A furosemide stress test may help predict progression to stage 3 acute kidney injury, according to findings published online Feb. 5 in the Journal of the American Society of Nephrology.
In a cohort of 77 patients with early acute kidney injury (AKI), 32.5% of patients progressed to stage 3 AKI, reported Dr. Jay L. Koyner of the University of Chicago and his colleagues (J. Am. Soc. Nephrol. 2015 Feb. 5 [doi: 110.1681/ASN.2014060535]).
Patients included in the study had either stage 1 or stage 2 AKI according to Acute Kidney Injury Network (AKIN) criteria, and had a furosemide stress test (FST) at either George Washington University, in Washington, or the University of Chicago between June 2009 and December 2012. The standardized dose for FST is 1 mg/kg of furosemide in naive patients and 1.5 mg/kg in patients with prior exposure.
Two-hour urine output (UOP) after FST predicted progression to stage 3 AKI significantly better than did several urinary biomarkers, with an area under the curve (AUC) of 0.87 (P < .001), the investigators said in the report. Of the biomarkers tested, plasma neutrophil gelatinase-associated lipocalin (NGAL) performed best, with an AUC of 0.75 (P = .007).
UOP also outperformed all biomarkers for predicting receipt of renal replacement therapy, with an AUC value of 0.86 (P < .001). Renal replacement therapy was administered to 14.2% of patients following FST.
A total of 20.7% of patients died in the hospital, with an AUC value of 0.70 (P = .02) for prediction of inpatient death following UOP, Dr. Koyner and his associates reported.
The results of this study “demonstrate the promise of FST in improving risk stratification of patients with early AKI,” the investigators wrote.
Although FST may be a “promising tool” for evaluating AKI severity, the study was limited by the small size of the cohort and limited number of patient events, the authors cautioned. Future studies should focus on “larger prospective validations” of FST with biomarkers, they added.
“Improving risk prediction in those with early AKI is likely to alter patient care and clinical decision making, as well as facilitate enrollment into future therapeutic AKI trials,” the researchers said.
Dr. Koyner and his associates reported receiving consulting fees from Abbott, Alere Medical, and Astute Medical.