In Reply to ‘Sodium-Chloride Difference as a Simple Parameter for Acid-Base Status Assessment’

We are pleased that Drs Havlin, Matousovic, and Schück1 are in agreement with the conclusions of our recent article.2 However, we would disagree with their assertion that serum sodium-chloride difference is a useful parameter for assessing acid-base status. Quite the contrary, when used as proposed, this parameter can be misleading and therefore can cause errors in diagnosis and management. Whereas the authors would interpret the narrowing of the serum sodium-chloride difference as indicative of normal anion gap (hyperchloremic) metabolic acidosis, it might well evidence respiratory alkalosis or a mixed acid-base disorder.