Early Diagnostic Value of Urinary NGAL in Acute Kidney Injury in Septic Patients.

BACKGROUND

The aim of this study was to evaluate the predictive value of urinary neutrophil gelatinase-associated lipid (uNGAL) for the prediction of sepsis-associated acute kidney injury (SA-AKI).

METHODS

From September to December 2012, 110 patients were prospectively enrolled from the intensive care units (ICUs) of 3 general hospitals. After being admitted to the ICU, the patients were continuously observed for 72 hours. According to the Kidney Disease Improving Global Outcomes (KDIGO) criteria for the diagnosis of acute kidney injury (AKI), the patients were divided into the AKI group (33 patients) and non-AKI group (77 patients). Per the sepsis diagnostic criteria, the patients were classified as septic (79 patients) and non-septic (31 patients). Serum creatinine and uNGAL of the patients were analyzed daily. The difference in uNGAL in septic and non-septic patients, patients with and without AKI, and septic patients with with and without AKI were compared. In addition, the difference in serum creatinine and uNGAL in patients with and without AKI were recorded and compared, and the sensitivity and specificity of uNGAL and sCr for the diagnosis of AKI in the ICU patients were evaluated using the receiver operating characteristic (ROC) curve.

RESULTS

uNGAL levels were all significantly different in septic and non-septic patients (P = .001, P = .028, P = .010, respectively), patients with and without AKI (P = .001, P = .042, P = .001, respectively), septic patients with AKI and septic patients without AKI (P = .003, P = .012, P = .001, respectively) at 24, 48 and 72 hours after being admitted to the ICU, while the difference in sCr was not significant (P = .169) after 24 hours. The area under the ROC curve of uNGAL and sCr in patients admitted to the ICU at 24 hours were 0.828 (95% CI, 0.742 to 0.914) and 0.583 (95% CI, 0.471 to 0.695), respectively. The cutoff value of uNGAL was 170 ng/mL in patients admitted to the ICU at 24 hours, and the sensitivity and specificity were 0.778 and 0.784, respectively. The sensitivity of uNGAL was superior sCr.

CONCLUSION

uNGAL has relatively high sensitivity and specificity in predicting the occurrence of AKI in septic patients, which is superior to sCr and has certain clinical early diagnostic value. uNGAL could be used as an indicator for early diagnosis of AKI in septic patients in the ICU.