Comment on “The influence of hyperchloraemia on acid--base interpretation in diabetic ketoacidosis” by Taylor et al.

Abstract

Sir: I read with great interest the paper “The influence of hyperchloraemia on acid–base interpretation in diabetic ketoacidosis” [1], especially after the introduction, “Diabetic ketoacidosis (DKA) is a common, life-threatening complication of diabetes mellitus in children. . . . The importance of acid–base monitoring during therapy is widely acknowledged, yet many guidelines do not provide detailed instructions on how to interpret and act upon acid–base abnormalities in this setting”. However, in the following seven pages the authors did not say what is life-threatening in DKA. Nor did they give “instructions on how to interpret and act upon acid–base abnormality” with the aim of treating life-threatening situations and preventing them. In DKA, immediately lifethreatening is coma, and according to Alberti et al. [2] the cause of coma is very low blood pH (= very high concentration of hydrogen ions H+). This inhibits the activity of the pH-dependent glycolytic enzyme phosphofructokinase, resulting in impaired utilization of glucose, deleterious especially for brain cells whose main energy-yielding substrate is glucose. Zero lethality in comatose patients with DKA is reported only by authors who have administered to the comatose patients, as soon as possible, infusions of alkalizing solutions to increase the low blood pH (e.g., Wagner et al., reference 18 in the authors’ paper, Umpierrez et al. [3], and Yordam et al. [4]). No doubt, very interesting is the authors’ observation that in DKA the proportion of chloride in the base deficit increases from 2% to 98% during the first 20 h after admission. However, the anions usually measured in DKA – chloride, acetoacetate, β-hydroxybutyrate, bicarbonate – are not life-threatening per se. If an anion is life-threatening, e.g., cyanide CN–, then it is life-threatening as acid HCN and also as alkaline salt KCN or NaCN, regardless of the pH of the solution. In DKA, life-threatening is the high concentration of H+ regardless of the accompanying anion (or anions). References