Preliminary Proposal For Insulin Pump Standards

1
Preliminary Proposal For Insulin Pump Standards
Standards to improve insulin pump use and medical
outcomes These proposals are not yet final but
are made available for review and editorial
comment. Any suggestions you have for
improvements or changes, or for additional
approaches to improve diabetes care are welcomed.
Any major contributions will be attributed.
2
These Standards Are Supported By

• John Walsh, PA, CDE, and Ruth Roberts, MA
• You (4,6)

Any reservations you have about a particular
standard will be noted
3
ReviewDefinitions

• TDD total daily dose of insulin (all basals and
  boluses)
• Basal background insulin pumped slowly through
  the day to keep BG flat
• Bolus a quick surge of insulin as
• Carb boluses to cover carbs
• Correction boluses to lower high readings that
  arise from too little basal insulin delivery or
  insufficient carb boluses
• Bolus On Board (BOB) the units of bolus insulin
  or glucose-lowering activity still working from
  recent boluses
• Duration of Insulin Action (DIA) time that a
  bolus will lower the BG. This is used to
  calculate BOB.

4
The Role Of Insulin Pumps

• Insulin pumps should
• Lower A1c and eAG levels
• Decrease the frequency and severity of
  hypoglycemia
• Provide safe and reliable insulin dosing to users
• Reduce complications
• Improve quality of life

5
Proposal For Insulin Pump Standards

• These standards to improve pump use and outcomes
  are designed to
• Reduce inconsistencies in pump settings between
  pump manufacturers
• Improve the accuracy and safety of carb and
  correction factors in use
• Improve safety of DIA time increments and
  defaults that are in use
• Consistently account for and apply BOB
• Improve monitoring and identification of infusion
  set failure
• Improve monitoring of hypoglycemia
  hyperglycemia
• Identify excessive use of correction boluses
• Reduce blind bolusing and non-entry of glucose
  values into pumps

6
ReviewInconsistent Dosing From Insulin Pumps

• There are several significant sources for error
  in bolus doses from todays insulin pumps.
• Widespread use of inaccurate carb factors
• Excessively large carb factor increments
• Widespread use of inaccurate correction factors
• Wide variations in how BOB is handled and in DIA
  default times between pump manufacturers
• Wide variations in DIA defaults between pump
  manufacturers

7
Intellectual Property
1

• Issue Optimal glucose values for those who have
  diabetes is critical to prevention of disability
  and early death. Devices owned and used by those
  with diabetes contain unique information that can
  be used to improve control and reduce
  complication risks.

8
Standard ForIntellectual Property
1

• We recommend that all existing and future patents
  that may contribute to improvements in glucose
  control be made available at a reasonable cost to
  any device manufacturer who wants to use them to
  improve glucose control.

9
Carb Factor (CarbF) Increments
2

• Issue Current carb factor increments are too
  large for smaller carb factor numbers. This lack
  of precision for carb boluses may create excess
  hyperglycemia or hypoglycemia for many pump
  users.

10
ExampleCarb Factor Increments
2

• Most pumps offer 1 gram per unit as their
  smallest CarbF increment. This increment becomes
  relatively large for CarbFs below 15 or 20 g/u.
  For instance, when the carb factor is reduced
  from 10 to 9 g/u, all subsequent carb boluses are
  increased by 11.1 in most pumps.
• A shift in the carb factor from 1u/5g to 1u/4g
  causes each subsequent carb bolus to increase by
  25.
• When carb boluses make up 50 of the TDD, a
  change in the a carb factor larger than 2.5
  would be expected to create more than a 25 mg/dl
  shift in the glucose following each meal.
• Finer CarbF increments would allow safer and more
  precise adjustment of subsequent carb boluses.

Example TDD 40u, carb factor 1u/11g, corr
factor 1u/60 mg/dl carb boluses 20u or
6u/meal x 6 .36u x 60 a 22 mg/dl change in
BG
11
What Current Changes In CarbFs Do
2

• Table shows how a one-step reduction in the CarbF
  using various CarbF increments affect the size of
  subsequent carb boluses. Yellow area shows impact
  from most pumps. Green (preferred) areas show
  increments that impact subsequent boluses less
  than 5.

