Insulin pump
therapy
This guide was funded by Roche, which has been involved in the
development of the content, but did not have editorial control.
£3.50
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Written by Katharine Barnard, chartered health psychologist, and Steve Dixon, Sky News presenter
The Heights, 59-65 Lowlands Road Harrow, Middlesex HA1 3AW To subscribe call 0845 772 6100 www.nursingstandard.rcnpublishing.co.uk Further information:
email: [email protected] Cover photograph supplied by Roche
3 Overview
4 Biomedical implications
5 Psychosocial implications
7 Economic aspects
7 Reported concerns about pump therapy
7 What next for insulin pump therapy?
8 References
9 Life with an insulin pump
10 Using the pump
10 Blood glucose control
11 The overall experience
Contents
© Copyright RCN Publishing Company Ltd 2010. All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of the publisher.
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Diabetes mellitus is an increasingly common disease, for which no known cure exists. It is characterised by hyperglycaemia, caused by absolute insulin deficiency, relative inefficiency in the production and/or action of insulin, or insulin resistance (Williams and Pickup 2000).
Use of continuous subcutaneous insulin infusion (CSII) is becoming more prevalent as an intensive insulin delivery system, predominantly for people with type 1 diabetes but also less commonly for those with type 2.
Minimising the impact of diabetes and its treatment on quality of life is recognised as an important goal in its own right, along with achieving near-normal glycaemia, minimising the risk of severe hypoglycaemia, and delaying or preventing late vascular complications of diabetes (Bode et al 2002).
This guide looks at the use of insulin pumps for people with diabetes, including a patient’s perspective. First, chartered health psychologist Katharine Barnard explains the principles behind continuous subcutaneous insulin infusion and the benefits it can offer to patients with diabetes. Data from previous research will be cited to provide quantitative and qualitative findings. Then, on page 9, Sky news presenter Steve Dixon describes life with an insulin pump, and how being fitted with a pump has improved his blood glucose control.
Overview
CSII therapy was introduced in the UK in the late 1970s, primarily as a way of achieving and maintaining strict control of
Spring :: 2010 3 blood glucose concentrations in people with type 1 diabetes. Early problems with diabetic ketoacidosis (Bradley et al 1986) and the cost of therapy, which has historically been met by the patient, are important reasons why only a minority of people on insulin use CSII therapy.
CSII uses a small, battery-powered insulin pump (see below) and short-acting insulin (or rapid acting insulin analogue). The pump is worn 24 hours a day, and insulin is delivered via a subcutaneous needle sited in the abdomen or thigh. The pump holds enough insulin to last two to three days, after which the pump’s disposable cartridge is replaced and a new subcutaneous cannula is resited.
The pump can be programmed to infuse insulin continuously (basal rate), and patients are able to administer boluses of insulin, via a button on the pump, whenever they eat a meal. Therefore, a person who eats three meals a day would administer three boluses of insulin daily via the pump. This system more closely mimics the
body’s natural insulin production than
conventional insulin therapy (Figure 1).
This is because in conventional therapy insulin is injected two or three times a day, generally in the morning and evening. These injections are a combination of long-acting and short-acting insulin, and patients must time meals to avoid episodes of hypoglycaemia.
Multiple daily injections of insulin simply intensify conventional therapy by dividing the total amount of insulin required into basal injections of long-acting insulin that are generally given in the morning and at night, and with bolus injections of fast-acting insulin that are given at mealtimes.
A major advantage of CSII therapy is that it mimics the way the body naturally produces insulin and so more accurately replicates what happens in people without diabetes.
Insulin injection therapy cannot mimic the body in the same way because larger doses of insulin
are injected daily over periods of time. In comparison, CSII therapy provides a continuous drip-feed of insulin in much the same way as the pancreas would in someone without diabetes.
When food is eaten, the pump wearer can give an additional bolus of insulin to match the carbohydrate intake, mimicking the action of the pancreas in a person without diabetes. The pump enables the wearer to respond rapidly to abnormal blood glucose levels, and temporary basal rates can be used to ensure better glucose control during periods of exercise or illness.
