Eced Libre Manual

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Summary of Contents for Eced Libre

Page 2 You will ﬁnd one of these forms in your Libre pack. Please complete this – front and back (it’s double sided) and then hand it in to us before you leave tonight. This is the form we will be using to generate leBers to GPs and if we don’t get a form we won’t be able to send a leBer to your GP requesEng that they prescribe Libre sensors…...
Page 4 In the 1980s it was not enErely clear whether controlling glucose levels was important in reducing the risk of diabetes complicaEons: such as eye, kidney and nerve damage – as well as cardiovascular disease such as heart aBacks and strokes. A large study called the DCCT – Diabetes Control and ComplicaEons Trial – was performed in the United States to answer this quesEon. People with T1 were randomised to usual care (and maintained an HbA1c of around 9% (75 mmol/mol) or intensive control achieved by mulEple injecEons (or pumps) – the intensive control group achieved an HbA1c of around 7% (53 mmol/mol). People were in the study for an average of six years – aZerwards the average HbA1c of both groups merged to around 8% (64 mmol/mol).
Page 5 The DCCT was a real landmark study in diabetes. The early results showed huge reducEons in diabetes complicaEons such as eye and kidney disease.
Page 6 Even more impressively that HbA1c diﬀerence achieved for 6 years in the 1980s is sEll making a diﬀerence decades later – intensive control paEents sEll have much lower rates of eye and kidney complicaEons. Importantly the risk of cardiovascular disease is reduced by 42% and the risk of death by 33%. Tight glucose control makes a big diﬀerence and that diﬀerence lasts a long Eme! Finding ways to help people with diabetes get their glucose levels to target is very important.
Page 7 The following are the recommend glucose targets for adults with T1 diabetes in Scotland. Targets do need to be individualised as, in some circumstances, they may not be appropriate – this is something to discuss with your diabetes team.
Page 8 You are likely to be familiar with the term HbA1c. This is a measure of glucose levels over a 2 – 3 month period. What is actually being measured is the amount of glucose stuck to haemoglobin in red blood cells. The higher the glucose level the more sEcks to blood cells. Over the last few years the unit for HbA1c has changed from % to mmol/mol. Good control is typically described as 58 mmol/mol or less. Ideal control is less than 48 mmol/mol but this can be very diﬃcult to achieve without signiﬁcant hypoglycaemia.
Page 9 When you come to our clinics you may have seen HbA1c presented like this. Our aim is to help people achieve HbA1c levels within the green range. At the moment just under 30% of people aBending RIE achieve this target HbA1c. In some other centres in the Europe, parEcularly in the Netherlands and Scandinavia, closer to 50% of people achieve this target. One of the major diﬀerences between these centres and our is that there is a long-established system for people to review their glucose results and share this informaEon with their diabetes team using technology. We hope that widening Libre use will make this easier for people aBending RIE clinics.
Page 10 It is not easy to achieve Eght glucose control. Many people with on target HbA1c are checking ﬁnger-prick blood glucose over 7 Emes per day.
Page 11 We would strongly recommend all people with T1 diabetes do the DAFNE course. This has been proven to improve well-being and diabetes control, including fewer hypos, and is oﬀered at all 3 major hospitals in NHS Lothian. Please speak to your diabetes specialist team to reserve a place on the course or see our website for further details.
Page 12 We have also included informaEon in your packs on signing up to My Diabetes My Way which allows you access to your own diabetes medical record (including clinic leBers and results). We have also provided informaEon on signing up to the Scoish Diabetes Research Register which gives us permission to contact you regarding studies which may be of interest and also permission to use spare blood (from rouEne tests) for research purposes. The Libre form we have asked you to hand in tonight also oﬀers the opEon of giving us permission to contact you by email with news and updates from the diabetes clinic.
Page 13 These two guides – one on improving control in type 1 diabetes and the other a guide to using the Libre – have been included in your Libre packs. We would recommend having a look over both of them, as they summarise a lot of what will be discussed here. If you use an insulin pump there is a pump speciﬁc version of the 10 steps guide which you can download on our website.
