Posted by on Sunday 22 August 2010

My pump problem and CGMS envy

I've been considering writing a post about this for weeks, well months really if I'm honest. I've kept putting it off partly because I keep finding out new things which change how I feel; and partly because what I want to write doesn't feel very current, very 'now'. It's not a view I read other people expressing. But I can put it off no longer - I just have to put something down, and if I change my view tomorrow, well you can all have a good laugh.

I don't want an insulin pump. There. I said it.

Now don't get me wrong, I don't think MDI (multiple daily injections) is a perfect system, far from it - it's just that I don't think pumping is perfect either. Swapping a set of difficulties I have come to know and understand for a completely different set that I see pumpers experiencing (or not mentioning) doesn't entirely feel like the brave new world the pump-evangelists keep telling me it is.

I do know that pumping has demonstrable benefits for many people with diabetes. I do know that pumping is the current 'new and exciting' insulin therapy. Pumping is cool. But that's not enough for me. Not yet anyway.

For those who have no idea what I'm talking about, an insulin pump is a smallish electronic device, similar in size to a mobile phone but around twice as thick. Within it there is a reservoir of insulin attached to an 'infusion set' - a length of plastic tubing (cannula) connected to a longish needle (by MDI standards) surrounded by a big sticky pad. The pump itself often has some electronic wizardry built into it to help you work out how much insulin you might need for a meal. You fill the reservoir, prime the set, insert the needle and away you go. No more troublesome injections. Insulin at the push of a button. And no more need for different types of insulin either. The 'basal' delivery is taken care of by a programmable trickle of insulin. One type of insulin is all you need.

The ability to trickle is, I think, the pump's big win. In terms of insulin delivery they are incredibly subtle devices. Injection pens tend to come in 2 unit, 1 unit or half unit increments. With a pump you can specify increments of 1/40th of a unit, depending on the model. The onboard electronics also allow you to set up very finely-tuned basal (background) insulin delivery profiles. A little more here, a little less there. Carefully balanced to match what your body needs during a 24 hour period. By contrast one or two injections of long-acting insulin a day with an allegedly (though not genuinely) flat activity profile seems preposterously crude, even to me. Going to be a little more active tomorrow? Just reduce your pump's basal profile by 5-10%, or set up a temporary basal rate. Boluses for meals are similarly flexible. The onboard calculator will suggest a dose based on your estimate of carbs in the meal against whatever insulin ratio you have set for that time of day and however much 'active' insulin you have on board already. More in the mornings... less in the evenings... fractional adjustments 1.275u:10g rather than the generous rounding up and down that I go for to make the maths easy.

Alison from diabetes blog 'Shoot Up or Put Up' makes a very good case. Her HbA1c (a test to indicate overall control) has never looked better.

So, you say, this all sounds very marvellous. Why am I not banging the table demanding one? Why, when pumps were first suggested to me by a consultant something like 5 years ago did I start down my pump-averse road? Why am I being so bloomin stubborn?

Well I'm not sure I absolutely know myself to be honest. But,

I hear of pumpers who say they would never go back to MDI.
I hear of pumpers who go back to MDI.
I hear of pumpers whose HbA1c levels are utterly transformed
I hear of pumpers whose HbA1c's stay pretty much the same
I hear people on MDI who swing crazily from high to hypo being recommended pumps
I hear people on pumps who swing crazily from high to hypo

I hear of pumpers whose kinked infusion set sends their levels through the roof (one teenage boy hospitalised overnight with borderline DKA, many others seeing levels I have never reached on MDI)
I hear of pumpers complain of infected infusion sites seeping yellow pus (sorry about that)
I hear of pumpers dropping their pumps and/or snagging their cannulas on door handles (ouch)
I hear of pumpers who find the sticky pads intended to hold the infusion set in position keep falling off

As a pumper I'd still have to estimate the carbs in each meal (and I'd get it wrong just as often)
I'd still have to make a guess as to how much I'd been more (or less) active than usual in tweaking bolus doses
I'd still be affected (or not) by heat
I'd still have changes in my basal requirements that need to be evaluated and adjusted for
I'd still have to work out if my liver was up to any fun and games, dropping in a little surprise blood sugar to keep me on my toes

In addition to all this I'd have to be attached to it. All the time. 24 hours a day.

On MDI I can leave my diabetic gubbins on the table between doses. Walk around like a normal person, well almost. Not so on a pump. The trickle of insulin needs to keep coming. And if you temporarily take it off to nip into the shower, or whatever, then you need to put in an estimated correction dose when you reconnect. With a pump all your eggs are in one basket. And you need to keep that basket with you. Which brings me to...

