BLOOD KETONE TESTING
What are ketones?
Maintaining good blood glucose control is important. When there is not enough insulin in the body, or when the body is under stress such as infection, glucose in the blood cannot enter cells to provide energy and the body starts to break down fats for energy. This leads to ketone
production.
Ketones also need insulin to enter cells and if there is not enough they build up in the blood and are eventually passed through the kidneys into the urine.
While large quantities of ketones can be serious, small amounts of ketones are not harmful and can also be found in people who do not have diabetes (starvation ketones can occur if you miss a meal).
What is ketoacidosis?
In people with diabetes, rising ketones and blood glucose tend to go together, and without insulin, ketones may reach dangerously high levels and cause the blood to become acidic.
This is called diabetic ketoacidosis (DKA) and is an EMERGENCY REQUIRING
IMMEDIATE TREATMENT, IF LEFT UNTREATED THIS CAN BE A LIFE-THREATENING SITUATION.
High blood sugars with ketones lead to you feeling ill with early symptoms of increased thirst, passing urine more frequently. Later symptoms which develop include:
Stomach ache Drowsiness Blurred vision Nausea/vomiting Fast breathing
Fruity odour on the breath (smells of pear drops)
Why check blood ketones?
Detecting ketones early allows prompt action/advice to be given and prevents you becoming seriously ill.
Ketones can be checked in both blood and urine but blood ketone testing is more accurate and tells you what is happening now rather than a few hours ago. The accuracy of urine testing is also affected by some medicines and by how much you drink. Dilute urine can lead to false negatives and if you are dehydrated, a falsely high ketone measurement.
Blood testing gives an early warning of rising ketone levels and an immediate assessment of the response to treatment given. You will have a meter for ketone testing. This tests for blood ketones in the same way as you test for blood sugar levels, so is a familiar method.
When should I check for ketones?
Blood ketones should be tested in the following circumstances:
If your blood glucose level is above 14mmols, on two consecutive tests if you are on a pen, or straight away if you are on a pump
When you are ill/have a high temperature (even minor illnesses can cause ketones) If you have diarrhoea/vomiting (it could be high ketones making you feel sick)
High levels of ketones make your insulin work less effectively, so it may be necessary to give increased doses of insulin
What to do if you have blood ketones and your blood sugar level is
14 or above
Blood ketones mmol/L Action
Less than 0.6mmol/l Normal Repeat test after 2 hours to check level isn’t rising 0.6 – 1.4mmol/l Risk of DKA Drink plenty of sugar free
fluids. Give a correction dose of insulin and retest blood sugar and ketones 1-2 hourly
1.5 – 2.9mmol/l Risk of DKA As above and contact
diabetes team for advice
3.0 or above DKA As above and phone for
URGENT MEDICAL ADVICE – to attend PAU
Abbreviations: DKA – diabetic ketoacidosis, PAU – paediatric assessment unit.
When your ketone levels are raised the most important thing is to give extra insulin and on re-testing the ketone levels should have decreased after 2 hours. Don’t worry if your blood sugar doesn’t decrease as quickly.
What to do if you have blood ketones with a low or normal blood
sugar
If your blood ketone levels are raised but your blood glucose levels are 10mmols/l or below, then you have starvation ketones and you need more carbohydrate food or drink and should phone the diabetes team for advice.
Contact us
When you first go home after diagnosis you will be speaking to the diabetes nurses on the phone every day.
Please ring them between clinic visits with any questions, advice or help you need with your diabetes. If you need advice out of office hours ring the ward.
Diabetes Nurses - Katie Beddows, Sarah Ghezaiel, Francine Lewis (office hours ):0161 419 2103 email address – [email protected]
Brambles Ward: (24 hours) 0161 419 2155
Dr Cooper, Dr Connell: (Secretary) 0161 419 2090 Dietitian: Cathy Head: 0161 419 2103
If you would like this leaflet in a different format, for example, in large print, or on audiotape, or for people with learning disabilities, please contact:
Patient and Customer Services, Poplar Suite, Stepping Hill Hospital. Tel: 0161 419 5678 Information Leaflet. Email: [email protected].
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