Hyperosmolar hyperglycemic state

Hyperosmolar hyperglycaemic state (HHS) (previously known as hyperosmolar non-ketotic coma (HONK))is a serious metabolic derangement that can occur in patients with diabetes mellitus, predominantly those with type 2. While there are no distinct imaging features, it is useful for a radiologist to be familiar with this condition.

Epidemiology

It usually occurs in type 2 diabetics who have some concomitant illness that leads to reduced fluid intake. The typical patient is 50-70 years old and there may be a precipitating event such as a stroke, MI, chest/urinary infection or systemic inflammatory response ².

Pathology

High blood glucose levels lead to severe dehydration, increases in osmolarity (relative concentration of solute) and, in turn, carries a high risk of complications, coma, and death.

Treatment and prognosis

Hyperosmolar hyperglycaemic state is common in more elderly diabetic patients and is associated with volume depletion without a compensating fluid intake. Principles of management are as follows ²:

• correction of volume depletion with intravenous fluids
• insulin infusion to correct high blood sugar levels (BSLs)
  • rehydration often produces significant reductions in BSLs and HHS patients often require less insulin than DKA patients
• BSL and electrolyte monitoring
• search for precipitating cause

History and etymology

Hyperosmolar hyperglycaemic state is thought to have been first described by von Frerichs and Dreschfeld in the 1880s ¹.

Related pathology

• non-ketotic hyperglycaemic hemichorea
• non-ketotic hyperglycaemic seizures