Provided by A.D.A.M., Inc.
Definition
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, which can cause other complications).
Alternative Names
Nonketotic hyperglycemic coma; NKHHC; HONK - hyperosmolar non-ketotic coma
Causes, incidence, and risk factors
Diabetic hyperglycemic hyperosmolar coma is a condition characterized by 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 and may occur in those previously undiagnosed with diabetes or in those who have improperly managed their medications and diet. The condition may be precipitated 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 are older age; underlying kidney insufficiency; congestive heart failure; recent discontinuation of insulin or oral hypoglycemic agents; improper management of diabetes; and a precipitating event such as infection, heart attack, stroke, or recent surgery.
Symptoms
Weakness
Increased thirst
Nausea
Lethargy
Confusion
Convulsions
Coma
Note: 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
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
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)
The death rate associated with this condition is up to 40%.
Complications
Acute circulatory collapse (shock)
Blood clot formation
Brain swelling (cerebral edema)
Increased blood acid levels (lactic acidosis)
Calling your health care provider
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
Good control of type 2 diabetes, coupled with recognition of early signs of dehydration and infection, can help prevent this condition.
Last Reviewed: 7/26/2002 by Todd T. Brown, M.D., Division of Endocrinology and Metabolism, Johns Hopkins Hospital, Baltimore, MD. Review provided by VeriMed Healthcare Network.
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