Healthcare Across Borders - September 2003 Current And Emerging Technologies In Insulin Pumps And...
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Transcript of Healthcare Across Borders - September 2003 Current And Emerging Technologies In Insulin Pumps And...
Healthcare Across Borders - September 2003
Current And Emerging Technologies In Current And Emerging Technologies In Insulin Pumps And Continuous MonitorsInsulin Pumps And Continuous Monitors
John Walsh, P.A., C.D.E. John Walsh, P.A., C.D.E.
North County EndocrineNorth County Endocrine
700 West El Norte Pkwy700 West El Norte Pkwy
Escondido, CA 92126Escondido, CA 92126
(760) 743-1431 (760) 743-1431
The Diabetes Mall
www diabetesnet.com
(619) 497-0900 (619) 497-0900 [email protected]@diabetesnet.com
Children With Diabetes Children With Diabetes Toronto August 18, 2007Toronto August 18, 2007
Healthcare Across Borders - September 2003
Highlights
Smart Pump Capabilities
Duration Of Insulin Action
Bolus On Board (BOB)
Continuous Monitors
Continuous Monitor Tips
Future Devices/Pumps
Wrap Up
Healthcare Across Borders - September 2003
Winning With Technology
8 Type 1s set a new speed record in the 2007 RAAM team race, riding from Oceanside, CA, to Atlantic City in just over 5.5 days.
They attribute their win to perseverance, reduced bonking using Navigator continuous monitors, and reliance on the ultimate energy hormone – insulin – delivered from Omnipod pumps.
Healthcare Across Borders - September 2003
Unique Pump Features
Accu-Chek Spirit
• Boluses determined by BG not by BOB
• Accu-Chek meter software has Low BG Index that may help predict hypo unawareness
• Strong motor and delivery
Animas 2020
• High contrast color screen for easy viewing
• Smallest mainstream pump
• Smallest basal rate increment – 0.025 u
Healthcare Across Borders - September 2003
Unique Pump Features
Insulet Omnipod
• No tubing for easy weari
• Automatic cannula insertion and priming
• Remote bolusing
Medtronic Paradigm
• Built-in CGM eliminates one device
• Simple to operate
• Carelink online software
Healthcare Across Borders - September 2003
Carb Counter
Pumps offer user-selected food lists to improve carb counting• Easy carb calculation • Improves bolus accuracy• Available in• Accu-Chek Spirit (#1000 on PDA)• Animas 1250 (#500) • Deltec Cozmo (#250)• Insulet Omnipod (#1000 on PDM)
Current Feature
Healthcare Across Borders - September 2003
Problem: Exposure And Variability
40
60
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360
380
400
2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00
PM
11:00 PM 12:00
AM
1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00
AM
11:00
AM
12:00
PM
1:00 PM 2:00 PM
glucose (mg/dl)
One day’s BG results with usual meals and insulin. The DCCT proved that exposure to high blood glucose was
damaging. New emphasis is on glucose variability.
Exposure or Average =
Variability or Swing =
A1c or avg. BG from meter
SD from PC or meter
Healthcare Across Borders - September 2003
Therapy Effectiveness Scorecard
Screen 1 :
Average BG
BG tests per day
BG standard deviation
Screen 2:
Carbs per day
TDD • % of TDD as correction boluses • % of TDD as carb boluses• of TDD as basal rates
Healthcare Across Borders - September 2003
Therapy Scorecard Screen 1
14 Day Average:
BG 146 mg/dl Tests 3.5/day Std Dev 53 mg/dl
Overall controlAdequate testingBG variability – aim for less than half of avg BG
Monitor control, testing frequency, and glucose variablility
Healthcare Across Borders - September 2003
Therapy Scorecard Screen 2
14 Day Average:
Carbs 206 g TDD 48.58 u Meal 38.07% Corr 4.95% Basal 56.98%
Boluses taken? Low carb?Guides therapy – A1c, lows, etcCarb bolus %Corrections less than 8% of TDD?Is basal at least 40-45% of TDD?
