Pumping insulin - Part 2

Coombe Abbey, June 2015

In part 1 I wrote about the basics of how a pump works in comparison with using insulin pens and MDI - multiple daily injections. Now we come to how I got on with the course, and some fancy features of the pump in more detail.

Tube or Not Tube?

The course I attended was run by a company whose pump delivers insulin to the cannula via a tube. Other pumps, like Mr M's, combine the pump and cannula in one unit and you stick the whole lot onto your body and control it from a separate handset. The pumps that we were using also had a handset that duplicated the interface on the pump and communicated with it via Bluetooth. The benefit of this approach is that when you administer insulin you can leave the pump in whatever inaccessible place you have stashed it - such as in your pants. Some pumps don't have this convenience, so you have to retrieve the actual pump in order to deliver insulin. You probably don't want to be fishing down the front of your trousers at the dinner table so your options for carrying the pump are more limited, and slinky dresses present a similar problem.


Here's a slightly blurry picture - the handset is on the left, and the pump with its tube is on the right.

There are a few different cannula types to choose from, but they all require you to stick a needle into your body. We were given the opportunity to try two types, one inserted manually and one using an insertion gadget, and I was very surprised that I hardly felt the insertion at all. You load the insulin into the pump either using a pre-filled cartridge or by filling the reservoir yourself with a syringe and a vial of insulin. Then you have to prime the tubing to fill it with insulin, connect the tube to the cannula and fill the cannula with insulin, and then it's all set and ready to go. The whole process takes a few minutes, which isn't long, but I imagine could be very annoying if it needs to be done at an inconvenient time.

Obviously I wasn't delivering any insulin through the cannula (I produce my own very nicely, thank you), and we weren't given strips to test our blood glucose. But we were given a pump to wear and encouraged to go through the process of estimating carbohydrate and programming a dose of insulin using the pump or its handset. This is something I'm pretty familiar with given that I've been interested in diabetes for some time above and beyond what the job requires.

12 hours connected to a pump

At dinner we were encouraged to estimate the carbohydrate portions and pretend to bolus insulin using the pump. I tend to forget that most normal people don't do this every now and again just for fun - for some it was actually the first time! We shared our guesses about the carbs in various dishes, and established the kind of variation in estimation that you get when there's no correct answer. But then one of the most enthusiastic pump reps suggested that to try and estimate carbs more accurately we should ask the chef, and then went as far as to haul the chef out of the kitchen to talk to us.

I had a problem with this. "Do you expect the chef to be more skilled at carb counting than a room full of diabetes healthcare professionals, including Diabetes Specialist Dietitians?" I wanted to know. Undaunted, the rep persisted in asking the chef his opinion on the goat's cheese tartlets. The chef obligingly came up with a figure. I continued to make myself unpopular. "What are you basing that figure on?" I asked. "Is it the pastry? How much does the pastry weigh?"

At this point there was a murmur from the room. My questions were perceived as 'a bit much' by some of the other delegates, and sympathy was building for the chef. He was prepared to take me on, though. He said, "I'm basing it on the pastry, and the cheese, and the onion."

"The cheese? But cheese doesn't contain any carbs..."

At this point the enthusiastic pump rep proposed a vote of thanks to the chef, we all complimented him on the delicious spread, and he was hastily bundled out of the room, poor man. Nobody wants a smartarse Dietitian making a chef look like he doesn't know his carbs from his elbow.

Pump features

Lots of the two-day course covered the range of sophisticated features available on this particular pump, many of which are possible on most pumps on the market. These features are designed to help the user decide on the dose of insulin, and deliver it over a period of time rather than in a single injection.

