1 INTRODUCTION TO CONTINUOUS GLUCOSE MONITORS H. Peter Chase, MD Vicky Gage, RN, CDE Laurel Messer, RN, CDE Susie Owen, RN, CDE Sally Sullivan, RN, CDE

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INTRODUCTION TO CONTINUOUS INTRODUCTION TO CONTINUOUS GLUCOSE MONITORSGLUCOSE MONITORS

H. Peter Chase, MD

Vicky Gage, RN, CDE

Laurel Messer, RN, CDE

Susie Owen, RN, CDE

Sally Sullivan, RN, CDE

Barbara Davis Center for Childhood Diabetes April 2010

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AgendaAgenda

• Dr. Chase will present a general CGM overview

• Nurses will explain device features and comparisons between sensors

• You will have an opportunity to handle each device and ask questions


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What is a CGM?What is a CGM? (Continuous Glucose Monitor) (Continuous Glucose Monitor)

• A device that provides “real-time” glucose readings and data about trends in glucose levels

• Reads the glucose levels under the skin every 1-5 minutes (10-15 minute delay)

• Provides alarms for high and low glucose levels and trend information

• The 3rd era in diabetes management


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Who Should Use a CGM?Who Should Use a CGM?

1) The person and the family must both want a CGM

2) A youth must be willing to wear the sensor (and carry the receiver)

3) Using good diabetes care (4 BGs/day)

4) Good support system

5) Adequate body “real estate”

6) Cost of CGM (RNs to elaborate)

Understanding Pumps and CGMs, p.100


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WHY Use CGM?

A.Prevention of low blood sugars (alarms)

B. Prevention of high blood sugars (ketones)

C.Minimize wide glucose fluctuations

D.Behavior Modification

E. Prevention of Complications (?)


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How common are glucose levels <60mg/dl How common are glucose levels <60mg/dl during the night in children with T1D?during the night in children with T1D?

– French (i) and Australian (ii) data showed approximately 50% of children with low BG (<60mg/dl) during the night (on NPH bid)

– DirecNet data (one night in hospital with blood sugars every 30 min.)

A) 2001-2002: 39 of 91 (43%) low BG

(44% of children on insulin pumps/56% on NPH)

B) 2004: 14 of 50 (28%) with low BG

(all on insulin pumps or Lantus)

(i) Beregszaszi M, et al. J Pediatr. 131, 27, 1997(ii) Porter PA, et al. J. Pediatr. 13, 366, 1997Barbara Davis Center for Childhood Diabetes April 2010

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WHY Use CGM?

A. Prevention of low blood sugars (alarms)

B.Prevention of high blood sugars (ketones)



E. Prevention of Complications (?)


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“Snapshot of BG levels”


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Continuous Glucose Monitoring


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Hyperglycemia is common, Hyperglycemia is common, especially after mealsespecially after meals

0%

10%

20%

30%

40%

50%

< 180 181 - 240 241 - 300 > 300

Breakfast

Lunch

Dinner

Boland et al, Diabetes Care 24:1858, 2001Barbara Davis Center for Childhood Diabetes April 2010

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WHY Use CGM?

A. Prevention of low blood sugars (alarms)

B. Prevention of high blood sugars (ketones)



E. Prevention of Complications?


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Three Parts to CGMs:Three Parts to CGMs:

A. Sensor

B. Transmitter

C. Receiver/MonitorUnderstanding Pumps and CGMs, p.103


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A) Sensor (p.103)


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B) Transmitter(p.103)


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C) Receiver or Monitor(p.103)


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What does “Calibration” mean and What does “Calibration” mean and why do I need to do it?why do I need to do it?

• Calibration is a process that gives a fingerstick BG value to the CGM system so the values will align with each other

• Number of Calibrations vary by device• Best times to calibrate are when the BG values

are stable: before meals and before bed• Do not calibrate when arrows are present


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What type of data will we get?

Two types of CGM data:

• Real Time data: seen on CGM

• Retrospective data: download to a computer


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Real Time Data Real Time Data

Three types of Real Time Data:

A) Trend graphs

B) Alarms

C) Trend Arrows

Understanding Pumps and CGM: pages 109-113


Trend graphs – Knowing a glucose level is 240 mg/dl may not be as important as knowing the “trend.”

