Data on early markers for acute kidney injury (AKI) after noncardiovascular
surgery are still limited. This study aimed to determine the diagnostic value
of plasma neutrophil-gelatinase-associated lipocalin (pNGAL) and
intraoperative diuresis for AKI in patients undergoing major abdominal surgery
treated within a goal-directed hemodynamic algorithm. This study is a post-hoc
analysis of a randomized controlled pilot trial comparing intravenous
solutions within a hemodynamic goal-directed algorithm based on the esophageal
Doppler in patients undergoing epithelial ovarian cancer surgery. The
diagnostic value of plasma NGAL obtained at ICU admission and intraoperative
diuresis was determined with respect to patients already meeting AKI criteria
6 hours after surgery (AKI6h) and to all patients meeting AKI criteria at
least once during the postoperative course (AKItotal). AKI was diagnosed by
the definition of the Kidney Disease Improving Global Outcome (KDIGO) group
creatinine criteria and was screened up to postoperative day 3. Receiver
operating characteristic curves including a gray zone approach were performed.
A total of 48 patients were analyzed. None of the patients had increased
creatinine levels before surgery and 14 patients (29.2%) developed AKI after
surgery. Plasma NGAL was predictive for AKI6h (AUCAKI6h 0.832 (95% confidence
interval [CI], 0.629–0.976), P = .001) and AKItotal (AUCAKItotal 0.710 (CI
0.511–0.878), P = .023). The gray zones of pNGAL calculated for AKI6h and
AKItotal were 210 to 245 and 207 to 274 ng mL−1, respectively. The lower
cutoffs of the gray zone at 207 and 210 ng mL−1 had a negative predictive
value (NPV) (i.e., no AKI during the postoperative course) of 96.8% (CI
90–100) and 87.1% (CI 78–97), respectively. Intraoperative diuresis was also
predictive for AKI6h (AUCAKI6h 0.742 (CI 0.581–0.871), P = .019) with a gray
zone of 0.5 to 2.0 mL kg−1 h−1. At the lower cutoff of the gray zone at 0.5 mL
kg−1 h−1, corresponding to the oliguric threshold, the NPV was 84.2% (78–92).
This study indicates that pNGAL can be used as an early marker to rule out AKI
occurring within 3 days after major abdominal surgery. Intraoperative diuresis
can be used to rule out AKI occurring up to 6 hours after surgery
