#1934 Association between transient AKI and all-cause mortality in critically ill patients according to baseline BUN/SCr ratio and diuretics use

Abstract Background and Aims Previous studies have yielded inconsistent results regarding the prognosis of transient acute kidney injury (AKI). We aimed to assess the risk of mortality and kidney outcomes in critically ill patients with transient AKI according to BUN/SCr ratio (BCR) level and diuretics treatment at baseline. Method We conducted a multicentre retrospective cohort study of critically ill patients, including 131,034 patients from China (CRDS) and 9,778 patients from US (MIMIC-IV) spanning from 2012 to 2021. Transient AKI was defined as AKI that recovered within two days. Study outcomes included one-year all-cause mortality and the occurrence of major adverse kidney events (MAKE). The associations between transient AKI and study outcomes were compared in patients stratified by BCR level and diuretics use at baseline. Results Of 140,812 eligible patients, 3,863 were diagnosed with AKI according to KDIGO criteria and classified as having transient AKI. In patients with a baseline BCR level ≤ 20 (N = 79,883), transient AKI was associated with 42% and 58% increased risk of mortality and MAKE, respectively, compared to those without AKI. However, these associations were not significant in those with a BCR level > 20 (N = 60,929) (P for interaction < 0.05). Similar modified effects of diuretics on the outcomes of transient AKI were also observed. The associations of transient AKI with mortality and MAKE were both significantly different in patients with (N = 26,140) or without (N = 114,672) diuretics treatment before AKI (P for interaction < 0.05). Conclusion The effects of transient AKI on mortality and kidney outcomes in critically ill patients were modified by the BCR level and diuretics use before AKI.