Page 14 There are also speciﬁc video guides to help keep your blood glucose in target in relaEon to exercise and a video guide to carbohydrate counEng.
Page 16 Many of you will have already used the Libre but, in brief, it is a glucose sensing technology which measures the glucose level in the intersEEal ﬂuid under your skin. The sensor lasts for 2 weeks aZer which it is simply peeled oﬀ like a plaster. We are not going to dwell too much on the pracEcaliEes of puing the sensor on, as the videos on the AbboB website are probably the best way to learn how to do this. The sensor is waterproof and you can bath, shower and swim whilst wearing it.
Page 17 When the Libre sensor is applied, a very small ﬁlament remains just under the skin to measure glucose – you cannot feels this and it is not a needle.
Page 18 You can either use the reader provided by AbboB – which is also a blood glucose and ketone meter – or you can download the LibreLink app on Android phones or iPhones (so long as it is iPhone 7 or above). One major beneﬁt of using the phone app is that it will automaEcally transfer data to the LibreView system without you having to plug anything in to a computer. If you use the reader and a phone always be sure to acEvate the sensor on the Reader ﬁrst. The screen on the reader shows the current glucose level, an arrow to show you whether the glucose is going up or down. There is also a trace at the boBom of the screen which shows you what has happened in the last 8 hours – the Libre records across the whole day, including overnight, as long as you scan several Emes per day.
Page 19 The arrows oﬀer a huge advantage compared to ﬁnger-prick tesEng. If it is a straight- down or straight-up arrow, this means the glucose will have changed by 1.7 in 15 minutes Eme and by over 3 in half an hour. If it is a slanted-up or slanted-down arrow, the glucose will have changed by 1 in 15 minutes and just under 2 in 30 minutes. You can start to use the arrows to avoid hypos before they happen and make some other changes which we will discuss later on.
Page 20 It is important to point out that Libre is not measuring blood glucose but intersEEal glucose which is the ﬂuid between cells under the skin. This means there is a lag of around 10 minutes – blood glucose will rise ﬁrst and fall ﬁrst aZer food and the intersiEal glucose then catches up. When the glucose level is not changing we would expect Libre and ﬁnger-prick tests to be similar.
Page 21 And this graph shows that across the two weeks of usage, the Libre result is typically within 10% of the ﬁnger-prick test. However…...
Page 22 Sensor accuracy can vary – some sensors will be highly accurate and others slightly less so – although this should never be dramaEc. Some people recommend checking a morning ﬁnger-prick glucose before breakfast (when the glucose should be relaEvely steady) to assess how accurate your current sensor is. Given that many people drive in the morning, DVLA regulaEons sEll sEpulate ﬁnger-prick glucose tests before driving. In the example on this slide the sensor is reading 1.1 to 1.8 lower than the ﬁnger-prick reading.
Page 23 Many people noEce that the sensor reads too low in the ﬁrst 24 hours. As you will see in this example, many of the episodes which seems like hypos on the Libre are not actually hypos on ﬁnger-prick tesEng. Some people insert a new sensor and leave it in place for 24hrs before acEvaEng it – this seems to help.
Page 24 Many people ask whether the you can rely on the Libre reading when selecEng an insulin dose. It is worth bearing in mind the issues raised in the previous few slides but the answer most people with diabetes reach is ‘yes’. This is supported by the biggest study of Libre in type 1 diabetes where people with on-target HbA1c were randomly assigned Libre or conEnued with ﬁnger-prick tesEng. The Libre group dropped to tesEng ﬁnger-prick glucose every other day – the other group conEnued with an average of 5 ﬁnger-prick tests per day. HbA1c remained excellent on both groups over 6 months but hypoglycaemia fell only in the Libre group who scanned around 15 Emes per day.
Page 25 There is no ‘right amount of scanning’ – this will vary from person to person. The prescribing guidelines sEpulate at least 6 scans per day which should generate enough informaEon to help with meal-Emes and prior to bed. Remember you can always look back at the trace so you don’t need to scan mulEple Emes aZer a meal. Generally it is only a good idea to scan if you feel the informaEon is likely to result in an acEon.