There are quite a number of factors that influence the delivery of insulin in addition to the quantity of carbs eaten - the type of carbohydrate (sweet, starchy, liquid) what is being eaten alongside the carbs (especially fat, protein and fibre content of food and drink), the size and duration of the meal (quick breakfast before work or three leisurely courses at a dinner party), time of day, ambient temperature, whether the user is ill or well, the menstrual cycle, the site of the cannula, planned activity or alcohol, recent past activity or alcohol, whether there has been low blood glucose in the last 24 hours... the list goes on. All of this should be considered before you can even take a bite. It's a massive overhead for something that most of us take for granted as we tuck into our food without a second thought.

The help that most pumps give is confined to the maths involved in applying a ratio of insulin to carbs and adjusting it for the factors given above. The 'bolus advisor' comes up with a suggested number of units of insulin to be injected, which the user can accept or overrule. Then the user can decide how those units should be delivered.

There are three different ways to deliver the insulin. A standard bolus just squirts all the insulin required over a few seconds, much as an insulin pen or syringe would. An extended bolus allows you to spread out the insulin over a longer period of time. You can have it delivered at a constant rate for the whole period of time you select, or you can combine the standard and extended bolus and specify 30% (or 50% or 70%) to go in straight away as a standard bolus and the rest extended over however many hours you want. This type of  'multiwave' or 'dual wave' bolus is for foods that are digested quite slowly (low glycaemic index or low GI), usually because a large amount of carbohydrate is combined with a lot of fat and protein. Fish and chips, pizza, pasta in a cheesy or creamy sauce and curry are the main culprits.

The third insulin delivery option is the super bolus. It's used less than the other bolus types, and is a more extreme version of the multiwave bolus for food that is digested quickly (high GI). It's a little bit complicated because it involves the background insulin that is usually not included in calculations around food. Remember, the background level is programmed automatically to feed insulin dripwise over 24 hours. For these high GI meals (think candyfloss, Halloween or birthday party) you calculate the insulin needed for the food, then you add on the amount of insulin that you'd be getting from background insulin for the next 2 (or 3) hours and give that whole amount up front. Then you turn off the background insulin for 2 (or 3) hours. It gives you a big 'kick' of insulin with the sugary food then turns it off so you don't go low later on.

Other features that may be used more often than the different bolusing options are the different basal profiles and temporary basal rates. The basal insulin is the background 'dripwise' insulin, and the rate it is delivered is programmed into the pump as a 'basal profile'. This generally varies hour by hour, giving a little more insulin in the early hours of the morning for example, when blood glucose naturally rises as the body prepares for waking. You may have different basal profiles if you work different shifts, for example, or if your routine and pattern of activity varies between weekdays and weekends. Temporary basal rates (TBR) can be handy if you are ill and you need more insulin, or if you are exercising and you need less. A TBR is selected for a number of hours rather than for a whole day.

Conclusions

Writing this pair of posts has reminded me just how much is involved in managing diabetes day-to-day, with or without a pump. It's a lifetime's work - I have left out far more in these 'essays' than I have been able to include. For example, how do we decide on how much background insulin to program into the pump, or how much to give for food? How do people manage sport or illness or pregnancy or holidays or airports? What if you get it wrong, or drop the pump or handset in the toilet, or run out of insulin or needles or test strips? What if you can't do maths, or read, or you live in prison, or are homeless? These are all matters for other blog posts on other days.

I complained to the last group we had for structured education that they had an advantage over me, because I can't experiment and test out my dietary theories. I can estimate carbs in meals and suggest matching insulin doses and bolus types as much as I like, but I will never know if I am right. Obviously they showed no sympathy (and I expected none), but having diabetes is a process and a lifestyle and a challenge as much as a diagnosis, and one that takes a lot of effort and commitment to master.

A pump doesn't cure diabetes, but it can help. There are other technologies being developed including the holy grail of the 'Artificial Pancreas' which is intended to match the natural pancreas even more closely, but even that won't detect blood glucose or deliver insulin in the non-diabetic physiological manner. Glucose-detecting contact lenses or wrist-watches have been proposed, but these are all sticking plasters on the gaping wound that is Type 1 diabetes, and we are nowhere near any sort of cure, or even identifying a cause.