12
ExampleImpact On BG From CarbF Adjustments
2

• This table shows the average additional fall in
  glucose that is likely after each meal of the day
  when a carb factor is reduced from 10 grams per
  unit to 9 grams per unit (for appropriate weight
  TDD), and again a reduction from 5 grams per
  unit to 4 grams per unit.

Calculated as carb grams per day X increase in
avg. carb bolus size 3
13
2
Standard For Carb Factor Increments

• We recommend that carb factor increments be small
  enough that a single step adjustment in a factor
  causes subsequent carb boluses to change by no
  more than 5 from previous bolus doses for the
  same number of grams of carb.

14
Inaccurate Carb Factors
3

• Issue A carb factor that does not match the
  individual using it will significantly magnify
  other sources of error in the calculation of carb
  bolus doses. Many carb factors used in insulin
  pumps today are poorly tuned to users.

15
Review Actual Carb Factors In Use 1
3

• Avg. carb factors for 468 consecutive Cozmo
  insulin pump downloads (gt126,000 boluses) are
  shown in blue
• Note that they are NOT bell-shaped or physiologic
• People prefer magic numbers 7, 10, 15, and 20
  g/unit for their carb factors
• Determined directly from grams of carb divided
  by carb bolus units for each carb bolus

10
7
115
20
1
16
ReviewActual Carb Factors In Use 1
3

• MANY magic carb factors, shown in blue, are
  inaccurate. A more normal or physiologic
  distribution is shown in green
• Use of magic numbers creates major, though
  consistent bolus errors that magnify other
  sources of error

10
7
115
20
1
17
3
Standards For Carb Factor Settings

• To encourage use of consistent and accurate carb
  factors in pumps, we request that insulin pump
  companies jointly determine what range of carb
  factor rule numbers (CarbF x TDD) provide optimal
  glucose results that lead to a lower eAG and less
  hypoglycemia for various TDD ranges and carb
  intakes as a percentage of calories.
• We request that insulin pump companies measure
  and publish each year the carb factors in use for
  200 random downloads from pumps that use carb
  factors. This information is needed as an
  overview to guide interventions directed at
  reducing errors in carb factor settings.
• We recommend that carb factors be monitored
  within each pump for accuracy and effectiveness
  with a report available to users or clinicians.

18
ExampleCarb Factor Settings
3

• To assist users in setting accurate CarbFs,
  insulin pumps should allow the user to compare
  their current CarbF against an optimal settings
  range of CarbF Rule Numbers. Proposed CarbF Rule
  Numbers for various TDDs

Optimal ranges would be determined from
research studies of best practices
19
Inaccurate Correction Factors
4

• Issue A correction factor that does not match
  the individual using it will significantly
  magnify other sources of error in the calculation
  of correction bolus doses. Many correction
  factors used in insulin pumps today are poorly
  tuned to users.

20
Review Actual Correction Factors In Use 1
4

• Avg. correction factors in use for 452
  consecutive Cozmo insulin pump downloads
• Like carb factors, correction factors in use are
  NOT bell-shaped or physiologic
• Users or clinicians often select magic numbers
  for their correction factors.

10
7
115
20
1
21
4
Standards For Correction Factor Settings

• To encourage use of consistent and accurate
  correction factors in pumps, we request that
  insulin pump companies jointly determine what
  range of correction factor rule numbers (CorrF x
  TDD) provide optimal glucose results that lead to
  a lower eAG and less hypoglycemia for various TDD
  ranges, and publish them for users and clinicians
  to use.
• We request that insulin pump companies
  voluntarily measure and publish each year the
  correction factors in use for 200 consecutive
  downloads from pumps that use correction factors.
• We recommend that correction factors be monitored
  within each pump for accuracy and effectiveness
  with a report available to users or clinicians.

