Knowing when a cannula site is "dodgy"

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Redkite

Redkite

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The last few days my son has had difficult BG levels, with persistent double figures, eventually falling back into target range after corrections and higher temp basals. I was on the point of making a few increases (suspecting growth hormones were the cause), but following a new set at bedtime yesterday, he had a night all in the 6's. So it seems he has had two cannulas in a row where absorption has just been poorer. I do find that this can be one of the limitations of pumping (ie the hardware), because unless you have an obvious occlusion and markedly high BGs, you can't always tell whether the site is dodgy!
 
Oh it's really annoying when that happens isn't it. We get that too occasionally, a day of running at 11-12 all the time, which isn't high enough to instantly suspect a problem, but then after a set change it immediately goes back to 5-6! I think the worst bit about pumping is the cannulas, but as you can't have one without the other you have to put up with them!

We had a problem in the early days with a cannula insertion that went horribly wrong (we use Roche Flexlink, you have to shoot them in with the twangy thing, basically it didn't fire properly and daughter got stuck with cannula and inserter hanging off her tummy and I couldn't see any way of removing it without inflicting pain!), and set changes after that became a nightmare for about four months. Screaming, crying, begging me to let her go back onto MDI; we tried cuddling her, shouting at her, bribing her with chocolate (!), everything. It was horrible, because she was upset I was upset, and I felt like a real mean old mum because I wouldn't let her go back onto MDI.

Then after about four months of this she suddenly decided that life would be a whole lot more pleasant if we just got set changes over and done with as quickly as possible with minimum fuss (i had been trying to explain this to her for weeks before), and hey presto since then things have been much better. I think we get far fewer cannula failures now that she isn't tensed up during changes.
 
Do you think it is due to a bad cannula or the site where the absorption occurs? I am a relatively new pumper (last November) and I find similar problems, but I think they are what I had before when I used a pen too.
 
Absolutely agree with both of you. Cannulas are the weak link for pumps no question. Well that and the fact that it *could* be any number of things... so that a dodgy cannula (or a sneaky bubble that is no longer there in tubing to be seen because you've been delivering it instead of basal for an hour if you get that problem too) is only one of the 'wait and see what happens' possibilities.

Still... in a way it proves to me how much more reliable my control generally is since getting to grips with the pump. These days unexpected 10s-to-teens seem to demand an explanation, or suggest 'something's up' because I don't have anything like so many of them. On MDI they were so much more frequent for me that I just put a lot of them down to diabetes-randomness.

Heartbreaking reading parents accounts of difficult set changes Sally. Glad things have settled again now.
 
I think it can be either. If you use Teflon cannulas they are so tiny that they can easily become kinked or squashed or something (I would have thought you would get an occlusion alarm in this case, but it doesn't always happen!). But I think sometimes depending on where the cannula is sited perhaps the insulin isn't being absorbed properly. Sometimes you get a cannula that works perfectly for 2 days and then somehow goes "off" on the third day and BGs keep rising, I think that is more likely the site going off rather than the cannula itself. We occasionally get this problem, but not yet often enough for me to start considering changing every 2 days all the time. We have also had a couple of occasions when the cannula failed completely overnight, we woke up to BG 20, ketones 2.5 or more, yet cannula was still attached and plugged in and there was no occlusion alarm! It's all fun and games isn't it, I still wouldn't want to go back to MDI though.
 
Glad we're not the only ones! However, it seems there might be something else going on AS WELL - after a lovely night all in the 6's he went up to 11 mmol by break time despite an hour of running in P.E. and hasn't been lower than 8.4 all day. So a few things need increasing I think.
 
Oh that's a bummer Redkite! We, on the other hand, have been in Hypo City all day today - two at school and one afterwards - and one yesterday also, if that trend continues I think we'll be doing basal adjustments in the opposite direction!
 
