The furosemide stress test (FST) is way to distinguish which patients with AKI will eventually progress to severe AKI and go on to require dialysis from those who will not. The FST in performed by giving large dose of furosemide IV (1.0 or 1.5 mg/kg) then measuring subsequent urine output in the next two hours. This test relies upon the concept that responding to a furosemide challenge requires an adequate GFR and a functional nephron. Recent small studies have suggested that the FST performs better than traditional and novel biomarkers for AKI such as NGAL and KIM-1.