22
ExampleCorrection Factor Settings
4

• To assist users in setting accurate CorrFs,
  insulin pumps should allow the user to compare
  their current CorrF against an optimal settings
  range of CorrF Rule Numbers. Proposed CorrF Rule
  Numbers for various TDDs

Optimal ranges would be determined from
research studies of best practices
23
Basal/Carb Bolus Balance
5

• Issue Correction boluses are used to correct for
  deficits in insulin that arise from inadequate
  basal delivery or inadequate carb boluses.
  Because the reason for their use cannot be
  clearly identified as basal or bolus, they should
  not be included in basal/bolus balance.

24
Standard ForBasal/Carb Bolus Balance
5

• We propose that basal/carb bolus balance is a
  more definitive term and should replace
  basal/bolus balance. Basal/carb bolus balance
  should NOT include correction bolus doses which
  will be listed separately to more clearly define
  and understand control issues.

25
ExampleBasal/Carb Bolus Balance
5

• How a pump might display insulin information
• TDD 40.0 u in last 7 days
• of TDD units
• Basal 30 12 u
• Carb boluses 50 20 u
• Corr. boluses 20(12) 8 u ( 4.8 u)
• Basal/Carb bolus balance 0.6 (12u/20u) or 60.
  This particular imbalance would typically favor
  adding more of the correction bolus excess to
  basal delivery.

26
Duration Of Insulin Action Default Times
6

• Issues
• The default DIA times in current pumps vary
  widely between 3 and 6 hours
• Many users shorten their default DIA to increase
  the size of their boluses without realizing that
  this introduces significant errors into bolus
  (and ultimately basal) doses.

DIA times that are too short hide bolus insulin
activity and create insulin stacking. DIA times
that are too long overestimate bolus activity.
27
Standard ForDuration Of Insulin Action (DIA)
Time
6

• We recommend that a panel of experts in insulin
  action review existing pharmacodynamic studies,
  consider differences between pharmacodynamics and
  DIA time, and provide guidance on an acceptable
  range of DIA times to recommend to clinicians and
  users to improve the accuracy of bolus
  calculations.

28
DIA Time Increments
7

• Issue Current DIA time increments vary from 15
  minutes to 1 hour in different pumps
• When a DIA time is changed in a pump, a larger
  time increment, such as 1 hr, can create an
  excessive change in subsequent estimates of BOB.
• For example, when the DIA is reduced from 5 hours
  to 4 hours, subsequent BOB estimates are
  decreased, while recommendations for carb boluses
  would increase.

29
ReviewGlucose Infusion Rate (GIR) Studies
7

• Most GIR studies suggest that pharmacodynamic
  action of insulin varies about 25 between
  individuals. For a DIA time of 5 hr, a 25 range
  is equivalent to 1 hr and 15 min, such as from 4
  hrs and 15 min to 5hr and 30 min.
• A pump that has only 1 hr DIA increments would
  enable the user to select only one setting within
  a physiologic range, while a 30 min increment
  would allow only 2 or 3 choices that are close to
  a physiologic range.

30
7
Standard For DIA Time Increments

• For safety and accuracy, we recommend that DIA
  time increments be no greater than 15 minutes to
  allow more accurate estimation of residual BOB.

31
ReviewBolus On Board (BOB)
8

• An accurate measurement of the glucose-lowering
  activity that remains from recent boluses helps
• Prevent insulin stacking
• Improve bolus accuracy
• Allows the current carb or insulin deficit to be
  determined

aka insulin on board, active insulin, unused
insulin Introduced as Unused Insulin in 1st ed
of Pumping Insulin (1989)
32
ExampleAn Accurate BOB Can Avoid Insulin Stacking
8

• Bedtime BG 173
• Is there an insulin or a carb deficit?