Monitor carb intake, TDD, basal/carb bolus balance, and correction bolus %
Healthcare Across Borders - September 2003
Check Your Correction Boluses
If correction boluses are NOT less than 8% of TDD:
Raise basal rates,
Raise carb boluses, or
Stop skipping carb boluses
Move half of the excess units above 8% into basal rates or carb boluses, whichever is smaller, or into both if basals and carb boluses are balanced
Note: Paradigm pumps give correction bolus % as a % of total bolus dose, not the TDD. Do not use this percentage here!
Healthcare Across Borders - September 2003
Example: Correction Boluses Over 8%
10 Day Average:
Carbs 175 g TDD 54.1 u Meal 36% Corr 21% Basal 43%
Move 1/3 to 1/2 of the overage to basals or carb boluses:
21% of 54.1 = 11.3 units, 8% of 54.1 = 4.3 units
11.3 u - 4.3 u = 7 units excess
1/3 to 1/2 of 7 u = 2.3 to 3.5 u to be added to basal rates or carb boluses
Over 8%
Healthcare Across Borders - September 2003
Weekly Schedule
The user’s basal profile changes automatically for specific days of the week
Different basal patterns and missed meal bolus alerts for each day of the week
No need to remember to change basal patterns or alerts
Great for regular exercise, college classes, shift work, and other routine variations in schedule
Current Feature
Healthcare Across Borders - September 2003
Disconnect Bolus
Disconnect for up to 2 hours for sports, sauna, etc.
User estimates time off pump
Pump offers to give up to 50% of missed basal as disconnect bolus
Alarm reminds user to re-connect at set time
On reconnecting, pump determines basal missed and offers to supply the missing basal amount
Current Feature
Healthcare Across Borders - September 2003
Duration Of Insulin Action (DIA) How long a bolus lowers the blood sugar
and
Bolus On Board (BOB) Bolus insulin still active from previous boluses
Healthcare Across Borders - September 2003
Duration Of Insulin Action (DIA)
4 hrs 6 hrs2 hrs0
Accurate boluses require an accurate DIA.G
luco
se-lo
werin
g Ac
tivity
Current Feature
Healthcare Across Borders - September 2003
A Short DIA Time May SEEM OK
Pumpers and clinicians often set the DIA too short because:
• Recommended boluses do not bring high BGs down (ie, basal rates or carb bolus are too low)
• Shortening the DIA seems easier or safer than raising basal rates or lowering the carb factor.
• The default DIA is too short and never gets reset
• A low basal rate hides the true bolus activity
Healthcare Across Borders - September 2003
A short DIA hides the true BOB and its glucose-lowering activity.
Hiding bolus activity makes boluses excessive and may cause basal rates to be lowered inappropriately
Set your DIA to your insulin’s action time.
Do not modify the DIA based on control problems.
A Short DIA Can Cause Problems
Healthcare Across Borders - September 2003
0
2
4
6
8
10
0 1 2 3 4 5
Curvilinear 5 hr Linear 4.5 hr
A Comparison Of Linear And Curvilinear DIAs
Set the DIA for a linear pump 30 minutes shorter to get results close to that of a curvilinear pump. A Deltec or Omnipod pump set at 4.5 hrs is equivalent to a Medtronic or Animas pump set at 5 hrs.
Hrs
Units of insulin activity left
Curvilinear DIA = 5 hrs
Linear DIA = 4.5 hrs
Healthcare Across Borders - September 2003
Recommended DIA Times
From Pumping Insulin, 4th ed., adapted fom Mudaliar et al: Diabetes Care, 22: 1501, 1999
Set DIA to 4 hrs or more to calculate BOB and bolus doses accurately
Linear
Curvilinear
Healthcare Across Borders - September 2003
Blind Boluses Also Hide BOB
89.8
57.7
32.5
14.2
0
10
20
30
40
50
60
70
80
90
100
With BG orcarb
With carb With BG With BG andcarb
% of Boluses with BG or Carb Inputs Only 32.5% of 204,005 boluses from over 500 Cozmo pumps used across the US were accompanied by a BG value.
