Insulin acts as a key to allow glucose to move from the blood into the cells where it is used as energy. If you have diabetes and do not have enough insulin, the body cannot use glucose properly. The body will try to make its own energy by releasing glucose from its own stores. It also breaks down fat leading to ketone production. The body also produces ketones if you starve for long periods as the body runs out of glucose.
Ketones can provide short term energy but they are acids and can make you feel very ill. Ketones cause insulin resistance which means you need more insulin than usual to have the same effect. If ketones are not treated quickly they can lead to diabetic ketoacidosis (DKA), which is discussed in more detail in section J7. Your body will try to get rid of ketones in the urine and also in your breath. They smell like pear drops but not everyone can smell them.
Early identification and management of rising ketone levels can reduce the risk of DKA.
Not enough insulin (insulin resistance) = Ketone Production:
Not enough glucose = Ketone Production:
There are several situations in which either the body does not have enough insulin or the body cannot respond as well to insulin. This causes glucose levels to rise increasing the risk of ketone production.
When your HbA1c is high, there is regularly not enough insulin in the body and blood glucose levels are high most of the time.
Children and young people whose diabetes control is optimised should not experience more illness or infections compared to children and young people without diabetes. However, routine childhood illnesses (e.g. viral infections) can make diabetes management more challenging and increase the risk of DKA. During illness, particularly those associated with high temperatures, the body works much harder and demands more glucose. As the body tries to fight infection it releases stress hormones, which both encourage the body to release more glucose and cause insulin resistance leading to ketones.
Illness can affect glucose levels prior to the onset of the illness, during the illness and for several days after. It is extremely important to monitor glucose levels and ketones when unwell.
During times of rapid growth and puberty the body needs more insulin as the pubertal hormones make your body less responsive to insulin. Young ladies with diabetes will often need more insulin around their periods.
Like puberty hormones, stress hormones make your body less able to respond to insulin. Stress can occur in lots of situations including illness, if you have hurt yourself (e.g. broken a bone) or school exams.
When you are on a pump, there is no long-acting insulin in the body only short acting insulin. If your pump insulin runs out or your pump is not working properly, your body will not have enough insulin to use glucose effectively. Therefore, one of the first things to consider if you feel unwell or have high glucose levels with or without ketones is ‘is my pump and infusion set working?’
Check for ketones after any unexpected high glucose result. Pump users should follow these rules:
Ketones will also be produced if there is not enough glucose in the body. These are known as ‘starvation ketones.’ When this occurs your glucose levels may be low or on the lower end of normal range. This tends to be more common in the following situations:
If you miss food for long periods, particularly carbohydrates, the body will naturally form ketones for energy once it has used up its own glucose stores.
Illness associated with vomiting and diarrhoea (e.g. gastroenteritis) may lower blood glucose levels especially if you struggle to tolerate fluids and food.
Exercise demands energy and if there is not enough glucose from carbohydrate, more fats will be broken down to form ketones. Exercise is good for you but if your blood glucose is high or low and ketones are present you should not exercise until your ketones have gone and blood glucose normalised. This is why the diabetes team will support exercise advice individually with you.
General tips:
All patients will be provided with a blood ketone meter and should have access to it at all times. Blood ketones are measured by a finger prick. The result guides management. The higher the result the quicker you need to act.
Ketones must be checked if:
Levels of blood ketones:
The blood ketone and blood glucose level help to determine the specific treatment advised.Below are the key principles of ketone management. All children and young people with diabetes will receive individualised ketone management plans at your annual review as a minimum.
Ketones must be checked if your blood glucose is 14mmol/l and above OR if you feel unwell regardless of your glucose level.
Check your blood glucose and ketones every 1-2 hours. Aim for glucose levels 4-10mmol/L and blood ketones < 0.6 mmol/L.
Contact the Diabetes team URGENTLY if your child has the following symptoms:
DO NOT STOP INSULIN even if not eating. If glucose is low, insulin may need reducing.
The body needs fluids, food and insulin to stop ketone production. Dehydration affects sensor accuracy.
