# Insulin delivery when cartridge gets low



## Phil65 (Jun 7, 2011)

I'm a little confused as to why the delivery of my insulin seems to be affected by a low level of insulin in my cartridge.....for instance my BSs seem to rise when my cartridge gets to about 60 units left.  It doesn't seem to deliver the amount that I require, I use a cartridge every 2 days and change my insertion set and cannula at least every 2 days sometimes every day, I'm coming to the conclusion that I need to change my cartridge once it gets down to 50 units! This happens regardless of the time of day.  Does anybody else have this problem?


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## Freddie99 (Jun 7, 2011)

What insulin do you use? As I understand, Apidra isn't as pump friendly as say Humalog and Novorapid. Maybe your sets are beginning to ware out or become too old at that point? Absorption might be an issue. One thing I find, with reservoirs that I've put in sans bubbles that after a little while with my body heat applied some do develop. Perhaps you're getting a few air bubbles towards the end of your reservoir?

Tom


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## Pumper_Sue (Jun 7, 2011)

Phil65 said:


> I'm a little confused as to why the delivery of my insulin seems to be affected by a low level of insulin in my cartridge.....for instance my BSs seem to rise when my cartridge gets to about 60 units left.  It doesn't seem to deliver the amount that I require, I use a cartridge every 2 days and change my insertion set and cannula at least every 2 days sometimes every day, I'm coming to the conclusion that I need to change my cartridge once it gets down to 50 units! This happens regardless of the time of day.  Does anybody else have this problem?



Hi Phil,
as Tom says Apidra does have a problem in pumps, if that's what you use.
But 60 units is not a low cartridge  it's more than 3 days worth of insulin for me 
When you say it doesn't seem to deliver, are you saying you are bolusing and it's not bolusing that amount or are you saying x delivery doesn't seem to work for some reason?
If you think the pump is not delivering insulin then ring your pump company and they will go through things with you and replace the pump if a problem is found.


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## Phil65 (Jun 8, 2011)

Pumper_Sue said:


> Hi Phil,
> as Tom says Apidra does have a problem in pumps, if that's what you use.
> But 60 units is not a low cartridge  it's more than 3 days worth of insulin for me
> When you say it doesn't seem to deliver, are you saying you are bolusing and it's not bolusing that amount or are you saying x delivery doesn't seem to work for some reason?
> If you think the pump is not delivering insulin then ring your pump company and they will go through things with you and replace the pump if a problem is found.



Hi Sue, I use novo rapid.  When I bolus with a cartridge with about 50 units or less left in it, I have a problem ......my BSs do not drop post bolus as they would normally, they drop a bit but not as much.  My cartridge only lasts me 2 days, I need a lot of insulin!


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## Phil65 (Jun 8, 2011)

TomH said:


> What insulin do you use? As I understand, Apidra isn't as pump friendly as say Humalog and Novorapid. Maybe your sets are beginning to ware out or become too old at that point? Absorption might be an issue. One thing I find, with reservoirs that I've put in sans bubbles that after a little while with my body heat applied some do develop. Perhaps you're getting a few air bubbles towards the end of your reservoir?
> 
> Tom



Hi Tom, could be an air bubble problem,.....like you say there isn't when I first prime it!


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## Pumper_Sue (Jun 8, 2011)

Phil65 said:


> Hi Tom, could be an air bubble problem,.....like you say there isn't when I first prime it!



Hi Phil,
the easiest way to check bubbles is to hold the tubing against a dark background i.e, trousers. With the amount of insulin you use it would be best to do this before meals and bedtime.

How much are you not dropping? Is there any routine change on these days? IE, not so much exercise on the days where there is a problem?
I'm just trying to throw dif thoughts about to see if anything clicks anywhere.
If nothing springs to mind and you have checked with the pump company that your pump is ok, perhaps a dif carb ratio would help on these days if it always happens.


