Incidence, Risk Factors, and Outcome of AKI in Preterm Neonates Admitted to the NICU

Abstract

Objective:To determine the incidence, potential risk factors, and outcomes of acute kidney injury (AKI) among preterm neonates.

Methodology: This prospective cohort study was conducted in the neonatal intensive care units (NICUs) of Fatima Memorial Hospital, Lahore, from April 2024 to October 2024. Preterm neonates born between 28 and 36 weeks of gestation were eligible for inclusion. A total of 432 preterm neonates admitted to the NICU of this tertiary care hospital during the study period were enrolled. Neonates with major congenital anomalies or chromosomal abnormalities were excluded. AKI was diagnosed using the modified Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The primary outcomes assessed were in-hospital mortality and duration of hospitalization.

Results: AKI was diagnosed in 178 preterm neonates (41.2%). Maternal anemia emerged as the most significant risk factor, increasing the risk of neonatal AKI by 5.8 times (487%), followed by hemodynamically significant patent ductus arteriosus (hsPDA) (2.89 times; 189%) and mechanical ventilation (1.7 times; 76.8%). In contrast, exposure to antenatal steroids was nephroprotective, reducing the risk of AKI by 63.6%. The mortality rate among neonates with AKI was 16.3% (p < 0.001), with stage 3 AKI demonstrating the highest mortality rate (30%). Kaplan–Meier survival analysis showed a significant reduction in survival duration among neonates with stage 3 AKI, with a mean survival time of 16.51 days.

Conclusion: Approximately two-fifths of preterm neonates in this cohort developed AKI, affecting 178 (41.2%) of the 432 enrolled neonates. Key risk factors included maternal anemia, hsPDA, and mechanical ventilation, while antenatal steroid exposure had a protective effect. Preterm neonates with stage 3 AKI experienced hospital stays that were twice as long and demonstrated a 50% reduction in mean survival (p < 0.001).