Hyperglycemic hyperosmolar state (HHS)

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Seen in unwell patients with type 2 DM.
The history is longer (e.g. 1wk) with marked dehydration and glucose >540 mg/dL.
There is no switch to ketone metabolism, so ketonemia stays <3mmol/L and pH >7.3.
Osmolality is typically >320mosmol/kg.

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Management

1. Give LMWH prophylaxis to all unless contraindication
   • Occlusive events are a danger (focal CNS signs, chorea, DIC, leg ischemia/rhabdomyolysis)
2. Rehydrate slowly with 0.9% saline IVI over 48h
   • Typical deficits are 110–220mL/kg, i.e. 8–15L for a 70kg adult.
3. Replace K⁺ when urine starts to flow (see DKA article for k⁺ replacement).
4. Only use insulin if blood glucose not falling by 90 mg/dL/h with rehydration or if ketonemia
   • Start slowly 0.05u/kg/h.
   • Keep blood glucose at least 180–270 mg/dL for first 24 hours to avoid cerebral oedema.
5. Look for the cause, e.g. MI, drugs, sepsis, or bowel infarct.

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