Bedtime BG 173 mg/dl
Correction
Dessert
Dinner
6 pm
8 pm
10 pm
12 am
33
ReviewInsulin Stacking Is Common
8

• CDA1 Study Results
• Of 201,538 boluses, 64.8 were given within 4.5
  hrs of a previous bolus
• An accurate DIA shows that some BOB is present
  for MOST boluses
• Note that 4.5 hours may underestimate true DIA

4.5 hrs
34
ReviewHow Current Pumps Handle BOB
8
Except when BG is below target BG
35
ExampleBolus Recommendations Differ Significantly
8

• Situation BOB 3.0 u and 30 gr. of
  carb will be eaten at these glucose levels
• Carb factor 1u / 10 gr
• Corr. Factor 1 u / 40 mg/dl over
  100
• Target BG 100
• TDD 50 u

The graphic shows how widely bolus
recommendations vary from one pump to another for
the same situation.
units
mg/dl
Omnipod bolus cannot be determined - it counts
only correction bolus insulin as BOB
36
ExampleUnsafe BOB Handling
8

• If a pump user gets frustrated with high BGs and
  they overdose to speed the drop in their BG, or
  they exercise longer or more intensely than they
  anticipated, they can acquire a significant
  excess in BOB.
• In this situation, most pumps bolus for all carb
  intake regardless of how much BOB is present. A
  subsequent bolus will deliver an excess of
  insulin if the glucose is not high enough to
  offset the excess BOB.1
• This introduces a significant risk for
  hypoglycemia from the pumpsexcessive bolus
  recommendations.

1 Pumping Insulin, 1st ed, 1989, Chap 12, pgs
70-73 The Unused Insulin Rule
37
Current BOB Handling
8

• Issue Most bolus calculators in current insulin
  pumps assume that excess BOB does not need to be
  taken into account when determining the next carb
  bolus.
• Because of the way they are determined, bolus
  dose recommendations from most pumps can cause
  unexplained and unnecessary insulin stacking and
  hypoglycemia.

38
Standard ForBOB Handling
8

• For safe and accurate BOB measurement, we
  recommend that
• BOB include all carb and correction boluses
• Residual BOB be subtracted from both carb and
  correction bolus recommendations delivered within
  the DIA

Assumes that the DIA time chosen by the
clincian or user is accurate.
39
BOB Handling
8

• Exception to usual BOB handling
• When a second bolus is taken for unplanned carb
  intake or desert that is consumed within 60
  minutes or so of a meal bolus, BOB should not be
  taken into account for the second bolus because
  the impact of the first bolus cannot be
  accurately determined.
• Given that, it is wise to account for BOB as soon
  after a meal as possible, such as within 60 to 90
  minutes (adjustable), to provide early warning if
  the bolus given was excessive or inadequate.

It is always safer, though not always more
accurate, to account for and apply all BOB in
subsequent boluses.
Adjustable
40
Blind Bolusing
9

• Issue Pump users often bolus for carbs without
  checking their glucose first. With no glucose
  reading, the pump does not account for BOB that
  may be present at the time, and the bolus is not
  appropriately adjusted for potentially high or
  low glucose levels.
• Blind bolusing often leads to insulin stacking.

41
Standard ForBlind Bolusing
9

• We recommend that insulin pumps alert the wearer
  when there is sufficient insulin stacking to
  introduce a significant error in a current bolus.

Adjustable for an expected mg/dl drop in
glucose with visible, audio, or vibratory output.
42
ExampleInsulin Stacking or BOB Alert
9

• When a carb bolus is planned without a recent BG
  check, but BOB is more than 1.25 of the average
  TDD (enough to cause about a 25 mg/dl drop in the
  glucose), the pump will recommend that the wearer
  do a BG check due to an excess in BOB.
• For instance, for someone with
• Avg TDD 1.25 of TDD
• 43 units 0.54 units
• This individual would be alerted whenever they
  give a bolus but have 0.54 u or more of BOB
  present.

1.25 of TDD provides a reasonable degree of
safety but may need modification
43
Inadequate Manual Entry Of BGs
10

• Issue Pump users often do not enter BG values
  into their pump if they must do it manually.

