What are the diagnostic criteria and lab results for euglycemic Diabetic Ketoacidosis (DKA)?

Diagnostic Criteria and Lab Results for Euglycemic Diabetic Ketoacidosis (DKA)

Euglycemic DKA is characterized by metabolic acidosis and ketosis with relatively normal blood glucose levels (<250 mg/dL), requiring the same urgent treatment as traditional DKA despite the absence of significant hyperglycemia. 1, 2

Diagnostic Criteria for Euglycemic DKA

• Blood glucose <250 mg/dL (typically <200 mg/dL) - the defining feature that distinguishes it from traditional DKA 3, 4
• Arterial pH <7.3 (metabolic acidosis) 5, 6
• Serum bicarbonate <15-18 mEq/L 5, 6
• Elevated anion gap >10-12 mEq/L 7
• Presence of ketones in blood and/or urine 5, 6

Laboratory Findings

• Blood glucose: <250 mg/dL (often between 150-200 mg/dL), in contrast to traditional DKA where glucose is typically >250 mg/dL 4, 2
• Arterial blood gases:
  • pH <7.3 (indicating acidosis) 6
  • Reduced serum bicarbonate (<15-18 mEq/L) 5, 6
• Serum ketones: Positive (beta-hydroxybutyrate is the predominant ketone body) 5, 6
• Anion gap: Elevated (>10 mEq/L in mild cases, >12 mEq/L in moderate to severe cases) 7
• Urine ketones: Positive 5, 6
• Effective serum osmolality: Variable, but typically lower than in hyperosmolar hyperglycemic state 5

Additional Laboratory Tests to Obtain

• Complete blood count with differential 6
• Blood urea nitrogen and creatinine 6
• Electrolytes (sodium, potassium, chloride) 6
• Phosphate, calcium, and magnesium levels 6
• Electrocardiogram (to assess for cardiac effects of electrolyte abnormalities) 6

Important Considerations

• Beta-hydroxybutyrate (β-OHB) is the predominant ketone body in DKA and direct measurement in blood is preferred over nitroprusside method, which only measures acetoacetic acid and acetone 5
• During treatment, β-OHB converts to acetoacetic acid, which may falsely suggest worsening ketosis if using nitroprusside method 5
• Venous pH (typically 0.03 units lower than arterial pH) can be used to monitor resolution of acidosis 5

Common Pitfalls in Diagnosis

• Missing the diagnosis due to absence of significant hyperglycemia 1
• Relying solely on urine ketones, which may be less sensitive than serum ketones 6
• Failure to consider euglycemic DKA in patients with risk factors such as SGLT2 inhibitor use, pregnancy, decreased caloric intake, alcohol use, or recent insulin administration 3, 1
• Not distinguishing from other causes of high anion gap metabolic acidosis (lactic acidosis, alcoholic ketoacidosis, salicylate toxicity, etc.) 6, 7

Resolution Criteria

• Blood glucose <200 mg/dL 6
• Serum bicarbonate ≥15-18 mEq/L 6
• Venous pH >7.3 6
• Normalized anion gap 6

Euglycemic DKA requires the same aggressive treatment approach as traditional DKA, with the important modification of earlier administration of dextrose-containing fluids to maintain adequate glucose levels while continuing insulin therapy to clear ketones 3, 1.