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Hyperosmolar hyperglycaemic state — UKMLA MCQ

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HardEndocrinology & DiabetesHyperosmolar hyperglycaemic stateUKMLA

A dehydrated adult with type 2 diabetes has glucose 44 mmol/L, measured osmolality 356 mOsm/kg, pH 7.36 and blood ketones 1.0 mmol/L. There is no shock or heart failure. What should be started first?

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Correct answer: E — Begin intravenous 0.9% sodium chloride replacement

E is correct. This is HHS without significant ketoacidosis. JBDS recommends intravenous 0.9% sodium chloride first because fluids alone lower glucose and osmolality; routine early insulin can make osmolality fall too rapidly and precipitate circulatory collapse. A is the usual DKA insulin rate and is inappropriate at presentation here. B is not the initial HHS regimen. C is not indicated with pH 7.36. D is unsafe in severe hyperosmolality and dehydration. Insulin is added later if osmolality stops falling despite adequate fluid replacement, or earlier when substantial ketonaemia indicates mixed DKA/HHS.

Reference: JBDS/Norfolk and Norwich NHS: HHS national quick-reference guidance: https://www.nnuh.nhs.uk/publication/download/hyperosmolar-hyperglycaemic-state-hhs-in-adults-with-diabetes-quick-reference-guide-national-guidance-quick-reference/