Advanced Pumping

Della Matheson, RN, CDEUniversity of Miami

Research Coordinator

Thinking Like a Pancreas: utilizing advanced pump features

Adjustment Guidelines

• Make changes based on patterns• Fix lows before making ANY increases• When increasing, start with the first high of

the day• Make one change at a time and give it a few

days to see effect

How do we determine TDD and Basal Rate?

• Total Insulin Replacement Average adult: 0.5 – 0.7 u/kg BW

Average adolescent: 0.7- 1.4 u/kg BW

Example: female, age 23, 120 lbs (54 kg), 32u/day 32 units = 0.6 units/kg

54 kg

@ 50% of the TDD should be BASAL!!!

32÷2 = 16 ÷ 24hours = 0.66 u/hour

Basal Rate

Basal Rates are designed to keep blood sugarsin range while in the fasting state!!!

Start with a single basal rate Move to multiple basal rates to individualize

An Optimal Basal Rate keeps glucose from rising orfalling more than 30mg/dl when you are sleeping orskip a meal.

Basal Rate: checking overnight rates

• Check on a night when your last bolus was taken before dinner and bedtime starts 5 hours after that bolus (Ex 6:00 p.m. dinner; 11:00 p.m. bedtime) and is within your target range

• Wear CGM to bed OR wake up and test at 3:00 a.m. (or more if you can)

• Test at rising• Want blood glucose at rising to be within

30mg/dl of target!

Basal Rate: testing daytime rates • Harder – fasting involved!• Split day into 3 segments • Be sure last bolus was 5 hours earlier• Only do this when BG in target, no unusual activity or

circumstances, and you can frequently test or wear CGM

Breakfast Lunch

8:00 a.m. 1:00 p.m. 6:00 p.m.

Dinner

Basal Rate: when and how much to change

• Don’t change WHEN the rise or fall in BG occurs – BEGIN THE CHANGE AT LEAST 2 HOURS EARLIER!!!

• 90% of pumpers use more than a single basal rate but beware of over manipulation and too many basal rates!

12 mn 2 a.m. 12 noon 2:00 p.m.

Bolus Calculation or Insulin:CHO Ratio

• @ 50% of Total Daily Dose = Bolus

• A Quick calculation guide (the “2.6 rule”)Weight in pounds x 2.6 ÷ TDD = INS:CHO Ratio

Example: 120 x 2.6 = 312÷ 32u/day = 9.75

This is a starting point, then, it needs to beevaluated!!

Bolus AdjustmentsThings To Do Before changing Ins:Cho ratios

Know how insulin works!Know how food works!Be sure you are CHO counting correctly!Most foods digest and start to raise your glucose quicker thantoday’s rapid acting insulins can lower it!

Glucose

Time: minutes

10 40 80 120 150 180 240 300 Take insulin 15 to 20 minutes

BEFORE the start of the meal!!

Bolus Adjustments: Be Realistic!• Expect some elevation 2 hours after a normal

meal;• ADA = 180mg/dl or less• European Policy Group = 165mg/dl• International Diabetes Federation = 140 mg/dl as long as

hypoglycemia can be avoided• Pregnancy = 120mg/dl

• Bolus should be adjusted if BG stays more than 30mg/dl above the pre-meal level 4 – 5 hours after the meal: avoid “stacking” insulin!!

Insulin on Board/Active Insulin

• IOB feature helps you to calculate how much glucose lowering activity still remains from your last bolus

• If set properly it should prevent “stacking of insulin” Average duration of action of today’s rapid acting insulin = 5 to 6 hours**variability exists!!!Pumps offer IOB to be set on average between 2 and 8 hours; default usually set at 4 hours

Insulin on Board: variability • Volume If taking more than 12 to

15 units, you may want to set your IOB at 6 -6.5 hours vs. 4

2 units 20 units

• Placement

• Calculation of IOB depends on your pump

Insulin on Board: pump variation• Linear: Accu-Chek and OmniPod

use set amount, 20% to 25%, per hourWorks best if set from 4.25 to 6 hours

Bolus 0 1 2 3 4 5 6

• Curvi-linear (more accurate because they better match delayed tailing action of Insulin): Animas, Medtronic, and Tandem

Works best if set from 4.5 to 6.25 hours

Bolus 0 1 2 3 4 5 6

Know Your Pump: How is “Insulin on Board” counted on your pump ?

Is Bolus INCLUDED in IOB Is Bolus SUBTRACTED from IOB

Carb Correction Carb Correction

Best Practice Yes Yes Yes YesAnimas Yes Yes No (only if < target) Yes

Medtronic Yes Yes No YesOmniPod No (new Model

will)Yes No Yes

Tandem Yes Yes No (only if < 70) Yes (only if < 70)

Accu-Chek Spirit

Yes Yes Yes Yes

Adapted from “Pumping Insulin” Walsh, J, Roberts, R Torrey Pines Press , 5th Edition 2012

Bolus: Combo Bolus • Used for foods that are slowly digested Low glycemic CHO’s + lots of fiber High fat/protein + dense CHO• Gastroparesis• Symlin, Acarbose, GLP-1 agonist = all these slow digestion

Ask yourself this question: With a standard bolus, do I go low immediately after this meal and then go high 2 – 4 hours later?

