A bit of a mystery!

[Sally71]

Hello fellow pumpers, does anyone have any ideas on this?

We use the Combo pump, which means that usually you do a cannula-only change midway between pump refill/whole set changes. We don't get many cannula failures any more, but do usually find that if we have sustained high blood sugars that it's almost always the cannula that's the problem, and changing that alone will usually fix it.

Twice now we have had the following scenario: do complete pump refill, blood sugars rapidly shoot up into the stratosphere, we then spend the following 4 days fighting to bring them down again with loads of corrections and ever-increasing temp basals. Corrections work briefly but basal has to be almost doubled to have any effect at all, which makes no sense to me as it's all coming from the same reservoir! Changing cannula alone has no effect, then after 4 days pump is empty, we change whole shebang and BGs instantly drop straight back down to normal!

As the high BGs fit so perfectly between pump refills, that would suggest that something isn't working properly and it isn't anything to do with hormones or whatever. BUT:

Pump isn't reporting any problem
Changing cannula has no effect at all
Tubing checked for damage, none found, and when unclipped and primed insulin can be seen coming out of the end
And here's the killer, when pump is refilled for the second time, the same bottle of insulin is used and it works, so it isn't that the insulin has gone off either! (And I'd be surprised if it had gone off in the pump as BGs start rising almost immediately after it was put in there)

What else can it be, the only thing left to blame is the cartridge but I don't see how that can be the problem! I wondered if it would be worth changing tubing as well as cannula if it happens again, would that make sense? Otherwise I'm a bit loath to chuck it all away and start again when we still have half a cartridge left, pumping creates enough waste as it is

Any ideas gratefully received, or is it one of those little mysteries that will never be solved? (Diabetes fairy?!)

Many thanks 🙂

 

[SB2015]

Hello fellow pumpers, does anyone have any ideas on this?

We use the Combo pump, which means that usually you do a cannula-only change midway between pump refill/whole set changes. We don't get many cannula failures any more, but do usually find that if we have sustained high blood sugars that it's almost always the cannula that's the problem, and changing that alone will usually fix it.

Twice now we have had the following scenario: do complete pump refill, blood sugars rapidly shoot up into the stratosphere, we then spend the following 4 days fighting to bring them down again with loads of corrections and ever-increasing temp basals. Corrections work briefly but basal has to be almost doubled to have any effect at all, which makes no sense to me as it's all coming from the same reservoir! Changing cannula alone has no effect, then after 4 days pump is empty, we change whole shebang and BGs instantly drop straight back down to normal!

As the high BGs fit so perfectly between pump refills, that would suggest that something isn't working properly and it isn't anything to do with hormones or whatever. BUT:

Pump isn't reporting any problem
Changing cannula has no effect at all
Tubing checked for damage, none found, and when unclipped and primed insulin can be seen coming out of the end
And here's the killer, when pump is refilled for the second time, the same bottle of insulin is used and it works, so it isn't that the insulin has gone off either! (And I'd be surprised if it had gone off in the pump as BGs start rising almost immediately after it was put in there)

What else can it be, the only thing left to blame is the cartridge but I don't see how that can be the problem! I wondered if it would be worth changing tubing as well as cannula if it happens again, would that make sense? Otherwise I'm a bit loath to chuck it all away and start again when we still have half a cartridge left, pumping creates enough waste as it is

Any ideas gratefully received, or is it one of those little mysteries that will never be solved? (Diabetes fairy?!)

Many thanks 🙂

Mmmmm. I first thought it was the insulin vial, but then you say that even using the same vail it can correct itself and work on the next fill. As you say, often just a change of cannula will work. I have found that I have gone through three cannulas in a day in one occasion where I just hit a blood vessel and went ouch on the first two. This seems to be the DiabetEs Fairy at play, as I have no other ideas. Sorry not to be of any help.

 

[everydayupsanddowns]

Yikes. Sounds a complete nightmare. Especially since the thing that apparently causes the problem also eventually fixes the problem!!

