Value of indices in early diagnosis of cardiac surgery associated acute kidney injury

Jin Ke; Wang Qiu-hui; Dong Liang; Yan Jie

doi:10.3969/j.issn.1002-1949.2017.09.008

Abstract：Objective To evaluate the diagnostic value of urinary indices of cardiac surgery associated acute kidney injury (AKI) at early stage.Methods We performed a prospective study on patients undergoing cardiac surgery.The urine neutrophil gelatinase-associated lipocalin (NGAL), fractional excretion of sodium (FENa), fractional excretion of urea (FEU) measured at before surgery and 1, 6, 24 h following surgery.According to the incidence of AKI, the patients were divided into AKI group and no AKI group.The changes of those urinary indices were analyzed.Results 76 patients were enrolled;21 (27.6%) patients after cardiac surgery developed AKI.Age, male rate, APACHE Ⅱ score, aortic cross-clamp time and length of ICU stay in AKI group were significantly higher than in no AKI group (P<0.05).Urine NGAL in patients with AKI was significantly higher compared with that in patients without AKI 24 h after cardiac surgery (P<0.05).FENa was statistically significant 1,6, 24 h after cardiac surgery between two groups (P<0.05);and it was also statistically significant 6 h after cardiac surgery between two groups (P<0.05).24 h after cardiac surgery, the AUC of urinary NGAL was 1.000;the sensitivity was 1.0 and specificity was 1.0 with a cutoff value of 36.9 ng/mL.The AUC of FENa was 0.897;the sensitivity was 0.851 and specificity was 0.782 with a cutoff value of 1.8, at the time point of 1 h after cardiac surgery.FEU showed a 0.952 sensitivity and 1.000 specificity with a cutoff value of 26.5;the AUC was 0.997 6 h after cardiac surgery.Conclusion 6 h FEU, 24 h urine NGAL after cardiac surgery are predictive of AKI.6 h FEU is useful as an early diagnosis indicator.