase ≥ 0.3 mg/dL or urine output ≤ 0.5 mL/kg/hour according to KDIGO criteria) * Informed consent provided by the patient or person with decisional responsibility * Indwelling bladder catheter * Documented cause of acute kidney injury from acute tubular necrosis e.g. presence of granular or epithelial casts on urine sediment, FeNa more than 1%, Feurea more than 50%, urine or plasma neutrophil gelatinase-associated lipocalin (NGAL) more than 150 mg/dL * Opinion of the treating clinical team that patient was well resuscitated and sufficiently clinically stable for the intervention or by noninvasive or invasive measurements i.e. fluid accumulation at least 5% plus at least one of the following e.g. chest radiography, central venous pressure ≥ 8 mmHg, pulse pressure variation \< 13%, inferior vena cava collapsibility index \< 50% in spontaneously breathing patients or distensibility index \< 18% in mechanically ventilated patients Exclusion Criteria: * Baseline serum creatinine ≥ 2 mg/dL (male) and ≥ 1.5 mg/dL (female) within 3 months * Evidence of volume depletion at the time of furosemide administration or active bleeding * Evidence of obstructive uropathy, renal vein thrombosis or renal artery stenosis, thrombotic microangiopathy, glomerulonephritis, tumor lysis syndrome * History of renal allograft * Known pregnancy * Allergy or known sensitivity to loop diuretics * Need for emergency renal replacement therapy at randomization or evaluation by the clinical team that the renal replacement therapy should be deferred * Patient is moribund with expected death within 24 hr or whom survival to 28 days is unlikely due to an uncontrollable comorbidity (cardiac, pulmonary or hepatic end-stage disease; hepatorenal syndrome; poorly controlled cancer; severe post-anoxic encephalopathy; etc.) * Patients with advance directives issued expressing the desire not to be resuscitated * Prior treatment with RRT within 30 days