Abstract
Background: Overlap between diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) is associated with significantly higher mortality than either condition alone. While hypertonic (trans locational) hyponatremia is common in hyperglycemic crises, clinically significant hypernatremia in mixed DKA/HHS presents with certain treatment challenges due to rapid osmotic shifts during insulin therapy.
Case presentations: A 40-year-old woman with non-significant past medical history presented with vomiting, polyuria, polydipsia, and confusion for two days. Laboratory evaluation revealed serum glucose 1280 mg/dL, arterial pH 7.214, bicarbonate 13.1 mmol/L, anion gap 24, β-hydroxybutyrate 6.0 mmol/L, corrected sodium 152 mmol/L (measured sodium 133 mmol/L), and calculated effective osmolality 337 mOsm/kg. Initial treatment with isotonic saline and intravenous insulin led to improvement in hyperglycemia but worsening corrected hypernatremia to 160 mmol/L after 3 liters of normal saline. Free water deficit was calculated at 6.3 L. Fluid therapy was transitioned to hypotonic solutions with titration to limit sodium correction to ≤10 mmol/L per 24 hours. Sodium levels gradually normalized with resolution of ketoacidosis, and improvement in mental status without significant neurologic complications.
Conclusion: In mixed DKA/HHS, early assessment of corrected sodium and effective osmolality is critical. Insulin-mediated intracellular water shifts may unmask or worsen hypernatremia. Prompt reassessment of corrected sodium and individualized fluid management is needed to avoid treatment-related exacerbation of hypertonicity.
Keywords
Diabetic ketoacidosis, Hyperosmolar hyperglycemic state, Hypernatremia