Programming Your Pump

The basal rate replaces the insulin that your body is not producing naturally. The rate is programmed as unit(s) per half hour or per hour. You can program different patterns to meet different needs. Some examples that might prompt additional programming are: weekend or shift work, exercise, hormonal fluctuations, or travel. The basal infusion occurs automatically; it just keeps delivering insulin in the pre-programmed pattern until you decide to change the rate.

Bolus insulin

You can also pre-program your insulin pump with the bolus settings.

Insulin-to-carbohydrate ratio is programmed as 1 unit of insulin per number of carbohydrate grams. This means that 1 unit of insulin will dispose of so many grams of carbohydrate. Multiple insulin-to-carbohydrate ratios may be set for different meals – breakfast, lunch, dinner, snacks, etc. For example, if 1 unit of insulin disposes of 10 grams of carbohydrates, it is expressed as the ratio 1:10 g of carbohydrate.

The settings also can be pre-set to deliver different bolus infusion profiles, such as an extended (square wave) or dual (combination) bolus. An extended/square wave delivers the bolus insulin over a specified number of minutes, and a dual/combination bolus delivers a certain portion of the insulin immediately and the rest as an extended/square wave. The proportion of the immediate versus prolonged delivery, the overall time duration of the delivery, and the insulin to carbohydrate ratio can be varied.

Insulin sensitivity factor, or ISF, refers to how much or how many points (mg/dl) the blood sugar will drop in response to one unit of insulin. It is also known as a high blood sugar correction, and is set as one unit of insulin to lower a specific amount of glucose (in mg/dl). Different ISFs can be pre-programmed for different times of the day. A common example would be 1 per 50. This means that 1 unit of insulin will drop blood sugars 50 points.

Unlike the basal insulin infusion, bolus infusions are NOT automatic. Every time you want to receive an insulin bolus, you have to manually instruct the pump to deliver the bolus insulin.

Although the insulin-to-carbohydrate ratio, bolus profile and ISF are pre-programmed, you still have to tell the pump how many grams of carbohydrate you are planning to eat, and enter your blood sugar before the pump can suggest an insulin dose.

The insulin pump or continuous subcutaneous insulin infusion device (CSII)  continuously administers rapid acting insulin into the fatty tissue beneath the skin. The insulin pump is especially suited to covering different patterns of insulin resistance or sensitivity throughout the day. The pump also has multiple bolus profiles including standard, dual, multiple and extended boluses.

Target blood glucose

You can program your pump with your individual target or desired blood glucose level.

Examples of target glucose, insulin-to-carbohydrate ratio and insulin sensitivity factor (ISF):

Pre-programmed:

• Target glucose: 110 mg/dl
• Insulin-to-carbohydrate ratio: 1:10 (1 unit insulin for every 10 grams of carbohydrate)
• ISF: 1 per 50 (1 unit of insulin to lower glucose 50 points [mg/dl])

Example 1:

ISF

• Current glucose: 160 mg/dl (entered by user)
• Target glucose: 110 mg/dl
• ISF: 1 per 50
• Calculation: 160 minus 110 = 50 points higher than target
• Recommendation: 1 unit of insulin to correct high glucose

Example 2:

Insulin-to-carbohydrate ratio

• Carbohydrate grams: 50 grams (entered by user)
• Insulin-to-carbohydrate ratio: 1:10 (1 unit insulin for every 10 grams of carbohydrate)
• Calculation: 50 divided by 10
• Recommendation: 5 units of insulin for 50 grams of carbohydrates

Example 3:

Insulin-to-carbohydrate ratio and ISF

• Current glucose: 160 mg/dl (entered by user)
• Carbohydrate grams: 50 grams (entered by user)
• Target glucose: 110 mg/dl
• ISF: 1 per 50
• Insulin-to-carbohydrate ratio: 1:10
• Calculation: 160 minus 110 = 50 points higher than target
• Recommendation:
  1 unit insulin to correct high glucose
  5 units insulin for 50 grams of carbohydate
  Total insulin recommended: 6 units

Self-assessment Quiz

Self assessment quizzes are available for topics covered in this website. To find out how much you have learned about  Insulin Pumps, take our self assessment quiz when you have completed this section.  The quiz is multiple choice. Please choose the single best answer to each question. At the end of the quiz, your score will display. If your score is over 70% correct, you are doing very well. If your score is less than 70%, you can return to this section and review the information.