Kidney Week

Abstract: SA-PO0683

Optimizing Early AKI Definitions in Preterm Neonates Using the PENUT Trial

Session Information

• Pediatric Nephrology: Transplantation, Hypertension, AKI, Genetics, and Developmental Diseases
  November 08, 2025 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

• 1900 Pediatric Nephrology

Authors

• Starr, Michelle C., Indiana University School of Medicine, Indianapolis, Indiana, United States

Michelle C. Starr, MD, FASN, MPH

• Griffin, Russell, University of Alabama at Birmingham Health System Authority, Birmingham, Alabama, United States

Russell Griffin

• Harer, Matthew W., University of Wisconsin-Madison, Madison, Wisconsin, United States

Matthew W. Harer, MD

• Menon, Shina, Stanford Medicine, Stanford, California, United States

Shina Menon, MD, FASN

• Gist, Katja M., Children's Hospital Colorado, Aurora, Colorado, United States

Katja M. Gist, DO, MS

• Allegaert, Karel, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium

Karel Allegaert, MD, PhD

• Schwartz, Samantha Rose, University of Wisconsin-Madison, Madison, Wisconsin, United States

Samantha Rose Schwartz, MD, MS

• Baeta Baptista, Rute, Universidade Nova de Lisboa Medical School, Lisbon, Lisbon, Portugal

Rute Baeta Baptista, MD

• Selewski, David T., Medical University of South Carolina, Charleston, South Carolina, United States

David T. Selewski, MD, MS, FASN

• Askenazi, David J., University of Alabama at Birmingham Health System Authority, Birmingham, Alabama, United States

David J. Askenazi, MD, MS, FASN

Background

Acute kidney injury (AKI) is common in preterm neonates. Current definitions are adapted from adults and may not be optimal for preterm neonates. Optimized definitions are essential to improve outcome prediction and guide interventions.

Methods

Using serum creatinine (SCr) from the Preterm Erythropoietin Neuroprotection (PENUT) Trial, a RCT in neonates 24-27 weeks gestation, we evaluated 11 SCr-AKI definitions (Table1). Performance was assessed by ability to predict mortality. Youden’s index (YI) was calculated to find SCr thresholds most predictive of mortality (Day 0-2, 3-7 and 8-14).

Results

This study included 923 infants; AKI incidence varied (6.4% [SCr peak >1.5mg/dL] to 58.4% [SCr >75^th% for age]). SCr percentiles had the highest sensitivity for predicting mortality (0.65, 0.5 and 0.38 for 75^th%, 90^th%, and 95^th%, respectively), but uniformly low positive predictive value (Table1).

When evaluating optimal cutoffs, the Day 0-2 fluid-adjusted SCr threshold was 0.87mg/dL. Compared to those below 0.87mg/dL, those with SCr higher than threshold had a higher risk of death (LR+1.83[1.32-2.34,p=.0014]). Infants with an absolute or fluid-adjusted Day 3-7 SCr (1.16mg/dL and 1.05mg/dL) had a higher risk of death (LR+1.85[1.18-2.52,p=.013 and LR+1.76[1.32-2.34,p=.0014] respectively (Table2).

Conclusion

Current neonatal SCr-AKI definitions have limited ability to predict death. Improved definitions may require thresholds at different timepoints (fluid-adjusted or absolute SCr on Days 3-7) plus elements with high specificity (biomarkers, urine output, clinical factors or a combination). Optimizing the definition of neonatal AKI remains a balance between predicting adverse outcomes and timely identification to allow intervention.

Funding

• NIDDK Support

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.2025sjqc1d3g