Transcript PowerPoint Presentation - Advanced Pump And Monitor

Current And Emerging Technologies In
Insulin Pumps And Continuous Monitors
Santa Barbara, January, 2007
John Walsh, P.A., C.D.E.
North County Endocrine
700 West El Norte Pkwy
Escondido, CA 92126
(760) 743-1431
The Diabetes Mall
www diabetesnet.com
(619) 497-0900
[email protected]
Healthcare Across Borders - September 2003
Highlights
Helpful Points To Review In Pump Settings
•
•
•
•
Therapy Effectiveness
Basal/Bolus Balance
Bolus Timing
Correction Bolus %
DIA
BOB
Pump Features
Continuous Monitors
Future pump features
Wrap up
Healthcare Across Borders - September 2003
The Dual Nightmares Of Diabetes
BLOOD GLUCOSE LEVELS
TARGET
LOW
HIGH
Hypo
Hyper
Loss of consciousness
Diminished cognitive
function
Fear of tight control
Potential death
Blindness
Kidney failure
Amputation
Cardiovascular disease
Nerve degeneration
Acute complications
Healthcare Across Borders - September 2003
EDIC’s Lessons
Improved Control Lessens Heart And Nerve Damage
Since ending the DCCT in 1993, the EDIC study has followed participants. In this
12 years, A1c levels in the intensive and conventional control groups have
been identical at 7.9% (was 7.4% and 9.1%).
98 heart attacks and strokes occurred in conventional control participants, only 46
in the intensive group. This 53% reduction occurred even though A1c levels
were the same since the end of the DCCT trial over 11 years before.
The tight control group was also 51% less
likely to have neuropathy symptoms
compared to the conventional control
group.
Take Home: Improve control ASAP
1. EDIC Study Group presentation at 2005 ADA, K.M. Venkat Narayan: Clinical Diabetes 24:88-89, 2006
Healthcare Across Borders - September 2003
2. Diabetes Care, Vol 29, No. 2, pp.
340-344
HbA1c
Today’s Level Of Control
2/3 with diabetes remain out of
10%
control, including most pumpers
9%
Avg. A1c on Pumps
8%
Goal A1c
ADA
7%
EASD/AACE
6%
ADA = American Diabetes Assoc., IDF = Inter. Diabetes
Federation, EASD is European Assoc. for the Study
of Diabetes, AACE is American Association of Clinical
Endocrinologists
From Novo Nordisk Type 2 diabetes market research,
Roper Starch, ADA, EASD, IDF, AACE, Wright A.,
Burden et al, Diabetes Care 2002; 25:330–336,
Turner RC, Cull et al, JAMA 1999; 281:2005–2012
Healthcare Across Borders - September 2003
5%
Avg. A1c in
TYPE 1s
Narrowing The Gap To A Closed Loop
I
n
s
u
l
i
n
D
e
l
i
v
e
r
y
1922 Insulin & syringes
We are here
1979 Pumps
1983 Pens
Connectivity
2002 Smart Pumps
Data Management
M
o
n
i
t
o
r
i
n
g
Closed Loop
2006 Continuous Monitors and
Early Intelligent Pumps
1971 Home Monitors
More work!!!
1926 Clinic Monitoring
HCP
Self Management
Healthcare Across Borders - September 2003
Automation
Adapted courtesy Roche/Disetronic
Ways That Smart Pumps Improve Control
Testing produces better results
Fewer missed doses
More dependable insulin action
Accurate carb counting
Accurate bolus calculations
based
on carb and BG need while accounting for BOB to
avoid insulin stacking
Accessible history
Precise basal adjustment
Reminders to reduce skipped boluses
Across UP
Bordersand
- September
2003 CORRECTLY!
When pumpHealthcare
is SET
USED
Helpful Points To Review
In Pump Settings
Healthcare Across Borders - September 2003
Smart Pump Settings
•
•
•
•
•
•
•
•
•
•
Time*
Beasal Rates*/Options
Carb Factor*
Correction Factor*
Target(s)
Duration of Insulin Action*
Bolus on Board
Direct Meter Entry
Reminders and Alerts
History of insulin use:
• TDD
• Basal/Bolus Balance
• Correction Bolus %
* Critical settings
Healthcare Across Borders - September 2003
Pump Data Can Improve Control
The Cozmo Therapy Effectiveness Scorecard
Screen 1:
Days to Average (7-14 days provide good average)
Average # of Carbs per day (Are carb boluses taken? Low carbs?)
Average Total Daily Dose (TDD) (How steady?)
Average % of TDD for correction boluses (Over 8% of TDD?)
Average % of TDD for carb boluses
Average % of TDD for basal rates (At least 40-45%?)
Screen 2 :
Average # of BG tests (Sufficient testing? Before and after meals?)
Average BG value (Overall control?)
BG Standard Deviation (Glucose variability? Aim for half of average
BG or less than 65.)