2/3 of boluses are given without a BG test
Only 1 of every 7 boluses had both carbs and a BG
Data in preparation for publication
67.5
% b
lind
bolu
ses
Healthcare Across Borders - September 2003
Bolus On Board (BOB) The glucose-lowering activity that remains
from recent boluses
An accurate BOB calculation
• Prevents insulin stacking
• Improves bolus accuracy
• Reveals current carb or insulin deficit
Your BOB can be determined only after a BG has been entered into pump!
aka: insulin on board, active insulin, unused insulin** Introduced as Unused Insulin in 1st ed of Pumping Insulin (1989)
Healthcare Across Borders - September 2003
BOB Prevents Insulin StackingWith a bedtime BG of 173,
is there an insulin deficit or a carb deficit?
6 pm 8 pm 10 pm 12 am
DinnerDinner
DessertDessertCorrectionCorrection Bedtime BG
= 173 mg/dl
Insulin stacking is common for anyone who gives
frequent boluses!
Healthcare Across Borders - September 2003
Hypo Manager Do you eat carbs or take insulin?
1BG = 173 mg/dl (9.6 mmol)
Bolus on board = 0.4 u
Correction bolus: 1.2 u
Insulin deficit = - 0.8 u
Give 0.8 u now? Y or N
2BG = 173 mg/dl (9.6 mmol)
Bolus on board = 4.6 u
Correction bolus: 1.2 u
Insulin excess = 3.4 u
You may need: 37 grams of carb later to prevent a low BG
Only after a BG has been entered can a pump determine whether carbs or insulin are needed
Helps prevent & treat hypoglycemia and avoid over-treatment
Current Feature
Healthcare Across Borders - September 2003
Recommended Boluses Differ Between Pumps Does Your Pump Subtract BOB From Carb Boluses?
Whenever BOB is greater than correction need, recommended boluses may be excessive for Paradigm and Omnipod pumps, or Animas pump when BG is above target
3.0U 45 gr 160 3.0U 1.0U 3.0U
Excess BOB is subtracted from correction bolus, but NOT carb bolus
3 u + 1 u– 3 u
- = 1 u bolus
Healthcare Across Borders - September 2003
Recommended Boluses Differ Between Pumps
Carb factor = 1u / 10 gr
Corr. Factor = 1 u / 40 mg/dl (2.2 mmol) over 100 mg/dl (5.6 mmol)
Target BG = 100 mg/dl
TDD = ~50 u
0
1
2
3
4
60 90 120 150 180 210 240
Deltec Cozmo Animas 1250 Medtronic 522
units
BG inmg/dl
Bolus recommendations from different pump for various BGs when BOB = 3.0 u and 30 grams of carb will be eaten
Healthcare Across Borders - September 2003
Helpful Features Often Go Unused
• Reminders, alerts
• Entry of BG results
• Carb counting aids
• Temporary basal rates
• Alternate and temporary basal patterns
• Tracking and use of BOB
• Review of glucose history and insulin use
Use features that can improve your control!
Healthcare Across Borders - September 2003
Helpful Reminders And Alerts
• Chech BG after a bolus after a low after a high
• Bolus at certain times
• Warn if bolus was not given for a particular meal *
• Warn if bolus was not completed *
• When to change infusion set
• Low reservoir (ie, 20, 10, 5 and 0 units, with extra 10 “hidden” units for basal delivery)*
Current Feature
* in Cozmo pump
Healthcare Across Borders - September 2003
Looking At History Helps
Pump & Meter for direct BG entry
• Deltec Cozmo + Freestyle CoZmonitor
• Omnipod + Freestyle
• Paradigm + BD Logic
Pump & Cont Mon, no direct BG entry
•Medtronic 5/722 + Paradigm RT
Future Pumps & Cont Mons
• Abbott Navigator + Deltec Cozmo, or Insulet Omnipod
• Animas + Lifescan
• AccuChek
Current Feature
Healthcare Across Borders - September 2003
The Value of Frequent Testing
Breakfast
100 (5.6)
200 (11)
400 (22)
300 (17)
DinnerLunch Bed
4 opportunities
1 opportunity to intervene
288 opportunities
Healthcare Across Borders - September 2003
Continuous Monitors Reduce Exposure & Variability15 users with implanted Dexcom continuous monitors blind to glucose readout for 50 days, then open readout for the next 44 days.
