Epidemiology and risk factors for acute kidney injury in staphylococcus aureus bacteremia

Abstract

Background Staphylococcus aureus bacteremia is a fulminant disease with a high morbidity and mortality. A frequent complication is the development of acute kidney injury, which occurs in up to 40% of these patients, and has been associated with poor outcome and increased mortality. Previous studies have focused mainly on identifying risk factors contributing to the occurrence of acute kidney injury, however, the distribution of etiologies and provided clinical diagnoses have yet not been described. Objectives To determine the epidemiology, risk factors and etiological distribution for the occurrence of acute kidney injury in patients admitted to the hospital with a methicillin-sensitive staphylococcus aureus bloodstream infection. Methods In this retrospective study, medical records were reviewed from patients admitted between 2019 and 2021 to a tertiary-care hospital located in the Netherlands with a staphylococcus aureus bloodstream infection. All patients older than 18 years, without pre-existing renal failure were included. Univariate and multivariate regression analysis was performed to determine the association between clinical, demographical, and biochemical factors with the occurrence of acute kidney injury. Results A total of 158 patients were included in whom 166 staphylococcus aureus bacteremia events occurred. According to the RIFLE criteria, acute kidney injury developed in 49 (30%) patients. Etiologically, acute kidney injury occurred due to pre-renal causes in 27 patients (56%), drug-induced tubulointerstitial nephritis in 7 (14%) patients, acute tubular necrosis in 4 (8%) patients, and renal causes in 4 (8%), of which 3 (6%) immune-related and 1 (2%) thromboembolic. Occurrence of acute kidney injury was associated with higher 30-day -and 1-year mortality, (OR 6.213, p <0.001) and (OR 3.961, p <0.001). Risk factors significantly associated with acute kidney injury in the multivariate analysis were age ≥ 65 (OR 2.353, p =0.039), IC/MC admission (OR 4.408, p =0.001), sepsis (OR 2.653, p =0.021) and severe infective focus (device-related and/or endocarditis) (OR 3.108, p =0.010). Conclusion In this study conducted, acute kidney injury occurred in 30% of patients. Older age, sepsis, IC/MC admission, and focus of infection were identified as indepented risk factors in patients admitted with methicilin sensitive staphylococcus aureus bacteremia. Future research should focus on describing the distribution of causal mechanism leading to AKI and identifying etiology-associated risk factors to detect high-risk patients prone to develop AKI. Thereby aiming to improve early detection, prevention and management of acute kidney injury and reduce kidney-related morbidity, mortality, and clinical burden.