title: Urinary neutrophil gelatinase-associated lipocalin and acute kidney injury after cardiac surgery.
abstract: BACKGROUND
  Neutrophil gelatinase-associated lipocalin (NGAL) is proposed as an early marker of kidney injury. We report the association of urinary NGAL with indexes of intraoperative renal hypoperfusion (cardiopulmonary bypass time and aortic cross-clamp time) and acute kidney injury (AKI) after adult cardiac surgery.
  
  
  METHODS
  Diagnostic test accuracy.
  
  
  METHODS
  Adult cardiac surgical patients (n = 426) in a single center from 2004 to 2006.
  
  
  METHODS
  Urinary NGAL immediately and 3, 18, and 24 hours after cardiac surgery, using an enzyme-linked immunosorbent assay.
  
  
  METHODS
  Serum creatinine-based definition for AKI (increase in serum creatinine from preoperative values by >50% or >0.3 mg/dL within 48 hours).
  
  
  RESULTS
  Mean urinary NGAL level was 165 +/- 663 (SD) ng/mL preoperatively, peaked immediately after cardiac surgery at 1,490 +/- 102 ng/mL, and remained significantly higher 3, 18, and 24 hours after surgery. 85 patients (20%) developed AKI. Areas under the receiver operating characteristic curve for urinary NGAL immediately after and 3, 18, and 24 hours later as a predictor for AKI were 0.573 (95% confidence interval [CI], 0.506 to 0.640), 0.603 (95% CI, 0.533 to 0.674), 0.611 (95% CI, 0.544 to 0.679), and 0.584 (95% CI, 0.510 to 0.657), respectively. Urinary NGAL, but not serum creatinine, level correlated significantly with cardiopulmonary bypass and aortic cross-clamp times. Areas under receiver operating characteristic curves for cardiopulmonary bypass time and aortic cross-clamp time to predict AKI were 0.592 (95% CI, 0.518 to 0.666) and 0.593 (95% CI, 0.523 to 0.665), respectively.
  
  
  CONCLUSIONS
  Limited sensitivity of changes in serum creatinine levels for kidney injury.
  
  
  CONCLUSIONS
  Urinary NGAL has limited diagnostic accuracy to predict AKI defined by change in serum creatinine after cardiac surgery.
authors.affiliation: Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032-3784, USA. gw72@columbia.edu
authors.forename: Gebhard
authors.initials: G
authors.lastname: Wagener
authors.forename: Gina
authors.initials: G
authors.lastname: Gubitosa
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Niels
authors.initials: N
authors.lastname: Borregaard
authors.forename: Mihwa
authors.initials: M
authors.lastname: Kim
authors.forename: H Thomas
authors.initials: HT
authors.lastname: Lee
mesh_terms: D000208:Acute Disease; D000209:Acute-Phase Proteins / Q000652:urine*; D000368:Aged; D001011:Aorta; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass; D003250:Constriction; D003404:Creatinine / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology* / Q000652:urine*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011518:Proto-Oncogene Proteins / Q000652:urine*; D012372:ROC Curve; D013997:Time Factors
chemical_list: D000209:Acute-Phase Proteins; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine