The What, Why, Who & How of Insulin Pumps. Bridget Lydon May 2014

Transcription

1 The What, Why, Who & How of Insulin Pumps Bridget Lydon May 2014

2 Topics WHAT is an insulin pump HOW a pump works WHY use a pump WHO should use a pump Pharmac criteria for funded pumps

3 All began back in the 1970s... THEN

4 NOW Also known as CSII Continuous Subcutaneous Insulin Infusion

5 What is an insulin pump? Small computerised device Delivers rapid-acting insulin only Delivers insulin 24 hours/day in precise amounts (down to 0.025unit) Pre-programme variable delivery rates Provides potential to mimic insulin release from healthy pancreas

6 Pump & Consumables Pump cartridge

7 HOW does a pump work? Infusion set delivers insulin from pump cartridge to cannula Insulin pump contains cartridge filled with insulin Teflon or metal cannula infuses insulin into subcutaneous tissue

8 Cannula options Angled teflon cannula Good for lean people Good for active people Anchors better than 90 degree cannula Straight-in 90 degree teflon Easy to insert Good for hard-to-reach sites but easy in, easy out Straight-in 90 degree metal Won t kink Good for hard-to-reach sites Alternative to teflon

9 Manual insertion vs inserting device

10 Site options

11

12 Pump vs MDI Pump programmed to mimic normal Basal Bolus release of insulin Basal is background insulin Bolus is spurt of insulin in response to food Multiple Daily Injections : BASAL replaced by long-acting insulin via pen/syringe eg. Lantus or intermediate-acting insulin eg. Protaphane BOLUS replaced by rapid-acting insulin via pen/syringe eg. Novorapid, Humalog or short-acting insulin eg. Actrapid

13 Endogenous release of Insulin in person without diabetes BOLUS secretion spurt of insulin release in response to food BASAL secretion constant background insulin to control BG when not eating - prevents liver release of glucose

14 Mimicking normal basal bolus release with MDI Rapid-acting insulin mimicking endogenous bolus insulin Long-acting insulin mimicking endogenous basal insulin

15 Pump has best technology to date to mimic normal basal bolus release Rapid-acting insulin matching individual insulin requiements via a pump

16 HOW the pump delivers basal insulin Pre-programmed to automatically trickle in rapid-acting insulin continuously vary the rate hourly according to individual requirements this mimics normal pancreatic release of basal insulin Basal rates usually between 0.25 to 1.0unit/hr

17 Basal Insulin Requirements Can Vary Basal Insulin Levels 10pm Mid am Perriello, 1991

18 How the pump delivers BOLUS insulin key in dose of insulin to - match the carbs (CHO) - &/or to correct a high BG Food BOLUS - calculated using insulin to carb ratio (I:CHO) eg. 1:10 means 1 unit insulin to 10g of CHO Correction BOLUS - calculated using Insulin Sensitivity Factor (ISF) eg. ISF 3 means 1 unit insulin drop BG by ~ 3 mmol/l CARBOHYDRATE COUNTING key to successful pumping

19 Carb Counting Example Flossy s lunchtime I:CHO is 1:8 Flossy s lunch : 2 toast (30g) ½ can spaghetti (20g) cheese (0g) 1 pottle yoghurt (20g) 1 apple (14g) TOTAL: 84g 84g 8 = 10.5 Flossy takes 10.5 unit bolus for lunch

20 Correcting high BGs on a PUMP To correct high BG on pump: Current BG correction target BG ISF eg. Flossy s BG 3 hrs after lunch is 14.7 Her ISF is 3 and her correction target BG is 7 Current BG 14.7 target BG 7 = 2.56 units ISF 3

21 From manual to automatic Initially I:CHO & ISF calculated by the pump user I:CHO and ISF then programmed into the pump enter amount of carbs &/or BG into pump pump calculates bolus dose pump accounts for insulin bolus that is still active Pump-user can increase, decrease, or stop insulin delivery as situations demand pumps have continuous glucose monitoring (CGM) capability

22 However... The pump is a tool only as good as the pt s ability to use it Pumper needs to learn to think like a pancreas Accurate basal and bolus doses determined through frequent BG testing and analyzing recordsheets Requires motivation, perseverance, good record keeping willingness to work closely with diabetes team

23 Pump Myths Not an artificial pancreas Does not eliminate need to test BG levels Does not know how much insulin is needed Does not know when the user s insulin requirements change eg. exercise or stress

24 When to consider an insulin pump Patient with Type 1 diabetes > 1yr Poor BG control despite best efforts eg: Strong dawn phenomena Severe hypoglycaemia Hypo unawareness Diabetes negatively impacts lifestyle

25 What Patients need to know Pros & cons of pumps Refer to Insulin Pump Team for assessment Pump Course waiting list Pump Course group education: 2 full days, 2 ½ day follow-up classes Intense follow for 4-6 weeks Carb counting pre-requisite for course

26 The PROS Potential to mimic healthy pancreas 1 injection every 2-3 days vs ~5 /day on MDI Potential to improve BG control and reduce incidence or progression of complications Provides precise dosage delivery especially helpful if on very small doses individualized basal rates decreases hypoglycemia risk

27 Greater freedom/flexibility with diet & lifestyle eg: Improved control during exercise Improved control during illness, stress, pregnancy Can skip/delay meals Can extend boluses for high fat food Other Benefits Now fully funded by Pharmac!

28 The CONS Steep learning curve: weeks to months Need to master CHO counting Requires frequent BG monitoring Attached to pump 24hrs/day Risk of site infections May increase risk of DKA Must meet criteria for Pharmac funding

29 The ideal pump candidate Motivated Realistic goals Intellectual ability to operate the pump Test & record BGs frequently Ability to analyze recordsheets Carbohydrate Counting

30 Patients who do well on pumps Somewhat obsessive Tech savvy Can think like a pancreas Proficient with carb counting Ability to analyze and troubleshoot Ability to self manage

31 Patients who don t do well on pumps False or unrealistic expectations of a pump Don t monitor BG levels Poor understanding of diabetes and insulin Not carb counting Lack formal pump education Lack support

32 Pharmac Funded Pump Brands Cozmo Medtronic Animas Medtronic

33 PHARMAC funded pump &/or consumables PRE REQUISITES: under the care of a diabetes MDT on multiple daily injections of insulin for 6/12 carbohydrate counting

34 Pharmac CRITERIA: 1. HbA1c Pump will improve (if new to pumping) or has improved HbA1c by at least 10mmol/mol (1%) since starting a pump Or 2. Severe Hypos pump expected to significantly reduce (if new to pumping) or has significantly reduced the no. of severe hypos on a pump compared to pre-pumping Or 3. Other eg. hypo unawareness, dawn phenomena, Pt anxiety, obsessive BGM

35 Special Authority Diabetes Consultant makes initial application for SA for funded pump &/or consumables Diabetes Consultant re-applies at 9 months then every 2 years for ongoing funding of consumables Pt must demonstrate they continue to meet criteria GP can write prescription for consumables in between these times

36 Key points Pump is a great tool - but not artificial intelligence or pancreas! Can provide greater flexibility of diet & lifestyle Can improve glycaemic control Not suitable for all Type 1 patients Requires hard work, committment, IQ now funded by Pharmac strict criteria: 1. HbA1c 2. Severe Hypos 3. Other Pt must demonstrate benefit to receive ongoing funding

37 Any Questions?