Diabetic ketoacidosis (DKA) is a potentially life-threatening complication that may occur in people who have diabetes, most often in those who have type 1 (insulin-dependent) diabetes. It involves the buildup of toxic substances called ketones that make the blood too acidic. High ketone levels can be readily managed, but if they aren't detected and treated in time, a person can eventually slip into a fatal coma.
DKA often leads to people being newly diagnosed with type 1 diabetes. It can also occur in people already diagnosed with type 1 diabetes who have missed an insulin dose, have an infection, or have suffered a traumatic event or injury.
Although much less common, DKA can occasionally occur in people with type 2 diabetes under extreme physiologic stress.
With type 1 diabetes, the pancreas is unable to make the hormone insulin, which the body's cells need in order to take in glucose from the blood. In the case of type 2 diabetes, the pancreas is unable to make sufficient amounts of insulin or your body can't use the insulin it makes properly.
Glucose, a simple sugar we get from the foods we eat, is necessary for making the energy our cells need to function. People with diabetes can't get glucose into their cells, so their bodies look for alternative energy sources. Meanwhile, glucose builds up in the bloodstream, and by the time DKA occurs, blood glucose levels are often greater than 14 mmol/L while insulin levels are very low.
Since glucose isn't available for cells to use, fat from fat cells is broken down for energy instead, releasing ketones. Ketones accumulate in the blood, causing it to become more acidic. As a result, many of the enzymes that control the body's metabolic processes aren't able to function as well. A higher level of ketones also affects levels of sugar and electrolytes in the body.
DKA may occur with insulin deficiency, under the following circumstances:
- during an infection or illness (e.g., urinary tract infection or pneumonia)
- after stressful events or trauma (including heart attack, stroke, or surgery)
- inadequate insulin treatment (e.g., when someone is not yet diagnosed, or someone who is diagnosed but misses a dose of insulin or does not give themselves enough insulin, or someone is using a faulty insulin pump)
- Some medications have been associated with increasing your risk of DKA, including steroids, thiazide diuretics (e.g., hydrochlorothiazide), sympathomimetics (e.g., amphetamine, pseudoephedrine), and a class of medications used in diabetes called SGLT2-inhibitors (e.g., canagliflozin, dapagliflozin, empagliflozin).
Symptoms and Complications
High levels of ketones usually build up in the blood and urine, causing the symptoms of DKA:
- abdominal pain (especially in children)
- decreased perspiration
- deep and laboured breathing (a later symptom)
- dry, cool skin
- excessive thirst and urination
- high blood glucose
- nausea and vomiting
- presence of ketones in the blood or urine
- rapid weight loss
- sweet, fruity odour on the breath (it may smell like nail polish remover)
As ketones accumulate in the blood, more ketones will be passed in the urine, taking sodium and potassium salts out with them. Over time, levels of sodium and potassium salts in the body become depleted, which can cause nausea and vomiting. The result is a vicious cycle.
Dehydration is another complication of DKA. High levels of ketones are associated with high sugar levels in the blood and urine. More water is drawn into the urine, resulting in frequent urination. Combined with vomiting – from an upset stomach, or possibly due to a bout of flu or illness – the body quickly loses too much water and electrolytes. Dehydration can occur rapidly (within hours) and is very serious.
Making the Diagnosis
The amount of ketones in the blood or urine should be checked if a person with diabetes has:
- symptoms of DKA
- fasting blood glucose levels above 14 mmol/L (252 mg/dL)
- infection or illness
Ketone levels can be easily measured at home; a positive test may require immediate medical attention. A doctor or health care professional can show you how to measure the amount of ketones in your blood or urine and let you know at what levels you will need to contact your doctor or go to the emergency department.
Your doctor or health care provider may also take blood tests to measure levels of ketones, electrolytes (e.g., sodium and potassium), pH (a measure of how acidic your blood is), and glucose.
Treatment and Prevention
Treatment for DKA must be done in consultation with a doctor or medical team, most often in a hospital setting. For mild cases, fluid supplementations and extra insulin injections are needed every few hours until ketones in the urine have either disappeared or fallen to low levels. Blood glucose and ketone levels should also be closely monitored during this period.
Dehydration will only make the progression of DKA worse, so it's important to maintain a steady intake of fluids.
For moderate-to-severe cases of DKA, hospitalization with fluid and electrolyte replacement is required. Blood glucose and acid levels will be monitored frequently and electrolytes such as potassium brought back into balance. Insulin will be given to help bring your blood sugar levels back to normal. Urine output will be monitored until your vital signs (temperature, pulse, breathing, blood pressure) are normal.
Appropriate medications will be used if it was an infection that triggered the episode of DKA.
Even with careful attention to insulin treatment, ketone levels may still go up once in a while. Missing even a single insulin injection can also lead to tissue "starvation," fat metabolism, and ketone accumulation. People are especially susceptible when they're ill.
The most important prevention strategies are to monitor blood glucose levels routinely, keep blood glucose levels controlled (e.g., following a treatment plan as recommended by your health care provider), and to detect ketones early on. When blood glucose levels exceed 14 mmol/L, or during a bout of illness, people with diabetes should test their urine or blood at least twice a day for ketones. This way, excess ketones can be dealt with quickly, before the symptoms of DKA progress and worsen. Ensuring you have a sick day management plan created in advance with your health care team can help to prevent DKA from occurring.