Risk factors for short-term mortality in elderly critically ill AKI patients treated with CRRT in the ICU: a retrospective cohort study

BACKGROUND: Continuous renal replacement therapy (CRRT) is important for elderly critically ill patients with acute kidney injury (AKI), but the mortality rate associated with this treatment remains high, and the risk factors for mortality have yet to be identified. This study explored the independent risk factors for 28-day mortality among elderly patients receiving CRRT. METHODS: This retrospective study included clinical data from 144 elderly (≥ 60 years old) critically ill AKI patients in the intensive care unit (ICU) who received CRRT at Jinqiu Hospital in Liaoning Province from December 2015 to December 2024. Baseline characteristics, laboratory indicators 24 h before CRRT and Sequential Organ Failure Assessment (SOFA) scores were recorded. Cox regression analysis was used to analyze the risk factors for all-cause mortality within 28 days. RESULTS: The 28-day mortality rate of elderly critically ill patients was 50%. Multivariate Cox regression analysis revealed that elevated lactate levels (HR = 1.167, 95% CI 1.061–1.283; P = 0.001) and elevated SOFA scores (HR = 1.152, 95% CI 1.045–1.269; P = 0.005) were independent risk factors for 28-day mortality. CONCLUSION: The SOFA score and elevated lactate level were found to be independent predictors of 28-day mortality among elderly critically ill AKI patients who underwent CRRT. Additional studies with larger sample sizes are needed to validate these results.