Ed Module - Pump Settings

Previous

5 Settings are Needed to Begin Insulin Pump Therapy

Bayer Contour NEXT LINK

Settings calculated using standard formulas

Basal Rate (BR)

Insulin-to-Carb Ratio (ICR)

Insulin Sensitivity Factor (ISF)

Settings determined using patient history/clinical judgment

Target Range

Active Insulin Time

Meet Heather

Pretend that Heather is a patient of yours and you have identified her
as an excellent candidate for pump therapy*

  • Her pump has been ordered
  • She has
    • Attended her pre-pump training classes
    • Read through the Insulin Pump Therapy Workbook that shipped with her pump
    • Reviewed the recommended e-learning modules that are available online
  • She is meeting with her diabetes educator and certified pump trainer tomorrow, and is excited about starting her new therapy
  • Before she can begin her therapy, you will need to calculate her initial pump settings

You will need to start by determining the appropriate pump total daily dose (TDD) – the total amount of insulin she will use each day for both her basal and bolus insulin needs.

So let's begin by calculating Heather's TDD…

Patient History and Pump TDD

To calculate Heather's initial settings, first determine her pump TDD, which is the average
of her Reduced Dose (75% of Total Daily Injection Dose) and her Weight Dose7:

Patient History:

27-year-old female
Weight: 154 lbs (70 kg)
Planning pregnancy
A1C: 8.2%
Frequent hypoglycemia
Type 1: diagnosed at age 10

Rapid-acting:

Breakfast: 12.0 units
Lunch: 8.0 units
Dinner: 13.0 units
Total:  33 units/day

Long-acting:

Morning: 12.0 units
Evening: 8.0 units
Total: 20 units/day

Total Daily Injection Dose:

  53 units/day
           

Reduced Dose = Injection Dose x 0.75

Test your knowledge: Reduced Dose = 53.0 units/day x 0.75

What is Heather's Reduced Dose?
  • 15.00 units/day
  • 25.00 units/day
  • 39.75 units/day
  • 115.00 units/day
Submit

Patient History and Pump TDD

Next, calculate Heather's Weight Dose using the formula below7:

Patient History:

27-year-old female
Weight: 154 lbs (70 kg)
Planning pregnancy
A1C: 8.2%
Frequent hypoglycemia
Type 1: diagnosed at age 10

Rapid-acting:

Breakfast: 12.0 units
Lunch: 8.0 units
Dinner: 13.0 units
Total:  33 units/day

Long-acting:

Morning: 12.0 units
Evening: 8.0 units
Total: 20 units/day

Total Daily Injection Dose:

  53 units/day
           

Weight Dose = Weight (lbs) x 0.23 or Weight (kg) x 0.50

Test your knowledge: Weight Dose = 154 lbs x 0.23

What is Heather's Weight Dose?
  • 16 units/day
  • 35 units/day
  • 77 units/day
  • 115 units/day
Submit

Patient History and Pump TDD

Then, average Heather's Reduced Dose plus her Weight Dose to determine her pump TDD7:

Patient History:

27-year-old female
Weight: 154 lbs (70 kg)
Planning pregnancy
A1C: 8.2%
Frequent hypoglycemia
Type 1: diagnosed at age 10

Rapid-acting:

Breakfast: 12.0 units
Lunch: 8.0 units
Dinner: 13.0 units
Total:  33 units/day

Long-acting:

Morning: 12.0 units
Evening: 8.0 units
Total: 20 units/day

Total Daily Injection Dose:

  53 units/day
           

Heather's Pump TDD =

Heather's Pump TDD = 37.4 units/day

First Pump Setting: Heather's Basal Rate7

The Basal Rate is the amount of insulin that the pump is programmed to deliver evenly over each hour.
The total amount of insulin delivered over 24 hours is the Total Daily Basal Dose

Clinical Guidelines for Total Daily Basal Dose:

Adults 40%-50% of Pump TDD
Puberty to adult* 30%-40% of Pump TDD
Prepuberty to puberty* 20%-40% of Pump TDD

Based on these clinical guidelines, you might decide to use 50% to calculate Heather's Total Daily Basal Dose

In which case, her Total Daily Basal Dose:

= TDD x 50%

= 37.4 units/day x 50%

= 18.7 units/day


NOTE: Not all Medtronic products are indicated for all age groups. For example, the MiniMed 530G with Enlite system is only indicated for use in individuals 16 years of age and older.

Total Daily Basal Dose = Pump TDD x 40% to 50%

Basal Rate =

Test Your Knowledge:

Basal Rate =

What is Heather's Basal Rate?
  • 0.78 units/hour
  • 1.56 units/hour
  • 9.38 units/hour
  • 18.75 units/hour
Submit

Second Pump Setting: Heather's Insulin-to-Carbohydrate Ratio7

The Insulin-to-Carbohydrate Ratio (ICR) is the number of carbohydrates covered by 1 unit of insulin

The Total Daily Bolus Dose is the remainder of the TDD that is not being administered as the Total Daily Basal Dose.

