The role of renal angina index, renal artery and vein blood flow changes and tissue perfusion indicators in predicting the development and stage of acute kidney injury in sepsis patients in intensive care unit

The Role of Renal Angina Index, Renal Artery and Vein Blood Flow Changes and Tissue Perfusion Indicators in Predicting the Development and Stage of Acute Kidney Injury in Sepsis Patients in Intensive Care Unit Introduction: Accompanying acute kidney injury (AKI) is an important cause of morbidity and mortality in sepsis patients. Therefore, recognition of AKI is of great importance in the care of critically ill patients. In this study, we aimed to determine the role of renal angina index (RAI), renal blood flow, and tissue perfusion indicators in predicting early AKI and its stage in patients with sepsis. Method: This study was performed prospectively on 40 patients who were hospitalised with the diagnosis of sepsis in the Medical Intensive Care Unit Intensive Care Unit (ICU) of Çukurova University Faculty of Medicine between 13 February and 1 December 2023. Demographic data, clinical characteristics, capillary refill time (CRT), RAI, renal resistive index (RRI), intrarenal venous flow, development of ABH, ICU and 28-day mortality rates, hospital and ICU length of stay were evaluated. Results: Renal angina index positivity (10) was found to be higher in patients with AKI and severe AKI (p<0.001 and p=0.001, respectively). No significant difference was found between RRI and patients with AKI and severe AKI. Serum lactate levels at 24th, 48th and 72nd hours in the AKI group and serum lactate levels at all hours in patients with severe AKI were statistically significantly higher (p<0.05). The rate of prolongation in CRT was higher in patients with AKI and severe AKI (p<0.05). Sepsis-related organ failure assessment scores and mortality rates were significantly higher in patients with AKI (p<0.05). The AUC value of RAI value of 10 was 0.961 and the AUC value of 24 h lactate value >2.1 mmol/L was 0.895 in predicting severe ABH. Conclusion: In predicting the development and severity of AKI in septic patients, the practical, cost-effective, and effective indices of the RAI and serum lactate levels can be utilized. The combined use of serum lactate and RAI may be more effective in predicting AKI and its severity. Further studies, involving a larger number of patients, are needed to evaluate renal blood flows in predicting acute kidney injury and its severity. Keywords: Sepsis, Acute Kidney Injury, Renal Angina Index, Lactate, Capillary Refill Time, Renal Resistive Index