2.62
1.53 1.522.06
4.75
8.91
6.386.16
7.23
4.57
0
1
2
3
4
5
6
7
8
9
40-55 56-80 81-140 141-240 241-400
Blinded Open
hrs/day
More normal BGs
- 65 min+ 32 min
+ 250 min -13 min
-160 min
Fewer lows Fewer highs
Healthcare Across Borders - September 2003
Continuous Monitoring
Benefits• Lots more info• Alarms to
prevent lows & highs
• Security in knowing where the BG is and where it is going
• Trends shown by graph, arrows, or predictors
Limitations• Less accuracy• Data gaps• Minimal insurance
coverage in U.S.• Occ. cell phone,
microwave, other interference
Healthcare Across Borders - September 2003
Continuus Monitor Components
1. Sensor through the skin
2. Radio transmitter on sensor
3. Receiver display
• BG readings every 1-5 min
• Trend graphs for 1, 3, 9, 24 hrs showing where BG has been and is going
• Trend arrows
• High and low alarms
4. Software to download & analyze data
Healthcare Across Borders - September 2003
Dexcom STS
• FDA approved 3/27/06 for 18 and older
• 7 day sensor
• Readings every 5 min.
• 3-14 days of readings per sensor
• One high, two low alerts
• $475 + $60 for each 7 day sensor
• Transmitter: ~$250 every 6 mos
• Good analysis software
Transmitter ~0.8 x 1.5”
Healthcare Across Borders - September 2003
Medtronic Paradigm RT
No closed loop
• FDA approved: 4/13/06, now for 7 and older
• One high and one low alert, trend arrow
• Readings every 5 min.
• $1340 + $35 for each 3 day sensor
• Transmitter: ~$900 every 6 mos
Transmitter ~1.1 x 1.4”
Healthcare Across Borders - September 2003
Freestyle Navigator
• FDA approval expected soon
• Good accuracy below 100 mg/dl
• Calibration requires 10 hrs, then 1-2 times per day for 1st two days
• Readings every 1-2 minutes with trend arrow (4 clicks to trend graphic)
• 5 day use
• High and low glucose alarms
• Rate of change alarm
• Likely to be used in Deltec Cozmo and Insulet Omnipod pumps
Investigational Device.Limited by U.S. Law to Investigational Use
Healthcare Across Borders - September 2003
TRU Directional Trend Arrows
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 (3.3 mmol/hr)
Glucose rising quickly> 2 (mg/dL)/min
Healthcare Across Borders - September 2003
Trend Arrows Have Limits
No trend arrow = BG change up to 60 mg/dl (3.3 mmol) / hr
An hour later159 mg/dl (8.8 mmol)
Now100 mg/dl (5.6 mmol)
41 mg/dl (2.3 mmol)
With a bedtime BG of 300 (16.7 mmol) and a level trend arrow, the breakfast reading could be 0 or 750 mg/dl (0 to 41.7 mmol)!
Large BG changes
with no trend arrow
Trend arrows lack accuracy!
Healthcare Across Borders - September 2003
200150
050
100
2 4p 6 8p 10 12a
250300
Line Graphs Provide Better Trend Info
Shortest Trend1 Hr – Dexcom2 Hr – Navigator3 Hr – Paradigm
Longest Trend9 Hr – Dexcom24 Hr – Navigator & Paradigm
Target Zone – all
Event Icons – Navigator
Healthcare Across Borders - September 2003
Easy Basal Testing
10 pm 2 am 8 am
120 mg/dl
© Pumping Insulin, 2006© Pumping Insulin, 2006
Overnight basal test
Goal: green line
Healthcare Across Borders - September 2003
Easy Bolus Testing
6 pm 8 pm 10 pm
300
200
100
60
Carb bolus Correction bolus
© Pumping Insulin, 2006© Pumping Insulin, 2006
6 pm 8 pm 10 pm
Goal: green line
Healthcare Across Borders - September 2003
A Comparison Of Continuous Monitors
The Dexcom STS 3 Day & Paradigm RT continuous monitors were available for this studyA head to head comparison of monitors while worn by one person with Type 1 diabetes.Each monitor’s accuracy tested against Ultra readings
Monitor screens above show glucoses over the same 3 hour time span (range of 0 to 400 mg/dl). Ultra reading at the time was 73 mg/dl compared to 93 and 122 mg/dl.