Healthcare Across Borders - September 2003
Therapy Effectiveness Guidelines
TDD – Raise when often high
Lower when often low or when low and high
Basal/Bolus Balance – Keep basals & boluses near 50% of TDD
Correction Factor = 4.4 x Carb Factor
Correction Bolus % – if correction boluses make up over 8% of the
TDD, move the excess into basals or boluses
Average Blood Glucose – Keep < 160 when checking before and
after meals or < 140 when checking mainly before meals
Standard Deviation (BG variability) –
Keep less than half of your average BG or below 65 mg/dl
For tight control, keep less than 1/3 of avg. BG
Healthcare Across Borders - September 2003
The TDD Is The Kingpin To Control
An accurate TDD is critical to great control.
When a major control problem occurs, check the TDD:
1. What is your average TDD?
Is your TDD
2. How steady is it?
too much
3. Change your TDD when
or too little?
• A recent A1c is high
• You have frequent highs
(or a high avg. BG on meter)
• You have frequent lows
• Or both highs and lows (which comes first?)
4. Adjust by 5% to 10% (usually)
5. Redistribute about equally between basals and carb boluses
Healthcare Across Borders - September 2003
Use A High A1c To Raise The TDD
Example: someone with a TDD of 35 units and an A1c of 9% (with
few lows) needs more insulin: about 3.2 units.
Healthcare Across Borders - September 2003
© Pumping Insulin, 2006
Pump Clues To Better Control
Start asking questions when:
• The correction bolus % is >8% of the TDD
• Basal rates make up less than 40-45% of the TDD
• The DIA is less than 4 hours
Healthcare Across Borders - September 2003
What % Of TDD Are Correction Boluses?
Goal: Use less than 8% of TDD for correction boluses
or ~16% of bolus insulin in Paradigm
10 day average:
Meal
Corr
Basal
Total
Carb
19.4 u
11.3 u
23.3 u
54.1 u
175 g
Insulin Use
36%
21%
43%
TDD (100%)
This pumper’s correction boluses are 21% or well above 8% of TDD.
Move 1/3 to 1/2 of the overage to basals or carb boluses
8% of 54.1 = 4.3
11.3 - 4.3 = 7 units
1/3 to 1/2 of 7 units = add 2.3 to 3.5 units to basals or carb
Healthcare Across Borders - September 2003
When Correction Bolus % Is High,
Basal Rates Or Carb Boluses Need To Rise
 A high Corr. Bolus % says basal rates or carb boluses are
too low, or that carb boluses are being skipped
 Check correction bolus % at least once a month
 Move any excess above 8% to basal rates or carb
boluses
 Move the excess into basals or carb boluses whichever is smaller
or into both if basals and carb boluses are balanced
Note: Paradigm pumps give correction bolus % as a percentage of
the bolus dose total, not the TDD. Don’t use this percentage here!
Healthcare Across Borders - September 2003
First Half Of Control: Basal Rates
Tips
• 50% Rule: basals make up
40-65% of TDD
• Start with 50% of an accurate TDD as basal
• Basal rates will be similar through the day, such as
between 0.45 and 0.7, or between 1.0 and 1.4
• Adjust basal rate in small steps – 0.05 to 0.1 u/hr,
unless a major change is required for illness, etc
• Make change 3 to 6 hours before need arises
Healthcare Across Borders - September 2003
Basal/Bolus Balance
Usual balance = ~50% basal and ~50% bolus
< 50% Basal
Duration < 5 yrs
Thin
Physically active
High carb/low fat diet
~ 50% Basal
> 50% Basal
Most people
Duration > 5 yrs
Puberty
Less active
Insulin resistant
Low carb diet
Teens with hormones
Periodically check basal/bolus balance to see how
insulin is being used!
Healthcare Across Borders - September 2003
Carb Coverage: The Second Half Of Control
Requires:
Accurate carb factor
Accurate carb counting
Proper timing for carb
boluses
Healthcare Across Borders - September 2003
Timing: Most Carbs Are Faster Than Insulin
One hour after a meal, half of a meal’s
glucose rise has occurred, but 80% of
rapid insulin activity remains
Time over which most meals raise the BG
Time over which rapid
insulin lowers the BG
0
Take Home:
2 hrs
4 hrs
6 hrs
Bolus 15 to 30 minutes before meals when possible.
Use extended and square wave boluses sparingly.
Healthcare Across Borders - September 2003
Bolus Timing
Critical to control:
Figure shows rapid insulin
injected immediately, 30
min, and 60 minutes
before a meal
Normal glucose and insulin
profiles are indicated by
the shaded areas
Need
# -of
subjects
and origin
Healthcareinfo
Across on
Borders
September
2003
Adjust Bolus Timing To Glucose Level
Premeal
Glucose
Bolus Timing
Low
Use fast carbs, check BOB, and give carb bolus
at start of meal with current BG
Normal
If possible, bolus 15 to 20 minutes before meal
High
Give carb and correction bolus even earlier
Retest 2 hours after the meal to verify the dose
Healthcare Across Borders - September 2003
Duration Of Insulin Action
How long a bolus lowers the blood sugar
Healthcare Across Borders - September 2003
Duration Of Insulin Action
0
2 hrs
4 hrs
Healthcare Across Borders - September 2003
6 hrs
Why The DIA Gets Set Too Short
Many pumpers set the DIA too short.