Biomedical implications
Biomedical benefits of pump therapy include improvement in glycaemic control, reduction in glucose fluctuations, prevention of the dawn phenomenon, and reduction in the number and FIGURE 1
Insulin delivery using continuous subcutaneous insulin infusion
6.00 12.00 18.00 24.00 6.00
Time
B B B
Insulin on boar
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Spring :: 2010 5 severity of hypoglycaemic episodes. Most people
choose CSII because they wish to achieve improved blood glucose control and fewer episodes of hypoglycaemia. Patients report either fewer or less severe hypoglycaemic episodes when using pump therapy; others choose pump therapy for the flexibility and quality of life benefits associated with it (Barnard and Skinner 2008).
But whether CSII therapy is started to achieve psychosocial or biomedical benefits, patients often report improvements in both areas once they have transferred to pumps. Although not all patients achieve an improved glycated haemoglobin (HbA1c) when using pump therapy, the smaller glycaemic variation and reduction in hypoglycaemia mean that greater control of diabetes is reported. Only 1-2% of patients who try pump therapy end up switching back to multiple daily injections (Barnard et al 2007).
In one study (Barnard and Skinner 2008), expectations of CSII therapy among patients included improved blood glucose control (44%), flexibility to fit lifestyle (25%), improved HbA1c (14%) and improved coping/quality of life (10%).
Although more than a quarter of participants reported having no concerns before starting CSII therapy (26%), the same number of participants cited a steep learning curve/painful cannula insertion (26%), and 22% cited permanent attachment to the pump as potential challenges and difficulties.
Once they had transferred to the pump therapy, however, responses to a question on preferences about CSII in comparison with their previous insulin regimen included: flexibility of
lifestyle (60%), improved blood glucose control (54%), fewer injections (15%) and improved basal insulin (14%) (Barnard and Skinner 2008).
Psychosocial implications
Diabetes has complex self-care requirements that demand a high level of commitment from the patient to sustain long-term good health and quality of life. Frequent monitoring of blood glucose levels, constant balancing of mealtimes and energy consumption, and administration of insulin therapy, place a heavy burden on people living with the disease. Such demands do not fit easily with the unpredictable nature of everyday life, and patients see little short-term gain from such strict management to prevent or delay the onset of long-term complications.
Many insulin pump users report the feeling of a more ‘normal’ lifestyle. They report experiencing greater freedom in meal timings, work and school life, and sleep and physical activity because the interruptions of insulin injections have been removed (Barnard and Skinner 2007).
Pump users no longer need to eat structured meals at times to coincide with insulin injections. CSII therapy offers greater flexibility in the composition and timing of meals because patients can adapt the amount of bolus insulin they give themselves according to their meal preferences. Similarly, CSII is better able to deal with the fluctuations in blood glucose produced by increased exercise levels, by allowing people to monitor their blood glucose level and immediately adjust their insulin level. This offers greater flexibility than insulin injections, for which patients must calculate their level of exercise and juggle insulin injections and food
intake/timing accordingly. Different patient groups have reported different benefits (Barnard and Skinner 2007).
Adults with diabetes
Patients have reported that CSII offers a chance to live as normal a life as possible (Barnard and Skinner 2007). For some, this involves the freedom to take part in activities previously restricted under their former insulin regimen; for others, it represents the removal of something unpleasant, such as fear. One patient reported: ‘Oh it is far better because I have got rid of those ups and downs all the time. It was really making me feel ill before. To be honest, I was on my own and was frightened because I wasn’t waking up in the mornings. You know, because I had gone so bad into a hypo that I just wasn’t waking up. It has made a big difference to me’ (Barnard and Skinner 2007).
The entire family can be affected by a patient’s diabetes, and introducing CSII means that quality of life benefits can be realised by other family members as well as the person with diabetes. One woman explained: ‘I was completely reliant on my family; now I am living with my partner, I have a job, I have a life.’
Adolescents and children with diabetes All the children and adolescents with diabetes who were surveyed (Barnard et al 2008) cited family, friends and school as important to their quality of life. All participants said being on insulin pump therapy had improved their quality of life in these key areas, as well as their overall quality of life. Ensuring that delivery of insulin is
as convenient as possible is therefore important to children. At school, for example, the main theme that emerged among adolescents in the study was the ability to fit in with friends rather than being identified as ‘different’. Connected to this was the increased dietary freedom reported by participants, which increased their ability to eat the same foods as their friends, at the same times, engendering feelings of similarity rather than difference. One adolescent said: ‘It is just less stressful so I can concentrate on my school work.’
Other quotes from children and adolescents about family life included: ‘I can go to friends’ houses without my mum following me everywhere’, ‘It is easier than having to do the injections’, ‘It just means everything is much easier so we can do stuff that we like together rather than being interrupted by injections’ and ‘I am less narky with my parents, it is a nice atmosphere’.
These quotes reflect a reduction in the additional level of stress that diabetes can place on families.
Parents of adolescents and children who have diabetes
All parents in the study (100%) reported that pump therapy had a positive effect on their own overall quality of life, as well as that of their children (Barnard et al 2008). Key areas in which pump therapy had a positive impact included family, work and health. Many defined the benefits for their family in terms of the increased freedom that pump therapy had provided, particularly in relation to food. Being able to function more as a family, without interruptions for meals at pre-specified times, was a major benefit.
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Spring :: 2010 7 Another major advantage seemed to be fewer
interruptions at work, which equated to reductions in anxiety levels. Parents were much more relaxed about going to work following the transfer to pump therapy for their children.
Parents’ comments included: ‘When she is at school I know she can be bolusing for her food and her general health is good, so I do not come to work and worry’ and ‘I used to get phone calls from school saying she has just had a hypo, she is not feeling well, she’s this, she’s that, and since she has been on the insulin pump we have not had a single phone call’.
A third of parents (33%) reported health as the most important factor influencing quality of life. Rather than being specific to diabetes, ‘health’ reflected the health of the entire family.
One respondent said: ‘It means life on a daily basis is much less stressful than before.’ And in terms of the child with diabetes: ‘Her long-term health prospects are looking far more positive than we could have achieved on multiple injection therapy.’
Economic aspects
The approximate cost of insulin pump therapy in the UK is £1,700 per patient per year. This covers the cost of the pump (total cost divided by life-years of pump), plus consumables such as cannulas and tubing. The National Institute for Health and Clinical Excellence (NICE) estimated the additional cost of pump therapy compared with a multiple daily injection regimen to be £1,100 to £1,400 a year depending on the life of the pump (NICE 2008).
Little information is available on any associated cost savings in terms of fewer hospital admissions
or long-term complications of diabetes. Specific cost savings are made through reduced contact with primary care, and reductions in hospital admissions and outpatient consultations.
Reported concerns about pump therapy
One concern with CSII is the increased likelihood of diabetic ketoacidosis compared with multiple daily injection regimens, although the incidence of this is rare (Barnard et al 2007). It can occur because the pump contains only short-acting insulin, so a blockage in the cannula or tubing, or a pump malfunction, will result in a complete lack of insulin delivery. Regular and frequent finger-prick testing – approximately four to seven times a day – is therefore advised.
Fear of pump failure is more common than the reality of pump failure, and acknowledging and discussing these fears when starting this type of therapy is important. Good training from the beginning can help to avoid diabetic ketoacidosis and allay patients’ fears.
Permanent attachment to the pump can also be a problem for some patients, not least because it can be perceived as a visible sign of disability. Having to wear the pump all the time can interfere with exercise, physical intimacy and choice of clothes, although patients can disconnect the pump for periods of up to an hour, which is convenient when playing sports for example. Finally, a small possibility of marking or scarring at cannula insertion sites exists (Barnard and Skinner 2007),.
What next for insulin pump therapy?
NICE guidance was updated in July 2008 and now states that (NICE 2008):
Continuous subcutaneous insulin infusion or ‘insulin pump’ therapy is recommended as a possible treatment for adults and children 12 years and over with type 1 diabetes mellitus if:
Attempts to reach target haemoglobin A1c (HbA1c) levels with multiple daily injections result in the person having ‘disabling hypoglycaemia’, or
HbA1clevels have remained high (8.5 per cent or above) with multiple daily injections (including using long-acting insulin analogues if appropriate) despite the person and/or their carer carefully trying to manage their diabetes.
Insulin pump therapy is recommended as a possible treatment for children under 12 years with type 1 diabetes mellitus if treatment with multiple daily injections is not practical or is not considered appropriate.
Children who use insulin pump therapy should have a trial of multiple daily injections when they are between the age of 12 and 18 years.
