Hyperchloremic Metabolic Acidosis in Diabetic Ketoacidosis – Boon or Bane in Paediatrics? Prospective Cohort Study

Introduction: Patients with DKA generally present with a high anion gap metabolic acidosis (AG > 16) due to the presence of ketones but may also develop a narrow anion gap metabolic acidosis related to hyperchloremia. This study attempts to determine the incidence of hyperchloremic metabolic acidosis (before starting IV fluids) in children with DKA and to evaluate the impact of hyperchloremic metabolic acidosis on acute kidney injury and cerebral edema and inturn on mortality and duration of PICU stay.  Methods: This was a prospective study conducted in the Department of Paediatrics, VIMS, Bellary between May 2016 to December 2017 and a total of 32 patients with DKA were enrolled in the study. Along with routine investigations, ABG and serum chloride levels were measured at the time of admission for categorization into normochloremic (high anion-gap) metabolic acidosis and hyperchloremic (normal anion-gap) metabolic acidosis. Incidence of hyperchloremic metabolic acidosis and its impact on the development of acute kidney injury and cerebral edema was taken as the primary outcome of the study. Mortality rate and duration of PICU stay were taken as a secondary outcome.  Results: Hyperchloremic metabolic acidosis was observed in 18.8% of the study group. Acute kidney injury was seen in 38.4% of children who had normochloremic metabolic acidosis and in 83.3% of children with hyperchloremia. About 50% patients developed cerebral edema in the hyperchloremia group and only 3.8% developed cerebral edema in normochloremic group. These differences were statistically significant. Mortality rate in normochloremic and hyperchloremic metabolic acidosis was 3.8% and 50% respectively. Conclusions: Hyperchloremia at presentation in DKA is a risk factor for increased mortality. This fact should be born in mind while treating patients aggressively with chloride-containing fluids. Simple investigations like ABG and serum chloride levels can direct careful management of DKA and appropriate selection of IV fluids.