Any pattern to the site locations?

Have you tried doin another full change during the 4 day struggle?

Does it make a difference if you correct with pen/syringe?

Sorry... no answers - only questions!

 

[Pumper_Sue]

Are you 100% certain there is no insulin leaking from the cartridge/tubing connection? Have a look in the cartridge chamber with a torch and see if it's damp and have a good sniff, can you smell insulin? Also do check the actual site as I've now had two cannulas that have leaked insulin.

 

[Sally71]

Thank you all for your replies!
@everydayupsanddowns : not really any pattern to sites, we always use tummy and swap sides each time, obviously trying to move it around a bit and stay away from where we can see recent cannulas have been. I'd like to give the tummy a rest and use buttocks occasionally, but daughter won't let me.
Haven't done full change during the 4 days, cannula only change will sort the problem in 99% of these cases so I always do that first. Suspect that full change might solve the problem but I like to understand why and exhaust all other possibilities first, don't want to chuck away half a cartridge of insulin if there might be another way of solving it! Corrections via pump seem to work most of the time so I've never quite got as far as doing pen corrections.

@Pumper_Sue : that's an excellent point about leakage from either end of the tube, I hadn't thought of that. I couldn't smell anything, but wasn't actively trying to so that doesn't mean anything in itself: we once had the scenario that our pet rabbit had bitten right through the tube, but because daughter was ill at the time and not changing out of her night clothes for a few days we didn't notice, damaged tube was conveniently hidden under the clothes. BGs were obviously very high but would have been worse if she'd been eating normally! At about the same time as the low cartridge alarm went off I was just starting to get suspicious that pen corrections were working perfectly but the pump didn't seem to be doing anything at all even though it was running at 250%... There must have been a right old stink that time, as at least half a cartridgeful of insulin had pumped straight into the clothes, but I didn't notice a smell at all, how stupid did I feel when we discovered what had happened!!
Hence I do check the tube now but hadn't thought about the ends, I've only been doing this 6 years, I guess there's always something new to learn! 😳

I suppose we could also have been really unlucky and had two duff cannulas/cannula sites in a row, I used to think that that was highly unlikely, but maybe it isn't

This has only happened twice in about a year so hopefully will be a while before it happens again, but you've given me some good things to think about, thank you all 🙂

 

[Sally71]

Similar scenario the last couple of days, veering between almost normal numbers and high teens/nudging into 20s 😱😱, 150% basal not making much difference although correction boluses mostly working.

So checked tube, nothing untoward at cannula end, at pump end there was a smell of insulin and it was perhaps a bit damp, when I tightened the connection it did seem to be a bit loose, and there were bubbles in the cartridge and the tubing! So have primed bubbles out and done cannula change for good measure, triple checked that tube is on tightly now and then waited with bated breath. Last Libre scan showed 8.8 and dropping fast

So I hope to goodness that we have found the problem now, I thought you weren't supposed to over tighten the Luer connections, but I jolly well shall be from now on!! Thank you soooo much @Pumper_Sue for helping me to work out what was going on 🙂

(Although we have been pumping for 6 years, very strange that I've suddenly developed a habit of not screwing the tube on tight enough, oops... 😳)

 

[Pumper_Sue]

So I hope to goodness that we have found the problem now, I thought you weren't supposed to over tighten the Luer connections, but I jolly well shall be from now on!! Thank you soooo much @Pumper_Sue for helping me to work out what was going on 🙂

(Although we have been pumping for 6 years, very strange that I've suddenly developed a habit of not screwing the tube on tight enough, oops... 😳)

You are more than welcome, fingers crossed all sorted now.

I doubt very much you have done anything wrong at all seems very odd doesn't it more than one person was having problems. So suspect like you there are some faulty cartridges/tubing about.

 

[SB2015]

Similar scenario the last couple of days, veering between almost normal numbers and high teens/nudging into 20s 😱😱, 150% basal not making much difference although correction boluses mostly working.

