Mean Arterial Pressure to Renal Resistive Index Ratio Predicts Sepsis-Associated Acute Kidney Injury in Intra-Abdominal Infections

Abstract

Background

Sepsis-associated acute kidney injury (s-AKI) is a frequent and severe complication in patients with intra-abdominal infections, however, early prediction remains challenging. This study aimed to evaluate the predictive value of the mean arterial pressure(MAP) to the renal resistive index(RRI) ratio (MAPRRI) for s-AKI in this population.

Methods

In this single-center, retrospective observational study, 530 patients with sepsis secondary to intra-abdominal infections were enrolled between January 2021 and December 2024. Participants were classified into AKI and No-AKI groups on the basis of the KDIGO criteria. Univariate and multivariate logistic regression analyses were performed to identify risk factors for AKI. Propensity score matching (PSM) was applied to reduce confounding effects. Receiver operating characteristic (ROC) curves were generated to assess the predictive performance of MAPRRI, MAP, and RRI.

Results

Among the 530 patients, 104 (19.62%) developed AKI. Multivariate analysis revealed that the MAPRRI was an independent predictor of s-AKI (OR 0.861, 95% CI: 0.830-0.893; p < 0.001). After PSM, the MAPRRI remained significantly lower in the AKI group (84.6 vs 87.8, p < 0.001) and predicted s-AKI with an AUC value of 0.821 (95% CI: 0.760-0.881), outperforming MAP (AUC = 0.758, p = 0.003) and the RRI (AUC = 0.708, p < 0.001) alone. The optimal MAPRRI cutoff was 101.3, with 88.5% sensitivity and 68.1% specificity.

Conclusion

Compared with individual parameters, the MAPRRI is a strong independent predictor of s-AKI in septic patients with intra-abdominal infection and has superior predictive ability. It shows promise for early risk stratification and merits further multicenter validation.