Urinary nitrate detects acute kidney injury in children presenting to the emergency department

Objectives: Nitric oxide (NO) is perturbed during kidney injury. Our objective was to assess the ability of the urinary NO metabolite nitrate to detect early acute kidney injury(AKI) in the emergency department (ED).Methods: Patients (pts) were recruited if they had a urinalysis and serum creatinine (SCr) obtained. Using SCr in the ED and after hospitalization, AKI was defined by validated pediatric pRIFLE (Risk[R], Injury[I], Failure[F]) criteria; pts without AKI were controls. Urinary nitrate was determined by HPLC. Statistical comparison between groups was done using non-parametric methods and t-test. Diagnostic accuracy was assessed using ROC curves.Results: Urine nitrate was assayed from 252 pts. Mean (SD) age was 11.4(4.8) yrs, (50% male), 138 (60%) admitted. AKI results: 233 controls, 12 pRIFLE-R, 6 pRIFLE-I. Absolute median urinary nitrate and urinary creatinine normalized mean log nitrate were signifi cantly lower for the injury group (pRIFLE-I) compared with the combined risk (pRIFLE-R) and no AKI groups (p=0.012 and p=0.026, respectively). Urinary nitrate demonstrated good accuracy (AUC 0.726; 95%CI 0.609-0.844) to predict pts with pRIFLE-I versus pts with pRIFLE-R or without AKI.Conclusions: Low urinary nitrate detects AKI early in the pediatric ED. Future Monday, August 30 studies will determine the biomarker’s ability to predict AKI progression in hospitalized patients