Predicting Renal Replacement Therapy Requirement In Sepsis-Associated Acute Kidney Injury Using Furosemide Stress Testing and Urinary Biomarkers.

This study aimed to investigate the predictive value of a model combining the furosemide stress test (FST) with urinary tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP-7) for predicting renal replacement therapy (RRT) initiation within 7 days in patients with sepsis-associated acute kidney injury (SA-AKI). A total of 63 patients with SA-AKI admitted to the intensive care units (ICU) of Zhongwei People's Hospital and the Affiliated Hospital of Ningxia Medical University between January 2025 and November 2025 were enrolled in this study. According to whether RRT was initiated within 7 days, patients were divided into an RRT group (n = 20) and a non-RRT group (n = 43). Clinical characteristics, laboratory parameters, and urinary biomarkers were collected. Urinary TIMP-2 and IGFBP-7 levels were measured using enzyme-linked immunosorbent assay, and the predictive performance of FST combined with urinary [TIMP-2] * [IGFBP-7] was evaluated using multivariate logistic regression and receiver operating characteristic (ROC) curve analysis. The results showed that 20 patients (31.7%) required RRT during follow-up, while 43 patients (68.3%) did not. Compared with the non-RRT group, patients in the RRT group exhibited more severe renal dysfunction and higher incidence of adverse kidney events. ROC analysis demonstrated that the area under the curve (AUC) for FST, baseline TIMP-2*IGFBP-7, TIMP-2*IGFBP-7 measured 2 h after FST, and the combined model were 0.878, 0.820, 0.845, and 0.966, respectively. Multivariate logistic regression further confirmed that the combined FST and urinary TIMP-2*IGFBP-7 indicator was an independent predictor of RRT requirement. These findings suggest that the combined FST and urinary TIMP-2*IGFBP-7 model may be useful for early risk stratification of SA-AKI patients at high risk of requiring RRT.