Pumping insulin - Part 1

Coombe Abbey Hotel and Conference Centre, June 2015

This pair of posts have been brewing for a very long time, mainly because it's an interesting but a complicated subject, and I wanted to make sure I covered as much as possible in one go. Mr M has written a guest post about his insulin pump, and reading back over that gives quite a comprehensive view of pumping. On the course I attended I discovered there is much more to say, and I won't even be covering everything in these two posts. For more information from people with greater expertise, go to the INPUT website.

The insulin pump course I attended took place almost immediately after my extended (TEN DAYS!) U.S. holiday and before my Solitary Holiday, and was held in a very posh hotel and conference centre constructed within a former Abbey with adjoining Country Park. There were no bedrooms, only 'bedchambers'. Initially I wasn't going to be staying overnight because it is well within commuting distance of home, but the company who organised the whole event contacted me shortly beforehand to say that some attendees had dropped out but their rooms were booked and paid for, so I might as well use one. Which was nice, because dinner was included and I probably wouldn't have stayed for that if I weren't staying overnight.

Insulin Pumps and Insulin Pens

In the UK, insulin pumps are only available to people with Type 1 diabetes, i.e. their pancreas is completely broken and not producing any insulin. As a Type 1 without insulin you end up dead before too long, so you have to inject a modified synthetic insulin into subcutaneous fat, which most people do using 'pen' devices. There are different types of synthetic insulin which have been designed to enter the bloodstream from the subcutaneous depot at particular rates. There are a rare few people who haven't moved on from bovine or porcine insulin and some who even use old-fashioned hypodermic syringes, but these are a tiny minority.

A working pancreas responds automatically to blood glucose levels, secreting exactly the right amount of insulin to maintain blood glucose within the ideal range. The person with diabetes has to take on the role of the pancreas by measuring capillary blood glucose via a finger-prick, then guessing at what blood glucose levels will do next, and injecting insulin according to their guess. Insulin pen users inject a long-acting insulin once or twice a day and rapid-acting insulin at mealtimes or with snacks, or else a twice-a-day mixture of long- and short-acting insulins.

The insulin pump is designed to try and mimic the physiological action of a working pancreas more closely. It contains a reservoir of rapid-acting insulin, and a background rate is programmed to inject this dripwise at an adjustable rate instead of the daily or twice-daily injections of long-acting insulin. With food there is the same process of estimation and guesswork about what blood glucose is likely to do, and the user tells the pump how much insulin to deliver from the same reservoir of rapid-acting insulin.

The pump delivers its insulin into subcutaneous fat via a cannula, which is a hollow needle made of metal or teflon that you insert into your body. The cannula stays in place for only two or three days otherwise you risk irritation around the insertion site and the formation of lipohypertrophy, which is a lump caused by insulin being delivered into a specific location for too long. Available sites are round the abdomen, the top of the buttocks, back of arms and sides of legs as long as there is a decent covering of fat - the same locations as for standard insulin injections.

Benefits and drawbacks

We often come across people in our service who are desperate to have a pump because they think it will make their diabetes management easier. In fact a pump is no easy option, and if you don't put any effort into managing diet and insulin and lifestyle then your outcomes will be as bad or worse than on multiple injections with an insulin pen. None of the benefits I list below relate to doing less work in managing calculations and all the rest of the overheads associated with doing the job of your defunct pancreas.

So what are the pros and cons of pump vs pen? The obvious disadvantage of the pump is that you're attached to it 24 hours a day, although you can remove some pumps for bathing or swimming or sports for up to an hour. Some people don't have any sort of a problem with having a pump attached to them day and night, at work, in bed, on holiday, doing sport - everywhere. Some people just don't like the idea, and ladies who want to wear figure-hugging clothing or a bikini may not be keen to display their condition. It's a very individual choice.

