Evaluation of acute kidney injury in preterm infants using serum creatinine decline in comparison with KDIGO criteria.

Abstract

Background: Acute kidney injury (AKI) is commonly observed in critically ill neonates; however, early identification of AKI in the first week of life is challenging due to the influence of maternal serum creatinine (SCr). An alternative criterion proposed by Gupta et al. based on SCr decline may identify additional infants at risk beyond the KDIGO definition.

Methods: We retrospectively reviewed 409 infants with a gestational age < 32 weeks who were admitted to our NICU between 2018 and 2024. AKI was defined according to the KDIGO guidelines or the Gupta threshold for days 3, 5, or 7 SCr. We compared mortality, bronchopulmonary dysplasia (BPD), and length of hospital stay among the No-AKI, Gupta-only AKI, and KDIGO-AKI groups.

Results: Among 409 infants, 145 (35.5%) had Gupta-only AKI, 9 (2.2%) had KDIGO-only AKI, and 54 (13.2%) had both definitions. The infants with AKI were premature and had lower birth weights than those without AKI. Both AKI groups showed higher rates of composite outcomes (mortality or BPD) than the No-AKI (p < 0.001) group. Gupta-only AKI was associated with prolonged stay (+ 10.1 days, p = 0.01) and increased odds of BPD (adjusted OR 2.12, p = 0.023), while KDIGO-AKI had a stronger association with mortality (27.0%, p < 0.001).

Conclusions: The Gupta definition identified a substantial subset of highly preterm infants at a higher risk of adverse outcomes who were missed using the KDIGO criteria. Integrating SCr level decline-based methods may improve early AKI detection and enhance outcomes in this vulnerable population.