INCREASE IN CHLORIDE IS ASSOCIATED WITH MAJOR ADVERSE KIDNEY EVENTS IN CRITICALLY ILL PATIENTS

Purpose: This study aimed to identify the association between hyperchloremia at intensive care unit (ICU) admission and/or the increase of blood chloride levels and the incidence of major adverse kidney events within 30 days (MAKE30) in critically ill adults. Methods: We conducted a retrospective study to analyze the data of all adult patients admitted to the ICU of a tertiary academic hospital in China between April 2020 and April 2022. Patients were categorized based on their admission chloride levels (hyperchloremia ≥110 mmol/L and nonhyperchloremia <110 mmol/L) and stratified on the increased chloride levels 48 h after ICU admission (∆Cl ≥5 mmol/L and ∆Cl <5 mmol/L). The primary outcome was the MAKE30 incidence, including in-hospital death, new receipt of renal replacement therapy (RRT), and persistent renal dysfunction (PRD). Association between hyperchloremia at ICU admission and/or the increase of chloride and the incidence of MAKE30 were assessed using logistic regression. Result: A total of 2,024 patients with a median age of 67 years (interquartile range [IQR], 55-76 years) and a median Acute Physiology and Chronic Health Evaluation II score of 22 (IQR, 17-28) were included. Hyperchloremia occurred in 30.9% (n = 625), and ΔCl ≥5 mmol/L occurred in 18.5% (n = 375) of all ICU patients. The overall MAKE30 incidence was 33.6% (n = 680), including a 10.9% of 30-day hospital mortality (n = 220; as well as overall in-hospital mortality, 11.8% [n = 238]), a 20.2% (n = 408) of PRD, and a 18.0% (n = 365) of new RRT. After adjusted for confounders, it was found that ΔCl ≥5 mmol/L (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.096-1.93; P = 0.010), but not hyperchloremia (OR, 0.99; 95% CI, 0.77-1.28; P = 0.947), was associated with increased incidence of MAKE30. Conclusion: An increased chloride level in the first 48 h of ICU admission was an independent risk factor for MAKE30, whereas hyperchloremia at ICU admission was not associated with an increased incidence of MAKE30. Large-scale prospective studies are needed to verify our findings.