This means that children up to age 12 should be offered an insulin pump as a treatment choice if
the healthcare team and parents believe they will benefit either medically or psychosocially. Adolescents and adults should also be eligible for pump therapy if they are able to show that they would achieve significant quality of life benefits from the therapy.
There is increasing pressure on the NHS to provide insulin pump therapy more widely across the UK. This is helping to prompt commissioning bodies to revisit their policies on pump therapy, although it is unlikely that all diabetes centres throughout the UK will offer pump therapy in the short term. Patients are taking greater control over their own diabetes, with the support of multidisciplinary medical teams. They are making decisions about which therapy best fits their needs and lifestyle, and are well informed about their expectations both medically and psychosocially. They are taking steps to try to prevent or delay the onset of complications, and pump therapy is helping to provide this control for many patients with type 1 diabetes.
References
Barnard K, Skinner T (2007) Qualitative study into quality of life issues surrounding insulin pump use in type 1 diabetes. Practical Diabetes International. 24, 3, 143-148.
Barnard K, Skinner T (2008) Patient Choice and Insulin Pump Therapy: Patient Reported Outcomes. Therapeutic Patient Education conference, Budapest. Barnard K, Lloyd S, Skinner T
(2007) Systematic literature review: quality of life issues surrounding insulin pump use in
type 1 diabetes. Diabetic Medicine. 24, 6, 607-617. Barnard K, Speight J, Skinner T
(2008) Quality of life and impact of continuous
subcutaneous insulin infusion for children and their parents. Practical Diabetes International. 25, 7, 278-283.
Bode B, Sabbah H, Gross T et al (2002) Diabetes management in the new millennium using insulin pump therapy. Diabetes/ Metabolism Research and Reviews. 18, Suppl 1, S14-S20. Bradley C, Gamsu D, Knight G
et al (1986) Predicting risk of diabetic ketoacidosis in patients using continuous subcutaneous insulin infusion. British Medical Journal. 293, 6541, 242-243. National Institute for Health and
Clinical Excellence (2008) Continuous Subcutaneous Insulin Infusion for the Treatment of Diabetes Mellitus: Review of Technology Appraisal Guidance 57. Nice, London.
Williams G, Pickup J (2000) Handbook of Diabetes. Second Edition. Blackwell Sciences, Oxford.
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Spring :: 2010 9 People with type 1 diabetes tend to achieve a
‘normality’ in life, no matter how good or bad their blood glucose control is, because something that you live with 24 hours a day, seven days a week, does become normal eventually.
That has certainly been the case with me. I was diagnosed at 17 years of age – 18 years ago – so having type 1 diabetes is just part of my life. I have always been told, right from diagnosis, that I had a good handle on the situation and was maintaining good control.
To a certain extent that was correct, but these things are always relative. Was I frequently, or ever, admitted to hospital? No. Did I collapse in the street, at work, in the supermarket? No. Did I have any signs of any complications? No.
Consequently, I have always had a fair degree of confidence about my diabetes. I have not let it interfere with my life too much or affect my career. It has just been an everyday part of life.
Shattered illusions
I have always been aware, of course, that life for me is not exactly the same as for someone without diabetes – from eating what I want to exercising when I want, having those minor hypos two or three times a week and happily stuffing my face with chocolate – but I had assumed that my life was on a par with those of other people with supposedly well-controlled diabetes.
That illusion was shattered in two stages. The first was meeting some people on pumps whose lives were radically different from mine, with
steady blood glucose, much greater general control and more confidence. They told me that the feeling of being really off-colour, lethargic, sickly sweet and generally ‘yuk’ that I, and most other people with diabetes, seem to have in the mornings, is not a necessary part of having diabetes and that being on a pump had eliminated that for them.
Second, as part of my mission to receive pump therapy, I was required to take a five-day dose adjustment for normal eating (DAFNE) course. This proved to be a radical re-education in how to manage and control my diabetes in a much more structured manner. I would not have liked
to have embarked on the pump journey without that knowledge and understanding.
Using the pump
My first experience with my pump was having it ‘fitted’, which is the day you actually start insulin infusion therapy. I was terrified, despite how much I had wanted the pump. The thought of coming off a pen-based basal-bolus regimen was awful, and I questioned why I was taking this step. Although I was put under no pressure to carry on, my diabetes specialist nurse did say that it was worth trying and that if I wanted to come off the pump at any time, I could. That level of reassurance was tremendously important to me in starting to feel in control.
