Advanced Pumping
Della Matheson, RN, CDE
University 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 sugars
in 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 or
falling more than 30mg/dl when you are sleeping or
skip 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
8:00 a.m.
Lunch
1:00 p.m.
Dinner
6:00 p.m.
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!!!
12 mn
2 a.m.
12 noon
2:00 p.m.
• 90% of pumpers use more than a single basal rate but
beware of over manipulation and too many basal
rates!
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 be
evaluated!!
Bolus Adjustments
Things 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 than
today’s rapid acting insulins can lower it!
Glucose
10
40
80
Time: minutes
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 hour
Works 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
Yes
Best Practice
Yes
Yes
Yes
Animas
Yes
Yes
No (only if < target) Yes
Medtronic
Yes
Yes
No
Yes
OmniPod
No (new Model
Yes
No
Yes
will)
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
SUPER BOLUS:
Increasing pre-meal bolus
while decreasing basal
using temporary basal rate
40 grams of CHO or
more and are high
glycemic foods
Example:
60 grams CHO Meal
INS:CHO ratio = 1:10
Basal Rate = 1 unit/hour
6 units per usual calculation
Temporary 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 to
Insulin 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
trend
2. Timing of exercise relative to recent meals and
boluses
3. Duration and intensity of exercise
4. Your training level
5. Whether the exercise is aerobic or anaerobic
6. 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:
FFA provide fuel
FFA, @ 25% available glucose;
50% glucose; 50% FFA
Insulin
Glucagon
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 fluctuations
Once 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 minutes
Insulin 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 who
never made a mistake never
tried anything new”
Try something new….
“Insanity: doing the same thing
over and over again and
expecting different results.”
“Everything should be made as
Simple as possible, but not
Simpler”
Perseverance is priceless
Knowledge comes from
experience
Learn the “Rules” and then play
better