ICU · Endocrine

Hyperosmolar hyperglycaemic state (HHS)

Also known as Hyperosmolar hyperglycaemic state (HHS) · Hyperosmolar non-ketotic coma (HONK) · Hyperosmolar hyperglycaemic non-ketotic syndrome · Hyperosmolar non-ketotic state (HNS)

HHS is a hyperglycaemic emergency of predominantly type 2 diabetes defined by marked hypovolaemia, hyperglycaemia and hyperosmolality without significant ketoacidosis. Diagnostic thresholds differ by guideline: ADA/Diabetes Canada use glucose ≥33.3 mmol/L with osmolality ≥320 mOsm/kg, while the UK JBDS uses glucose ≥30 mmol/L, osmolality ≥320 mOsm/kg calculated as 2×Na + glucose + urea, ketonaemia ≤3.0 mmol/L, pH 7.3 and bicarbonate ≥15 mmol/L. Management is fluid-first: IV 0.9% sodium chloride to restore circulating volume (estimated fluid losses 100-220 mL/kg), a fixed-rate IV insulin infusion (JBDS 0.05 units/kg/h; ADA 0.1 units/kg/h), a 5% or 10% glucose infusion once glucose falls under 14 mmol/L, potassium replacement according to serial levels, and a gradual osmolality decline of 3.0-8.0 mOsm/kg/h. Pooled mortality is 21.1% and is driven by precipitants (non-infective illness 49.5%, infection 44.0%) and vascular complications.

Checked against its sources on 2 Sept 2026