Usually caused when a pumper finds that their
recommended bolus doses do not bring down
elevated BGs.
Many pumpers have inadequate basal delivery or carb
boluses, indicated by an elevated A1c.
Shortening the DIA is perceived to be easier or safer
than raising basal rates or lowering the carb factor
Healthcare Across Borders - September 2003
Problems Arise With Short/Long DIAs
If DIA is set too short --> hides boluses and makes the
basal appear to be too high
when a low occurs
If DIA is set too long -->
exaggerates bolus action and
makes basals appear to be too low when a high
occurs
Today’s pumps’ DIA range of 2 to 8 hrs is
too wide for today’s insulins!
Healthcare Across Borders - September 2003
What DIA Should I Select?
4 hrs
An accurate DIA
can significantly
improve control.
Enables accurate
boluses when
BOB is present
Best DIAs: 4-6 hrs
Adapted fom Mudaliar et al: Diabetes Care, 22: 1501, 1999
Healthcare Across Borders - September 2003
Different Pumps Calculate DIAs
Differently
Recommended times:
For curvilinear DIAs (Animas 1250 & Paradigm 5/715
& 5/722), use 4 to 6 hours
(Deltec Cozmo & Insulet Omnipod), use 3.5 to 5.25
hrs
Large boluses (>12-20 u at a time) require a longer DIA
Healthcare Across Borders - September 2003
Bolus On Board (BOB)
How much glucose-lowering potential remains
from recent boluses
aka: insulin on board, active insulin, unused insulin
Healthcare Across Borders - September 2003
Bolus On Board
• Prevents insulin stacking
• Improves bolus accuracy
• Reveals current carb deficit or insulin deficit
For an accurate BOB, the pump must have
an accurate duration of insulin action.
You must enter a BG to determine your BOB!
Healthcare Across Borders - September 2003
Use BOB To Prevent Insulin Stacking
How much BOB remains when the bedtime BG is 173? Is there an
insulin deficit or a carb deficit at this time?
Insulin stacking is common
in adults and especially in
children who use frequent
boluses!
Correction
Dessert
Bedtime BG
= 173 mg/dl
Dinner
6 pm
8 pm
10 pm
Healthcare Across Borders - September 2003
12 am
Should I Eat Or Should I Bolus
When My Glucose Is 173?
Scene 1
Scene 2
BOB = 0 u
Insulin deficit = 1.6 u
BOB = 4.6 u
Carb deficit = 3.0 u x 12 g/u
You may need 36 grams
Give 1.6 units now?
Y or N
Time till 120: ~30 min.
Set alert for 30 min?
Y or N
Available as Low BG Manager in Cozmo pumps
Healthcare Across Borders - September 2003
All Pumps Subtract BOB From Correction Boluses
Excess BOB is
subtracted from
correction bolus
3+2
- -1
-= 4 u bolus
Healthcare Across Borders - September 2003
Paradigm & Omnipod Do Not Subtract BOB From Carb
Bolus, Animas Only When BG Is Below Target
Excess BOB is
subtracted from
3.0U correction bolus,
45 gr but NOT carb bolus
160
3.0U
3+2
2.0U
5.0U - - 5
-= 0 u bolus
When a carb bolus is given within 3-4 hrs of last bolus, these
pumps’ recommended boluses may be too large.
Healthcare Across Borders - September 2003
Pumps Do Not Recommend The Same Boluses
Recommended boluses
when:
the IOB = 3.0 u,
for 30 gr. of carb,
at each glucose
level
units
4
3
2
1
0
60
90
120
Deltec Cozmo
150
180
Animas 1250
210
240
Medtronic 522
mg/dl
Carb factor = 1u / 10 gr
Corr. Factor = 1 u / 40
mg/dl over 100
TDD = ~50 u
Bolus recommendation errors may arise:
• When a bolus is given within 4 hrs of another
• A glucose test is entered into the pump
• And the BOB is greater than the current correction dose requirement
Healthcare Across Borders - September 2003
Pump Features
Smart And Intelligent
Intelligent Features
• make accurate dosing easier
• improve carb counting
• enable pattern recognition
• simplifies testing of basals and boluses
• simplifies basal and bolus shifting
Healthcare Across Borders - September 2003
Reminders And Alerts
• Test after a bolus
• Test after a low reading
• Test after a high reading
• Give a bolus at certain time
• Warn if bolus was not given at a certain time of the day
• Warn if bolus delivery was not completed due to
distraction.
• Change infusion site
• Warn of low reservoir (20, 10, 5 and 0 units, with an
extra 10 “hidden” units in Cozmo for basal delivery)
Healthcare Across Borders - September 2003
Pumps With Meters Or Con Mons
Many BG tests are never entered into pump dataset
Meters with direct BG entry
• Deltec Cozmo + Freestyle CoZmonitor
• Omnipod + Freestyle
Current Con Mon, no direct BG entry
•Medtronic 5/722 + Paradigm RT
Coming Con Mons
• Abbott Navigator + Abbott
Aviator, Deltec Cozmo, or
Insulet Omnipod
• Animas + Lifescan?
• AccuChek pump + meter?