44
Inadequate Manual Entry Of BGs
10

• Issue In the CDA study where BG values can be
  entered either manually or automatically, users
  entered only 2.6 BG values per day manually
  versus 4.1 values per day for pumps that had an
  attached glucose meter. This means that BOB may
  be taken into account for 1.5 additional boluses
  per day when BG readings are not automatically
  entered.

45
Standard ForInadequate Manual Entry Of BGs
10

• Due to a significant decrease in glucose entry
  when BGs must be entered manually, and the
  benefit to control that this provides, we
  recommend that all pumps be enabled to have
  direct BG entry of BG test results from two or
  more meters.

46
Correction Bolus Excess
11

• Issue Hyperglycemia is more common than
  hypoglycemia for most people on insulin pumps.
• When glucose levels consistently run high, many
  pump users address the problem by giving frequent
  correction boluses rather than increasing their
  basal rates or carb boluses.
• In these cases, the correction bolus of the TDD
  can become excessive, but this information is
  either not shown in some pumps or no alert is
  given regarding the excess.

47
Standards ForCorrection Bolus Excess
11

• We suggest that the pump wearer and clinician be
  alerted when the wearer uses more than 8
  (adjustable) of their TDD for correction bolus
  doses for at least 4 days in a row (adjustable).
• We recommend that, once an excess in correction
  bolus is identified, that the user be given
  instruction in how to safely distribute any
  excess into carb boluses or basal rates.

48
Excess Hypoglycemia
12

• Issue Current insulin pumps and glucose monitors
  do not warn users that they are experiencing
  hypoglycemia that is too severe or too frequent.
• Although most insulin pumps contain adequate data
  to do so, they do not provide sufficient guidance
  for correcting this serious problem.

49
Standard ForExcess Hypoglycemia
12

• We recommend that insulin pumps which store
  glucose and insulin dosing data alert users when
  they experience severe or excessive hypoglycemia
  and provide specific guidance regarding likely
  causes.

50
Excess Hyperglycemia
13

• Issue Current insulin pumps and glucose monitors
  do not warn users that they are experiencing
  hyperglycemia that is too severe or too frequent.
  
• Although most insulin pumps contain adequate data
  to do so, they do not provide sufficient guidance
  for correcting this serious problem.

51
Standard ForExcess Hyperglycemia
13

• We recommend that insulin pumps which store
  glucose and insulin dosing data alert users when
  they experience severe or excessive hyperglycemia
  and provide specific guidance regarding likely
  causes.

52
Duration Of Insulin Action
14

• Issue Although DIA is designed to measure the
  glucose-lowering activity of a carb or correction
  bolus at any time, various clinicians recommend
  DIA times that vary from 2 to 6 hours or more,
  despite the fact that interindividual variation
  in pharmaco-dynamics time is generally less than
  25.
• There are also questions about whether
  pharmaco-dynamic time from GIR studies is
  equivalent to DIA time?

53
ReviewHow Long Do Boluses Lower The BG?
14

• Novolog claims 3 to 5 hours 10, but numerous
  studies show rapid insulin lowers the glucose for
  5 hours or more.
• With Novolog (aspart) at 0.2 u/kg (0.091 u/lb),
  23 of glucose lowering activity remained after 4
  hours.12
• Another study found Novolog (0.2 u/kg) lowered
  the glucose for 5 hours and 43 min. /- 1 hour.13
• After 0.3 u/kg or 0.136 u/lb of Humalog (lispro),
  peak glucose-lowering activity was seen at 2.4
  hours and 30 of activity remained after 4 hours.
  11
• These times would be longer if the unmeasured
  basal suppression in pharmacodynamic studies were
  accounted for.

