What are the typical laboratory criteria for diagnosing diabetic ketoacidosis (DKA)?

• A. Hyperglycemia >250 mg/dL; anion-gap metabolic acidosis (pH < 7.3 or HCO3- < 18 mEq/L); ketonemia/ketonuria.
• B. Hyperglycemia >600 mg/dL; no acidosis; normal ketones.
• C. Hypoglycemia <70 mg/dL; low bicarbonate.
• D. Hyperosmolar hyperglycemic state criteria only.

Answer: (A)

Diagnosing diabetic ketoacidosis hinges on a trio of lab features: high blood glucose, a metabolic acidosis with an elevated anion gap, and ketosis. The best answer reflects this combination: glucose above about 250 mg/dL, a metabolic acidosis with pH less than 7.3 or bicarbonate under 18 mEq/L, and the presence of ketones in blood or urine. The acidosis comes from accumulating ketoacids produced when insulin is low and counterregulatory hormones are high, leading to both hyperglycemia and ketosis. The anion gap metabolic acidosis is the telltale pattern because the ketoacids raise the gap.

Why the other options don’t fit: one describes very high glucose with no acidosis and no ketosis, which aligns more with a hyperosmolar state rather than DKA. Another mentions low glucose, which isn’t DKA. The last implies only hyperosmolar state criteria, not the ketoacidosis component that defines DKA.