Renal Resistive Index in Severe Preeclampsia: Correlation With Glomerular Filtration Rate and Diagnostic Accuracy for Acute Kidney Injury

Background This study aimed to evaluate the diagnostic performance of renal resistive index (RRI) for predicting acute kidney injury (AKI) and glomerular filtration rate (GFR) in patients with severe preeclampsia. Methods This observational study included 22 patients admitted with severe preeclampsia. RRI was measured at admission. AKI was defined and staged according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Receiver operating characteristic (ROC) curve analysis was used to assess RRI’s ability to predict AKI and measured creatinine clearance. Results Of the 22 patients, 9 (40.9%) developed AKI. Patients who developed AKI had significantly higher admission RRI values compared to those who did not (mean 0.75 ± 0.19 vs. 0.45 ± 0.13, respectively; p < 0.001). The area under the ROC curve for RRI predicting AKI was 0.87 (95% CI, 0.65–0.97). In the multivariate linear regression analysis, RRI showed a borderline significant negative association with adjusted GFR ( β = −112.67; p = 0.095), though the overall model was not statistically significant ( p = 0.23). Conclusion The RRI measured at ICU admission is a promising, noninvasive predictor of AKI in patients with severe preeclampsia, demonstrating good diagnostic accuracy with high specificity at an optimal cutoff.