Sally71 said:
Oh that's a bummer Redkite! We, on the other hand, have been in Hypo City all day today - two at school and one afterwards - and one yesterday also, if that trend continues I think we'll be doing basal adjustments in the opposite direction!
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That's not good either! But normally for us we do see lots more hypos when the days get lighter and warmer. However, d wouldn't be d if it was nice and predictable....🙂
 
I did wonder if I had accidentally switched the pump on to basal 2 (school holiday one) in my sleep or something, but no, that's not the answer :D

Lots of people have mentioned the weather so am going on that theory at the moment. Hope you get sorted soon too. 🙂
 
Basal checks never seem to indicate problems though, which always make me think the cannula or bubbles aren't the problem. I still seem to get many 'random' highs and lows, obviously some due to bad guessing of carbs (although with new apps to help I don't think so) but still some with the same food. The joys of diabetes! (I want a CGM!) And I will still keep checking cannulas and bubbles!
 
heasandford said:
Basal checks never seem to indicate problems though, which always make me think the cannula or bubbles aren't the problem. I still seem to get many 'random' highs and lows, obviously some due to bad guessing of carbs (although with new apps to help I don't think so) but still some with the same food. The joys of diabetes! (I want a CGM!) And I will still keep checking cannulas and bubbles!
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Could it be that one of your ratios needs a tweak? Either a mealtime one or the correction factor? Sorry if I'm stating the obvious and you've already thought of that!
 
Alternative Type of Canula

My son had loads of problems with his readings towards the end of last year which constantly required a set change. They generally came after he sat in a sofa or after he went to bed. As his site is in his buttock, it was probably something to do with that.

In any case we switched to a metal canula and everything has been so much better since.
 
Sally71 said:
Could it be that one of your ratios needs a tweak? Either a mealtime one or the correction factor? Sorry if I'm stating the obvious and you've already thought of that!
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Don't worry, all answers appreciated!
However it is the seriously 'random' results I am talking about eg I am on porridge these days and I get occasional highs mid morning (>14!) wheras normally it is gloriously stable all morning, maximum 8 after 2 hours. But you are right, these things need watching, and it's attention to detail that works most of the time - what a pain it is, isn't it!!
 
Tee hee, I find porridge a right royal pain in the backside as well, I think I've found a system that works and then it goes wrong again. My daughter could eat exactly the same amount of porridge for breakfast 5 days in a row and have completely different results 2 hours later. I don't think there is much that you can do about that!
 
I've always done this since a small child so you are talking nearly 50 years 😱
Blood sugars will be fine for a few weeks then rise to silly amounts which involves about 5 units of insulin increased over a 24 hour period. The main bulk from 10 AM until 12.30 PM. It will stay like that for a couple of weeks then just drop like a bomb so back to square one I go and have to reset everything again.
Obviously back in the 1960's there were no blood testing kits so it was guess work on my Mum's part as to what was needed regarding increase and decrease.

Having a pump for the last 7 years has been an eye opener so can see exactly where the changes need to be made, also as have some sensors I can hopefully catch the next bomb and see exactly what is happening.

As I have done this both on injections and pump I can not blame the cannulas.
 
Hi Redkite,

In the 4.5 years Alex has been on a pump I think we have had 3 dodgy canulas🙂We very rarely need to do an unscheduled set-change- but then Alex has to change every 2 days anyway as he cant tolerate for longer so perhaps as we change more often than most we dont have that issue. But - we had been experiencing highs and put it down to growth/hormones but clinic explained that although the sites werent 'lumpy' you can still get deep rooted scars from the canula's that cause highs so we moved sites altogether and have seen a drop in highs so think that was our problem. I knew about looking for lumpy sites but hadnt realised about the deep scarring which has been a good lesson as Alex had got used to using his bum! He now uses his hips but doesnt have any fat so is getting a bit fed up of that - maybe we can go back to his tummy which he prefers🙂Bev
 
Hi Bev, I'm sure this is part of the problem, ie. scarring under the skin where we can't see it. Unfortunately he can ONLY use his butt for sites. We got the DSN (Louise) to give her opinion on other bits of him (abdomen, legs, arms) but he doesn't have a scrap of subcutaneous fat anywhere and she said we had no choice but to stick to his butt! So it's a case of doing our best to rotate sites within that limited area.

P.S. The reason we asked her opinion (at last clinic) is because I can't see how he can ever learn to insert his own cannulas while they are round the back, and obviously it would be easier to learn if he could use tummy or legs....
 
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Bad sites is one of the reason why I got a pump in the first place. Really pleased with results. 4 injections or more verses change every 3 days Much better 🙂
 
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