Prediction of cardiac surgery associated acute kidney injury using response to loop diuretic and urine neutrophil gelatinase associated lipocalin

Background Cardiac surgery associated acute kidney injury (CS-AKI) is common. Urine response to loop diuretic and urine neutrophil gelatinase associated lipocalin (uNGAL) are separately associated with CS-AKI. We aimed to determine whether urine response to loop diuretic and uNGAL together were associated with postoperative day 2–4 CS-AKI. Methods Two-center prospective observational study (ages 0–18 years). uNGAL (8–12 h after admission) (ng/mL) and urine response to loop diuretic (6 h for bolus furosemide and 12 h for infusion bumetanide) (mL/kg/hr) were measured. All diuretic doses were converted to furosemide equivalents. The primary outcome was day 2–4 CS-AKI. Patients were sub-phenotyped using a priori cutoffs (uNGAL + ≥ 100 ng/mL and UOP +