Neutrophil gelatinase-associated lipocalin as a predictor of complications and mortality in patients undergoing non-cardiac major surgery.

INTRODUCTION We tested the hypothesis that urinary and serum neutrophil gelatinase-associated lipocalins (NGAL) early after non-cardiac major surgery predict postoperative acute kidney injury (AKI), complications and mortality. METHODS We studied 74 patients undergoing orthopedic, vascular and abdominal surgery lasting ≥2 h. NGAL was measured in preoperative, as well as 2- and 6-hour postoperative samples. The primary outcome was AKI. Secondary outcome was postoperative infection and death. RESULTS 10 patients (13.5%) developed AKI, 19 (26%) reached secondary outcomes, of whom 5 (7%) died. Serum NGAL was significantly higher in patients with diabetes and chronic kidney disease (CKD). No significant correlation was detected between serum or urine NGAL and subsequent development of AKI. Urine NGAL at 6 h and serum NGAL at 2 and 6 h were strongly correlated with postoperative infection and death (p = 0.004, p = 0.013 and p = 0.001, respectively). CONCLUSIONS Our data suggest that in the general surgical population, NGAL could serve as a potent early biomarker for postoperative infection, and that the presence of CKD and diabetes mellitus is associated with higher levels of NGAL and may influence its predictive value.