Effect of chloride level on outcome in critically ill patients

Abstract

Background Chloride (Cl) abnormalities in the critical care units have received great attention, especially hyperchloremia as a cause of metabolic acidosis and hypochloremia as a cause of metabolic alkalosis. However, Cl abnormalities themselves have not been studied sufficiently. Aim The aim of this study was to show the effect of Cl abnormalities in critically ill patients. Settings The study was conducted in Critical Care Medicine Department in Alexandria University Hospital. Patients and methods A Prospective clinical study was conducted on 375 critically ill adult patients admitted to Alexandria University hospitals. All patients included were subjected to demographics, diagnosis and cause of admission, relevant medical history, calculated APACHE-II score, and laboratory data (days 1 and 3 after admission), including serum electrolyte level, ABG analysis (anion gap–gap/gap ratio–corrected anion gap), and serum albumin level. According to the recorded Cl levels at days 1 and 3 from ICU admission, patients were defined as normochloremic (99–110 mEq/l), hypochloremic ( 110). Outcome measures were all-cause mortality and length of stay (LOS) in ICU. Results Cl abnormalities at day 1 were associated with increased mortality. The mortality rate was significantly higher in hyperchloremic (67.3%) compared with hypochloremic (72.1%) and normochloremic patients (36.3%) (P Conclusion In a mixed general intensive care population, after careful controlling for confounders, Cl abnormalities (outside 99–110 mEq/l) were independent predictors for poorer outcomes such as ICU mortality and LOS.