TREND GRAPHS

Understanding Pumps and CGM: p.103


Real Time data

ALARMS ALARMS


Warn patients of current or

projected high and low blood

sugar

Real Time data

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Alarms continuedAlarms continued

Threshold alarm:Warning when glucose is above or below a set value

--all devices have this

Projected Alarms:10,20 or 30 minute warning ofImpending hypo- or hyperglycemia

Real-Time Revel System, Guardian Real-Time and the Navigator have these

Real Time data


TREND ARROWSTREND ARROWS

Arrows that indicate the rate and direction of change

Glucose going down-1 to -2 (mg/dL)/min

Glucose going up1 to 2 (mg/dL)/min

Glucose falling quickly>-2 (mg/dL)/min

Fairly stable glucose -1 to 1 (mg/dL)/min

Glucose rising quickly>2 (mg/dL)/min


Real Time data

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Retrospective DataRetrospective Data

Three types of Retrospective data

(viewed on computer download)

A) Trend graphs

B) Pie charts

C) Data tables

Understanding Pumps and CGMs, Chapter 17


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Reports that show one or more days of CGM data– also called sensor overlay

A) Trend GraphsA) Trend GraphsRetrospective data

Barbara Davis Center for Childhood Diabetes August 2009


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Case Study:Case Study:Using Trend GraphsUsing Trend Graphs

• Three Trend Graphs showing change over time:

– Teenager with T1D for 9.5 years– Started Navigator: Sept. 2005– Starting HbA1c: 7.1%– Most recent HbA1c: 6.0%– Current number of low BGs per week (<60 mg/dL or

<3.3 mmol/L): 1/week


Retrospective data

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BASELINE GLUCOSE Trend Graph #1BASELINE GLUCOSE Trend Graph #1Prior to CGM UsePrior to CGM Use


Retrospective data

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Glucose Trend Graph #2Glucose Trend Graph #2After three months of CGM useAfter three months of CGM use


Retrospective data

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GLUCOSE Trend Graph #3 Most recent CGM reportMost recent CGM report


Retrospective data

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B) PIE CHARTS


Retrospective data

Show percentage of time glucose is above,below and in target range

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C) Data Tables


Retrospective data

Show statistical information about different periods of the day

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USING CGM RESULTS:(To make insulin adjustments)

• Important not to get overwhelmed by data

** Make One Change At A Time

• Look for patterns 2 out of 3 days

• A behavior modification device Missed boluses, snacking, low BGs on CGM

• Good initial communication with HCP


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Interpreting CGM dataInterpreting CGM data


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Interpreting CGM dataInterpreting CGM data


Realistic Expectations of CGM

• You will still need to test your blood sugar levels

• Using CGM does not make Diabetes Management a “Breeze”

• You will still experience low and high blood sugar values

• Sensor values will not always “MATCH” the blood sugar values

• The most significant improvements will be seen with consistent CGM wear


You will still need to test your blood sugar levels for:



•Calibrations

•Insulin dosing

•Treating high and low blood sugar levels

•Questioning the accuracy of the CGM values

•Times when you do not feel right

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Realistic Expectations of CGMRealistic Expectations of CGM

Using CGM does not make Diabetes Management a “Breeze”

• Initially, people are overwhelmed from all the data

•Subjects will follow an algorithm early on in the use of CGM

•Family weekly downloads of CGM data are important

•CGM works as a behavior modification device




You will still experience low and high blood sugar levels

•There will ALWAYS be some lows and highs

•Alarms may NOT be sensitive to slowly falling blood sugar values

•The time spent in hypoglycemia and hyperglycemia can be reduced

•CGM is an additional tool to help make decisions

•CGM values are not very helpful in treating lows



Sensor values will not always “MATCH” the blood sugar values

•CGM values are about 10 minutes behind blood sugar values

•Values are less accurate early after insertion

•Values are furthest off when blood sugars are rapidly rising or falling

•Calibrations are important determinants of accuracy of the CGM

The most significant improvements will be seen with consistent CGM wear ( >6 days/week)



•Good initial education helps patients and families to learn what to expect

•Regular use of Real-time and Retrospective data is necessary for optimal benefits

•Follow up with Diabetes Team is important to continue to make adjustments

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Questions?Questions?

