What is Hyperosmolar Hyperglycemic Nonketotic Syndrome?

Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS), also called hyperglycemic hyperosmolar coma or similar names, is a medical emergency. It is a complication of type 2 diabetes that is most frequently seen in elderly dehydrated people with diabetes. Dehydration may result in extremely high blood glucose levels, and increased viscosity of the blood. The thickened blood may cause intravascular clotting, including strokes and clots in blood vessels anywhere in the body. HHNS may be fatal, even with aggressive treatment.

What are the signs and symptoms of Hyperosmolar Hyperglycemic Nonketotic Syndrome?

Symptoms may begin gradually and worsen over a few days or weeks. High blood glucose levels is a warning sign of HHNS. Findings may include:

• Blood glucose level over 600 mg/dL (33.3 mmol/L)
• Dry, parched mouth
• Extreme thirst (although this may gradually disappear)
• Warm, dry skin that does not sweat
• Sleepiness or confusion
• Decreased consciousness (obtundation or coma)

Who is likely to develop Hyperosmolar Hyperglycemic Nonketotic Syndrome?

Hyperosmolar Hyperglycemic Nonketotic Syndrome is most likely to develop in elderly dehydrated patients with type 2 diabetes. It may occur in people who were not previously diagnosed as having diabetes.

How is Hyperosmolar Hyperglycemic Nonketotic Syndrome diagnosed?

Diagnosis begins with the medical history and physical examination. HHNS may be brought on by infection, or other illnesses such as heart attack or stroke. Medications such as diuretics that increase fluid loss, or medications that increase blood glucose such as corticosteroids, might also trigger HHNS.

Physical examination will reveal severe dehydration and lowered level of consciousness.

Blood glucose levels are usually the first testing to be performed. This blood test is the most accurate measure of HHNS. Generally, a BG reading above 600 in an obtunded patient means a person has HHNS.

Unlike diabetic ketoacidosis, there is minimal buildup of ketones in the bloodstream.

How is Hyperosmolar Hyperglycemic Nonketotic Syndrome treated?

Treatment is based on intravenous rehydration. Supplemental insulin will usually be required, although sometimes only small doses are needed. Replacement of minerals such as potassium, sodium or phosphate may be needed. Treatment of the underlying cause of the dehydration will also be necessary.

Points to Remember

• Hyperosmolar Hyperglycemic Nonketotic Syndrome is a complication of diabetes that may be fatal.

• Hyperosmolar Hyperglycemic Nonketotic Syndrome most often occurs in elderly people with type 2 diabetes.

• Hyperosmolar Hyperglycemic Nonketotic Syndrome may occur in people with "mild" type 2 diabetes, or who have not previously been diagnosed as having diabetes.

• Signs and symptoms of Hyperosmolar Hyperglycemic Nonketotic Syndrome include blood glucose level over 600 mg/dl; dry, parched mouth and extreme thirst; and warm, dry skin that does not sweat. Other findings might include sleepiness or confusion or unconsciousness.

• Hospitalization for rehydration and insulin therapy will be advisable.

Also see:

• Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS)
• Diabetic hyperglycemic hyperosmolar syndrome
• Diabetic hyperosmolar syndrome
• Diabetic Hyperglycemic Hyperosmolar Syndrome