Page 26 Over-treaEng hypos and then giving too much insulin (or stacking insulin doses on top of each other) can result in swinging between highs and lows. SomeEmes it pays to wait.
Page 27 Unfortunately a minority of people develop skin reacEons to the sensor – oZen mild but someEmes severe enough to make it too uncomfortable to conEnue. Here are potenEal approaches to minimize the reacEon where it has developed. There have also been changes made to the sensor to prevent it becoming too moist under the adhesive, so it is possible the number of people aﬀected may be smaller than previously.
Page 28 Many people ask if the sensor needs to be on the arm and the answer appears to be yes. The graph at the top is a way of assessing how accurate a glucose measurement is – you basically want to see all the results form along the diagonal line in the middle and just around it – Zone A. The further out into zones B to E, the less accurate the result. The one study that looked at arm vs. tummy suggested 86% of arm readings were in zone A compared to only 64% on the tummy.
Page 29 There are two extremely important Emes when ﬁnger-prick glucose tesEng is sEll essenEal. It remains the law, as mandated by the DVLA, that insulin-treated individuals check ﬁnger-prick blood glucose before driving (and every 2 hours during longer drives). Libre results would not be regarded as acceptable and would leave you open to prosecuEon or invalidate your insurance in the context of an accident. This situaEon may change in the future and if that occurs we will inform people. The other important Eme to check a ﬁnger-prick test is if you are feeling hypoglycaemic and the Libre suggests you’re not – it is always beBer in this situaEon to trust the blood glucose.
Page 30 If you haven’t had the opportunity to sign-up and complete the free Libre Academy course, we would highly recommend it. ParEcularly in relaEon to the use of LibreView, LibreLink and making sense of the summary glucose proﬁles.
Page 31 Similarly, watching this series of introductory videos should leave you in no doubt about the basics and pracEcaliEes of geing started with the Libre.
Page 33 The purpose of this slide is simply to show how many factors people with diabetes oZen need to consider when working out the correct insulin dose. Although it can someEmes seem overwhelming, oZen picking one factor at a Eme can help you work through things step-by-step.
Page 35 Before talking in more detail about insulin dose adjustment – it is important to emphasise the importance of insulin injecEon site rotaEon (or in pump users the importance of replacing the giving set at least every 3 days). InjecEng in to lipohypertrophy (caused by repeated insulin injecEon) leads to massive variaEon in the dose of insulin absorbed which will, in turn, result in very unpredictable glucose levels.
Page 36 For the remainder of this presentaEon we will be presenEng glucose traces like the one on this slide. The black line represents the glucose level over Eme. Ideally we want to see this in the green band 65% of the Eme or greater. The traces on these slides are similar to the type of traces you will see on a Libre.
Page 37 One of the striking discoveries for many people using a Libre is how oZen their glucose level dips low overnight – diﬃcult to detect when using only ﬁnger-prick tests. This is a problem as, if it occurs oZen, it reduces your ability to detect hypos. Low glucose overnight can also make it diﬃcult to control the glucose level aZer breakfast.
Page 38 If you detect lows overnight, it is important to consider why they are happening – is it too much background insulin (too high overnight basal for pump users)? Is it related to exercise the previous day (in which case a 10 – 20% reducEon in dose of overnight insulin could be considered with future exercise) or was it related to alcohol (which iniEally causes glucose to go up but then later causes it to drop signiﬁcantly).
Page 39 The view you see here is a summary of glucose results over the past 2 weeks. The dark blue line is the average glucose and the dark blue shading is where half of all the glucose results have fallen over that period. The lighter blue shading is where 80% of all results in the past 2 weeks have fallen. LibreView provides a traﬃc light style guide to the risk of hypos at diﬀerent Emes of the day. This person appears to be at quite high risk of hypos at all Emes – perhaps because their background insulin dose is too high.
Page 40 AZer excluding frequent overnight lows it is oZen a good idea to make ‘geing the morning glucose on target’ a priority. If glucose is persistently too high overnight then people are exposed to 8 hours or so of high glucose – whereas during the dayEme you have the opportunity to idenEfy that and correct it down if necessary. There are two main causes of higher morning glucose. The ﬁrst possible reason is too liBle basal/background insulin cover over night but this is oZen not the case but despite this background insulin doses are increased. A much commoner cause for high glucose in the morning is that the bolus dose of insulin with the previous night’s evening meal (or later snack) has not been enough to bring the glucose back down to target – so it remains high and steady overnight. Background insulin’s job is to keep the glucose steady – not to bring it down when it’s high. Some people have something called the Dawn phenomenon where their glucose is ﬁne unEl around 3am and starts to rise consistently up unEl breakfast Eme – this can be tricky and if it is genuinely happening oZen pump is the best opEon.
Page 41 Too much background insulin is a problem as it tends to increase the risk of hypos and also weight gain. As a rule of thumb background insulin is usually 40 – 50% of the total dose in people with well-controlled diabetes, although there are always excepEons. The best way to assess background insulin is to see what happens to the glucose trace aZer either missing a meal or having a carb-free meal. The ideal trace is the black line – nice and steady. The red line shows what might happen to someone with too much background insulin and the blue line shows what might happen with not enough background. It is important to look at this at all the Eme windows across the day – ideally on diﬀerent days. These things can change over Eme and it’s worth reassessing every few months, parEcularly if your weight or acEvity levels change. Lantus can someEmes run out before 24 hours – twice daily Levemir or once daily Tresiba may be beBer for some people.
Page 42 These examples of carb free meals are also listed in the ‘10 steps guide’ in your Libre pack.
Page 43 To test this – carefully assess the amount of carb in your meal (ideally less than 50g to test ICR) – no other QA insulin in previous 4 hours. Ideally not much more than 2 higher at 2 hours than before meal and roughly back to baseline at 4 hours.
Page 44 Are your raEos roughly in keeping with this?
Page 45 This quick guide to ICR is at the back of the 10 steps guide.
Page 47 The ﬁrst change would mean than a meal with 80 grams of carb would be covered with 10 units of insulin rather than 8 units previously. The second change would mean a meal with 60 grams of carb would be covered with 5 units of insulin rather than 6 units previously. The maths for 1:10 tend to be fairly easy – but harder for other raEons – consider using a bolus calculator – ask your diabetes team – unfortunately the Libre reader bolus calculator requires ﬁnger-prick glucose tests!
Page 49 This is one of the biggest insights from Libre use. Glucose almost always peaks very high in people who don’t bolus 15 to 20 minutes before meals and peaks extremely high in people who bolus aZer meals. Whilst the new quicker-acEng insulin FiAsp may be a liBle beBer – dosing before meals is always preferable. Delayed insulin runs the risk of hypoglycaemia at 3 – 4 hours.
Page 50 Using Libre gives the opportunity to watch and see when your insulin bolus starts to work. So long as you’re not close to hypoglycaemia – you can ‘wait for the bend’ as blood glucose starts to fall and start your meal. This strategy will help avoid big peaks in the 2 hours aZer meals. There is more informaEon on this in our CGM guide.
Page 51 High fat meals, in parEcular, cause a delayed and prolonged rise in blood glucose. It is quite oZen the reason why people wake up with high glucose levels the following morning. This is oZen very clearly seen when people have the beneﬁt of conEnuous glucose monitoring. High fat content (around 40g of fat) may require an addiEonal bolus dose of quick acEng insulin an hour or two aZer the pre-meal bolus (around 1/3 the dose of the pre-meal bolus) or, in pump users, an increased bolus dose (an extra 1/3) given as a dual wave with 50% given immediately and the remainder infused over the following 2 – 3 hours. There are no hard and fast rules about the best way to deal with protein and fat – it is worth discussing this with your specialist team and learning what works for you through trial and error.
Page 52 CorrecEon factor is important as it gives you an opportunity to correct down a high blood glucose. If you start with a high glucose value and only give the insulin to cover carbs in your next meal it is likely you will remain high over the next few hours. You can give a correcEon dose even if you don’t plan to eat but it is important to avoid insulin stacking – that is giving extra insulin doses before your last insulin dose has peaked and taken its full eﬀect – doing so runs the risk of hypoglycaemia.
