Factors and outcomes related to new-onset acute kidney injury in septic medical intensive care unit patients.

Objective: Sepsis-induced acute kidney injury (AKI) is a significant threat, contributing to worse outcomes in intensive care unit (ICU) patients. Thus, understanding the complex relationship between sepsis and renal dysfunction in ICU patients is crucial. We aimed to investigate the factors that may predispose to the development and the clinical consequences of new-onset AKI in septic medical ICU patients in this study.

Methods: This retrospective cohort was conducted between December 2019 and April 2023 in the tertiary medical ICU of Gazi University Hospital, Ankara, Turkiye. Participants included septic medical ICU patients aged ≥18 without AKI on ICU admission. Data included demographics, comorbidities, disease severity and prognostic scoring, ICU admission, and ICU follow-up data. Statistical analyses, including logistic regression, were performed to identify independent risk factors for new-onset AKI development and ICU mortality.

Results: Patients with new-onset AKI (36% incidence) had higher APACHE-II (21 [16-27] vs. 16 [12-18]) and SOFA (6 [3-9] vs. 3 [2-5]) scores and lower GCS (10 [6-15] vs. 14 [10-15]) on ICU admission (p<0.01 for all results). Independent risk factors for both new AKI development and ICU mortality included invasive mechanical ventilation (IMV) (OR (95% CI): 5.02 [1.59-15] for AKI and OR (95% CI): 13.2 [3-58.8] for ICU mortality, p<0.01), new-onset shock (OR (95% CI): 3.98 [1.42-11.1] for AKI, OR (95% CI): 14.5 [4.4-43.5] for mortality, p<0.01), and higher APACHE-II score (OR (95% CI): 1.08 [1.01-1.16]), for AKI, p=0.05 and (OR (95% CI): 1.04 [1.01-1.08], for mortality, p=0.01). AKI was more frequent in patients whose source of infection was the respiratory system (45% vs. 29%, p=0.01) and catheter-related bloodstream infection (CRBSI) (17% vs. 8%, p=0.03) than those who did not. New AKI development was associated with longer ICU stay (9 [5-18] vs. 5 [3-10] days, p<0.01) and was independently associated with ICU mortality (OR (95% CI): 28.6 [6.6-125], p<0.01).

Conclusion: This study reveals new-onset AKI incidence of 36% in septic medical ICU patients. Additionally, it underlines the potential impact of infection sources on new AKI development. New-onset shock, IMV, and disease severity were independently associated with both new-onset AKI and ICU mortality in this population.