Healthcare Across Borders - September 2003
Low BG Manager
At each glucose test, the pump alerts whether
there is an insulin or a carb deficit
BG = 172
OR
Bolus on board = 0.4 u
Insulin deficit: 1.2 u
Give correction now? Y or N
BG = 172
Bolus on board = 4.6 u
Insulin excess = 3.0 u
You will need: 33 grams of
carb to prevent a later low BG
• Helps prevent & treat hypoglycemia
• Shows how many carbs are needed to return the glucose to
normal or to prevent a low blood sugar.
• Helps prevent post-treatment hyperglycemia
Healthcare Across Borders - September 2003
Early Intelligent Pump Features
Disconnect – estimates bolus needed to replace basal
when disconnecting from a pump for an hour or more
Weekly Schedule – allows different basal rates and
alarms to be set for different days of the week
Basal Testing – provides assistance for testing
ovenight basal rates
Healthcare Across Borders - September 2003
Disconnect Bolus
Provides freedom, flexibility, & added certainty when
disconnecting for bathing, sports, etc.
User tells Cozmo how long they will disconnect up to 2
hours
Cozmo tells user how much basal insulin they will miss
while disconnected
Then asks if they would like to receive up to 50% of it as
immediate disconnect bolus
Alarm to re-connect at designated time
User reconnects & Cozmo shows the percentage of basal
insulin they missed while disconnected & asks if they
want to receive that % immediately
Included in the Bolus On Board to prevent stacking
Healthcare Across Borders - September 2003
Weekly Schedule
The user’s profile changes automatically for specific days
of the week
No need to remember to change basal patterns or alerts
Different basal patterns and alert times (such as missed
meal bolus) for different days of the week
Great for college, shift work or other work variation,
exercise
Healthcare Across Borders - September 2003
Weekly Schedule Example
Wednesday
Thursday
Friday
Saturday
Basal Pattern
Running Club
Missed Meal Bolus Alerts
Running Club
Basal Pattern
Weekday
Missed Meal Bolus Alerts
Weekday
Basal Pattern
Golf League
Missed Meal Bolus Alerts
Golf League
Basal Pattern
Weekend
Missed Meal Bolus Alerts
Weekend
Healthcare Across Borders - September 2003
Basal Test
Guide in pump simplifies basal testing
Evaluates basal patterns to make sure they are correct
Overnight, Morning, Afternoon, Evening
Up to 10 alerts may be set to check BG level for each
pattern
Test automatically ends when BG exceeds the “High” limit
or falls below the “Low” limit
Allows HCP and user to test basal patterns and review
basal patterns for different times of day
Healthcare Across Borders - September 2003
Sample
Basal Test
Healthcare Across Borders - September 2003
Pump As Carb Counter
Pumps offer user-selected food
lists to improve carb counting
• Easy carb calculation
• Improves bolus accuracy
• Available in
• Animas 1250 (#500)
• Deltec Cozmo (#150 to 200)
Healthcare Across Borders - September 2003
Many Smart Pump Features Are Underused
Underused features that can help control:
• Entry of glucose test results
• Carb counting or use of a carb database
• Alternate and temporary basals
• Use and tracking of BOB
• Review of glucose history and insulin use
• Reminders and alerts
Healthcare Across Borders - September 2003
Continuous Monitors
Healthcare Across Borders - September 2003
Healthcare Across Borders - September 2003
The Value of Frequent Testing
400 (22)
300 (17)
7 opportunities to intervene versus 1!
200 (11)
100 (5.6)
Breakfast
Lunch
Dinner
Healthcare Across Borders - September 2003
Bed
Continuous Monitors Reduce Exposure & Variability
15 users with implanted Dexcom continuous monitors blind to glucose readout for
50 days, then open readout for the next 44 days.
Blinded
8.91
9
-160 min
8
+ 250 min
7
hrs/day
Open
-13 min
6.38
6
5
4
3
2
6.16
4.75
- 65 min
7.23
4.57
+ 32 min
2.62
2.06
1.53
1.52
1
0
40-55
56-80
81-140
141-240
blood sugar
Healthcare Across Borders - September 2003
241-400
Continuous Monitoring
Benefits
Limitations
• Alarms to prevent
lows & highs
• Security in knowing
where you are and
where you’re going
• Trends shown by graph, arrows,
or predictors
• Lack of accuracy
• Data gaps
• Lack of insurance
coverage
• Occ. cell phone or
microwave interference
• “Body blocking” in bed
• Site bleeding may affect
accuracy
Healthcare Across Borders - September 2003
Continuous Monitoring Today
Today’s monitors
• Are not approved for independent use
• Cannot be used by pump for dose calculations
• Differ significantly in accuracy
• Give no warning when they are inaccurate
• Model-T styling
• Results must be used with caution
• Otherwise wonderful
Healthcare Across Borders - September 2003
Continuous Monitors Make Testing Easier
Basal test
120 mg/dl
10 pm
2 am
Healthcare Across Borders - September 2003
8 am
© Pumping Insulin, 2006
Bolus Testing With A Continuous Monitor
Correction bolus test
Carb bolus test
300
200
100
60
6 pm
8 pm
10 pm
6 pm
Healthcare Across Borders - September 2003
8 pm
10 pm
© Pumping Insulin, 2006
FreeStyle Navigator
TheraSense Continuous Glucose Monitor
Healthcare Across
Borders– -Limited
September by
2003U.S. Law to Investigational Use
Investigational
Device
Freestyle Navigator System
• Good accuracy
• First reading after 1st calibration
after 10 hrs
• Calibrated 1-2 times per day for 1st
two days
• Readings every 1-2 minutes
• 5 day use
• High and low glucose alarms
• Good accuracy below 100 mg/dl
• Trend arrow, distant graphic display
• May be used in Deltec Cozmo and
Omnipod pumps
Healthcare AcrossDevice.Limited
Borders - September 2003
Investigational
by U.S. Law to Investigational Use
Real-Time Results, TRU Directional Arrows
Glucose rising quickly
> 2 (mg/dL)/min
Glucose going up
1 to 2 (mg/dL)/min
Fairly stable glucose
-1 to 1 (mg/dL)/min
Glucose going down
-1 to -2 (mg/dL)/min
Glucose falling quickly
< -2 (mg/dL)/min
Healthcare Across Borders - September 2003
The Problem With Trend Arrows
Absence of a trend arrow means change in glucose is less
than 60 mg/dl up or down from the current reading.
