Base-excess chloride: the best approach to evaluate the effect of chloride on the acidbase status: a retrospective study

To practically determine the effect of chloride on the acid-base status, four approaches are currently used: accepted ranges of serum chloride values; chloride corrections; the serum Cl/Na ratio; and the serum sodium-chloride difference. However, these approaches are governed by different concepts. Our aim is to investigate which approach to the evaluation of the effect of chloride is the best. In this retrospective cohort study, 2529 critically ill patients who were admitted to the tertiary care unit between 2011 and 2018 were retrospectively evaluated. The effects of chloride on the acid-base status according to each evaluative approach were validated by the standard base excess and apparent strong ion difference. To compare approaches, kappa and Bland-Altman tests and a linear regression model were used. In the linear regression model, only base-excess chloride in all the chloride evaluation approaches was significantly related to the standard base excess. In the subgroup, limits of ...