Healthcare Across Borders - September 2003
GlycensitTM Analysis
Blue dotted lines = ISO standardsYellow area = where 95% of data points will fallRed lines = minimum and maximum deviation by star pointsIdeally, all readings would fall between the blue dotted lines -- this
is the standard for today’s glucose meters
A B
http://tomcatbackup.esat.kuleuven.be/GLYCENSIT/
Healthcare Across Borders - September 2003
Difference From Ultra Meter Readings For Each SensorSensor A Sensor B
0-9 mg/dl off 116 5210-19 mg/dl off 83 6220-29 mg/dl off 32 4630-39 mg/dl off 11 3640-49 mg/dl off 9 2750-59 mg/dl off 4 1460-69 mg/dl off 2 7over 70 mg/dl off 5 18
Monitor Accuracy
Table shows how much each monitor’s glucose values differed from a simultaneous reading on the Ultra meter.
44.3%31.7%12.2%
4.2%3.4%1.5%0.8%1.9%
19.8%23.7%17.6%13.7%10.3%
5.3%2.7%6.9%
76.0%
19.8%
4.2%
43.5%
41.6%
14.9%
Healthcare Across Borders - September 2003
Which Monitor Alerted First?
Accurate warning of low and high readings is desired. This table shows which monitor alerted at least 5 min earlier for true lows and highs.
Monitor A was first to alert for readings below 80 mg/dl 76% of the time, B was first 3% of the time, with 21% ties.
For detection of highs above 160, Monitor A was first 68% of the time, B was first 5% of the time, with 27% ties.
Monitor A Monitor B Tie
For BGs less than 80 28 1 8
For BGs over 160 25 2 10
Which Monitor Alerted First?
Healthcare Across Borders - September 2003
More On Accuracy
1 R L Weinstein et al: Diabetes Care, 30, 1125-1130, 2007
Navigator 5 day (shown in graph)1
Median ARD = 9.3%
Clark error grid
A: 81.7%
B: 16.7%
C and D: 1.7%
Dexcom 7-day (to FDA - not shown):
Median ARD = 17%
Clark error grid
A: 70%
B: 28%
C and D: 3%
Healthcare Across Borders - September 2003
Continuous Monitors Today
• Readings have to be validated with a meter
• Not used by pump for dose calculations
• No warning when a reading is inaccurate
• Need daily calibration with fingerstick BGs
• Accuracy varies between devices and over time
• Otherwise wonderful
Healthcare Across Borders - September 2003
Animas Debiotech Micropump
Animas is one of several companies developing very small insulin pumps from Micro-Electro-Mechanical Systems or MEMS technology. Made from silicon, can be mass-produced at low cost
Healthcare Across Borders - September 2003
Valeritas H-Patch Pump
Good introduction for Type 2s to basal/bolus therapy
• Automatic needle insertion
• Single basal available as 20, 30, or 40 units per day
• Button on pump delivers 2U per push
Healthcare Across Borders - September 2003
Pressure Pumps
Pressure from small solenoid drives precise insulin delivery
Eliminates need for motor and solid reservoir
Insulin can be stored in a bladder to reduce size
Two bladders with independent controls allow dual delivery
Dual pumping for:• Insulin + symlin
• Insulin + glucagon
• Or a micro pull/push interstitial glucose monitor
Healthcare Across Borders - September 2003
ExFactors For Activity
Enter into pump:
1. Exercise intensity (1-7 scale)
2. Exercise duration (15-480 min)
3. Current level of fitness for that activity (1-5 scale)
Pump then shows carb intake or insulin reduction needed for the activity
Future Pump Feature
Healthcare Across Borders - September 2003
Temporary Basal Reduction For Excess BOB
A temporary basal reduction offsets excess BOB so it is not necessary to eat at bedtime.
