Perinatal risk factors associated with acute kidney injury severity and duration among infants born extremely preterm.

BACKGROUND: We evaluated time-varying perinatal risk factors associated with early (≤7 post-natal days) and late (>7 post-natal days) severe acute kidney injury (AKI) occurrence and duration. METHODS: A secondary analysis of Preterm Erythropoietin Neuroprotection Trial data. We defined severe AKI (stage 2 or 3) per neonatal modified Kidney Disease: Improving Global Outcomes criteria. Adjusted Cox proportional hazards models were conducted with exposures occurring at least 72 h before severe AKI. Adjusted negative binomial regression models were completed to evaluate risk factors for severe AKI duration. RESULTS: Of 923 participants, 2% had early severe AKI. In the adjusted model, gestational diabetes (adjusted HR (aHR) 5.4, 95% CI 1.1-25.8), non-steroidal anti-inflammatory drugs (NSAIDs) (aHR 3.2, 95% CI 1.0-9.8), and vancomycin (aHR 13.9, 95% CI 2.3-45.1) were associated with early severe AKI. Late severe AKI occurred in 22% of participants. Early severe AKI (aHR 2.5, 95% CI 1.1-5.4), sepsis (aHR 2.5, 95% CI 1.4-4.4), vasopressors (aHR 2.9, 95% CI 1.8-4.6), and diuretics (aHR 2.6, 95% CI 1.9-3.6) were associated with late severe AKI. Participants who had necrotizing enterocolitis or received NSAIDs had longer severe AKI duration. CONCLUSION: We identified major risk factors for severe AKI that can be the focus of future research. IMPACT STATEMENT: Time-dependent risk factors for severe acute kidney injury (AKI) and its duration are not well defined among infants born <28 weeks' gestation. Over 1 in 5 infants born <28 weeks' gestation experienced severe AKI, and this study identified several major time-dependent perinatal risk factors occurring within 72 h prior to severe AKI. This study can support efforts to develop risk stratification and clinical decision support to help mitigate modifiable risk factors to reduce severe AKI occurrence and duration.

The Utility of Urinary NGAL as an Alternative for Serum Creatinine to Detect Acute Kidney Injury in Infants Exposed to Nephrotoxic Medications in the Neonatal Intensive Care Unit.

INTRODUCTION: Nephrotoxic medication (NTM) exposure is commonly associated with acute kidney injury (AKI) in the neonatal intensive care unit (NICU). Baby Nephrotoxic Injury Negated by Just-in-Time Action (NINJA) is a quality improvement program that assesses for AKI in those exposed to NTM with daily serum creatinine (SCr) levels. However, blood draws for SCr are invasive and have clinical disadvantages. Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is a promising indicator of AKI. We tested the hypothesis that uNGAL could reliably screen for NTM-AKI in the Baby NINJA program. METHODS: This two-center prospective study screened 174 NICU subjects, of whom 148 met screening criteria from January 29, 2019, to September 18, 2020. Daily SCr and urine samples were obtained for up to 7 days of NTM exposure plus 2 days after exposure ended or end of AKI. AKI was defined by a SCr rise of 50% from baseline. The highest uNGAL obtained was evaluated to determine its relationship to the diagnosis of AKI. Logistic regression models were used to determine optimal uNGAL cutoffs. RESULTS: The negative predictive value of a uNGAL value ≥250 ng/mL was 96.8% (95% CI = 93.3-100%). Urine NGAL ≥400 ng/mL demonstrated the highest ROC-AUC value of 0.72 with a positive likelihood risk for AKI of 2.76 (1.39-4.13). DISCUSSION/CONCLUSION: We propose that uNGAL could be used to screen for NTM-AKI and thus replace many blood draws needed in those exposed to NTM. The ideal uNGAL threshold requires further investigation in infants.

Association of Fluid Balance With Short- and Long-term Respiratory Outcomes in Extremely Premature Neonates: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Extremely low gestational age neonates are at risk of disorders of fluid balance (FB), defined as change in fluid weight over a specific period. Few data exist on the association between FB and respiratory outcomes in this population. Objective: To describe FB patterns and evaluate the association of FB with respiratory outcomes in a cohort of extremely low gestational age neonates. Design, Setting, and Participants: This study is a secondary analysis of the Preterm Erythropoietin Neuroprotection Trial (PENUT), a phase 3 placebo-controlled randomized clinical trial of erythropoietin in extremely premature neonates conducted in 30 neonatal intensive care units in the US from December 1, 2013, to September 31, 2016. This analysis included 874 extremely premature neonates born at 24 to 27 weeks' gestation who were enrolled in the PENUT study. Secondary analysis was performed in November 2021. Exposures: Primary exposure was peak FB during the first 14 postnatal days. The FB was calculated as percent change in weight from birth weight (BW) as a surrogate for FB. Main Outcomes and Measures: The primary outcome was mechanical ventilation on postnatal day 14. The secondary outcome was a composite of severe bronchopulmonary dysplasia (BPD) or death. Results: A total of 874 neonates (449 [51.4%] male; mean [SD] BW, 801 [188] g; 187 [21.4%] Hispanic, 676 [77.3%] non-Hispanic, and 11 [1.3%] of unknown ethnicity; 226 [25.9%] Black, 569 [65.1%] White, 51 [5.8%] of other race, and 28 [3.2%] of unknown race) were included in this analysis. Of these 874 neonates, 458 (52.4%) received mechanical ventilation on postnatal day 14, and 291 (33.3%) had severe BPD or had died. Median peak positive FB was 11% (IQR, 4%-20%), occurring on postnatal day 13 (IQR, 9-14). A total of 93 (10.6%) never decreased below their BW. Neonates requiring mechanical ventilation at postnatal day 14 had a higher peak FB compared with those who did not require mechanical ventilation (15% above BW vs 8% above BW, P < .001). On postnatal day 3, neonates requiring mechanical ventilation were more likely to have a higher FB (5% below BW vs 8% below BW, P < .001). The median time to return to BW was shorter in neonates who received mechanical ventilation (7 vs 8 days, P < .001) and those with severe BPD (7 vs 8 days, P < .001). After adjusting for confounding variables, for every 10% increase in peak FB during the first 14 postnatal days, there was 103% increased odds of receiving mechanical ventilation at postnatal day 14 (adjusted odds ratio, 2.03; 95% CI, 1.64-2.51). Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, peak FB was associated with mechanical ventilation on postnatal day 14 and severe BPD or death. Fluid balance in the first 3 postnatal days and time to return to BW may be potential targets to help guide management and improve respiratory outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT01378273.