In other words, if the current reading is 110:
An Hour Later
159
Now
Large BG changes
can occur with no
trend arrow
100 mg/dl
41
Across Borders
- September
2003
TrendHealthcare
arrows
are very
inaccurate!
Undetected High Excursions with SMBG
53 year old male; multiple injector; 240 lbs.; 10 yrs. diabetes; HbA1c 7.3
400
0.9h
7.6h
Glucose (mg/dl)
300
5.6h
4.3h
2.9h
1.3h
0.5h
1.0h
200
100
0
0
Max.
Sensor /SMBG
Reading
Day 68
1440
364 / 221
Day 69 2880
362 / 259
Day 70 4320
368 / 268
Day 71 5760
350 / 209
Healthcare Across Borders - September 2003
Day 72
7200
367 / 254
Improvement in Glucose Profiles
47%
decrease*
88% increase*
25%
decrease*
* p < 0.05, Wilcoxon signed rank test
Garg, Edelman &
Schwartz
Diabetes
Care.
Healthcare
Across Borders
- September
200327(3):734-738, 2004.
Monitor Graphics
Healthcare Across Borders - September 2003
A Comparison Of Two Monitors
Healthcare Across Borders - September 2003
Dexcom STS Monitor
FDA release 3/27/06
Approved for 18 and older
Readings every 5 min.
3-14 days of readings per sensor
One high and two low alerts
$800 (often less) + $35 per “3” day
sensor
Transmitter replacement: ~$250
every 6 mos
Transmitter ~0.8 x 1.5”
Healthcare Across Borders - September 2003
Medtronic Paradigm RT
FDA release: 4/13/06
Paradigm 522/722 pump
Sensor connected to
transmitter by wire
Approved for 18 and older
One high and one low alert
NOT a closed loop
Healthcare Across Borders - September 2003
Trend arrows
Readings every 5 min.
$999 + $35 per “3 day”
sensor
Transmitter replacement:
~$900 every 6 mos
Continuous Monitors Compared
The Dexcom STS & Paradigm RT continuous monitors are currently
available in the U.S.
This study was designed as a head to head comparison while being
worn by one person with Type 1 diabetes.
An Ultra meter was used as the standard against which each
monitor’s accuracy was tested.
Each monitor’s screen is shown above over the same 3 hour time span over a glucose
range of 0 to 400 mg/dl. The Ultra meter reading at the time read 73 mg/dl compared to
93 and 122 mg/dl.
Healthcare Across Borders - September 2003
Research Design
1. The low alert in each monitor was set at 80 mg/dl and the high
alert at 160 mg/dl
2. 262 readings from an Ultra meter were performed over 33 days
(7.94 tests per day)
3. Simultaneous readings from each monitor were compared to the
Ultra’s readings
4. Testing with the Ultra meter was performed:
• As soon as either monitor’s low or high alert sounded
• When values between the monitors disagreed
• And at routine intervals, including calibrations
Healthcare Across Borders - September 2003
Calibrations
Each monitor required 2 calibrations with an Ultra glucose meter each
day to reduce “drift” or loss of accuracy over time.
Calibrations were generally done when the glucose level was stable.
Calibrations were usually done on both monitors when requested by
one of them.
In all, 3 to 4 calibrations were done per day on both monitors.
Care was taken not to do more than 4 calibrations per day on either
monitor due to the recommendation by one of the manufactures
that no more than 4 be done per day. (This recommendation
makes no sense to us, though we have discussed it with various
engineering and sales personnel from the company.)
Accuracy of the other monitor appears to improve when more
calibrations are done from observations before and after the study.
