High blood glucose (hyperglycaemia)

You may experience high blood glucose whilst using your insulin pump. It is important to know how why this might occur and how you can manage it.

Reasons for high blood glucose levels fall into three main categories for an insulin pump user and include:

Increased insulin requirements

Infection
Illness
Stress
Inflammation at the insertion site
Reduced exercise
Hormonal (pregnancy/menstruation)
Steroids

Infusion set

Insertion into a hardened area
Infusion set left in too long
Infusion set dislodged
Infusion set blocked
Empty cartridge
Large air bubble in tubing
Infusion set leaking
Pump failure

Insufficient insulin delivery

Basal rate too low
Forgot to give bolus
Incorrect insulin to carbohydrate ratio/underestimated carbohydrate content of food
Excessive carbohydrates after hypoglycaemia
Rebound high blood glucose level following hypoglycaemia
Pump stopped working
Insulin expired
Insulin exposed to extreme temperatures

What do ketones mean?

In the absence of sufficient insulin, the body’s cells cannot use glucose for energy. The cells will then switch to an alternative energy source and body fat will be broken down to supply the necessary energy.

This rapid breakdown of fat can cause the build-up of substances known as ketones. Eventually, the blood glucose and ketones rise to levels that cause the blood to become acidic and this is known as diabetic ketoacidosis (DKA). The only treatment for DKA is insulin and fluids.

Ketones can be measured in urine by Ketostix or in blood by using a blood ketone meter which is more accurate. It is advisable to check the expiry date on urine and blood strips before use. Many diabetes centres recommend you use a blood ketone meter.

Remember: now you are on a pump, you have no long-acting insulin and ketones will be produced within a few hours if there is insufficient insulin delivered. You will become unwell more quickly on a pump and action needs to be taken immediately.

As DKA can develop and progress quickly and makes you feel very unwell, the next section gives guidelines for you to follow if you are ill.

Test your blood for ketones if you are feeling unwell and blood glucose levels are over 13 mmol/L.

What should I do if I have a positive ketone test? (greater than 0.6 mmol/L)

You should take rapid-acting insulin by syringe/pen injection
Take a correction dose according to your diabetes teams guidance/ using your ISF ratio
Drink plenty of water or sugar-free fluid
Change the infusion set and check pump settings
Consider temp basal increase
Try to identify the cause of high blood glucose and seek help or treatment as necessary
Test blood glucose and ketones every 1–2 hours
Take additional correction doses of insulin as per your diabetes team guidance until blood is negative for ketones
Remember you should not exercise if ketones are present
Contact the diabetes team if high blood glucose levels and ketones persist.

Contact your GP or Accident and Emergency if you are vomiting as dehydration may occur.

Managing high blood glucose without ketones

If your blood glucose level is above 13 mmol/L and your ketone test is negative take your usual correction dose via your pump
Drink plenty of water or sugar-free fluid
Try to identify the cause of high blood glucose and seek help or treatment as necessary
Test blood glucose and ketones every 1–2 hours. If your blood glucose remains above 13 mmol/l repeat your normal correction dose
If ketones are positive, treat as per “What should I do if I have a positive ketone test” above
Do not go to bed until blood glucose levels are normal
If in any doubt about insulin pump convert to pen devices as per your diabetes team guidelines.

Below is this sick day guidance for insulin pump therapy from the ABCD best practice guidelines: