Renal resistance index during septic shock.

Introduction: Acute kidney Injury (AKI) is the most frequent complication of septic shock. Bedside ultrasound measurement of the renal resistance index (RRI) is an interesting way of assessment of renal hemodynamics.

Aims: To study the variability of RRI during septic shock and its correlation with the occurrence of AKI.

Methods: This is a prospective observational study including patients in septic shock and on mechanical ventilation. Data collection was carried out between October 2022 and July 2023. RRI was measured during the first five days of shock.

Results: Forty patients were enrolled in the study. Mean age was equal to 51 years ±13.4 and sex ratio was equal to 2.33. The mean RRI value was 0.704, with extremes ranging from 0.52 to 0.83. Patients were divided into two groups : AKI(+) and AKI (-). RRI in the group AKI (+) was higher than in the group AKI (-) (0.757 vs. 0.672; p=0.013). RRI predicted the occurrence of AKI, with an area under the ROC curve of 0.75 (p=0.007) and a cut-off value of 0.71 (specificity=64%, sensitivity=73%).

Conclusion: Assessment of RRI could be a useful technique of predicting the onset of AKI in association with the conventional markers. Its validation will guide management towards optimal renal protection in patients with septic shock.