Healthcare Across Borders - September 2003
Readings Sorted By Ultra BG Values
Low to High
Date
Time
Ultra
New sensor A
New sensor B
28-Dec
15:38
15-Dec
11:28
29-Dec
6:52
15-Dec
11:24
12-Dec
12:53
11-Dec
23:32
3-Oct
21:24
10-Dec
15:45
15-Dec
23:06
31-Dec
17:27
31-Dec
14:34
16-Dec
8:22
31-Dec
14:48
29-Sep
19:34
14-Dec
20:07
1-Oct
20:29
11-Dec
23:40
16-Dec
11:19
16-Oct
16:15
29-Sep
19:52
7-Oct
11:39
30-Sep
16:37
15-Dec
20:57
3-Oct
21:18
15-Dec
9:23
High to Low
Sensor A Sensor B
42
43
46
47
50
50
51
52
53
54
55
56
56
56
57
57
57
58
58
58
59
60
60
60
61
45
57
63
67
74
70
43
50
59
62
65
51
52
54
60
68
65
75
40
50
55
67
80
54
51
68
78
78
90
124
88
78
66
62
80
92
70
78
95
76
44
76
78
78
65
76
90
78
84
72
Date
Time
Ultra
New sensor A
New sensor B
9-Oct
22:17
11-Oct
3:23
14-Oct
17:03
14-Oct
16:08
2-Oct
7:25
9-Oct
20:42
29-Dec
11:38
14-Oct
15:40
29-Dec
12:51
31-Dec
22:18
29-Dec
13:58
30-Sep
0:55
30-Sep
11:27
17-Oct
9:55
14-Oct
11:50
8-Oct
13:42
8-Oct
11:15
10-Dec
16:20
10-Dec
19:11
9-Oct
20:17
28-Dec
13:34
12-Dec
20:09
16-Oct
19:20
14-Oct
17:58
10-Oct
17:17
Sensor A Sensor B
341
297
286
282
278
273
271
252
237
236
233
231
229
227
218
217
212
211
211
211
210
210
209
208
205
344
230
276
280
294
249
201
234
230
209
159
163
144
217
231
210
218
207
231
250
168
212
221
206
219
358
188
166
144
272
196
164
142
270
222
238
158
224
164
130
164
202
138
220
164
116
168
162
140
172
Red = first to detect a low Yellow = first to detect a high Purple = over 50 mg/dl off
Healthcare Across Borders - September 2003
Plotted Readings With Trend Lines
Ultra
400
U
l
t
r
a
A
300
Monitor A shows linearity
from 50 mg/dl up to at least
240 mg/dl.
200
100
0
0
50
100
150
200
Sensor A
250
300
350
400
Ultra
400
U
l
t
r
a
Monitor B shows more
scattered values and
“flattens out” with higher
low readings and lower
high readings than the
Ultra.
B
300
200
100
0
0
100
200
Sensor B
300
400
Healthcare Across Borders - September 2003
GlycensitTM Analysis
A
B
Blue dotted lines = ISO standards
Yellow area = where 95% of data points will fall
Red lines = minimum and maximum deviation by star points
Ideally, all readings would fall between the blue dotted lines -- this
is the standard for today’s glucose meters
Healthcare Across Borders - September 2003
http://tomcatbackup.esat.kuleuven.be/GLYCENSIT/
Monitor Accuracy
Diffe re nce From Ultra M e te r Re adings For Each Se ns or
Se ns or A
Se ns or B
0-9 m g/dl off
116 44.3%
52 19.8%
43.5%
76.0%
10-19 m g/dl off
83 31.7%
62 23.7%
20-29 m g/dl off
32 12.2%
46 17.6%
30-39 m g/dl off
11
36 13.7% 41.6%
4.2% 19.8%
40-49 m g/dl off
9
27 10.3%
3.4%
50-59 m g/dl off
4
14
5.3%
1.5%
60-69 m g/dl off
2
7
4.2%
2.7% 14.9%
0.8%
ove r 70 m g/dl off
5
18
6.9%
1.9%
Table shows how much each monitor’s glucose values
differed from a simultaneous reading on the Ultra meter.
Healthcare Across Borders - September 2003
Monitor Accuracy
Av g. Diff. in mg/dl and % betw een Sensor and Ultra Meter at different BG ranges
Ultra
Sensor A
Sensor B
BG Range
# of Readings
Av g. BG
Diff in mg/dl Diff in %
Diff in mg/dl
0-80 mg/dl
66
64.74
3.23
5.00%
21.94
81-160 mg/dl
127
117.07
-0.12
0.00%
-3.02
161-240 mg/dl
61
188.7
-5.97
-3.16%
-32.25
241 or over mg/dl
8
285
-21.5
-7.54%
-81.25
Diff in %
33.89%
-2.58%
-17.09%
-28.51%
Monitor A read slightly high (5%) for readings below 80, while
B’s readings were 34% high for this range.
Between 81 and 160, both sensors were within 3% of the Ulta.
Between 161 and 240, A averaged 3% lower than the Ultra,
while B averaged 17% lower.
Above 240, there are too few readings to judge accuracy, but
both monitors appear to read lower, although the difference
was more pronounced for Monitor B.
