Diabetic ketoacidosis — DCH MCQ

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HardPaediatric emergenciesDiabetic ketoacidosisDCH

A 9-year-old girl presents with a 2-week history of polyuria, polydipsia and weight loss, followed by vomiting. Venous plasma glucose is 12.4 mmol/L, blood beta-hydroxybutyrate is 3.4 mmol/L, venous pH is 7.31 and bicarbonate is 14 mmol/L. What is the most likely diagnosis?

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Correct answer: B — Diabetic ketoacidosis

The diagnosis is diabetic ketoacidosis. NICE defines paediatric DKA by hyperglycaemia above 11 mmol/L, ketonaemia above 3 mmol/L or significant ketonuria, and acidosis demonstrated by either pH below 7.3 or bicarbonate below 15 mmol/L. This child meets all three components. The pH of 7.31 does not exclude DKA because the bicarbonate independently satisfies the acidosis criterion. Starvation ketosis may accompany vomiting but does not adequately explain the preceding osmotic symptoms and hyperglycaemia. Ketosis without ketoacidosis is excluded by the bicarbonate of 14 mmol/L. Hyperosmolar hyperglycaemic state usually involves much more marked hyperglycaemia without substantial ketoacidosis, while type 2 diabetes without ketosis is directly contradicted by the raised beta-hydroxybutyrate.

Reference: National Institute for Health and Care Excellence. NG18: Diabetes (type 1 and type 2) in children and young people: diagnosis and management, section 1.4, recommendation 1.4.8. Last updated 2023. https://www.nice.org.uk/guidance/NG18/chapter/recommendations