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

Abstract

ObjectiveThis study aims to assess the relationship between elevated renal resistive index (RRI) and acute kidney injury (AKI) related to extracorporeal membrane oxygenation (ECMO) in neonatal patients. DesignThis was a retrospective study. SettingThe study was performed in a teaching hospital. ParticipantsSixteen neonates treated with ECMO in our hospital between June 2021 and December 2022 were included in this study. InterventionsDemographic 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 curve (ROC curve) was constructed to evaluate the diagnostic value of elevation of RRI as an evidence of neonatal ECMO-related AKI. Logistic regression analysis was utilized to calculate the odds ratio (OR) with a 95% confidence interval. Measurements and Main ResultsA total of 16 patients met the inclusion criteria. For the primary outcome, we observed that the RRI during ECMO therapy was significantly elevated in patients with AKI compared to those without AKI. As for the secondary outcome, Receiver Operating Characteristic (ROC) curve analysis revealed an optimal RRI cutoff of 0.797, with an area under the curve (AUC) of 0.855 (95% CI, 0.664-1, p=0.027). The sensitivity and specificity of RRI values greater than 0.797 for diagnosing AKI were 72.7% and 80%, respectively. Univariate logistic regression analysis indicated an odds ratio (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 SOFA score, with an adjusted OR of 1.352 (95% CI 1.108-1.612, p < 0.05). ConclusionThe elevation of the RRI demonstrates a strong correlation with the onset of neonatal ECMO-related AKI, which may offer valuable support for diagnosing neonatal ECMO-related AKI.