Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening condition caused by a build-up of waste products called ketones in the blood. It occurs in people with diabetes mellitus when they have no, or very low levels of, insulin.

DKA mostly occurs in people with type 1 diabetes, but it can also occur in some people with type 2 diabetes and pregnant women with gestational diabetes.

Causes

Glucose is an essential energy source for the body's cells. When food containing carbohydrates is eaten, it is broken down into glucose that travels around the body in the blood, to be absorbed by cells that use it for energy.

Insulin works to help glucose pass into cells. Without insulin, the cells cannot absorb glucose to use for energy. This leads to a series of changes in metabolism that can affect the whole body.

The liver attempts to compensate for the lack of energy in the cells by producing more glucose, leading to increased levels of glucose in the blood, also known as hyperglycaemia.

The body switches to burning its stores of fat instead of glucose to produce energy. This leads to a build-up of acidic waste products called ketones in the blood and urine. This is known as ketoacidosis, and it can cause heart rhythm abnormalities, breathing changes and abdominal pain.

The kidneys try to remove some of the excess glucose and ketones. However, this requires taking large amounts of fluid from the body, which leads to dehydration.

This can cause:

• Increased concentration of ketones in the blood, worsening the ketoacidosis;
• Loss of electrolytes such as potassium and salt that are vital for the normal function of the body's cells, and;
• Very low blood pressure that can lead to shock and failure of vital organs.

Signs and symptoms

Symptoms of DKA can develop over the course of hours. They can include:

• Increased thirst;
• Increased frequency of urination;
• Abdominal pains, which can be severe;
• Nausea and vomiting;
• Shortness of breath and rapid breathing;
• A fruity smell to the breath, similar to the smell of nail polish;
• Drowsiness and confusion;
• Flushed cheeks;
• Headache, and;
• General weakness and fatigue.

DKA can rapidly cause severe dehydration.

People who self-test their own blood and urine may notice:

• Higher blood glucose levels, and;
• Higher ketone levels in the urine.

If you notice signs or symptoms of DKA, it is important to contact your doctor immediately or seek emergency treatment. This is the case even if there has not been a previous diagnosis of diabetes.

Methods for diagnosis

Your doctor may ask you about your symptoms, results of any self-testing of blood glucose and ketone levels and any factors that might have triggered DKA.

A physical examination can help to evaluate the severity of symptoms. In particular, your doctor may focus on checking for signs of dehydration.

Blood tests and urine tests are used to detect DKA by measuring the levels of glucose and ketones.

A hand-held portable glucose measuring device. 

Other tests may be recommended to detect any underlying conditions that may have triggered the DKA and determine if you have any complications.

These can include:

• Blood tests for electrolyte levels, such as sodium and potassium;
• Amylase test, which detects an enzyme released by the pancreas when it is inflamed;
• Arterial blood gas test, which measures levels of oxygen and carbon dioxide in the blood and can measure acidity in the blood;
• Glycated haemoglobin test, which can help to determine whether diabetes control is an ongoing problem, or whether it was due to a one-off problem with insulin levels;
• Chest X-ray, and;
• Electrocardiography (ECG) to check for any heart rhythm abnormalities.

Types of treatment

DKA usually requires treatment in a hospital. Treatment aims to:

• Treat dehydration by replacing lost fluids, either intravenously (IV) or by mouth;
• Replacing lost electrolytes to help your cells and organs function correctly, and;
• Reduce the high level of glucose in the blood by administering insulin, usually IV.

It is important that this treatment be monitored carefully to make sure that glucose and electrolyte levels are maintained at safe levels, or complications may develop.

Any underlying conditions that may have triggered DKA may also need treatment. If the DKA is a sign of undiagnosed diabetes, your doctor will develop a plan to help you manage your diabetes.

Potential complications

Complications that can occur with treatment of DKA include:

Hypoglycaemia

If insulin causes blood glucose levels to drop too low, this can cause hypoglycaemia, a serious condition that can cause people to lose consciousness.

Hypokalaemia

Replacement of fluids to treat dehydration can lead to potassium levels falling too low, known as hypokalaemia. As potassium is vital for the function of muscles, nerves and the heart, this can be dangerous.

Cerebral oedema

If blood sugar levels change too quickly, it can lead to swelling in the brain (cerebral oedema), particularly in children. In turn, this swelling restricts the flow of oxygen-rich blood to the brain, which can result in the damage or death of brain cells.

Careful monitoring of blood glucose and electrolyte levels during treatment can help to prevent these complications.

Prognosis

With prompt treatment, the prognosis of DKA is generally good. However, every year people still continue to die from diabetic ketoacidosis, often as a result of not seeking treatment early.

Prevention

While DKA cannot always be prevented, by managing diabetes well, you can significantly reduce the risk of it occurring.

Steps you can take include:

• Regularly monitoring your blood glucose to make sure it stays within healthy levels. Your doctor can advise on how often you may need to check it;
• Checking your ketone levels if advised to do so by your doctor, and;
• Taking insulin and/or other diabetes medications as directed by your doctor.