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Hyperosmolar hyperglycaemic state — SCE Acute Medicine MCQ

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HardAcute Renal and Metabolic EmergenciesHyperosmolar hyperglycaemic stateSCE Acute Medicine

A 79-year-old man with type 2 diabetes is admitted with confusion after a week of thirst and weight loss. Glucose is 46 mmol/L, osmolality 338 mOsm/kg, ketones 0.8 mmol/L, pH 7.36 and sodium is 154 mmol/L after correction. He is clinically dehydrated but not shocked. What is the most appropriate initial management?

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Correct answer: A — Start cautious intravenous 0.9% sodium chloride with close osmolality monitoring

HHS is primarily a profound dehydration and hyperosmolality problem, so cautious 0.9% saline replacement with osmolality monitoring is first-line. Early insulin can drop osmolality too quickly and precipitate circulatory collapse or neurological injury unless significant ketosis is present. Hypernatraemia after correction reflects water loss and does not mean fluids should be withheld. The safe target is gradual osmolality reduction.

Reference: JBDS HHS guideline, BNF