Ultrasound cardiac output monitoring compared to the renal angina index for early prediction of pediatric acute kidney injury.

BACKGROUND

Acute kidney injury (AKI) is a significant concern within pediatric intensive care units (PICUs), leading to increased morbidity, longer hospitalization, and increased healthcare costs. Serum creatinine and urinary output, conventional diagnostic parameters, are of low sensitivity for predefined AKI recognition. The Renal Angina Index (RAI) improves predictive capacity, but depends on laboratory data and baseline creatinine. This study explores the use of Ultrasound Cardiac Output Monitoring (USCOM), as an adjunctive tool for early AKI prediction.

METHODS

One hundred two children admitted to the PICU of Mofid Children's Hospital in 2024-2025 participated in this prospective observational study. Demographics, laboratory data, RAI score, and USCOM parameters were recorded. AKI was defined by KDIGO. The predictive ability of RAI and USCOM parameters was analyzed using the ROC curve and logistic regression.

RESULTS

Among USCOM parameters, only cardiac index (CI) showed predictive utility. The AUC for CI and RAI were 0.66 (95%CI 0.54-0.77) and 0.70 (95%CI 0.59-0.81), respectively. A positive RAI increased AKI risk 6.23-fold, while abnormal CI conferred a 3.92-fold risk. In addition, higher positive predictive values (60 and 57.1 for RAI and CI, respectively), in this study, indicated improved accuracy in identifying patients who truly developed AKI.

CONCLUSIONS

Both RAI and CI are helpful, informative adjuncts to preliminary AKI prediction in critically ill children. Although these data verify the promise of USCOM-derived cardiac index as a novel, real-time, and non-invasive marker, predictive capability was modest, and generalizability was limited by a single-center design.