10 Novolog product labeling information, October
21, 2005. 11 From Table 1 in Humalog Mix50/50
product information, PA 6872AMP, Eli Lilly and
Company, issued January 15, 2007. 12 Mudaliar S,
et al Insulin aspart (B28 Asp-insulin) a
fast-acting analog of human insulin. Diabetes
Care 1999 221501-1506. 13 L Heinemann, et al
Time-action profile of the insulin analogue
B28Asp. Diabetic Med 199613683-684.
54
An Accurate DIA Can Prevent Lows
14

• Accurate DIA Time
• Accurate BOB
• Accurate Boluses Accurate HypoManager
• Better Readings, Fewer Lows

Prevention
Prediction
55
ReviewShort DIAs Hide Bolus Insulin Activity
14

• A short DIA time creates significant problems
  because it hides true BOB level and its
  glucose-lowering activity. This
• Leads to unexplained lows
• Leads to incorrect adjustments in basal rates,
  carb factors, and correction factors
• Causes user to start ignoring their smart
  pumps advice
• In contrast, an inappropriately long DIA
  overestimates bolus insulin activity. DIA should
  be selected, based on its real insulin action
  time.
• Do NOT modify the DIA time to fix a control
  problem

56
ReviewDuration Of Insulin Action (DIA)
14
Accurate bolus estimates require an accurate DIA.
DIA times shorter than 4 to 7 hrs will hide BOB
and its glucose lowering activity
Glucose-lowering Activity
6 hrs
2 hrs
0
4 hrs
57
ReviewDIA
14

• Large doses (0.3 u/kg 15 u for 110 lb. person)
  of rapid insulin in 18 non-diabetic, obese
  people
• Med. doses (0.2 u/kg 10 u for 110 lb. person)

Regular
Apidra product handout, Rev. April 2004a
58
ReviewDoes Dose Size Affect Duration Of Action?
14

• This graphic suggests that smaller boluses do not
  lower the BG as long as larger boluses.
• However, this may not be true see next 2
  slides.
• For a 154 lb or 70 kg person
• 0.05 u/kg 3.5 u
• 0.1 u/kg 7 u
• 0.2 u/kg 14 u
• 0.3 u/kg 21 u

Woodworth et al. Diabetes. 199342(Suppl. 1)54A
59
ReviewPharmacodynamics Is Not DIA
14

• The DIA time entered into an insulin pump is
  based on studies of insulin pharmacodynamics.
• However, the traditional method used to determine
  the pharmacodynamics of insulin action routinely
  underestimates insulins true duration of action.
  See next slide.

60
ReviewPharmacodynamics Underestimates DIA And
Overestimates Impact Of Bolus Size
14

• To measure pharmacodynamics, glucose clamp
  studies are done in healthy individuals (0.05 to
  0.3 u/kg)
• Injected insulin ALSO SUPPRESSES normal basal
  release from the pancreas (grey area in figure)
• The basal suppression makes smaller boluses
  appear to have a shorter DIA

61
ReviewPharmacodynamic Time Does Not Equal DIA
14

• After accounting for the lack of basal
  suppression,
• True DIA times become longer than the
  pharmacodynamic times derived from typical
  research
• At least some of the apparent variation in DIA
  due to relative bolus size disappears
• Some of the apparent inter-individual variation
  in pharmacodynamics may also disappear

62
Standard ForDuration Of Insulin Action
14

• We recommend that a panel of researchers and
  clinicians who are familiar with insulin
  pharmacodynamics recommend consistent and safe
  guidelines for DIA times in pumps for children
  and adults.
• These guidelines will be used to advise
  clinicians, train pump users, and as a reference
  on the DIA setting screen in insulin pumps.

63
Linear Versus Curvilinear DIA
15

• Issue The current straight-linear method of
  measuring DIA is less accurate than curvilinear
  method for estimation of residual BOB.
• DIA times selected in pumps which use a linear
  method must be shorter to approximate the DIA in
  a pump that uses a curvilinear method.
• Pump manufacturers currently use at least 3
  different methods to measure glucose-lowering
  activity

64
Linear And Curvilinear DIA Compared
15

• Set

5 hr Linear
5 hr Curvilinear
From Pumping Insulin, 4th ed., adapted fom
Mudaliar et al Diabetes Care, 22 1501, 1999
65
The Modified Triple-Linear DIA
15

• An alternative and more accurate approach would
  be to modify the linear method into a
  triple-linear method to provide more precise BOB
  estimates.

66
ExampleTriple-Linear DIA Times
15

• A triple linear line can more closely imitate a
  curvilinear DIA.
• For a 5 hr DIA
• 30 min no change
• 3 hrs fall 75
• 1.5 hrs fall last 25 (approximate values)

5 hr Triple Linear
From Pumping Insulin, 4th ed., adapted fom
Mudaliar et al Diabetes Care, 22 1501, 1999
67
Standard ForLinear Versus Curvilinear DIA
15

• We recommend that insulin pumps use either a 100
  curvilinear or a triple-linear method to improve
  the accuracy of BOB estimates.

68
Infusion Sets
16

• Issue Infusion set design issues and inadequate
  site preparation training introduce erratic
  losses of control for a significant number of
  pump wearers.

69
ReviewInfusion Set Failure
16

• Loss of glucose control caused by infusion set
  failure can occur due unrecognized pullout of the
  set.
• A more common error occurs when Teflon infusion
  sets come loose and some insulin leaks back to
  the skin surface. This causes unexplained high
  readings rather than the complete loss of control
  typically seen with a complete pullout.
• Metal needle sets can also cause occasional
  bleeding under the skin that interferes with
  insulin delivery and leads to elevated glucose
  readings.
• Selecting the right infusion set plus good site
  technique can significantly reduce this
  unnecessary loss of control.

70
ReviewCauses For Infusion Sets Failure
16

• Certain infusion sets are more prone to failure
  due to their design.
• Other sets fail when tugging and pulling on an
  unanchored infusion line during routine wear
  loosens the Teflon beneath the skin.
• In a review of dozens of pictures of infusion
  sets online and insulin pump manuals, anchoring
  of the infusion line is usually not recommended
  and is not generally done. Anchoring of the
  infusion line can
• Stop movement of Teflon catheter under the skin
• Stop unexplained highs caused when insulin
  leaks back to surface
• Reduce skin irritation
• Prevent many pull outs

Example
71
ReviewDetection Of Bad Infusion Set Or Site
16

• If a pump user has unexplained highs, ask
• How often do unexplained highs happen?
• Do they usually correct when you replace your
  infusion set?
• For yes answers
• Always use tape to anchor the infusion line
• Consider changing to a different infusion set

The right infusion set and good site technique
prevents headaches and improves the A1c
72
ToolInfusion Set Monitor
16

• Insulin pumps with direct BG entry can identify
  those who may be having consistent but
  intermittent loss of glucose control secondary to
  infusion set failure. The pump can
• Show avgerage time and interval variation between
  use of reservoir loads or the prime function in
  the pump.
• Show average BGs for each 12 hour segment
  following set changes (indicated by the prime
  function) over at least the last 7 set changes
  (or as soon as statistical significance is
  reached).

73
Need For An Infusion Set Monitor
16

• Many pump wearers have random erratic readings
  that are greatly reduced in number when they
  change to a different infusion set or start to
  anchor their infusion lines with tape to stop
  line tugging.
• However, there is currently no tool for clincians
  or pump users to tell who is having problems with
  their infusion sets.

74
Standards ForInfusion Sets
16

• We recommend that infusion sets be expected to
  perform at least 72 hours without a loss of
  glucose control.
• We recommend that monitoring be provided in all
  insulin pumps to detect consistent patterns of
  infusion set problems or failure for individual
  pump users.

75
Standards ForInfusion Sets
16

• 3. We recommend that insulin pump manuals and
  training cover methods to identify and prevent
  infusion set failure.
• 4. We recommend that future infusion set designs
  incorporate easy to use methods to anchor
  infusion lines and minimize tugging of the
  infusion line near the infusion site.