You have to carry it somewhere. I only ever have things in the front pockets of jeans, can't abide sitting, or leaning on anything in a back pocket. Women pumpers clip to their bras (apparently), but for me I suppose it would have to be clipped to the waist band like an 80s style pager. I have visions of a pump yoyoing around my knees as I break into a run, late for another appointment.

Night time would be even worse I suspect. I'm what you might call an 'active' sleeper, in that I roll around quite a bit (steady on there). Ellen seems to have taken after me in this respect and has been known to tie a duvet in a knot inside the cover. Quite a skill I'm sure you'd agree, but all my rolling around is not really pump-friendly. I'm not sure what I'd do with a pump overnight... gaffer-tape it to my chest maybe?

Not dropping it when you are getting changed.... Trips to the gym and getting all hot and sweaty... Swimming... Attempting to squeeze into a wetsuit for some holiday surfing... Crawling about in awkward spaces for DIY purposes... Bedroom antics...

I am told that these things are not a problem. That after a week or so you don't even think about it, but they weigh surprisingly heavily on me whenever I consider the potentially life transforming benefits of a pump. They also seem to get mentioned when people explain their return to MDI.

And then there are CGMSs.

Many, but not all pumps come with an added box of tricks. A CGMS (Continuous Glucose Monitoring System). Without one I suspect my overall control might get a little better, but not much. But I am absolutely convinced that a CGMS would make an enormous difference to my control. The system involves placing a small sensor under the skin which communicates wirelessly with a monitor (sometimes integrated into the pump itself, sometimes a separate unit). The CGMS records glucose levels every 15 minutes or so. Rather than the blood plasma used in fingerstick tests, CGMS systems are measuring the glucose level in interstitial fluid, so the results lag 10 or 15 minutes behind 'actual' blood glucose levels. Users tend to continue to use traditional meters to calibrate the CGMS and check results a few times a day. Crucially though, because the monitoring is constant, you get not only an indicative one-off level, but almost as important, you get information about whether you are stable, or rising, or falling and at what rate. You can be alerted when you hit a predefined level and make a decision on what measures to take based on how quickly things are moving and in what direction.

No more correcting for hypos that never were. No more suddenly discovering you've massively spiked after a meal and have been in the teens for hours. Alarms that alert you if your levels drop at night. More information. All the time.

And because a CGMS is wireless, you can keep the device itself wherever is convenient. Bedside table, coat pocket. There's no piece of string joining you to it and getting tangled up on things.

Both pumps and CGMS are expensive therapies. The devices themselves and their durables (infusion sets, wireless sensors) are both costly. But so is any treatment for diabetic complications you could mention. I know of a number of pumpers in the UK who benefit from a CGMS as part of their pump but no one, NO ONE, who has a CGMS as part of MDI therapy. If you are lucky you might be able to borrow one for a few days. Probably one of the old skool ones which store the results and have to be 'downloaded' at the end of your allotted time for your Diabetic team to pore over. And this is despite the fact that 2003 research suggests that a CGMS is as effective in reducing HbA1c and numbers of hypos for MDI users as for pumpers:
We found no difference in low subcutaneous glucose frequency between the 2 treatment arms, nor between MDI and continuous subcutaneous insulin infusion users.
And more recently from a 2008 study:
People of all ages - adults, teenagers, and children - who use CGM devices regularly (at least 6 days per week) can see positive results in managing their diabetes... Even people who already have their diabetes in control - meeting the recommended standards for long-term blood sugar tests - see improvements by using CGM devices
I don't know why it is that you can have 2 expensive treatment options (pump and CGMS combo) on the NHS, or just a pump, but not a CGMS on its own.

But I'm going to ask.


  1. Just found your blog and heaved a sigh of relief to find a diabetes sufferer being so honest! I started using a pump just over a year ago, and had similar reservations to you. My control is definitely better now - but I often wonder if that's because switching to a pump motivated me more. Pumping is just as much work as MDI. My control is better, but for the first time in years I recently had ketones due to problems with an infusion set. Not fun! But, all things considered, I'm glad I'm on a pump now.
    Your point about the CGMS and MDI is one I hadn't thought about before. Definitely something to pursue!

  2. Thanks Emma. Yes it'll be interesting to see what my team say at my next annual review. I do like to go armed with a few pointy questions - makes the whole thing much more fun!