Future Pump Feature
Healthcare Across Borders - September 2003
Super Bolus For A High GI MealShift Basal To Bolus
A Super Bolus shifts part of the next 2-4 hours of basal insulin into an immediate bolus. Gives a faster insulin effect for high GI and large carb meals with less risk of a low.
Activated whenever user eats more than a selected quantity of carbs, such as 30 or 40 grams
Future Pump Feature
Healthcare Across Borders - September 2003
Super Bolus For A Postmeal High Shift Basal To Bolus
Enables a faster correction of highs with less risk of a low.
Future Pump Feature
Healthcare Across Borders - September 2003
Automatic Basal/Bolus Testing
A pump could automatically test:
The TDD from• Average blood sugar, stand. dev., frequency of lows
• % TDD used for corrections
• Basal/bolus balance
Basal rates from• Daytime when a meal is skipped (accounting for BOB)
• Overnight (accounting for BOB at bedtime)
The carb factor from• Premeal, 2 hr postmeal peak, normal in 4-5 hrs?
The correction factor from• High-to-normal in 4-5 hours?
Current And Future Pump Feature
Healthcare Across Borders - September 2003
Pattern Analysis
Pattern shows
• Inadequate or missed breakfast boluses or inadequate day basal rate
• Correction or carb boluses appear to be excessive at lunch
• Tests only when low in evenings
Devices • make sense of patterns in real time• analyze history accurately• much faster than MDs and RNs!
Future Pump Feature
Healthcare Across Borders - September 2003
Insulin Lookback
To find out if a low or high reading was caused by basals or boluses, a pump can compare:
• how much basal and
• how much bolus
• was active in the previous 5 hours
Lows – usually caused by the larger insulin amount
Highs – usually caused by the smaller insulin amount
Future Pump Feature
Healthcare Across Borders - September 2003
Lookbacks
# 1
BG = 47 at 1:00 am
5 hr. lookback:
Boluses = 9.2 u
Basal = 4.6 u
Healthcare Across Borders - September 2003
Lookbacks
# 2
BG = 228 at 4:30 pm
5 hr. lookback:
Boluses = 6.5 u
Basal = 2.4 u
Healthcare Across Borders - September 2003
Delay Eating Alert Delay eating when BG is OK for high GI meal
or a large # of carbs
Future Pump Feature
Allows insulin to start working before carbs begin to raise the blood sugar.
Result: less glucose exposure
Don’t forget to eat when pump alerts it is time!
Healthcare Across Borders - September 2003
Delay Eating AlertDelay eating when BG is high
A lower glucose at the start of a meal reduces glucose exposure.
Remember:
Test early
Don’t forget to eat on time
Don’t forget the bolus was given
Future Pump Feature
Healthcare Across Borders - September 2003
No Two Points Are Created Equal! Level of Risk Depends on Trend
20
30
40
50
60
70
80
90
100
0 50 100 150 200Minutes
Glucose (mg/dl)
Going UpLower Risk
Going DownHigher Risk
Healthcare Across Borders - September 2003
Going Up: Consider Action!
187
8:43 AM
1 hr
Bolus too small or too late
Healthcare Across Borders - September 2003
Look And Learn
Breakfast bolus too small or too late
Lunch bolus too small or afternoon basal too low
Excess night basal or bedtime bolus
Healthcare Across Borders - September 2003
Stay Between The Lines
As readings improve, lower the glucose for the upper alert
Healthcare Across Borders - September 2003
Continuous Monitoring Tips
• Be patient, have realistic expectations
• Don’t panic when your meter and sensor differ
• Expect some lag time
• Don’t react too quickly and stack your insulin
• Look at trends, not just individual values
• Rapid rises usually mean more insulin is needed
• Validate your readings with a meter
Healthcare Across Borders - September 2003
Wrap Up
Pumps and continuous monitors offer technology improves control
More flexibility and confidence, lesshypoglycemia, less glucose exposure, less variability, and a healthier life
Data easily analyzed with suggested improvements that guide user toward improved control through success
Requires commitment, responsibility and training, but less work for everyone overall
Healthcare Across Borders - September 2003
Questions & Discussion