Additional insulin doses should be given every 2 hours until glucose is normal and ketones are less than 0.6mmol/L. If you are on a pump you must give the first correction via a pen injection and then change your pump/cannula. Once confident the pump is re-sited and working illness doses can be delivered manually through the pump.
Contact your GP for general care of the illness. Most medications are sugar free. If not, the amount contained is negligible.
Ketones <0.6mmol/L
Ketones 0.6-1.5mmol/L
Ketones >1.5mmol/L
Glucose Level: 10-14mmol/L Blood Ketone Level: Below 0.6mmol/L (normal)
Recommended Actions:
Glucose Level: 14-22mmol/L Blood Ketone Level: Below 0.6mmol/L (normal)
Glucose Level: Above 22mmol/L Blood Ketone Level: Below 0.6mmol/L (normal)Recommended Actions:
Glucose Level: 10-14mmol/L Blood Ketone Level: 0.6-1.5mmol/L (moderate)
Glucose Level: Above 14mmol/L Blood Ketone Level: 0.6-1.5mmol/L (moderate)
Glucose Level: 10-14mmol/L Blood Ketone Level: Above 1.5mmol/L (high)
Your child is at risk of developing DKA. Watch for signs of abdominal pain, vomiting, drowsiness, confusion or fast breathing. If present take your child immediately to the Emergency Department whilst also following the advice below.
Glucose Level: Above 14mmol/L Blood Ketone Level: Above 1.5mmol/L (high)
Glucose Level: Glucose may occasionally be near normal but usually high. Blood Ketone Level: Above 3.0mmol/L (high)
The ketone level is high. Your child is at high risk of developing DKA. Watch for signs of abdominal pain, vomiting, drowsiness, confusion or fast breathing. If present take your child immediately to the Emergency Department whilst also following the advice below.
There are different ways to calculate the additional doses advised when ketones are elevated.
1. Based on weight in kg – this can be found at the top of your last clinic letter.
Example:
2. Based on total daily dose (TDD) – average insulin required in one day (e.g. long acting insulin (Tresiba or Levemir) dose plus all Novorapid/Fiasp boluses for food and corrections if on injections OR all basal insulin and boluses on a pump. This can be found on your pump/app/Glooko/Carelink upload depending on which system you are using.
Example
Your child has developed cough and cold symptoms with a temperature of 38 degrees. Their glucose is 20 mmol/L and ketones are 1.7 mmol/L. Their total daily dose of insulin is 50 units. The amount of fast acting insulin required is 20% of the total daily dose.
20% of 50 units = 10 units
You would give your child 10 units of fast acting insulin via pen injection and recheck their glucose and ketones in 2 hours. If your child was on a pump, you would change the pump/cannula and check all the equipment was working following pen injection.
2 hours later….
Your child’s temperature has improved and they are feeling a bit better. Their glucose is now 16 and ketones 1.2. You would now give a further correction as ketones are still elevated (this can be delivered via the pump once re-sited). This time the amount of fast acting insulin required is 10% of total daily dose.
10% of 50 units = 5 units
You would give your child 5 units of fast acting insulin and recheck again in 2 hours when the glucose is 9.8 and ketones are 0.5. You can now give your usual correction doses.
Starvation ketones can be challenging to manage, particularly if your child has diarrhoea and vomiting. They do not usually rise above 1.5mmol/L. Please call the diabetes team early for advice.
Key Points:
DKA is a VERY SERIOUS potential complication of diabetes. Ketones are acids and ketoacidosis describes how acidic the blood has become because there is NOT ENOUGH INSULIN in the body. Ketoacidosis can develop within a few hours, especially if you are on an insulin pump and there is an issue with insulin delivery.
DKA can be life threatening. Early recognition and prompt treatment may avoidhospital admission and the need for intravenous insulin and fluids. Please ring thediabetes team for advice.
EARLY Signs that your child is developing ketoacidosis:
LATE signs that your child has developed or is developing ketoacidosis * Seek Urgent Medical Attention: