Hyperosmolar Nonketotic Coma
(HHNC; Hyperosmolar Coma; Diabetic Nonketotic Coma; Hyperosmolar Nonketotic State)
Definition
Hyperosmolar nonketotic coma occurs in people with diabetes. It is a life-threatening event. Seek medical attention immediately if you think you have any symptoms of an impending hyperosmolar nonketotic coma.
Causes
Hyperosmolar nonketotic coma is a complication of hyperosmolar hyperglycemic nonketotic syndrome (HHNS). HHNS happens when blood glucose levels rise, often with an illness or infection. Your body trys to get rid of excess blood glucose by passing it through your urine. It also washes out other substances that your body and brain need to function. When HHNS is severe, it can lead to seizures, coma, and eventually death.
Risk Factors
The following factors are thought to increase the risk of hyperosmolar nonketotic coma:
- Older age
- Diabetes and poorly monitored glucose levels
- Infection
- Drugs (eg, diuretics, steroids, anticonvulsant, chemotherapy drugs)
- Disease states ( heart attack, stroke, kidney failure, overactive thyroid gland)
- Substance abuse
- Recent operation
Stroke
Symptoms
Symptoms that may occur before the onset of hyperosmolar nonketotic coma may include:
- High blood glucose (over 600 milligrams per deciliter)
- Dry mouth
- Thirst
- Warm, dry skin
- Absence of sweating
- Fever
- Leg cramps
- Sleepiness
- Confusion
- Vision loss
- Hallucinations
- Weakness or strange movements on one side of the body with or without seizures
- Frequent urination
Diagnosis
If you arrive at the hospital in a hyperosmolar nonketotic coma, your vital signs will be monitored and you may receive the following tests:
- Blood tests—to test blood sugar, electrolytes, kidney function
- Chest x-ray
- Urine tests
- Electrocardiogram (ECG, EKG)—to check your heart's activity
EKG
Treatment
You will likely need treatment in the emergency room and/or the intensive care unit at the hospital. Common treatments for hyperosmolar nonketotic coma include the following:
Prevention
The best way to prevent hyperosmolar nonketotic coma is to monitor your blood glucose levels regularly. Your doctor can instruct you about how often to check your levels, and what the numbers mean. Also, talk with your doctor about how to manage your blood glucose when you are sick.
American Diabetes Association
National Diabetes Information Clearinghouse
Canadian Diabetes Association
Health Canada
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What is hyperosmolar hyperglycemic nonketotic syndrome (HHNS)? American Diabetes Association website. Available at: http://www.diabetes.org/type-2-diabetes/treatment-conditions/hhns.jsp. Accessed December 31, 2012.
Last reviewed December 2012 by Kim A. Carmichael, M.D., FACP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
