Role of Loop Diuretic Challenge in Stage 3 Acute Kidney Injury

Abstract Objective To assess whether loop diuretic challenge predicts the need for dialysis among critically ill patients with acute kidney injury (AKI) stage 3. Patients and Methods Adult patients admitted to intensive care units between January 1, 2004, and December 31, 2016, were screened. Acute kidney injury stage 3 was identified by an electronic surveillance tool, and patients who received loop diuretics in a dosage of at least 1mg/kg intravenous bolus furosemide equivalent were included. Urine output following loop diuretic challenge was modeled as a restricted cubic spline. We then compared the area under the receiver operating characteristic curve for urine outputs at 2 hours and 6 hours after loop diuretic challenge to predict the need for dialysis within the next 24 hours. Results Of 687 patients included in the study, those who received dialysis were younger and had higher Sequential Organ Failure Assessment scores on the day of loop diuretic challenge. Urine outputs at 2 hours and 6 hours were lower in patients who needed dialysis, but urine output by 6 hours was better in predicting dialysis initiation within 24 hours (area under the curve, 0.71 vs 0.67; P =.02). The sensitivity and specificity of 6-hour urine output cutoff of 600 mL or less to predict dialysis was 80.9% and 50.5%, respectively, and that for 300 mL or less was 64.2% and 68.2%, respectively. Conclusion Among patients with stage 3 AKI, 6-hour urine output after the loop diuretic challenge had a modest discriminant capacity to identify dialysis initiation within the next 24 hours.