Summary

• A serious metabolic complication of diabetes characterised by severe hyperglycaemia, hyperosmolality, and volume depletion, in the absence of severe ketoacidosis.
• Occurs most commonly in older people with type 2 diabetes. Contributes to less than 1% of all diabetes-related admissions. However, mortality is high (5% to 15%).
• Presents with polyuria, polydipsia, polyphagia, weakness, weight loss, tachycardia, dry mucous membranes, poor skin turgor, hypotension, and, in severe cases, shock.
• Altered sensorium (lethargy, disorientation, stupor) is common and correlates best with effective serum osmolality. Coma is rare and, if seen, is usually associated with a serum osmolality >320 mmol/kg (>320 mOsm/kg)
• Treatment includes correction of fluid deficit and electrolyte abnormalities, and IV insulin.