47 - Acute Kidney Injury Incidence among Extremely Low Birthweight Infants

Poster Number: 47
Publication Number: 47.2254

Background: Acute kidney injury (AKI) is associated with worsened outcomes in the preterm neonatal population and has been found to be an independent risk factor for mortality and increased length of stay. Preterm infants have several risk factors for AKI, including perinatal asphyxia, low APGAR scores, maternal drug administration, respiratory distress syndrome, patent ductus arteriosus, phototherapy, neonatal medication administration (nonsteroidal anti-inflammatory drugs, antibiotics, diuretics.), and lower nephron endowment. Studies have also observed that incidence of AKI is higher in neonates with lower birth weights and gestational ages.

Objective: Therefore, the purpose of this study was to evaluate incidence of AKI in extremely low birthweight (ELBW, < 1000 grams) infants based on birth gestational age.

Design/Methods: After IRB approval, 47 ELBW infants ( < 1000 grams) who were admitted to the neonatal intensive care unit (NICU) between 2016 and 2020 were analyzed. Information about each patient was obtained via chart review. Infants were determined to have an AKI based on the neonatal modified KDIGO AKI criteria of serum creatinine (SCr) rise in ≥ 0.3 mg/dL within 48 hours. The reference SCr was 1.6, 1.1, and 1.0 mg/dL for < 27, 28-29, and 30-32 weeks corrected gestation, respectively. Fisher’s exact test was used to evaluate associations between gestational age and AKI during hospitalization. P-value < 0.05 was considered statistically significant.

Results: There was a significant difference (p = 0.0172) in the incidence of AKI during NICU hospitalization for ELBW infants based on birth gestational age. The incidence of AKI was highest in infants born at 22-23 weeks (81.8%), followed by 24-25 weeks (75.0%) per Table 1. In further evaluation of timing of AKI, there was no significant difference in the incidence within the first 28 days of life across categories of birth CGA (p=0.237).

Conclusion(s): The incidence of AKI in ELBW infants is high, with the highest incidence being in infants born at the lowest gestational ages. Unfortunately, it remains an under-recognized diagnosis in real-time clinical practice. Continued research is needed to better recognize and address AKI in the NICU, including to modify fluid and medication management as well as to identify other risk factors.