PRACTICAL ASPECTS OF
CONTINUOUS
GLUCOSE MONITORING
(CGM)
Barb Tallant, RN, MA
Laurel Messer, RN, BSN, CCRP
Eras of diabetes management
Urine Glucose
Pre-1978
SMBG
1978-2006
CGM?
2006 -
CGM vs. CGM Real-Time

Continuous glucose monitoring (CGM)


Retrospective analysis of data
Real-time continuous glucose monitoring (RT-CGM)

Retrospective analysis of data
PLUS

Continuous feedback of data to the wearer in “real time”

Additional features such as alarms, trend arrows
Medtronic Minimed CGMS® Gold™
(retrospective data)
•Available for many
years for HCP
• Sensor inserted under
skin cable  receiver
Medtronic Minimed CGMS® Gold™

Readings recorded every 5 minutes, glucose
range 40-400 mg/dl

Patient manually enters at least 4 BG values/day

Data downloaded from device to computer and
HCP can evaluate trends with wearer
CGM Real Time is here!



Wireless
Immediate feedback
Extra features like
alarms, line graphs,
trending arrows
CGM-RT systems
Medtronic/Minimed
Paradigm® Real-Time
(CGM available June 19)
DexCom™ STS™
(available and approved for adults)
Medtronic/Minimed
Guardian® RT
(only available in select cities)
Freestyle Navigator™
(Investigational Device/Non-FDA approved))
CGM-RT systems
Medtronic/Minimed
Paradigm® Real-Time
(CGM available June 19)
DexCom™ STS™
(available and approved for adults)
Medtronic/Minimed
Guardian® RT
(only available in select cities)
Freestyle Navigator™
(Investigational Device/Non-FDA approved))
Medtronic Guardian® RT
• Real time data collected
every 5 minutes
• Uses same type of sensor as
CGMS Gold
• Available in 7 selected cities
by prescription, for adults
18+
•
(Austin TX Boston MA,
Chicago IL, Houston TX,
Minneapolis MN, San Antonio TX,
Tampa FL)
Medtronic Guardian® RT

Unlike CGMS requires a
transmitter to project
information to the receiver

Interface is very similar to
other Medtronic products
CGM-RT systems
Medtronic/Minimed
Paradigm® Real-Time
(CGM available June 19)
DexCom™ STS™
(available and approved for adults)
Medtronic/Minimed
Guardian® RT
(only available in select cities)
Freestyle Navigator™
(Investigational Device/Non-FDA approved))
Minimed Paradigm® Real Time
Insulin Pump and CGM
Minimed Paradigm® Real Time
Insulin Pump and CGM

NOT A CLOSED LOOP SYSTEM!!

Pump works independently of CGM
(CGM optional)

Transmitter can store 40 minutes of readings in
case the connection to the receiver is broken
CGM-RT systems
Medtronic/Minimed
Paradigm® Real-Time
(CGM available June 19)
DexCom™ STS™
(available and approved for adults)
Medtronic/Minimed
Guardian® RT
(only available in select cities)
Freestyle Navigator™
(Investigational Device/Non-FDA approved)
Freestyle Navigator ™
Navigator™ Features



Uses the same technology that makes the
TheraSense FreeStyle and FreeStyle Flash meters
among the most precise and accurate.
Measures glucose levels in the patient's
interstitial fluid every sixty seconds and
transmits the results to a wireless pager-sized
receiver.
Sensor can be worn up to 5 days and is
waterproof
Designed as a three-part system:

PART 1: a sensor set in a support bracket

PART 2: a transmitter, designed to snap
into the sensor mount
PART 3: a receiver with a built in Freestyle
blood glucose meter. It receives information
wirelessly from the sensor/transmitter every
minute