Disconnect the pump for more than an hour and you start to risk rising blood glucose levels, because you don't have any long-acting insulin in your system. After about four hours insulin-free there is the further risk of developing ketoacidosis, which is unpleasant at best and life-threatening at worst. So another disadvantage is that if anything goes wrong with the pump or your cannula or your insulin, you'd better have a back-up option handy or you might find yourself in A&E. If you're away from home, even on a short trip, you may find the journey cut short or have to make a whole lot of calls or trips to hospitals or pharmacies unless you carry spare equipment with you.

One clear advantage of the pump is fewer injections - in the three days that one cannula lasts you might expect to give at least 12 injections using a pen, and probably more. Another advantage of the pump is the ability to reduce your dose of insulin as well as increase it - with a pen, once the injection is given you can't dial the dose down. The third main advantage is that the background dose can be varied in a diurnal pattern that better matches the body's requirement for insulin, and the fourth advantage is that insulin to match food can be delivered in an adjustable dose over a period of time, which better mimics the action of a working pancreas compared with one or more isolated injections. Lastly, insulin pens only allow administration of insulin in whole (or occasionally half) units, while the pump can deliver much smaller amounts.

Other pump features

The pumps on the market also have no end of other features that are useful rather than necessary, like alarms, and the ability to download data from the handset and pump for viewing in all sorts of different ways designed to help you improve your carb counting and insulin delivery. The software for the pump that nearly all our patients use has some further features such as the ability to create a new profile by adjusting the background insulin up or down by a percentage - the alternative would be to change each of the 24 hourly settings using the pump or handset menus. The main feature that this pump lacks is the ability to upload all its data to the Internet so that it can be accessed anywhere. In our department we can only view the data on the specific computer that it's downloaded to, although we're working on a networked option so at least we can see the data on more than one computer in the building.

Mr M has a number of objections to the way the the software for his pump works that are probably a bit too technical to discuss here. I expect there are annoying features with every pump and handset. We recently held a session where we invited all the different pump manufacturers to show us their wares in an afternoon, and while they all do roughly the same job they are all quite different.

Coming soon: Part 2 of the Pumping Insulin series covers my own experience on the course, including wearing a pump myself for 12 hours.

Tired (again)

Somewhere in Rugby, May 2015

Usually I make a start on writing something vaguely interesting at the weekend, and finish it off ready to publish on a Tuesday. This week that hasn't happened, so I am putting this out without benefit of deep consideration or self-editing. I am tired.

This is my last month of full-time work. From October I am reverting to either 27 or 30 hours a week (I don't yet know which it will be - either way, not more than 4 days) and I am looking forward to it immensely. They are certainly getting value for money out of me this final month. An extra clinic has started, we are still short of one Dietitian who has left and a replacement not yet recruited, one of the remaining Dietitians is on holiday, but a new service is due to start shortly after she gets back and needs a load of preparation, which I'm not sure is being done. Two of the Diabetes Nurses are now off sick and another is about to have an operation on her foot that will keep her at home for six weeks.

On top of all that, a couple of weeks ago I committed the most heinous crime that it is possible to commit - I didn't turn up for a clinic which I was supposed to be covering. I got confused with where I was supposed to be and whose clinic I was standing in for. Luckily there were only three patients and apparently they didn't get too angry, although they were entitled to be cross because their previous appointments had been moved to this new date at short notice because one of the remaining Dietitians not previously off sick had been put out of action with a bad back, due to being made to work in a room with a coffee table instead of a desk (thankfully she's back at work now). I felt bad about missing that clinic for days. Actually, I still feel bad about it. I hope the feeling will wear off soon.

It's all been a bit much, and now that my age has exceeded the half-century I am starting to appreciate that I am no longer a bright young thing who can just pack as much as I like into my days. Playing badminton makes me much more tired than it ever did before - not that I'm about to stop playing, but I used to start early and finish late at club nights and now I'm much more inclined to start late and finish early. I am significantly tired the day after any vigorous activity, where in the past I wasn't. Of course as well as the badminton I'm doing the running that leads up to the event in November, so that makes for extra tiredness. Perhaps I'm overdoing things.

