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Cerebral oedema during paediatric diabetic ketoacidosis — MRCEM SBA MCQ

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HardPaediatric emergenciesCerebral oedema during paediatric diabetic ketoacidosisMRCEM SBA

A 10-year-old girl is receiving intravenous 0.9% sodium chloride and an insulin infusion for diabetic ketoacidosis. Her initial venous pH was 7.05 and glucose 30 mmol/L. Two hours later, her glucose is 18 mmol/L and pH is 7.17, but her measured sodium has fallen from 134 to 132 mmol/L. She develops a headache, becomes difficult to rouse, and her GCS falls from 15 to 12. Her heart rate falls from 120 to 68 beats/minute while her blood pressure rises from 100/65 to 132/82 mmHg. She is well perfused. Intravenous 3% sodium chloride is immediately available; 20% mannitol would take at least 30 minutes to obtain. What is the most appropriate immediate management plan?

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Correct answer: D — Give intravenous 3% sodium chloride 3 mL/kg over 10–15 minutes and seek specialist advice.

The falling glucose and improving pH do not explain away this new neurological deterioration. Headache, an unexpected fall in heart rate and rising blood pressure are warning signs of cerebral oedema during paediatric diabetic ketoacidosis; the fall in GCS makes immediate treatment necessary. Sodium would ordinarily rise as glucose falls, so the falling measured sodium adds concern. NICE recommends the most readily available of 20% mannitol or 2.7–3% sodium chloride. The available 3% solution at 3 mL/kg over 10–15 minutes is within its recommended dose range. Seek immediate specialist advice after starting treatment, including advice on the appropriate care setting. ([nice.org.uk](https://www.nice.org.uk/guidance/ng18/chapter/Recommendations)) **A** addresses circulatory shock, but she is well perfused and has a rising blood pressure; it does not treat the suspected cerebral oedema. **B** uses a recommended agent, but waiting 30 minutes is inferior when another recommended agent is available now. **C** delays treatment for imaging despite clinical signs that require immediate action. **E** does not treat cerebral oedema; bicarbonate in paediatric ketoacidosis is reserved for specified cardiac compromise after discussion with a paediatric intensivist. ([nice.org.uk](https://www.nice.org.uk/guidance/ng18/chapter/Recommendations))

Reference: NICE NG18: Diabetes (type 1 and type 2) in children and young people: diagnosis and management — recommendations 1.4.33 and 1.4.54–1.4.58 (Relevant recommendations dated 2015 and 2020) — https://www.nice.org.uk/guidance/NG18/chapter/recommendations NICE NG18: Diabetes (type 1 and type 2) in children and young people: diagnosis and management — recommendation 1.4.34 (Recommendation dated 2020) — https://www.nice.org.uk/guidance/NG18/chapter/recommendations