So checked tube, nothing untoward at cannula end, at pump end there was a smell of insulin and it was perhaps a bit damp, when I tightened the connection it did seem to be a bit loose, and there were bubbles in the cartridge and the tubing! So have primed bubbles out and done cannula change for good measure, triple checked that tube is on tightly now and then waited with bated breath. Last Libre scan showed 8.8 and dropping fast

So I hope to goodness that we have found the problem now, I thought you weren't supposed to over tighten the Luer connections, but I jolly well shall be from now on!! Thank you soooo much @Pumper_Sue for helping me to work out what was going on 🙂

(Although we have been pumping for 6 years, very strange that I've suddenly developed a habit of not screwing the tube on tight enough, oops... 😳)

I hope that things are settling down Sally. There are so many variables to consider, it is amazing that we all manage this day to Day.

I know that when I am high the increased basal rate and corrections are less effective. I find I need a bit extra, especially if my levels have crept up into the upper teens.

 

[Sally71]

We have another curious scenario now! For the last 3 Wednesdays in a row daughter has come home from school with blood sugars around 20 😱😱 and Libre showing a steady increase since lunch time. New cannula and large correction with tea time bolus always brings it back down again, so nothing disastrously wrong, but I want to know why it's going up! 3 weeks ago daughter had potato balls with her dinner which I somehow forgot to give her a carb count for, which meant she didn't bolus for it, oops! So I thought that might be the problem that time. But 2 weeks ago she didn't have potato balls and the rest of the food was counted correctly, and last week she did have potato balls again but we remembered to count and bolus them that time.

Nothing in her timetable jumps out as being a potential problem, on Wednesdays she has Science, PE, Maths, lunch, Drama, English. Cookery lessons are on Tuesdays, so unlikely that she's having sneaky snacks and forgetting to bolus for them. Everything except drama she has on other days too with no problems, can't imagine that drama lessons would be an issue? If her basal or carb ratio needed a tweak I'd expect to see similar problems every day, not just Wednesdays, and I find it very hard to believe that we might have had cannula failures at exactly the same time on three successive Wednesdays! Unless moving about in the drama class is somehow dislodging the cannula, but she moves around more in PE and that doesn't usually cause problems (apart from the one occasion when she managed to yank the cannula right out in a PE lesson - ouch)

Hmmm, I'd love to know what's doing this but there's a definite touch of the diabetes fairy about it I think! Will be interesting to see what happens today

 

[Pumper_Sue]

Hmmm, I'd love to know what's doing this but there's a definite touch of the diabetes fairy about it I think! Will be interesting to see what happens today

Just a thought, is the timing of her bolus different?

 

[trophywench]

What's she having for lunch on Wednesdays?

 

[Sally71]

Bolus timing the same every day, she goes to the medical room, does bolus, goes to dining room and jumps the queue to get her food, and we always order the food in advance to make sure she gets what she has bolused for. Lunch is earlier on Wednesdays for some reason, but she had the earlier lunch time all last year with no problems and when they occasionally moved her to a later one it didn't muck things up. So I'm not convinced that's the problem, it doesn't change the carb count or carb ratio.

Food varies, last week she had a chicken wrap, potato balls and a cake. The week before I think it was a slice of pizza and a cake. (They do do healthier options such as roast dinner but she says the portions are huge and she never chooses them!)

Before 3 weeks ago we didn't have this problem, and I'm pretty sure nothing has changed since then, it's bizarre!!
Oh the fun and games you get with diabetes 🙄

 

[Pumper_Sue]

I wonder if your daughter needs a split/combi dose for the pizza and cake mix? It could be a lot of fat in the meals causing the late onset spike.

 

[Sally71]

Possibly, that might be worth a try, although the meals are pretty similar the rest of the week too, on Fridays she usually has pizza followed by jam or syrup sponge and custard, and no spike!

 

[Sally71]

Hurrah! The curse is broken - she's come home tonight with a reading of 8.2
Let's hope that's the end of it, although I am still none the wiser and might have to chalk it up to "one of those things"...