• Next: Device Information from

the nurses

• Hands on with CGM devices


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CGMs availableCGMs availableApril 2010April 2010


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Paradigm Real Time systemsParadigm Real Time systems(Paradigm pump and Revel pump)(Paradigm pump and Revel pump)

• A: Insulin pump and CGM receiver

• B: Infusion set• C: Sensor• D: Transmitter


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Paradigm Real-Time systemParadigm Real-Time system(Paradigm pump and Revel pump)(Paradigm pump and Revel pump)

• Pump is not controlled by CGM readings

• No extra receiver to carry

• Has high and low alarms

• Revel has predictive alarms

• Sensors last 3 days (6 days)

• Calibrations every 12 hours

• Great online download


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Guardian Real TimeGuardian Real Time

• For people not using a pump


• Has predictive alarms

• Sensor lasts 3 days (6 days)


• Why not buy a pump?


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Navigator CGMNavigator CGM


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Navigator CGMNavigator CGM

• Has built in Freestyle BG meter• Larger transmitter• Has high and low alarms • Has predictive alarms• Sensors last 5 days• Calibrations at 10, 12, 24 and 72 hours

• Well studied and highly accurate


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DexCom 7 PlusDexCom 7 Plus


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DexCom 7 PlusDexCom 7 Plus

• Most simple system to use

• Smallest transmitter


• Has rate of change alarms

• Sensor lasts 7 days


• Basic download software


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MiniMed MiniMed GuardianGuardian

MiniMed MiniMed Paradigm Paradigm 522/722522/722

Freestyle Freestyle NavigatorNavigator

Dexcom Seven Dexcom Seven PlusPlus

Sensor life Sensor life 3 days3 days 5 days5 days 7 days7 days

Initial Initial calibration calibration periodperiod

2 hours2 hours 10 hours10 hours 2 hours2 hours

Number of Number of calibrationscalibrations

2-4 per day2-4 per day 4 in 5 days4 in 5 days 2-4 per day2-4 per day

Trend arrowsTrend arrows YesYes YesYes YesYes

High/low High/low alarmsalarms

YesYes YesYes YesYes

Predictive Predictive high/low high/low alarmsalarms

YesYes No-Paradigm No-Paradigm Real-timeReal-time

Yes-Revel pumpYes-Revel pump

YesYes Rate of change Rate of change alarmsalarms

CostCost ~$1300 system ~$1300 system $35/sensor$35/sensor

$1000 system + $1000 system + 722/522 722/522 insulin pumpinsulin pump

$35/sensor$35/sensor

~$1000 system~$1000 system~$35-50/sensor~$35-50/sensor

~$400-800 system~$400-800 system~$60/sensor~$60/sensor


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CGM ReimbursementCGM Reimbursement

• Family will fill out an Authorization to release insurance information

• Physician will write prescription

(Letter of Medical Necessity)

• BDC will provide any other paperwork requested by the insurance company

• Call Mireya at BDC to get started

phone: 303-724-6763, fax: 303-724-6779Barbara Davis Center for Childhood Diabetes April 2010

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WebsitesWebsites

• Paradigm REAL-Time, Paradigm REAL-time Revel and

Guardian REAL-time:

www.minimed.com 1-866-948-6633

• Navigator:

www.abbottdiabetescare.com 1-888-522-5226

• Dexcom:

www.dexcom.com 1-877-339-2664


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CGM Start and Follow upCGM Start and Follow up

Medtronic Device Training—

Contact Mireya at 303-724-6763 to schedule

Navigator Training—

Trainer will contact you when your device ships

Dexcom Training—

Contact Michelle Perrot at 720-878-4099

Follow up CGM with Stephanie Kassels, FNP–

call Dahlia at 303-724-6748 to schedule


Documents

1 INTRODUCTION TO CONTINUOUS GLUCOSE MONITORS H. Peter Chase, MD Vicky Gage, RN, CDE Laurel Messer, RN, CDE Susie Owen, RN, CDE Sally Sullivan, RN, CDE