Higher serum chloride concentrations are associated with acute kidney injury in unselected critically ill patients

Abstract

Background: Chloride administration has been found to be harmful to the kidney in critically ill patients. However the association between plasma chloride concentration and renal function has never been investigated. Methods. This was a retrospective study conducted in a tertiary 24-bed intensive care unit from September 2010 to November 2012. Data on serum chloride for each patient during their ICU stay were abstracted from electronic database. Cl 0 referred to the initial chloride on ICU entry, Clmax, Clmin and Clmean referred to the maximum, minimum and mean chloride values before the onset of AKI, respectively. AKI was defined according to the conventional AKIN criteria. Univariate and multivariable analysis were performed to examine the association of chloride and AKI development. Results: A total of 1221 patients were included into analysis during study period. Three hundred and fifty-seven patients (29.2%) developed AKI. Clmax was significantly higher in AKI than in non-AKI group (111.8 ± 8.1 vs 107.9 ±5.4 mmol/l; p < 0.001); Cl0 was not significantly different between AKI and non-AKI patients; Cl mean was significantly higher in AKI than non-AKI (104.3 ±5.8 vs 103.4 ± 4.5; p = 0.0047) patients. Clmax remained to be associated with AKI in multivariable analysis (OR: 1.10, 95% CI: 1.08-1.13). Conclusion: Chloride overload as represented by Clmean and Cl max is significantly associated with the development of AKI. © 2013 Zhang et al.; licensee BioMed Central Ltd.