Therefore, Heather's Total Daily Bolus Dose:

= 37.4 units/day – 18.7 units/day

= 18.7 units/day

Heather's Total Daily Carb Intake:

= 225 g

Total Daily Bolus Dose = TDD – Total Daily Basal Dose

ICR = =

Test Your Knowledge:

What is Heather's Insulin-to-Carbohydrate Ratio? (Select one)
  • 6 g/unit
  • 12 g/unit
  • 18 g/unit
  • 24 g/unit
Submit

Third Pump Setting: Heather's Insulin Sensitivity Factor7

The Insulin Sensitivity Factor (ISF) is the number of mg/dL one unit of insulin lowers blood glucose

Given that Heather experiences frequent hypoglycemia, you might decide that she is very sensitive to insulin, and elect to use the 2000 rule to calculate her ISF

ISF =

Heather's Insulin Sensitivity Factor:

= 53 mg/dL

ISF =

  • There are 2 methods for calculating ISF – they are exactly the same – except one uses the number 1700 as the basis for this calculation and the other uses 2000
    • If the patient is sensitive to insulin doses and has a history of going low after giving a correction dose, use the 2000 rule
    • If the patient does not have a history of post-correction hypoglycemia, use the 1700 rule
Next

Fourth and Fifth Pump Settings: BG Target and Active Insulin Time

The other 2 settings are based on the patient's history and your clinical judgment. Let's look at some best practices on how these settings are determined

Bayer Contour NEXT LINK

Settings calculated using standard formulas

Basal Rate (BR)
0.78 units/hour

Insulin-to-Carb Ratio (ICR)
12 g/unit

Insulin Sensitivity Factor (ISF)
53 mg/dL

Settings determined using patient history/clinical judgement

Bolus Wizard® Target Range

Active Insulin Time

WARNING: The Bolus Wizard does NOT account for manual injections, and could prompt delivery of more insulin than needed when used in conjunction with manual injections. Too much insulin can cause hypoglycemia. When receiving manual insulin injections, it is therefore necessary to consider that additional amount and type of insulin before employing the Bolus Wizard feature.
  • The Basal Rate (BR), Insulin-to-Carb Ratio (ICR), and Insulin Sensitivity Factor (ISF) are calculated using a set of standard formulas
  • Active Insulin Time and BG Target Range are based primarily on patient history and the physician’s clinical knowledge and judgment
    • Examples of relevant factors include hypoglycemia, nocturnal hypoglycemia, hypoglycemia unawareness, recurrent hyperglycemia, and erratic glycemic control
  • The range of glucose values (both a high and low) the Bolus Wizard uses to determine if a correction dose needs to be calculated
  • The pump uses the following formula to calculate correction doses:
    Correction Dose = (Current BG - Target BG) ÷ ISF
  • To determine the Bolus Wizard Target Range: Decide on the high BG value you want the pump to use when correcting elevated BGs, and the low BG value you want it to use when correcting low BGs
  • For example, in an adult patient you may choose to use 90 mg/dL - 100 mg/dL during the day and 100 mg/dL - 110 mg/dL at night
  • The pump can use up to 8 different target ranges to accommodate needs such as daytime targets and bedtime targets
  • Active Insulin: The amount of insulin remaining from previous boluses that has not been fully metabolized and continues to have the pharmacodynamic ability to lower glucose
  • Active Insulin Time: The selectable period of time the Bolus Wizard will track active insulin after a bolus is given
  • The length of time rapid-acting insulin lowers glucose can vary in each individual; therefore, Active Insulin Time can be adjusted to track for 2, 3, 4, 5, 6, 7, or 8 hours
  • Active insulin is subtracted from the correction dose before calculating the total bolus amount to be given

That is correct

Heather's Reduced Dose is 39.75 units/day

That is incorrect

Heather's Reduced Dose = Total Daily Injection Dose x 0.75
= 53.0 units/day x 0.75
= 39.75 units/day

That is correct

Heather's Weight Dose is 35 units/day

That is incorrect

Heather's Weight Dose = Weight (lbs) x 0.23
= 154 lbs x 0.23
= 35 units/day
or
= Weight (kg) x 0.50
= 70 kg x 0.50
= 35 units/day

That is correct

Heather's Basal Rate is 0.78 units/hour

Because the pump delivers basal insulin in 0.025-unit increments, Heather's starting basal rate should be rounded down to 0.775 units/hour or rounded up to 0.8 units/hour

That is incorrect

Heather's Basal Rate = Total Daily Basal Dose
24 hours
= 18.7 units/day
   24 hours
= 0.78 units/hour

Because the pump delivers basal insulin in 0.025-unit increments, Heather's starting basal rate should be rounded down to 0.775 units/hour or rounded up to 0.8 units/hour

That is correct

Heather's Insulin-to-Carbohydrate Ratio is 12 g/unit

That is incorrect

Heather's Insulin-to-Carbohydrate Ratio = 225 g = 12 g/unit
18.7 units/day

References

  1. American Diabetes Association. Standards of medical care in diabetes—2012. Diabetes Care. 2012;35(suppl 1):S11-S63.
  2. Hoogma RPLM, Hammond PJ, Gomist R, et al. Comparison of the effects of continuous subcutaneous insulin infusion (CSII) and NPH-based multiple daily insulin injections (MDI) on glycaemic control and quality of life: results of the 5-nations trial. Diabet Med. 2006;23(2):141-147.
  3. American Diabetes Association. Continuous subcutaneous insulin infusion. Diabetes Care. 2004;27(suppl 1):S110.
  4. Lepore M, Pampanelli S, Fanelli C, et al. Pharmacokinetics and pharmacodynamics of subcutaneous injection of long-acting human insulin analog glargine, NPH insulin, and ultralente human insulin and continuous subcutaneous infusion of insulin lispro. Diabetes. 2000;49(12):2142-2148.
  5. Gross TM, Kayne D, King A, Rother C, Juth S. A bolus calculator is an effective means of controlling postprandial glycemia in patients on insulin pump therapy. Diabetes Technol Ther. 2003;5(3):365-369.
  6. Scheiner G, Boyer BA. Characteristics of basal insulin requirements by age and gender in type-1 diabetes patients using insulin pump therapy. Diabetes Res Clin Pract. 2005;69(1):14-21.
  7. Bode BW, Kyllo J, Kaufman FR. Pumping Protocol: A Guide to Insulin Pump Therapy Initiation. Northridge, CA: Medtronic, Inc; 2008.
References | 950M10996-012 20140701