LAUSR

BACKGROUND The association between baseline serum chloride levels and mortality in patients with severe AKI is unknown. Our aim was to investigate the relationship between baseline blood chloride levels and 28-day mortality in patients with AKI admitted to the ICU and to detect possible effect modifiers in this population. METHODS AKI patients with severe critical illness were extracted from the MIMICIV. During ICU admission, chloride levels were measured for the first time. Our primary outcome was 28-day mortality in patients with AKI after 24 hours in the ICU. Multivariable logistic regression was used to examine the association between three groups of chloride levels and 28-day mortality, and logistic regression with restricted cubic spline was applied to detect the non-linear trendy. RESULTSː A total of 24,166 patients with critically ill AKI were included in this retrospective cohort study. The total 28-day mortality rate in the ICU was 15.9%. Overall, there was a U-shaped relationship between baseline serum chloride levels and 28-day mortality (non-linear p<0.001). Accordingly, patients with low serum chloride (<96mEq/L) had a significantly increased risk of death compared to patients with normal serum chloride (96-108meq/L) (adjusted OR=1.96, 95% CI=1.70-2.27, P<0.001). None of the variables, including age, gender, 24-hour fluid intake, continuous renal replacement therapy, ventilation, Atrial fibrillation, Sequential Organ Failure Assessment score and whether to measure lactate, significantly modified the association between lower chloride levels and 28-day mortality. CONCLUSIONSː Low serum chloride levels at baseline were associated with death at 28 days in intensive illnesses with AKI.