Worked Examples: Sick Day Guidance for Type 1 Diabetes

Web Resource Last Updated: 17-12-2024

Calculating extra insulin doses (ketones 1.6 to 2.9 mmol/L)

Here is an example calculation to help you calculate extra insulin doses.

Alex feels ill and thinks he might have the flu. Alex checks his blood glucose and ketones.

His blood glucose is 16 mmol/L and his ketones are 1.7 mmol/L.

Alex checks the Insulin adjusting flowchart and sees he should:

  • check his blood glucose and ketones every 2 hours
  • stay hydrated with sugar-free fluids
  • take an extra quick-acting insulin dose that is 10% of his total daily dose

Alex already calculated his total daily dose here and found that it was 38 units. To calculate 10% of his total daily dose he divides his total daily dose by 10.

Extra dose = total daily dose ÷ 10

Extra dose = 38 ÷ 10

Extra dose = 3.8 units which is rounded to 4 units

 Alex takes an extra quick-acting insulin dose of 4 units, aims to recheck his blood glucose and ketones in 2 hours, and contacts his diabetes team.

Calculating extra insulin doses (ketones greater than 3.0mmol/L)

Here is an example calculation to help you calculate your total daily dose.

Alex feels ill and thinks he might have the flu. Alex checks his blood glucose and ketones.

His blood glucose is 16 mmol/L and his ketones are 3.1 mmol/L.

Alex checks the Insulin adjusting flowchart and sees he should:

  • check his blood glucose and ketones every 2 hours
  • stay hydrated with sugar-free fluids
  • take an extra quick-acting insulin dose that is 20% of his total daily dose

Alex already calculated his total daily dose here and found that it was 38 units. To calculate 20% of his total daily dose he divides his total daily dose by 5.

Extra dose = total daily dose ÷ 5

Extra dose = 38 ÷ 5

Extra dose = 7.6 units which is rounded to 8 units

Alex takes an extra quick-acting insulin dose of 8 units, aims to rechecks his blood glucose and ketones in 2 hours, and immediately contacts his diabetes team for urgent advice.