Page 53 In the example here – the correcEon factor at lunchEme has been too much and resulted in a hypo – if this is a consistent ﬁnding, the correcEon factor would need adjusted.
Page 54 You can also use the Libre to work out exactly what your correcEon factor is – for example if your glucose is high ﬁrst thing in the morning and you take only a correcEon but skip breakfast – then how much your glucose drops in the next few hours will be your correcEon factor. For example if you took 2 units and dropped 4 in the next 3 hours – 1 unit lowers 2. This can be diﬀerent at diﬀerent Emes of day.
Page 56 You can use the direcEon arrows to help guide how much more/less insulin to use with a meal in addiEon to your normal carb counEng and correcEon factor.
Page 57 You can also see here (using the example of Humalog – although Novorapid and Apidra are preBy much the same) that almost no insulin reaches the bloodstream in the ﬁrst 15 minutes aZer an injecEon – emphasizing the importance of pre-meal dosing. Insulin peaks at around 1 hour and is falling to around half maximum by 2 hours.
Page 58 Use the Libre to develop the conﬁdence to take just enough carb to correct a hypo and not over-correct. Previous hypos are the biggest risk for a further hypo and you should scan regularly to idenEfy/prevent recurrent hypos.
Page 59 If this is too much for you – you can modify your approach.
Page 60 There is a lot to say about exercise and most of it is covered in our website video guide. Overnight hypos are one of the biggest risks and reducEon in overnight basal insulin aZer exercise is oZen needed.
Page 61 Reviewing your own glucose results is the best way to idenEfy paBerns – ﬁnd out what works, what doesn’t work and solve problems related to exercise, stress, diﬀerent types of food, exercise etc. LibreView or Diasend are both ways to do this. If you link your LibreView or Diasend accounts to our clinic, we can have a look and try and provide some useful advice. If you use your phone – this data is transferred automaEcally to your LibreView account. If you use the Reader, you will need to connect it to your computer using the provided USB cable.
Page 62 We typically see you in a clinic for a few minutes once or twice a year. You deal with your diabetes 24/7. We want to provide ﬂexible support when you need it. One of the best ways to do this is through sharing data remotely – and as technology develops this may become a central part of the diabetes service – replacing the need for many clinic visits. However we equally happy to arrange face-to-face consultaEons…...
Page 63 Phone us. Email us. We will keep working with you unEl you’re happy with how things are.
Page 64 It is really diﬃcult to resist the temptaEon to take lots of extra carb during hypoglycaemia but it worth reﬂecEng on how oZen this results in large glucose peaks. If so, aim to take less carb the next Eme and carefully monitor your glucose to make sure it is rising. Whenever pracEcal aim to take your bolus insulin well in advance of meals. Aim to take bolus insulin with snacks – parEcularly if they have more than 10g carb. Aim to use your pump bolus wizard or ‘smart meter’ dose calculator – if you ﬁnd you are over-riding it, consider why – is the ICR wrong? Is the CF wrong? Could you do with a carb counEng refresher? Using bolus calculators is typically associated with improved control so it is worth sEcking with it. Good injecEon sites and regularly changed pump sets are essenEal to predictable insulin delivery. Just because your ICR or CF or basal insulin was correct 6 months ago – doesn’t mean it is now – assess this periodically and change your seings as needed. If you’re not conﬁdent – ask your specialist team for help – it’s what they’re there for!
Page 65 AbboB have agreed with NHS Lothian to provide one box of glucose test strips per month to people geing Libre on prescripEon. The process for this is perhaps not as easy as we’d like but following it will save the NHS money. This is important as we need to be able to show that Libre is not just an addiEonal cost but is saving money elsewhere (i.e. test strips). Of course, if you need more test strips we will sEll be advising your GP to provide them to you without any hindrance – as glucose tesEng remains mandatory for driving and is important as a safety measure to back up Libre use.