MedlinePlus Medical Encyclopedia: Diabetic hyperglycemic hyperosmolar coma

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Diabetic hyperglycemic hyperosmolar coma

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Illustrations

Food and insulin release

Alternative names Return to top

Nonketotic hyperglycemic coma; NKHHC; HONK - hyperosmolar non-ketotic coma

Definition Return to top

Diabetic hyperglycemic hyperosmolar coma is a complication of type 2 diabetes that results in extremely high glucose levels without the presence of ketones (a by-product of fat that can cause other complications).

Causes, incidence, and risk factors Return to top

Diabetic hyperglycemic hyperosmolar coma is a condition of decreased consciousness, extreme dehydration (lack of water), and extremely high blood glucose (sugar) levels, which is not accompanied by ketoacidosis.

The condition is usually seen in people with non-insulin-dependent diabetes (type 2 diabetes) and may occur in those previously undiagnosed with diabetes or in those who have improperly managed their medications and diet. The condition may be brought on by an infection or by certain medications that impair glucose tolerance or increase fluid loss.

Normally, the kidneys compensate for high glucose levels in the blood by excreting excess glucose in the urine. However, when water is scarce, the kidneys conserve fluid, and glucose levels become higher. This results in greater need for water.

Hyperosmolarity is a condition in which the blood is concentrated with sodium, glucose, and other molecules that normally attract water into the bloodstream. When the kidneys are conserving water, however, this creates a vicious cycle of increasing blood-glucose levels and increasing dehydration.

Risk factors include:

Older age
Underlying kidney insufficiency
Congestive heart failure
Recent discontinuation of insulin or oral hypoglycemic agents
Improper management of diabetes
A precipitating event such as infection, heart attack, stroke, or recent surgery.

Symptoms Return to top

The onset of symptoms may be over a period of days or weeks.

Additional symptoms that may be associated with this disease:

Speech impairment
Loss of feeling or function of muscles
Dysfunctional movement

Signs and tests Return to top

Vital signs (temperature, pulse, rate of breathing, blood pressure):

Temperature -- higher than 38 degrees Centigrade (100.4 degrees Fahrenheit)
Heart rate -- greater than 100
Systolic blood pressure -- low (less than 100)

Tests:

Blood glucose -- severely elevated (from 600 to 2,400 mg/dL)
Elevated serum osmolarity
Elevated serum sodium
Evaluation for possible underlying causes
- Chest x-ray
- Blood cultures
- Urinanalysis
- Electrocardiogram (ECG)

Treatment Return to top

The goal of treatment is to correct the dehydration, which will improve the blood pressure, urine output, and poor circulation. Fluids and potassium are replaced by intravenous therapy. High glucose levels are treated with intravenous insulin.

Expectations (prognosis) Return to top

The death rate associated with this condition is as much as 40%.

Complications Return to top

Acute circulatory collapse (shock)
Blood clot formation
Brain swelling (cerebral edema)
Increased blood acid levels (lactic acidosis)

Calling your health care provider Return to top

This condition is a MEDICAL EMERGENCY! Go to the emergency room or call the local emergency number (such as 911) if signs or symptoms of diabetic hyperglycemic hyperosmolar coma develop.

Prevention Return to top

Good control of type 2 diabetes, coupled with recognition of early signs of dehydration and infection, can help prevent this condition.

Update Date: 8/6/2004

Updated by: Aniket R. Sidhaye, M.D., Division of Endocrinology and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.