Urine neutrophil gelatinase-associated lipocalin at SICU admission predicts for cardiac surgery-associated acute kidney injury

Background Acute Kidney Injury （AKI） is a common and serious complication of cardiovascular surgery. There is a need to find biomarkers that are involved in the etiology of cardiac surgery-associated acute kidney injury （CSA-AKI） and have an earlier response to acute kidney injury. The association between urine neutrophil gelatinase-associated lipocalin （NGAL） concentrations and AKI progression is not well established. Methods The prospective-cohort study included 1631 consecutive adult patients undergoing cardiac surgery at Fuwai Hospital between September 2012 and November 2013. AKI defined by Acute Kidney Injury Network （AKIN） criteria with a postoperative increase in plasma creatinine 〉/50% baseline or/〉0.3 mg/dL. Urine NGAL was measured us- ing latex particle-enhanced turbidimetric immunoassay. Associations between Urine NGAL levels and AKI were determined by estimating areas under receiver operating characteristic curves （AUC）. Results A total of 438 （26.9%） patients developed CSA-AKI. And the patients were divided into four groups： 1193 non-AKI patients, 368（22.6%） patients with AKIN stage I AKI, 49（3.0%） with AKIN stage 2 AKI and 21（1.3%） with AKIN stage 3 AKI. urine NGAL concentrations at surgical intensive care unit （SICU） admission were significantly related to AKI severity. The AUCs for urine NGAL were for AKIN stage 1 （0.54±0.02）, AKIN stage 2 （0.67±0.04）, and AKIN stage 3 （0.76±0.06）, respectively. Conclusions Urinary NGAL is associated with CSA-AKI and its progression, indicating their potential use as prognostic markers. Urine NGAL level measured at SICU admission predicts the development of severe AKI after cardiac surgery.