Diabetic coma
Diabetic coma
About diabetes
Diabetes
is a condition characterised by
high blood glucose (sugar) levels
.
Uncontrolled diabetes may lead to a diabetic coma or unconsciousness.
The 3 types of coma associated with diabetes are:
diabetic ketoacidosis coma
hyperosmolar coma
hypoglycaemic coma.
Diabetic ketoacidosis coma
Diabetic ketoacidosis typically occurs in people with
type 1 diabetes,
which was previously known as juvenile diabetes or insulin dependent diabetes mellitus (IDDM), though it can occasionally occur in
type 2 diabetes
.
This type of coma is triggered by the build-up of chemicals called ketones. Ketones are strongly acidic and cause the blood to become too acidic.
When there is not enough insulin circulating, the body cannot use glucose for energy. Instead, fat is broken down and then converted to ketones in the liver. The ketones can build up excessively when insulin levels remain too low.
Common causes of ketoacidosis include a missed dose of insulin or an acute infection in a person with type 1 diabetes. Ketoacidosis may be the first sign that a person has developed type 1 diabetes.
Symptoms of ketoacidosis
Symptoms of ketoacidosis are:
extreme thirst
lethargy
frequent urination (due to high blood glucose levels)
nausea
vomiting
abdominal pain
progressive drowsiness
deep, rapid breathing
a fruity or acetone smell on the breath.
In order to pick up the earliest signs of ketoacidosis, people with type 1 diabetes whose blood glucose levels are particularly high require more frequent monitoring of blood glucose.
Checking of ketone levels is also recommended. If available, blood ketone testing is preferred. If blood ketone testing is not available, urine testing may be used.
Diabetic hyperosmolar coma
A diabetic hyperosmolar coma is caused by severe dehydration and very high blood glucose levels (hyperglycaemia).
Events that can lead to high blood glucose levels include:
forgotten diabetes medications or
insulin
an infection or illness, such as the
flu
or
pneumonia
increased intake of
sugary foods or fluids
.
Those at most risk of this type of coma are people with type 2 diabetes, who have an infection or acute illness and have reduced their intake of fluids.
The kidneys respond to high levels of blood glucose by doing their best to remove it, along with a great deal of
water
. The person experiencing diabetic hyperosmolarity will be very thirsty, but they can’t drink enough water to replace the lost fluids. They will become dehydrated and urgently need intravenous fluids. Without this kind of treatment, they may lapse into hyperosmolar coma.
Hyperosmolar coma develops slowly over several days or weeks, so if the high blood glucose levels or dehydration are detected and treated early, coma can be prevented.
Diabetic hypoglycaemic coma
Hypoglycaemia
, or low blood glucose levels (below 3.5 mmol/l), may occur if a person on insulin or certain other diabetes medications (such as sulphonylureas tablets):
takes an extra dose or an increased dose
exercises strenuously without eating extra food or reducing their medication
misses a meal or snack
drinks too much
alcohol
or drinks alcohol without eating food.
If the blood glucose falls to very low levels, the person may become unconscious (hypoglycaemic coma) and seizures may occur.
Symptoms of hypoglycaemia
Symptoms of hypoglycaemia include:
tremor
racing pulse or heart palpitations
sweating
weakness
intense hunger
confusion, altered behaviour, drowsiness or coma – these may occur if the blood glucose level becomes very low.
Prolonged or frequent coma should be avoided and hypoglycaemia needs to be treated quickly.
First aid for diabetic coma
First aid
for someone who has lapsed into a diabetic coma includes:
Call triple zero (000) for an ambulance immediately.
Don’t try to give them anything to eat or drink, as they may choke.
Turn them onto their side to prevent obstruction to breathing.
Follow any instructions given to you by the operator until the ambulance officers arrive.
Don’t try to give them an insulin injection.
If available, administer 1 mg of glucagon for rapid reversal of hypoglycaemia.
Diagnosis of diabetic coma
A coma is a medical emergency. A quick diagnosis can save the person’s life. The cause of a diabetic coma is diagnosed using a number of tests including:
medical history
physical examination – the person may be wearing an emergency bracelet identifying their medical condition
blood tests
– including tests for glucose and ketone levels.
Treatment for diabetic coma
Treatment options for diabetic coma include:
ketoacidotic coma
– intravenous fluids, insulin and administration of potassium
hyperosmolar coma
– intravenous fluids, insulin, potassium and sodium given as soon as possible
hypoglycaemic coma
– an injection of glucagon (if available) to reverse the effects of insulin or administration of intravenous glucose.
Where to get help
In an emergency, always call triple zero (000)
Emergency department of the nearest hospital
Your
GP (doctor)
Diabetes specialist
National Diabetes Services Scheme
(NDSS)
External Link
Tel.
1800 637 700
Baker Heart and Diabetes Institute
Clinic
External Link
Tel.
(03) 8532 1800
Diabetes
Victoria
External Link
Tel. 1300 437 386
Juvenile Diabetes Research
Foundation
External Link
Tel.
1300 363 126