Healthcare Across Borders - September 2003
Monitor Accuracy
B
A
Lower than the Ultra
Higher than the Ultra
BGs
< 80
BGs
80-160
BGs
> 160
BGs
< 80
BGs
80-160
BGs
> 160
This GlycensitTM graphic summarizes data shown on the previous slide. The
average reading for Monitor A, shown by the middle of the spool-shaped
objects for low, middle, and high, is much closer to that of the Ultra meter (the
green line in the middle) with less variation (the height of the spool the
standard deviation) than Monitor B. The shorter the spool and the closer it’s
middle is to the line the more accurate the Monitor.
Healthcare Across Borders - September 2003
http://tomcatbackup.esat.kuleuven.be/GLYCENSIT/
Which Monitor Alerted First?
Which Monitor Alerted First?
Monitor A Monitor B
Tie
For BGs less than 80
28
1
8
For BGs over 160
25
2
10
One of the most important functions of a continuous monitor is to
accurately warn of low and high readings. This table shows which
monitor alerted at least 5 min earlier for lows and highs.
Monitor A was first to alert for a reading below 80 mg/dl 76% of the time,
Monitor B was first 3% of the time, and 21% were ties.
For detection of highs above 160, Monitor A was first 68% of the time, Monitor
B was first 5% of the time, and 27% were ties.
Healthcare Across Borders - September 2003
Time Advantge For First Alerts
Time Advantage To First Alert For Each Monitor
Readings Less Than 80 mg/dl
Advantage
A&B
Details
8 ties
A
19* firsts – time advantage averaged 30.3 min with median of 18 min
A
9 additional firsts – no alert given by B
B
1 first – no alert given by A
Readings Above 160 mg/dl
A&B
10 ties
A
17** firsts – time advantage averaged 32.1 min with median of 27 min
A
8 additional firsts – no alert given by B
B
2 firsts with time advantage of 11 and 14 minutes
Healthcare
Borders
* Time not recorded for 2 of
theseAcross
events
** Time not recorded for 4 of these
- September 2003
Time Delays For Low
And High Alerts
In situations where Monitor A was
first to alert*, the time delays
for Monitor B to give an alert
are shown.
* confirmed with the Ultra meter
** Readings were maintained below
80 mg/dl for long periods to test
these delays.
Minutes Of Advance Warning
Less than 80 mg/dl
+ 15 min
Over 160 mg/dl
+ 33 min
+6
+ 49
+ 14
+ 83
+ 80 **
+ 24
+ 90 **
+ 42
+8
+ 36
+ 18
+ 37
+ 17
+7
+ 20
+ 27
+ 45 **
+ 24
+8
+ 19
+8
+ 20
+ 19
+ 16
+ 16
Avg = 32.1 min
+ 80 **
Median = 27 min
+ 14
+ 57 **
Healthcare Across Borders - September 2003
Avg = 30.3 m Med 17
Con Mon Tips
Healthcare Across Borders - September 2003
Level of Risk Depends on Trend: No Two Points
Are Created Equal!
100
Going Up
Lower Risk
Glucose (mg/dl)
90
80
70
60
50
40
30
20
0
50
100
Minutes
150
200
Healthcare Across Borders - September 2003
Going Down
Higher Risk
Going Up:
Consider Action!
Healthcare Across Borders - September 2003
Did Not Act
Early Enough or Effectively!
Healthcare Across Borders - September 2003
Wait and Watch!
Healthcare Across Borders - September 2003
Cone of Possibilities
260
240
Glucose (mg/dl)
220
200
180
160
140
120
100
0
20
40
Minutes
Healthcare Across Borders - September 2003
60
80
An Object in Motion Stays in Motion:
Turnaround Time
Healthcare Across Borders - September 2003
Education: Don’t Stack The Insulin
Healthcare Across Borders - September 2003
CGM Devices May Have Lag Times During Periods of
Rapid Change (~5 to 10 minutes)
500
195000
450
175000
400
155000
350
135000
300
115000
250
95000
200
75000
150
55000
100
35000
50
15000
0
13:40 13:54 14:08 14:23 14:37 14:52 15:06 15:20 15:35 15:49 16:04 16:18
Healthcare Across Borders - September 2003
Staying Between the Lines
Healthcare Across Borders - September 2003
Staying Between the Lines
Healthcare Across Borders - September 2003
Conclusion: Continuous is More Than Extra Data Points
Feature
Single-Point
Continuous
Samples/day
2-4
2880
Displayed to user per day
2-4
288*
Direction?
No
Yes
Rate?
No
Yes
Change in rate?
No
Yes
Show trends?
No
Yes
Verification of value
Requires 2nd SMBG
Automatic
Sensor level: Every 30 sec.
Receiver level: Every 5 min.