  3. Great post Mike, sounds like you've really thought it through. I love my pump and it gives me great results but it isn't a magic bullet, its just as much work as MDI and I could happily throw the thing out the window at times.

    Re CGM on MDI, I trialled CGM for a week while I was on MDI and it helped a lot, for all the reasons you listed. But, I did find the combo of pump and CGM meant I could react much more quickly and easily to the data it was giving me - sorry ;-)

    I can honestly say I've never tried to put a wetsuit on so have no useful input on how difficult that is with a pump, I would imagine pretty horrendous though!

  4. Thanks Alison.

    As I say, I may well change my mind tomorrow - your pumping-success-story is so very convincing :)

  5. I feel exactly the same about the pump at the moment. I'm definitely holding out for the artificial pancreas!

    I would love to have a CGM for the time being though.


  6. Absolutely! Close the loop already!

  7. Mike, I know how you feel. I'm still not 100% convinced about pumping as a practicality. It's the very fine control that has made me say yes, more than anything else.

    It isn't, nor will it ever be, right for everyone. And that's fine too! :)

  8. Having a pump is a very personal thing. For me, the benefits (steady trickle of insulin, not having to constantly remember to pick up my insulin before I go out) outweigh the cons (being constantly attached, higher chance of ketones, trying to find places to put the pump (I cant get on with it on my bra, so it usually remains attached to a belt)).
    Its not 100%. Its not even 80%. For me, its better than MDI was. But if you're happy with your MDI for the moment, then why change? Eventually something will come along that you feel will help you; then jump!

  9. That's a very interesting point. I think you are right, they are both flawed systems, both with pros and cons, and as close as I've got to wanting a pump for all the benefits you mention I've just not quite gone over the hump yet. It certainly wouldn't surprise me at some point though, especially as the artificial pancreas looms ever closer (something like 3-4 years away I read yesterday)

  10. Enjoyed your post! If you like your level of control and you've managed to fit diabetes care into your lifestyle, why change just for change's sake? If you don't like your level of control, have felt unable to do things you want to do, and/or cost is not a consideration, then it can sometimes pay off to try a "new experiment" in your ongoing one-person clinical trial that is life with type 1 diabetes. What works for you, works. What works for other people--doesn't really matter to YOUR blood sugars.

  11. Just for your info. We have managed to obtain a CGM (Freestyle Navigator) for my teenage son who is on MDI as he does not want a pump. Originally self funding but managed to get funding after fighting for 1 year with several tribunals. Still subject to 6 monthly reviews.
    The technology is young (so far from perfect) but never the less, entirely wonderful, The CGM allows him to take action over highs and more importantly for him, lows before they happen. He has not had a bad hypo since commencing it 18 months ago. It is such a relief to know that he will be aware that his blood sugar is dropping before it happens. His HBa1cs have been good for the last since diagnosis 7 years ago (5.8-6.2) but hypos started to become a problem. Now they are not!
    Incidentally, we taught ourselves carb counting and insulin adjustment as it was never mentioned by the NHS. I agree entirely with your subsequent post re carb counting and the fact that carb counting is only taught with pump therapy. Completely insane.

  12. Thank you all so much for your comments. Especially the poster who HAS been able to acquire funding for their son's CGM while on MDI. So pleased that it has provided such tangible benefits. Well done for persevering in the face of what sounds like quite entrenched resistance.


  13. Anonymous - Carb counting is taught in several programs run by the NHS - DAFNE nationally (Dose Adjustment for Normal Eating) and where I live the hospital in Windsor runs a course called CHOICE which I attend a few years ago. Either are well worth attending if you can.

  14. Thanks for your comment Hamish. I completely agree. I'm a firm believer that Carb Counting MUST be taught to T1s at diagnosis, with ongoing support thereafter. Posted about my soap box moment here:

  15. Hi I have had a pump for 12 years in the UK. I have had IDDM for 33 years since 4 years of age. I also privately fund CGMS. Both in combination have revolutionised my diabetes treatment. Having lived through the late 70s and 80s of relative darkness in diabetes awareness, discrimination and isolation. I completed two degrees with annorexia then bullimia, took illicit substances at universitym thoroughly enjoyed myself and am now a very well respected professional in the family justice system. I am from the days before diet drinks were available, of a scoop of mash potato is 10g CHO, 5 chips is 10g CHO, etc. Dafne, 12 years of pump therapy and now CGMS allow me to maximise my life as a lone parent alongside a very demanding professional life. I have side effects neuropathy, retinopathy, necrobiosis, autonomic neuropathy but now my diabetes is so closely monitored that I live to tell the story another day.