Adjusting insulin when using an insulin pump follows the same rules as when on insulin injections. You will also be looking for patterns in blood sugar levels that fall outside your target range at the same time of the day. Remember that when adjusting insulin doses based on patterns, you are trying to prevent the problem with blood sugar level rather than correcting it afterward.
These are the pattern rules you should follow when adjusting insulin doses when using an insulin pump:
- High blood sugar levels for three days in a row at the same time of the day; increase insulin dose.
- Low blood sugar levels for two days in a row at the same time of the day; decrease insulin dose.
Adjusting bolus doses on an insulin pump using the insulin-to-carbohydrate ratio
The I:C is the amount of carbohydrates (in grams) that one unit of rapid-acting insulin makes available to the body cells to consume. The I:C tells you how much rapid-acting insulin your child needs to cover a certain amount of eaten carbohydrates. Each child has a specific I:C that your dietitian will help you determine. The I:C is expressed as 1 unit: X grams of carbohydrates.
For example, an I:C of 1:10 means that 1 unit of insulin makes 10 grams of carbohydrates consumed. Each child has a specific I:C that your dietitian will help you determine.
The blood sugar checks at two hours and four hours after a meal tell us how well the bolus for that meal worked. The bolus doses are working if the pre-meal blood sugar levels are within the target range.
| Insulin-to-carbohydrate ratio (I:C) adjustment | |
|---|---|
| Current I:C
(unit of insulin : gram(s) of carbohydrates) | Increase or decrease the insulin to carbohydrate ratio by |
| From 1:1 to 1:15 | 1 gram of carbohydrates |
| From 1:15 to 1:25 | 2 grams of carbohydrates |
| More than 1:25 | 3 grams of carbohydrates |
To know when to increase or decrease, please see Adjusting for high blood sugar levels and Adjusting for low blood sugar levels.
Basal rate adjustment
Blood sugar levels checked more than four hours after a bolus usually tells how well the basal rate was working in the previous hours.
| Basal rate adjustment | |
|---|---|
| Current basal rate
(units of insulin/hour) | Increase or decrease the basal amount by
(units of insulin/hour) |
| Less than 0.3 | 0.025 |
| 0.3–0.5 | 0.05 |
| 0.5–2 | 0.1 |
To know when to increase or decrease, please see Adjusting for high blood sugar levels and Adjusting for low blood sugar levels below.
Adjusting for high blood sugar levels
Adjusting for high blood sugar level checked 2 to 4 hours after a previous bolus using an insulin pump
Before breakfast
Blood sugar level is high three days in a row before breakfast
- Action: Increase the basal insulin amount four hours before breakfast
- Example: If your child’s basal insulin amount is 0.4 units/hour, set the basal rate to 0.45 units/hour at 4 a.m. if breakfast is at 8 a.m.
Before lunch
Blood sugar level is high three days in a row before lunch
- Action: Decrease the insulin-to-carbohydrate ratio (I:C) for breakfast
- Example: If your child’s I:C is 1:10 (1 unit of insulin: 10 grams of carbohydrates), decrease the ratio to 1:9 specifically for breakfast
Before dinner
Blood sugar level is high three days in a row before dinner
- Action: Decrease the I:C for lunch
- Example: If your child’s I:C is 1: 10 (1 unit of insulin: 10 grams of carbohydrates), decrease the ratio to 1:9 specifically for lunch
Before bedtime
Blood sugar level is high three days in a row before bedtime
- Action: Decrease the I:C for dinner
- Example: If your child’s I:C is 1:10 (1 unit of insulin: 10 grams of carbohydrates), decrease the ratio to 1:9 specifically for dinner
2 to 4 hours after bedtime snack
Blood sugar level is high three days in a row 2 to 4 hours after bedtime snack
- Action: Decrease the I:C for the bedtime snack
- Example: If your child’s I:C is 1:10 (1 unit of insulin: 10 grams of carbohydrates), decrease the ratio to 1:9 specifically for the bedtime snack
Adjusting for low blood sugar levels
Adjusting for low blood sugar levels checked 2 to 4 hours after a previous bolus using an insulin pump
Before breakfast
Blood sugar level is low two days in a row before breakfast
- Action: Decrease the basal insulin 4 hours before breakfast.
- Example: If your child’s basal insulin amount is 0.4 units/hour, set the pump to release 0.35 units/hour at 4 a.m. if breakfast is at 8 a.m.
Before lunch
Blood sugar level is low two days in a row before lunch
- Action: Increase the insulin-to-carbohydrate ratio (I:C) for breakfast
- Example: If your child’s I:C is 1:10 (1 unit of insulin: 20 grams of carbohydrates), increase the ratio to 1:22 specifically for breakfast
Before dinner
Blood sugar level is low two days in a row before dinner
- Action: Increase the I:C for lunch
- Example: If your child’s I:C is 1:10 (1 unit of insulin: 20 grams of carbohydrates), increase the ratio to 1:22 specifically for lunch
Before bedtime
Blood sugar level is low two days in a row before bedtime
- Action: Increase the I:C for dinner
- Example: If your child’s I:C is 1:10 (1 unit of insulin: 20 grams of carbohydrates), increase the ratio to 1:22 specifically for dinner
2 to 4 hours after bedtime snack
Blood sugar level is low two days in a row 2 to 4 hours after bedtime snack
- Action: Increase the I:C for the bedtime snack
- Example: If your child’s I:C is 1:10 (1 unit of insulin: 20 grams of carbohydrates), increase the ratio to 1:22 specifically for the bedtime snack