Sodium-chloride difference is not strongly correlated with base excess in chronic kidney disease: an anion gap problem.

Introduction: The prevalence of metabolic acidosis is high in patients with chronic kidney disease (CKD). For the diagnosis, a blood gas analysis is necessary, but not always available. The aim of the study was to evaluate the base excess (BE) of the sodium-chloride difference (BE = Na-Cl-34 mmol/l) as a screening parameter for hyperchloremic metabolic acidosis.