[Nostalgia note: When I was a child, my grandmother used to say that I was always overdoing things. "Do not overdo," is one of the few phrases I remember her saying, along with "Speak more slowly," the numbers in German and a rhyme that started "Hoppe hoppe Reiter" which I still remember word for word.]

This has turned into a bit of a whine - it's interesting what manifests itself when I sit with a blank screen and write whatever comes into my head. Things are fine. I am essentially fit and healthy and most of my complaining is about activity that I have chosen to do of my own free will and could stop at any time - in fact, I have missed a badminton opportunity tonight. I have completed some significant and difficult tasks and am optimistic that I will manage a few more by the end of the year. Work is essentially fine too, although there are and always will be annoyances and inefficiencies and personalities and conflict, as well as satisfaction and success and achievement and progress.

Outside work I've already mentioned badminton and running - there are also films on DVD, the usual reading in print and audio, food shopping and cooking, watching the one TV programme of the year that I like (The Great British Bake Off), cleaning the house, a massage, and welcoming Lola II and Mr M for the annual Leamington Food and Drink Festival. As usual I made sure I examined every stall in the arena over the two days of the Festival, and this year purchased three packs of sausages, a sachet of curry paste, a mushroom and garlic vegetarian Scotch Egg, three different cheese scones, a chocolate and cherry brownie, a Thai curry with cashew nuts and rice, and a pastrami and cheese toasted sandwich. I have already eaten all of them except one pack of sausages, but not necessarily in that order.

My ongoing plan for this evening is to go to sleep quite soon. I'm looking forward to recovering at the weekend before starting my penultimate week of full time work.

Developments at work

Caldecott Park, Rugby, May 2015

Crack open the champagne - they've finally installed an alternative web browser on my work PC! I tried for an upgrade to IE long ago but it was incompatible with another application on the PC and had to be removed again. At the time I didn't think to ask for a different browser, and they didn't offer it, but a colleague mentioned the option and now I've got Chrome. It's such a treat to be able to see websites that aren't completely garbled, and more and more sites were just refusing to load at all with the ancient version of IE. Now I can update my yogurt document (don't ask - it's just a list of the nutritional content of various strawberry yogurts).

Another work-related thing is that I've volunteered to be a subject in a research project. On a day when I'm being a guinea pig, using an app or via a website I have to:

• weigh myself first thing
• collect and measure all my urine throughout the day
• put two small urine samples in a test tube on each occasion
• eat less than 1200 Calories in the day, comprising a normal breakfast, a carb-free meal, and a snack that's less than 200 Calories
• record everything that I eat and drink and any activity that I do as well as weight, urine volume and test tube numbers.

I've managed two days so far (it's not an every day thing) and it's actually quite demanding. The research is very relevant and all about a person's insulin response to food throughout the day - apparently there is measurable insulin in urine, which surprised me.

Then there's been our Teen course. I've written a lot about structured education, because it really is the key to managing diabetes. If you don't really understand the condition or how best to manage it (and it's quite a complicated business) then I don't see how you can expect to avoid having higher blood glucose than is ideal, and we know that this raises the risk of complications. But we find people are very reluctant to spend the time attending our structured education, and this is a particular problem with young people with Type 1 diabetes.

Most will have been diagnosed when they were too young to be expected to manage everything themselves, so if any education had been provided in the past it was probably aimed at parents. So we want to catch young people at a point when they are managing their own diet and insulin, to make sure they acquire all the knowledge that they need to stay healthy for the 50, 60 70 or more years that they may have ahead of them.

We decided we would try to attract 16-21 year olds, so we got together with the paediatric team to contact as many of this age group as we could. We did a mailshot and we encouraged people at their routine appointments to consider signing up, and ended up with 13 people who said they would attend. This seemed enough to justify putting on a course, so we cooked up a programme based on the usual version of our Type 1 Structured Education, but shorter, and including more that might be relevant to the younger audience - eating out, snacking, alcohol, drugs, festivals, travelling, sport and exercise, living away from home, that sort of thing.

