Diabetic Comas
Diabetic Comas
What is Diabetes?
Diabetes is a common disorder caused by a lack of insulin or insulin resistance leading to impaired glucose metabolism. Glucose (a simple sugar) is the key component used by the body’s cells to make energy. In order for glucose to move from the blood into most cells insulin is required (exceptions are the brain and exercising muscles). Insulin is a hormone made in the cells of the pancreas and is secreted into the blood in response to the blood glucose level increasing.
There are two different types of diabetes. People with Type I diabetes require insulin injections on a regular basis, it is referred to as ‘insulin dependant diabetes’. This type of diabetes affects around 10-15% of those with diabetes. People with Type II diabetes have ‘insulin resistance’. This means their pancreas is making the insulin but due to a number of factors, most commonly weight, the cells of the body are unable to use this insulin properly. This affects 85-90% of those with diabetes. Type II diabetes is managed by a combination diet, weight loss and medications (called hypoglycaemics). Type 1 diabetes was called juvenile diabetes and Type 2 was called mature onset diabetes. These terms are used less these days, as they do not accurately describe the conditions.
Diabetic Keto-acidosis (DKA)
Keto-acidosis is a serious condition caused by not enough or a lack of insulin in the body. Diabetic ketoacidosis more commonly affects type 1 diabetics and may be the first sign that a person has developed diabetes. Without insulin the body’s cells cannot absorb glucose. The body’s cells begin to use fat as an energy source, which produces ketones (ketoacidosis. The blood glucose level begins to rise, triggering the early characteristic signs of thirst and frequent urination.As the blood glucose level continues to rise, the person becomes more dehydrated and other more serious signs begin to emerge. These can include abdominal pain, vomiting, deep rapid breathing and a ‘sweet smelling’ breath. Diabetic ketoacidosis is a medical emergency, which requires prompt attention. Left untreated the person will become drowsy and may fall into a coma as the blood glucose level and dehydration increase to dangerous levels.
Hyper osmolar Hyperglycaemic Non-Ketotic Coma (HHNKC)
This diabetic emergency is similar to diabetic ketoacidosis (DKA) however there are some notable differences.- The patient produces excess glucose and becomes hyperglycaemic (high blood sugar - BSL).
- The patient quickly becomes dehydrated as the high BSL causes a high urine output (called an osmotic diuresis).
- The patient’s blood becomes very concentrated as the BSL rises and dehydration increases. The blood becomes ‘hyper osmolar’ or very concentrated.
- The rise in blood sugar and blood osmolarity tends to be a lot higher than in DKA. The patient will become drowsier with HHNKC.
- In HHNKC fat metabolism is not a predominant feature and there doesn’t tend ot be a large production of ketones (non-ketotic).
- HHNKC normally affects non-insulin dependant diabetics.
HHNKC is treated the same as DKA. Patients will require insulin and large amounts of fluids.
Hypoglycaemic Coma
Hypoglycaemic coma occurs when the blood sugar level is extremely low and there is not enough sugar or glucose for normal brain metabolism. A patient will become unconscious very quickly and requires a source of glucose urgently. All diabetics should have a emergency plan in place in the event of this occurring. This would usually include keeping a source of rapid glucose on hand in case symptoms occur. These symptoms would include sweating and light-headedness. It is important that if you are unable to wake a diabetic that you do not put anything in their mouth as they may choke. Some diabetics have injections of ‘glucagon’ on hand. This drug stimulates the production of glucose. Treatment of hypoglycaemic coma is usually a dose of concentrated glucose and most patients will recover within minutes. Admission to an intensive care unit would not be required unless there are other problems. However if they have been in a coma for several hours there may be some brain damage.
What happens In Intensive Care?
A person suffering from DKA or HHNKC will require insulin and rapid rehydration (fluid replacement) with intravenous fluid. This will be started in the Emergency Department. Under most circumstances the patient requires a high dependency bed, as they will need frequent blood tests , especially arterial blood gases and a larger amount of intravenous fluids. An insulin infusion will be required to ensure a reliable source of insulin and the blood sugar level (BSL) will be checked frequently. This will be done hourly to start, then less often as the BSL stabilises and falls. An arterial line may be used as the patient will require frequent blood tests to check the BSL, potassium, osmolality (blood concentration) and acid-base status. Once the BSL has fallen a glucose infusion will probably be started to prevent the BSL from falling too quickly. The patient will be connected to a patient monitor. An indwelling urinary catheter will be used to accurately monitor urine output and the amount of ketones in the urine. The amount of ketones is a good indicator of whether the DKA is resolving and the patient’s condition improving. Generally the patient will be ‘nil by mouth’ until the urine is ketone free. Occasionally a nasogastric tube may be needed if the patient is vomiting a lot. Replacement of the body’s electrolytes, especially potassium will also be required. Tests will also be carried out to identify the illness, which has led to the diabetes becoming unstable.
How long will the patient remain in Intensive Care?
A patient’s stay in intensive care will usually only be a few days unless they have other problems or complications.
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The information contained on this page is general in nature and therefore cannot reflect individual patient variation. In addition it reflects Australian intensive care practice which may differ from other countries. It is meant as a back up to specific information which will be discussed with you by the Doctors and Nurses caring for your loved one. ICCMU attests to the accuracy of the information contained here BUT takes no responsibility for how it may apply to an individual patient. Please refer to the full disclaimer.
Diabetic Comas Version 1, K Rolls Clinical Project Officer ICCMU
First published April 2005, revised October 2005
