Nephrology

Furosemide Stress Test (FST for AKI Progression)

Evaluates 2-hour urinary response to loop diuretic challenge to predict progression to severe Stage 3 AKI and RRT.

Parameters

Furosemide Stress Test (FST for AKI Progression) Result

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FormulaFST Challenge: 1.0 mg/kg IV (diuretic naive) or 1.5 mg/kg IV (prior loop diuretic use). Cutoff: 2-hour cumulative urine output < 200 mL indicates severe AKI progression risk (AUC-ROC 0.87).

Clinical Pearls

Provides a reliable functional dynamic assessment of renal reserve, identifying critically ill patients who will fail conservative management and require early dialytic intervention.

Limitations

Contraindicated in anuria, pre-existing Stage 5 CKD (baseline eGFR < 15), renal allograft, or acute volume depletion.