Adjusting insulin

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The target range for your blood glucose results is from 4 to 7mmol/l - aim to have four out of every five blood glucose results in this range. If three results in a row at the same time of day are not in the target range, then consider each of these 4 things:
  1. Food - time of day, amount and type of food eaten
  2. Exercise - time of day, amount of activity, and food taken before activity
  3. Injections - time of day, times before meals, and if injection sites are healthy
  4. Illness - see sick day guidelines
After considering all of the above, you can then look at changing the dose of insulin. Here is a step-by-step guide on how to do this safely. Remember, you may need to do this up to twice a week - make a change, and be prepared to make another change in three days.
Targets3

Top three tips for glucose control

There are three main ways to changing your insulin dose:

1. Changing basal insulin dose for long-term, background effect

If the blood glucose level is high in the morning (more than 7.0 mmol/l for 4 days or more in the week), and these are not because of high levels before bed, increase the basal insulin (Lantus or Levemir).
  • If taking less than 10 units, increase by ½ unit at a time (ask the team for a ½ unit pen).
  • If taking 10-20 units, increase by 1 unit at a time
  • If taking more than 20 units, increase by 2 units at a time

2. Changing bolus insulin dose for carbohydrate at meals

The carbohydrate ratio is used to work out the number of grams of carbohydrate (CHO) covered by a certain amount of bolus insulin. If you know your carbohydrate ratio, the dose of insulin can be calculated as follows:
bolus2
If the blood glucose level is high for four or more days in a week before a particular meal, increase the insulin dose for the meal eaten earlier in the day BEFORE the high levels (for example, if the level is high before lunchtime, increase the breakfast dose). By giving more insulin for the same amount of food, you are effectively increasing the carbohydrate ratio for that meal.

If you are using a glucose meter that provides advice to guide dosing, then the insulin to carbohydrate ratio will need to be changed. The table below gives you some information on how to do this. If you are not sure about this then please call a member of the team to discuss how to do this.
table 47

3. Correction boluses for high blood glucose results

If blood glucose is above target, extra insulin needs to be given. This is called the correction factor. The correction factor depends on the average total daily dose of the insulin.
Correction factor
This is given, in addition to the bolus insulin to cover carbohydrate, to ‘correct’ pre meal blood glucose readings that are above the target of 7mmol/L.

If you are using a glucose meter that gives dosing advice, then this correction factor is automatically calculated. The correction factor (also called “insulin sensitivity”) needs to be changed according to how much insulin you are taking. If you are not sure about this then please call a member of the team to discuss how to do this.

Remember to check ketones if the blood glucose is more than 14 mmol/l and follow the sick day rules if unwell.

Worked example

Glucose meters that provide dosing advice take into account how much carbohydrate you are about to eat; your insulin to carbohydrate ratio; and the correction factor required. It automatically does a calculation to provide a suggested dose of insulin.

The following example is given to show how the smart meter does this:
flowchart
This example is purely for illustration purposes. If your meter provides dosing advice, all you need to know is how much carbohydrate you are about to eat and what your glucose level is.

You can keep track of your insulin to carbohydrate ratio and correction factor by either printing out and completing an Insulin to Carbohydrate ratio paper form, or completing the electronic form below - all the information submitted is then automatically emailed to you.
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