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Insulin Pump Therapy - Bruce W. Bode, MD and Sandra Weber, MD
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Insulin Pump TherapyInsulin Pump Therapy
Bruce W. Bode, MDand
Sandra Weber, MD
Goals of Targeted Insulin Therapy Goals of Targeted Insulin Therapy (Intensive/Physiologic/Flexible)(Intensive/Physiologic/Flexible)
• Maintain near-normal glycemia• Avoid short-term crisis• Minimize long-term complications• Improve the quality of life
0 12 24
Hours
4:004:00
2525
5050
7575
8:008:00 12:0012:00 16:0016:00 20:00 20:00 24:0024:00 4:004:00
BreakfastBreakfast LunchLunch DinnerDinner
Pla
sma
insu
lin
(P
lasm
a in
suli
n (µ U
/ml)
U
/ml)
TimeTime
8:008:00
Physiological Serum Insulin Physiological Serum Insulin Secretion ProfileSecretion Profile
4:00 16:00 20:00 24:00 4:00
Breakfast Lunch Dinner
8:0012:008:00
Time
Glargine
Pla
sma
insu
lin
Basal/Bolus Treatment Program with Basal/Bolus Treatment Program with Rapid-acting and Long-acting AnalogsRapid-acting and Long-acting Analogs
Lispro Lispro Lispro
Aspart Aspart Aspartor oror
4:004:00 16:0016:00 20:00 20:00 24:0024:00 4:004:00
BreakfastBreakfast LunchLunch DinnerDinner
8:008:0012:0012:008:008:00
TimeTime
Basal infusion
Bolus Bolus Bolus
Pla
sma
insu
lin
Pla
sma
insu
lin
Variable Basal Rate: Variable Basal Rate: CSII ProgramCSII Program
Metabolic Advantages with CSIIMetabolic Advantages with CSII
• Improved glycemic control
• Better pharmacokinetic delivery of insulin
— Less hypoglycemia
— Less insulin required
• Improved quality of life
Photograph reproduced with permission of manufacturer.
Pump Infusion SetsPump Infusion Sets
Current Pump Therapy Current Pump Therapy IndicationsIndications
• Diagnosed with diabetes
(even new-onset type 1 diabetes)
• Need to normalize blood glucose
— A1C > 6.5%
— Glycemic excursions
— Hypoglycemia
• Need for flexible insulin program
• Monitoring— A1C = 8.3 - (0.21 x BG per day)
• Recording 7.4 vs 7.8• Diet practiced
— CHO: 7.2— Fixed: 7.5— WAG: 8.0
• Insulin type (Aspart)
CSIICSIIFactors Affecting A1CFactors Affecting A1C
Bode et al. Diabetes 1999;48 Suppl 1:264
Bode et al. Diabetes Care 2002;25 439
Initial Adult Dosage: CalculationsInitial Adult Dosage: Calculations
Starting doses
• Based on pre-pump total daily dose (TDD)
reduce TDD by 25% to 30% for pump TDD
• Calculated based on weight
0.24 x weight in lb (0.53 x weight in kg)
Bode BW, et al. Diabetes. 1999;48(suppl 1):84.Bell D, Ovalle F. Endocr Pract. 2000;6:357-360.Crawford LM. Endocr Pract. 2000;6:239-243.
• Normal—Preprandial: 70 - 140 mg/dl—1 hr postprandial: <160 mg/dl
• Hypoglycemic unawareness—Preprandial: 100 - 160 mg/dl
• Pregnant—Preprandial: 60 - 90 mg/dl—1 hr postprandial: <120 mg/dl
Individually set for each patient
Target BG Ranges for CSIITarget BG Ranges for CSII
Fanelli CG et al., Diabetologia 1994, 37:1265-76.
Jovanovich L, AMJObGynec 1991, 164:103-11.