Low and high alerts
No
Yes
Retrospective data
displayed
Points
Graphs showing trendline
going back 1, 3 and 9 hours
Fail-safe indicator
No
More so
Prediction of future
No
About 30 minutes
Healthcare Across Borders - September 2003
Tips for CGM
• Be patient and have realistic expectations
• Don’t panic when the meter and sensor numbers
are different
• Look at the trend, not just the individual value
• Rapid rises usually mean you need more insulin
• Expect some lag period
• Drifting may occur
• No Tylenol
Healthcare Across Borders - September 2003
What Is Needed To Close The Loop
Insulin
Glucose
Sensor accuracy
Reliability
Slow insulin
Lifestyle variability
Control algorithm
Sensor lag time
Insulin overdose
Healthcare Across Borders - September 2003
Engineering / Materials
Internal Checking
Viaject / Oral insulin
Rapid Prediction
Software / Testing
Engineering
Dual delivery / Glucagon
Future Pump Features
Healthcare Across Borders - September 2003
Pump Features That Can Improve Control
• Automatic Basal/Bolus Testing*
• Pattern Analysis
• Alternate Insulin Profiles (adjustment of both basals and
bolus factors)
• Insulin or carb deficit shown for each BG test*
• Insulin Lookback
• Time To Eat Alert & Delayed Eating Alert
• Exercise Compensator
• Basal/bolus shifting*, Super Bolus
• Dual basal reductions
* Available now in early version
Healthcare Across Borders - September 2003
Automatic Basal/Bolus Testing
Pumps can automatically test:
The TDD
• Average blood sugar, standard deviation, frequency of lows
• % TDD used for corrections
Auto testing can be done with
• Basal/bolus balance
current pumps and meters
Basal rates
using 6-9 tests that day. NO
continuous monitor required!
• Daytime when a meal is skipped
• Overnight (accounting for BOB at bedtime)
The carb factor
• Premeal, 2 hr postmeal peak, normal in 4-5 hrs?
The correction factor
• High-to-normal in 4-5 hours?
Borders - September
2003 Feature
Current Healthcare
And Across
Future
Pump
Pattern Analysis
Pattern to left shows
• Inadequate or missed breakfast
boluses or inadequate day basal
rate (Pump knows which from it’s
history.)
• Correction or carb boluses appear
to be excessive at lunch (Pump
knows which from it’s history.)
• Tests only when low in evenings
(Pump brings issue to user’s
attention.)
Your pump and meter can easily spot patterns!
Healthcare Across
Borders - September
2003
Future
Pump
Feature
Insulin Lookback
Did Basal Or Bolus Cause The High Or Low Reading?
When a low or high reading occurs, a pump can compare:
how much basal and
how much bolus*
was active during the previous 5 hours.
Lows are usually caused by the larger insulin amount
Highs are usually caused by the smaller insulin amount
* After taking into account BOB
Healthcare Across
Borders - September
2003
Future
Pump
Feature
Lookback Examples
#1
BG = 47 at 1:00 am
5 hr. lookback:
Boluses = 9.2 u
Basal = 4.6 u
#2
BG = 228 at 4:30 pm
5 hr. lookback:
Boluses = 6.5 u
Basal = 2.4 u
Healthcare Across Borders - September 2003
Time To Eat Alert
Enables delayed eating when BG is OK
An alert to remind after a bolus
that it is time to eat. Allows
insulin to start working before
carbs begin to raise the blood
sugar. Reduces glucose
exposure.
* Not for children or anyone
acting like a child!
A timer would alert pumper 15 to 30 minutes after a bolus that it is now
OK to eat a high GI food or a meal with a large amount of carb.
Healthcare Across
Borders - September
2003
Future
Pump
Feature
Delay Eating Alert
Delay eating until BG is lower
A lower glucose at the
start of a meal reduces
glucose exposure.
Rules:
Test early
Bolus early
Don’t forget to eat on time
Don’t forget you’ve already
bolused
Healthcare Across
Borders - September
2003
Future
Pump
Feature
Exercise Compensator
Pump Screen allows entry of:
Exercise intensity (1-7 scale)
Exercise duration (15-480 min)
Your current level of fitness for
that activity (1-5 scale)
Pump informs you of appropriate
carb intake or insulin reduction
needed for the activity, and
accounts for any BOB
Healthcare Across
Borders - September
2003
Future
Pump
Feature
Basal/Bolus Shifting Improves Control
Static basals and boluses are old concepts
Healthcare Across Borders - September 2003
Basal/Bolus Shifting
Basal Reduction For Excess BOB
A temporary basal reduction offsets excess BOB so it is not necessary to
eat at bedtime.
Healthcare Across
Borders - September
2003
Future
Pump
Feature
A Super Bolus For A High GI Meal
Could be activated
when user wants
to eat more than a
pre-selected
quantity of carbs,
such as 30 or 40
grams
A Super Bolus shifts future basal insulin into an immediate bolus. Part of
the next 2-4 hours of basal insulin is shifted into a bolus to give a faster
insulin effect for high GI and large carb meals without causing lows.
Healthcare Across
Borders - September
2003
Future
Pump
Feature
Using A Super Bolus For A Postmeal High
When the carb content of a meal has been underestimated, a super
bolus enables a faster, safe correction.
Healthcare Across
Borders - September
2003
Future
Pump
Feature
Wrap Up
Pumps and devices offer the latest
technology for improved control
Benefits: more flexibility, less
hypoglycemia, less glucose exposure
and variability, and a healthier life
Change doses for seasons & schedules
Involves user in how to improve control
Devices require commitment, responsibility, and training
The best in pumps and monitors is yet to come
Healthcare Across Borders - September 2003
Questions & Discussion
Healthcare Across Borders - September 2003