32 - Accuracy of Acute Kidney Injury Diagnosis in the Neonatal Intensive Care Unit

Poster Number: 32
Publication Number: 32.1822

Background: Acute kidney injury (AKI) is frequent in the neonatal intensive care unit (NICU), yet AKI is often undetected.

Objective: To determine how frequently AKI goes undetected and identify factors which may impact AKI detection in the NICU.

Design/Methods: Single center, retrospective cohort study including neonates admitted to the NICU between 01/01/2020-06/30/2021. Modified neonatal Kidney Disease: Improving Global Outcomes criteria were used to identify and stage AKI episodes. Comparisons were made between neonates in whom AKI was identified by the medical team during the NICU stay (‘detected AKI’) and neonates in whom AKI was not diagnosed in NICU but was identified by the research team on retrospective review (‘missed AKI’). Statistical methods included Chi Square, Fisher’s Exact, Student’s t, and Wilcoxon Rank Sum tests.

Results: Of the 869 neonates included, 164 (18.9%) experienced AKI during their NICU stay. Of those, 73 (44.5%) had detected AKI and 91 (55.5%) had missed AKI. The 73 neonates with detected AKI experienced 174 AKI episodes; the 91 neonates with missed AKI experienced 134 AKI episodes.

Compared to those with detected AKI, neonates with missed AKI had higher birth weight (BW), higher gestational age (GA), and were more frequently male (p < 0.05, Table). These neonates experienced shorter durations of mechanical ventilation and hospitalization, were less frequently referred to pediatric nephrology at discharge, less frequently completed outpatient nephrology follow-up and had lower mortality (p < 0.05, Table).

Differences in AKI severity and recurrence rates were identified when comparing those with detected AKI to those with missed AKI (p < 0.05, Table). Most missed AKI episodes were stage 1 AKI (114/134, 85.1%) but 20 episodes (14.9%) of missed AKI were stage 2 AKI (p < 0.05). No stage 3 AKI episodes were missed.

Risk factors for AKI including patent ductus arteriosus, sepsis, nephrotoxic medication exposure, hypoxic ischemic encephalopathy, and hypotension requiring pressors were less common in neonates with missed AKI compared to neonates with detected AKI (p < 0.05, Table). Caffeine citrate exposure, which is likely protective for AKI, was less common in those with missed AKI than those with detected AKI (p < 0.05).

Conclusion(s): Despite protocolized AKI care in our NICU, AKI detection remains low, particularly in healthier neonates with higher BW, later GA, lower stages of AKI, fewer risk factors for AKI, and even when AKI was recurrent. Ongoing education is thus warranted. Improvements in recognition and diagnosis of AKI are important next steps in reducing morbidity and mortality.