Initial Adult Dosage: CalculationsInitial Adult Dosage: Calculations
Basal rate
• 45% to 50% of pump TDD
• Divide total basal by 24 hours to decide on hourly basal
• Start with only 1 basal rate
• See how it goes before adding basals
Basal Dose Adjustment OvernightBasal Dose Adjustment Overnight
Rule of 30:Check BG
Bedtime 12 AM3 AM6AM
Adjust overnight basal if readings vary > 30 mg/dl
• Adults often need an increase in basal rate in the “Dawn” hours (4 am to 9 am)
• Children often need an increase in basal rate earlier starting at 10 pm to 2 am
Basal Dose Adjustment OvernightBasal Dose Adjustment Overnight
4:004:00 16:0016:00 20:00 20:00 24:0024:00 4:004:00
BreakfastBreakfast LunchLunch DinnerDinner
8:008:0012:0012:008:008:00
TimeTime
Basal infusion
Bolus Bolus Bolus
Pla
sma
insu
lin
Pla
sma
insu
lin
Variable Basal Rate: CSII ProgramVariable Basal Rate: CSII Program
Basal Dose Adjustment DaytimeBasal Dose Adjustment Daytime
Rule of 30:
Check BG Before usual meal timeSkip mealEvery 2 hrs (for 6 hrs)
Adjust daytime basal if readings vary > 30 mg/dl
Bolus Dose CalculationsBolus Dose Calculations
Meal (food) Bolus Method 1
• Test BG before meal• Give pre-determined insulin dose for
pre-determined CHO content
• Test BG after meal• Goal < 60 mg/dl rise post meal or < 160 mg/dl
Individually determined
• CIR = (2.8 x wgt in lbs) / TDD
• Anywhere from 5 to 25 g CHO is covered by 1 unit of insulin
Estimating the Estimating the Carbohydrate to Insulin Ratio (CIR)Carbohydrate to Insulin Ratio (CIR)
Davidson et al: Diabetes Tech & Therap. April 2003
Correction Bolus Correction Bolus
• Must determine how much glucose is lowered by 1 U of rapid-acting insulin
• This number is known as the correction factor (CF)
• Use the 1700 rule to estimate the CF• CF=1700 divided by TDD example: if TDD=36 U, then
CF=1700/36=50, meaning 1 U will lower the BG 50 mg/dL
Correction Bolus FormulaCorrection Bolus Formula
Example:—Current BG: 220 mg/dL—Ideal BG: 100 mg/dL—Glucose CF: 50
mg/dL
Current BG - Ideal BGGlucose Correction Factor
220 - 100
50= 2.4 U
If A1C is Not to GoalIf A1C is Not to Goal
• SMBG frequency and recording
• Diet practiced—Do they know what
they are eating?
—Do they bolus for all food and snacks?
• Infusion site areas—Are they in areas of
lipohypertrophy?
• Other factors:—Fear of low BG
—Overtreatment of low BG
Must look at:
Case Study # 1Case Study # 1
• GL, male, age 39
• Type 1 X 8 years
• A1C= 7%; recent increase from 6%
• CSII basal rates: 12 am 1.0 u/h;
4:30 am 1.6 u/h; 11:30 am 1.0 u/h
• Insulin: carbohydrate ratio =1u : 10 grams
• Correction Factor: BG - 100 divided by 40
• CGMS done to assist with improving overall glycemic control
Modal Day ViewModal Day View
Cheese / Crackers 20 g; 3units
30 gm CHO; Heavy Exercise 80 CHO; 7u 2u; 57 g CHO
Milk choc 15g; 8u
Juice box; no insulin
Ice Cream; 3 u
6u
Most common bolusing errorsMost common bolusing errors
• Under-estimation of carbohydrates consumed (CHO bolus)
• Over-correction of post-prandial elevations (CF bolus)— Remaining unused, active insulin— Stacking of boluses
Bolus: Source of ErrorsBolus: Source of Errors
• “Inability” to count carbs correctly— Lack of knowledge, skill— Lack of time— Too much work
• Incorrect use of SMBG number• Incorrect math in calculation• “WAG” estimations
The Major ProblemsThe Major Problems
♦ Up until now we have not taken the active insulin issue into consideration
♦ The math involved with this has become too complicated, and it would be impossible to accurately calculate the active insulin without assistance
Smart PumpsSmart Pumps
• Monitor sends BG value to pump via radio waves : No transcribing error
• Enter carbohydrate intake into pump• “Bolus Wizard” calculates suggested dose
Paradigm Link™
Paradigm 512™) ) ) ) ) ) ) ) ) )
) ) )
Bolus Wizard Calculator :Bolus Wizard Calculator : meter-meter-entered entered
Insulin Activity Over TimeInsulin Activity Over Time
0
100
200
300
400
500
600
700
0 1 2 3 4 5 6 7 8
Rapid ActingRegular
Insu
lin A
ctiv
ity
(GIR
)
Time (hrs)
Insulin Pharmacodynamic Data
Adapted from Henry R: Diabetes Care 1999
0
20
40
60
80
100
0 1 2 3 4 5 6 7 8
Rapid ActingRegular
Time (hrs)
Per
cen
t R
emai
nin
gAdjusting for Active Insulin:Adjusting for Active Insulin:
How smart pumps do itHow smart pumps do it
Wizard: OnCarb Units: gramsCarb Ratios: 10BG Units: mg/dlSensitivity: 50BG Target: 100
Wizard: OnCarb Units: gramsCarb Ratios: 10BG Units: mg/dlSensitivity: 50BG Target: 100
Bolus Wizard Set Up ScreenBolus Wizard Set Up Screen
For This System To WorkFor This System To Work
♦ It is critical the target, basal doses, the correction doses, and the carbohydrate ratios are accurate
♦ Understanding how to match carbohydrate amounts with insulin is critical
Do Smart Pumps Enable Others To Do Smart Pumps Enable Others To Go To CSII? Go To CSII?
• YES
• All patients with diabetes not at goal are candidates for Insulin Pump Therapy
- Type 1 any age - Type 2 - Diabetes in Pregnancy
SummarySummary
• Insulin pump therapy offers improved glucose control with less risk of hypoglycemia and an improvement in quality of life
• Appropriate candidate selection, training, and follow-up ensures safe and effective therapy
QuestionsQuestions
• For a copy or viewing of these slides, contact
• WWW.adaendo.com