Monica with sensor &
support mount
Connecting receiver with
sensor/transmitter
CGM-RT systems
Medtronic/Minimed
Paradigm® Real-Time
(CGM available June 19)
DexCom™ STS™
(available and approved for adults)
Medtronic/Minimed
Guardian® RT
(only available in select cities)
Freestyle Navigator™
(Investigational Device/Non-FDA approved)
DexCom™ STS™
System consists of 4 different parts:
1. Sensor designed to be worn for 72 hours.
2. Battery operated transmitter that snaps into
support mount and must be replaced.
3. Rechargeable receiver (much like cell
phone).
4. One Touch Ultra home glucose meter with
a download cable to receiver.
Transmitter
attached to
support mount
(not water proof)
One Touch
Ultra linked to
download BG
for calibration
MiniMed Guardian® RT
MiniMed Paradigm® Real-Time
Freestyle Navigator™
Dexcom™ STS™
Parts of system
Sensor connected to
transmitter, receiver
Sensor connected to transmitter,
insulin pump receiver
Sensor, transmitter,
receiver
Sensor, transmitter,
receiver
Distance of communication
6 feet
6 feet
10 feet
5 feet
Sensor life
3 days
3 days
5 days
3 days
How it obtains BG data
Manually enter from any
blood glucose meter
BD link or manual entry
Freestyle meter built into
receiver
Cable link to One
Touch Ultra
Initial calibration period
2 hours
2 hours
10 hours
2 hours
Number of calibrations/day
2 per day
2 per day
4 in 5 days
2 per day
Frequency of real time
readings
5 minutes
5 minutes
**Displays 1 minute
**Downloads either 1 or
10 minute readings
5 minutes
Trend arrows
N
Y
Y
N
Hypo and hyper alarms
Y
Y
Y
Y
Graphs on monitor
N
Y
Y
Y
Downloading software
Y
Y
Y
Y
Waterproof transmitter
Y
Y
Y
N
Reconnection
Manual
Manual
Manual
Automatic
Downloading
DL: ComStation DL
Analysis: software
DL: Radio-frequency
Analysis: CareLink (web-based)
DL: Bluetooth
Analysis: software
DL: cable
Analysis: software
Unique features
**Similar to CGMS in format
and sensor design
**Can use pump independent of CGM
capabilities
**Transmitter can hold 40
minutes of data if transmitter
and receiver lose connectivity
**Pending high and low
alarms (in addition to
actual high and low
alarms)
**Option to blind user
from the data
**Hard low alarm at
55mg/dl cannot be
turned off (also
programmable
low and high)
Cost of system
$2795.00
Cost of Paradigm pump plus $999.00
start up kit: Transmitter and 10 sensors
unknown
$800.00 (transmitter
replaced every 6
months at $250.00
Cost of sensors
$35.00 ea (10 per pack)
$35.00 ea (10 per pack)
unknown
$35.00 ea (5 per pk)
FDA approved: adults/children
Yes/No
Yes/No
No/No
Yes/No
CGM requires calibrations




All CGMs require blood glucose tests for
calibrating.
Calibrations are necessary to ensure that the
system will calculate glucose readings accurately.
Calibrations work best during periods
of stable BG (before meals)
Time insertions so that calibrations
won’t drive you crazy
Indications for Use





To improve glycemic control
For hypoglycemia prevention
To assess trends, especially during night or
exercise
To adjust insulin dosing—can assess basal (longacting) insulin effects and short acting insulin
effects, i.e. onset of action, peak and duration
Ongoing use for those who can afford it
Is my patient ready for CGM?



Like most diabetes care, the patient = family
Developmental considerations
Responsibility for CGM tasks





Who enters blood sugars?
Who uses trend data?
Who responds to alarms?
Who troubleshoots?
(calibrations)
CSII: clear explanation that CGM does not give insulin
Is my patient ready for CGM?

NEEDLE FEAR

Different issue for MDI vs.
pump patients

Different issue for long vs.
short term use

DexCom STS and Freestyle
Navigator have concealed
needles
Is my patient ready for CGM?
 ANXIETY
with real time CGM
Example: 4 BG/day versus 288 BG/day
 Trend arrows

 Anxious
parent + 284 extra BG
values/day + precipitating event

Evaluate if anxiety component is greater than
the need for CGM

Discuss tendency to want to correct for every
high blood sugar and strategies to avoid this

Reminding good diabetes practice:
 Do take a deep breath!
 Don’t correct more often than every 2 hours
 Don’t make several insulin changes at once
Efficacy in Clinical Practice
1. Through education/training:






Device set-up
System functions
Sensor insertion
Use of system
Calibrations
Insulin Dosing
2. Through Follow-up
 Data review
 Diabetes management
 Technical support
Practical suggestions,
solutions, and stories
•Skin care
•Alarms
•Device protection
•Carrying device
Skin care:

POSITION

PREPERATION

PROTECTION

PEELING

PULLING
Alarms:

Hypoglycemia
Ranges

Hyperglycemia
Ranges

Night time
1. Volume
2. Treating

Projections
Muting
Practicalities:
Device Protection

All CGM-RT transmitters are waterproof except the
DexCom STS (uses special shower pad)

All devices come with a carrying case and belt clip

2 major dangers of giving a child a wireless device:
1)
2)
Drop it (oops)
Lose it (big oops)
Practicalities

Dropping the wireless receiver:
Guardian RT receiver has screwed on battery door/ thin
leather carrying case
 DexCom receiver is one piece/ harder carrying case
 Navigator receiver has a battery door that may snap
open/ harder carrying case


Losing the wireless receiver:

All devices have same potential for loss
(except Paradigm real time because connected to infusion set)

Especially easy to lose in bathrooms, bed, school
Practicalities:
Carrying the Wireless Receiver

Short term use:
With child at all times
 Belly bag/fanny pack, pocket, belt clip
 2nd choice: backpack, lunchbox, purse, jacket, etc.


Long term use:

Parent can hold device if child is close (i.e. watching a
movie, grocery shopping, car trips)
Practicalities:
Carrying the Wireless Receiver

Sports and activity
#1 concern is the receiver
 Parent holds receiver on sidelines of soccer game, or
kayaks out to swimming child
 Medtronic technology can store data in transmitter, so can
reconnect at breaks and not lose any data


Bedtime:
clip receiver to underwear or pajamas
 leave on bedside table

Conclusion



CGM Real Time has potential of revolutionizing
diabetes care
Many practical, psycho-social, and economic
aspects to consider
Further discussion is needed in implementing
CGM-RT into standard of care management for
diabetes
Questions and discussion