The Influence of Chloride for the Interpretation of Plasma Bicarbonate During the Treatment of Diabetic Ketoacidosis

Abstract

Introduction: Hyperchloremic metabolic acidosis can occur in diabetic ketoacidosis (DKA) and may affect the acid-base interpretation during treatment.

Objectives: This study aims to describe the prevalence of hyperchloremia during the treatment of DKA and its effect on the interpretation of bicarbonate value.

Methods: A cross-sectional study, including all cases of DKA in patients aged 1 to 18 years old admitted from 2010 to 2015, was performed. Laboratory tests were performed on admission (baseline), 2 and 6 hours after admission, and when resolution of DKA was achieved. Adjusted bicarbonate value was calculated using regression equations.

Results: Seventy-nine DKA episodes were included. The average age was 13.3 ± 3.8 years. Baseline levels were as follows: plasma glucose, 479 ± 133 mg/dL; pH 7.1 ± 0.083; bicarbonate, 9.65 ± 2.9; and anion gap, 23.9 ± 7.5. The time to achieve resolution of DKA was 12.2 ± 4.4 hours, and the decrease in capillary glucose was 25.5 (19.7-38.2) mg/dL per hour. After 6 hours of treatment, the proportion of patients presenting hyperchloremia increased from 23% to 77%. By using adjusted bicarbonate, the percentage of patients achieving resolution of DKA after 6 hours of treatment would have been 35.4% (confidence interval 95%, 28-49), in comparison with 24.1% (confidence interval 95%, 18-37) using observed bicarbonate (P = 0.004).

Conclusions: The hyperchloremia developed during the treatment of DKA could modify the value of measured plasma bicarbonate concentration and unnecessarily prolong the initial phase of treatment.