#1414 Acute kidney injury in critically ill cancer patients: risk factors and impact on survival

Abstract Background and Aims Acute kidney injury (AKI) is a common complication in critically ill cancer patients, influencing morbidity and mortality. This study aims to evaluate AKI incidence, risk factors, and outcomes in cancer patients admitted to a intensive care unit (ICU). Method We conducted a retrospective analysis of 4861 ICU admissions of cancer patients from a tertiary hospital. Patients were classified according to KDIGO criteria for AKI. Multivariate Cox proportional hazards models and survival analysis (Kaplan-Meier curves, Log-Rank test) were used to assess risk factors and mortality. Results Our population presented a median age of 69 years-old and 56,9% were male. The most common comorbidities included hypertension (37.3%), diabetes (32.9%), obesity (19.9%), and heart failure (19.1%). Around 10% of patients had chronic kidney disease. AKI was observed in 87.1% of patients (n = 4234), of which 7.7% (n = 325) had KDIGO stage 1, 20.4% (n = 865) had stage 2, and 71,9% (n = 3044) had stage 3. A total of 19.9% (n = 844) of AKI patients required kidney replacement therapy (KRT). A total of 783 patients (16.1%) had neoplastic disease. Regarding cancer distribution, 87.4% (n = 684) had solid tumors, 37.0% (n = 290) had metastatic disease, and 15.5% (n = 121) had hematological malignancies. Compared to non-cancer patients, cancer patients had a significantly higher incidence of AKI (P < 0.001), a greater need for KRT (P = 0.003) and increased mortality (Log Rank P < 0.001). The main risk factors associated with severe AKI included age (HR 1.02, 95% CI 1.01–1.02, P < 0.001), higher SAPSII score (HR 1.02, 95% CI 1.01–1.02, P < 0.001), sepsis (HR 1.47, 95% CI 1.28–1.70, P < 0.001), chronic hepatic disease (HR 1.70, 95% CI 1.30–2.22, P < 0.001), obesity (HR 1.26, 95% CI 1.07–1.48, P = 0.005), and invasive mechanical ventilation (HR 1.28, 95% CI 1.10–1.50, P = 0.001). Hematological malignancies had a stronger association with AKI compared to solid tumors. Though metastatic disease did not independently predict AKI severity. Mortality at one and two years was significantly higher in patients with severe AKI (Log-Rank test P < 0.001). Conclusion AKI is highly prevalent in ICU cancer patients and significantly impacts short- and long-term survival. Identifying modifiable risk factors may aid in early intervention strategies. Hematological malignancies appear more susceptible to AKI than solid tumors.