START: 50% immediate, and 50% delayed for 2 – 3 hours

Foods That Cause Excessive Rapid Highs: The Super Bolus

40 grams of CHO or more and are high glycemic foods

Example: 60 grams CHO MealINS:CHO ratio = 1:10Basal Rate = 1 unit/hour

SUPER BOLUS:Increasing pre-meal bolus while decreasing basal using temporary basal rate

6 units per usual calculationTemporary basal rate: decrease by 70% x 3 hours (- 0.7u x 3 hours = 2.1)ADD 2.1 units to 6 units for a total pre-meal of 8.1

Better bolus coverage with less risk of low later

Bolus: Combo Bolus & Super Boluses

WRITE YOUR RESULTS DOWN AND “TWEAK” TO MATCH YOUR PERSONAL “DIGESTIVE PATTERNS”

Correction Factors: how are they derived?

The number of mg/dl that 1 unit of insulin takes to reduce you blood sugar.

That amount depends on how sensitive toInsulin you are = Insulin Sensitivity Factor

Rule of 1800 Divide 1800 by Total Daily Dose

Example: 120 woman, TDD 32u/day

1800 ÷ 32 = 56

When is it OK to Over-ride the pump calculation??

When you know more than it does!!• Foods you know have a greater

affect on your BG than the actual stated CHO amount

• Stress factors that you know historically alter BG

• Adjustments for exercise

Our Biggest Challenge: Exercise

Benefits• Improved cardiovascular outcomes• Reduces fatigue and improves musculoskeletal system• Combats depression, increases sense of well-being, and lowers stress

DOWN-SIDE: “sometimes it feels like more trouble than it’s worth”……

Our Biggest Challenge: Exercise

Control During Exercise Depends On:1. Your current insulin on board, glucose, glucose

trend2. Timing of exercise relative to recent meals and

boluses3. Duration and intensity of exercise4. Your training level5. Whether the exercise is aerobic or anaerobic6. Stress hormone release in competitive sports

How energy is created during exercise Sources of Fuel:• Circulating Glucose from recently consumed CHO• Stored glucose in Muscle• Stored glucose in Liver • Fat = body’s largest fuel reserve; 2,000 times as large as stored glucose

Balancing the Fuel:

InsulinGlucagon

FFA provide fuelFFA, @ 25% available glucose;

50% glucose; 50% FFA

Anaerobic Exercise

Very Intense, short duration Competitive exercise

Raises glucose immediately after the exercise due to release of stress hormones

Glucose and Insulin Levels Impact Performance

Blood Glucose Insulin level Effect on metabolism Impact on performance

< 70 High Not enough glucose available to cells

Fatigue, poor performance

70-180 Ideal Glucose & fat released as fuel normally

Maximum performance

> 180 Ideal to ? If insulin level OK, fuel use normal

Performance might be reduced – OK to exercise

> 250 Low to ? If insulin is OK (ketone level not moderate or high) exercise should lower ; if insulin levels low, fuel use inadequate and high BG might occur

Reduced performance – if insulin levels OK, moderate exercise OK,No strenuous exercise.DO NOT EXERCISE if moderate to high ketones

Carbohydrate Intake & Exercise

< 120mg/dl = 30 grams CHO before exercise

120 – 200 mg/dl = 15 grams CHO before exercise

> 200mg/dl = no additional CHO needed

RE-TEST every 30 minutes of exercise and re-evaluate need for additional CHO

Ex Carbs =How many Carbs an exercise is likely to consume

From “Pumping Insulin” Walsh, J, Roberts, R Torrey Pines Press , 5th Edition 2012

Your Training Status

Training builds glycogen stores in the muscles large glycogen stores tend to reduce glucose fluctuationsOnce basal rates and boluses are appropriately adjusted, the fit person tends to have more stable blood glucoses.

If Untrained or lapsed = 25% more glucose

After unusual or prolonged activity larger fall in glucose occurs several hours (in some cases up to 24 hours) after as glycogen stores are replenished { “Carb loading” before and after prolonged, intense exercise enhances muscle glycogen stores: important in preventing exhaustion}

From “Pumping Insulin” Walsh, J, Roberts, R Torrey Pines Press , 5th Edition 2012 ©2012 Diabetes Services, Inc

When & how do I lower insulin?

For very short, unplanned for exercise: • increase CHO intake• no insulin adjustment necessary

For moderate duration (60-90 minutes): • increase CHO • OR decrease bolus before activity

For prolonged duration (90 minutes or longer): • increase CHO • Make adjustments to bolus and basal rates

Decreasing Insulin for Exercise

Stopping Insulin: never should stop or disconnect for more than 60 to 90 minutesInsulin is needed to utilize circulating glucose for energy and to suppress uncontrolled release of glucose from liver and muscle = this uncontrolled release can lead to hyperglycemia; potential DKA

Reducing Insulin:Moderate exercise of > 60 minutes = Lower by 20%

Strenuous exercise of > 60 minutes = Lower by 50%

Decreasing Insulin for Exercise

Life Lessons You Can Learn from Albert Einstein:

Follow your curiosity

Make Mistakes “a person whonever made a mistake nevertried anything new”

Try something new….“Insanity: doing the same thingover and over again and expecting different results.”

“Everything should be made asSimple as possible, but not Simpler”

Perseverance is priceless

Knowledge comes from experience

Learn the “Rules” and then playbetter