As I wrote a while ago, only two turned up for the first week. The second week was scheduled on the same day as A level results are published, and one of our two attendees was due to get his results that day, so we agreed to skip that week and get them back the following week, covering everything in just two sessions seeing as how they were both pretty quick on the uptake. Only one of them came to the second session.

That solitary participant, however, gave us some good feedback and ideas about how we might attract more attendees if we tried again:

• offer food e.g. doughnuts/pizza
• start later in the day
• change some of the wording in the invitation letter
• arrange for transport from the city centre.

I'm not sure if we'll try this again, and it certainly won't be until next summer holidays, but it was a worthwhile exercise even if only one and a half people benefitted.

Sun + rain = camping + walking

Sudeley Castle, August 2015

It's been a rainy Bank Holiday weekend, although to be fair, some of Saturday wasn't bad. As I write, I hear muffled clapping, cheering and shouts of encouragement or triumph from the bowling greens, where we are reaching the end of a month of National Bowling action. Our period of exclusive entry to our little trio of streets guarded by high-vis-vest-clad doormen is nearly over.

In the past couple of weeks I've had quite a few evening appointments, including appearing on a panel for a different Diabetes UK local group from the one I used to attend until I'd had enough of their rudeness. The demographic was very similar - nobody under 50, a couple of opinionated and outspoken members, polite attention and some interesting questions. The panel consisted of two podiatrists, an optometrist, me, and a retired local GP who is fairly eminent in the Diabetes professional world. People were very interested in what the podiatrists had to say and much less interested in my contribution. I expect it's because someone's always banging on at them about food, whereas they have few opportunities to raise questions about feet.

I also enjoyed a weekend away camping with Lola II. The campsite was fine, including excellent hot showers but with fields mostly on a slope. I managed to find a relatively flat bit to pitch the tent before collecting Lola II from the station. We did a bit of campsite cooking and some eating out, but I'd brought quite a lot of salad ingredients, because a) that's what I had in the fridge, b) it's supposed to be summer and c) Lola II and I are both grappling with weight management.

We visited an old prison and a castle. The prison also contained a Cotswolds information centre, and Sudeley Castle (and Gardens) was staging an event including re-enactment of the period of Richard III, including costumes, armour, archery and music. The castle was home to Henry VIII's last wife, Katherine Parr, and she is buried there too - the only Queen of England to be buried in the grounds of a private home. There are gardens as well as the castle, and exhibitions on all sorts of aspects of historical interest. We were there for hours and didn't see everything - there was plenty to keep us occupied, and it was really hot.

On Sunday we met up with Landrover Man and Bee Lady for a lovely walk in the countryside. LRM can always be relied on to plan a route and guide us around it, thus saving endless hours of getting lost which would happen if I were in charge.

The Weather Gods had a hand in the loveliness of the countryside, providing torrential rain halfway through when we were in the middle of a field, far from shelter. I had been too lazy to bother wearing proper boots so I was in trainers, and could wring my socks out at the end, but it was worth it - not cold, and good to catch up with bees, farmyard machinery, sheep and septic tanks. I can vouch for the impressive improvement to the vista chez LRM and BL because we were sent 'before' and 'after' pictures of the septic tank cover.

So that was a good weekend away. For the Bank Holiday weekend I decided I had procrastinated long enough and it was time to put in a bit of effort into choosing and buying a car. So early on Saturday I got up and did a Parkrun instead. I find that buying a car (or in fact buying anything except food and charity shop clothes) is really difficult and fairly unpleasant, but I found one in the end and it's probable that the ordeal will be over in a month or so. The dreadful experience is too fresh to write about now, but I'm sure I'll manage to bring further vehicular news at some point.

Sudeley Castle again