Dynamic assessment of renal resistive index using point-of-care ultrasonography for early detection of sepsis-induced acute kidney injury: A multicenter clinical trial protocol

BACKGROUND: Acute kidney injury (AKI) is a common and serious complication of sepsis, significantly increasing both mortality risk and healthcare costs. Early prediction and diagnosis of sepsis-associated AKI (SA-AKI) remain challenging due to the delayed detection of existing renal injury markers. Although research suggests that the Renal Resistive Index (RRI) shows promise for earlier prediction of AKI, large-scale, multicenter clinical studies to support this are currently lacking. METHODS: This multicenter, open-label, prospective observational cohort study enrolled 238 patients who were diagnosed with sepsis according to the Sepsis 3.0 criteria. The Renal Resistive Index (RRI) was measured using bedside ultrasound within 2 hours of diagnosis and subsequently every 8 hours during their individualized standard treatment. Concurrently, blood samples were collected to quantify creatinine and cystatin C, and urine samples were obtained to detect kidney injury markers, including TIMP-2/IGFBP-7. The primary endpoint is to determine the threshold and accuracy of the Renal Resistive Index in predicting sepsis-associated acute kidney injury (SA-AKI). Secondary endpoints include examining the dynamic trend of the RRI, assessing the RRI's predictive value for 28-day mortality in sepsis, and evaluating the correlation between the RRI and creatinine, cystatin C, and urinary TIMP-2/IGFBP-7 levels. DISCUSSION: This study assesses the accuracy and feasibility of using bedside ultrasonography to monitor the Renal Resistive Index (RRI) for the early detection of sepsis-associated acute kidney injury (SA-AKI). Early identification of SA-AKI is crucial for improving clinical outcomes in sepsis, making this approach highly relevant for timely intervention. ETHICS AND DISSEMINATION: This study received ethical approval from the Ethics Committee of the initiator's institution. Study results will be initially reported to the collaborating investigators. Following review and consensus by the Trial Steering Committee, the research report will be drafted by the initiating investigator and disseminated through peer-reviewed publications and presentations at scientific conferences. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2400082420), Registered on March 28, 2024.