The DAFNE course had shown me the basics of pump therapy, insulin ratios, carbohydrate counting and correction doses. Now I just had to focus on how to physically use the pump and change infusion sets. All of this proved to be remarkably easy and stress-free.
A major concern was actually wearing the pump. I had geared myself up for this being a problem – having to carry the unit about at all times, where to put it, how it would affect clothing choices, showers, bathing, holidays and sex. This, again, proved to be a worry I need not have had.
The pump is small and lightweight, and 95% of the time I pop it into my trouser pocket and forget about it. It is easily disconnected for showers and sex, and is also discreet enough to not be a problem when on the beach. These may sound like trivial matters, but they are important because the whole pump experience is about quality of life, in which these factors play a significant role.
Blood glucose control
As for the therapy itself, I have seen an immediate positive impact on my day-to-day wellbeing and blood glucose control.
My basal levels of insulin are down to just over 20 units a day, from 35 units six months ago, and yet my blood sugars remain consistently lower. The ‘drip’ effect of having a tiny dose delivered every three minutes seems to have made me much more sensitive to insulin.
This became apparent when setting up the basal profile through a series of fasting over eight-hour blocks, allowing me to monitor the effects of insulin on blood glucose without the impact of carbohydrate. This has allowed me, in close conjunction with my diabetes specialist nurse, to alter hourly doses by as little as 0.01u/hr (for combo), which is having a noticeable impact on my blood glucose and has allowed me to have a basal rate that varies from 0.6 to 1.1u/hr, countering natural dips in blood glucose during the night and a delayed dawn phenomenon that I seem to experience. Bolus injections are also much better using the pump. I have discovered that delivering an ‘extended bolus’ seems to improve my control significantly.
A little bit of guesswork is needed about how long to extend the bolus for, depending on what type of food you are eating, but even when unsure I have found that I have much better results when a bolus is delivered over a longer period, anywhere from 30 minutes to six hours, than when it is delivered in one shot. This has also proved to be the case with correction doses delivered more within the 15-30 minute range.
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because of a cold, I have also found I can adjust my temporary basal rate to 120-150% of normal for several hours at a time, bringing much better control but allowing for easy checks and easy cancellation down to the original basal levels when necessary.
The other big advantage has been the ability to apply a reduced temporary basal rate after exercise and gym work. This was always a problem in the past because trying to keep fit and healthy required me to eat excess carbohydrates after a gym routine as my bloods would drop significantly.
While this was not good for any sort of calorie burn, it also often led to higher blood sugars later, because of either blood glucose dropping too low and the liver kicking in or simply over-eating carbohydrates when hypoglycaemic.
Now, on pump therapy, I can reduce my basal insulin rate to 50-70% for a couple of hours after exercise, which stops my blood glucose dropping significantly.
Although my blood glucose control is not perfect, and probably never will be, I am seeing a huge improvement. After just a few months with a pump, my HbA1chas dropped to just over 6%, which is well within range.
The overall experience
The injection aspect of a pump was not something I had expected to be a significant part of its benefit, but it has surprised me immensely. I have never struggled with injections and never considered them to be problematic. But I have to say that being able to take insulin without injecting has made
an impact and affords me much greater freedom and discretion. This has been a real bonus to the whole experience, something I was not expecting to be a significant factor. Insulin infusion is proving to be a worthwhile step for me. In conjunction with the proper education via DAFNE, it has helped to bring my blood glucose to a much more consistent level, ending many of the ‘swings’ so familiar to people with diabetes. It has given me a much better sense of wellbeing on a daily basis and a real sense of freedom from needles.
It is difficult to quantify and explain to someone who is not in the same position, but my quality of life seems to have increased immensely. I feel as if my diabetes is no longer controlling me; I am controlling it.
I no longer try to ignore having diabetes by just letting it carry on in the background; instead I embrace it as a condition that I now understand more clearly and can influence in a controlled and calculated way – and I can do this any time of the day or night without having to inject.
The only real downside to the pump, that of being directly hooked up to a little box, is so insignificant to me that it hardly warrants a mention. It had been a concern before starting, but is no longer one. It may at times be a minor inconvenience, but that’s all.
In terms of my blood glucose control and general quality of life, pump infusion therapy has been tremendously beneficial.
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