Elevated Renal-Resistive Index as an Indicator of Acute Kidney Injury Associated With Neonatal Extracorporeal Membrane Oxygenation

Objective: The authors aimed to assess the relationship between elevated renal-resistive index (RRI) and acute kidney injury (AKI) related to extracorporeal membrane oxygenation (ECMO) in neonatal patients. Design: This was a retrospective study. Setting: The study was conducted at a teaching hospital. Participants: Sixteen neonates treated with ECMO at the authors' hospital between June 2021 and December 2022 were included in this study. Interventions: Demographic and clinical data of patients were collected from the computer database. The RRI of patients before and during ECMO treatment was measured by bedside ultrasound. A receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic value of elevation of RRI as evidence of neonatal ECMO-related AKI. Logistic regression analysis was utilized to calculate the odds ratio (OR) with a 95% CI. Measurements and Main Results: A total of 16 patients met the inclusion criteria. For the primary outcome, the authors observed that the RRI during ECMO therapy was significantly elevated in patients with AKI compared to those without AKI. As for the secondary outcome, ROC curve analysis revealed an optimal RRI cutoff of 0.797, with an area under the curve of 0.855 (95% CI, 0.664-1, p = 0.027). The sensitivity and specificity of RRI values >0.797 for diagnosing AKI were 72.7% and 80%, respectively. Univariate logistic regression analysis indicated an OR of 1.433 (95% CI 1.192-1.873, p < 0.05) for RRI values above 0.797. This association remained statistically significant even after adjusting for serum cystatin C and Sequential Organ Failure Assessment score, with an adjusted OR of 1.352 (95% CI 1.108-1.612, p < 0.05). Conclusion: The elevation of the RRI demonstrated a strong correlation with the onset of neonatal ECMO-related AKI, which may offer valuable support for diagnosing neonatal ECMO-related AKI. (c) 2023 Elsevier Inc. All rights reserved.