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## Twitchy (Jun 8, 2011)

hiya, I've not had anything like this (having run the cartridge nearly dry the last few times, eek!), but if it's always happening at around 50u or less I would at least call the pump company to run it by them - it starts to sound like a technical issue if (as it sounds like) you have ruled out coincidental issues / factors that would normally account for the lack of post bolus drop... is is a new pump, has this always happened with it or has this pattern started recently?


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## trophywench (Jun 9, 2011)

Wonder if it's an iffy batch of cartridges, Phil? that get's 'sticky' at that point in the tube?

Is it one of the 'odd' ones you brought home from the hosp, or one out of a box you got yourself from Roche?

Have only got through 1.5 since I had my pump the other week so am hardly expert, but it did used to happen with syringes from time to time and I've even had it with the odd prefilled Flexpen over the years that utterly refused to budge and have had to bin.


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## Pumper_Sue (Jun 9, 2011)

My pump delivery started to mess around awhile back at the 20 unit mark. Messing around as in no delivery when I bolused. Obviously the 2nd time it did this a replacement pump was sent and the cartridges were sent back as well for testing.
When I spoke to my pump company I was told it was probably something to do with the gears (I think) I very non techi. A replacement pump was sent out the same day. It hasn't happened since


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## Phil65 (Jun 9, 2011)

Thanks for all your ideas and comments, I am still a bit dumbfounded!  There appears to be nothing wrong with the pump, I have changed cannulas from teflon to steel, I have tried 6mm and 8mm. I change my cannula at least every 2 days, often I change it every day if I get consecutive high readings.  My insulin/carb ratio is definitely correct.....I'm still playing around a bit with my basal but sure that is not the problem.  I've only had a couple of 'sticky' cartridges in all that I have used and I am sure that it is not a bubble or 'kink' problem but for some reason an absorbtion problem. It's not all of the time just sometimes! Usually on the second day of a cartridge/cannula/infusion set


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## Pumper_Sue (Jun 9, 2011)

Phil if it's around the same amount it messes around each time than I would suspect the pump is jamming at that level so needs replacing.
Save the NHS some money by ringing your pump company for a replacement pump instead of chucking all those cannulas out. It will get to the stage when the pump will malfunction completely then you are stuck with no pump until a replacement arrives.


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## Ellie Jones (Jun 9, 2011)

Phil

It could be that you have insulin residue on your pistion rod!

The way to check this is when you change your cartridge, you have to check your manual on this if you'll using a different pump to the accu-chek Combi

With the combi

When you get to the bit that you can adjust the piston to suit the amount in the cartridge, take the counter back to zero so the piston is full extended, then look at the rod, if there's any insulin residued on the pistion this will show up whiteish in colour..

If you do or even if you think that there might be, then shunt the pistion back and forth several times to see if this clears it..

If you got a really noticable amount on the piston rod, then give customer services a phone to see how to clean it safely and/or arrange for it to be returned to be cleaned and checked..


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## Phil65 (Jun 10, 2011)

Think i've sussed my problem.........i reckon that sometimes i insert my cannula in an area that has lippy......lumpy tummy!  so am now going to insert in the side or towards my back.  Had an awful day today.....in the 20s for about 5 hours......ok now though.  my muscles in my arms were like lead weights and cramping, never felt anything like it before!!


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## trophywench (Jun 10, 2011)

Phil I had that prob with cannulas no 2 and no 4, and I'm only on about no 6 as I type this LOL

I mean in the past it would just be the occasional one out of 5 jabs in a day that got into a lump.  And we'd go, Oh heck, wind must be blowing the wrong way this morning and get on with it.  Now we are pretty much up a gum tree without a paddle when we hit an iffy bit, with no Lantus or Lev to fall back on and help us out.  Second time it happened I actually bolussed by pen somewhere else and that worked properly so I changed the thing a lot quicker than the first one it happened with.  And yes, it's vile isn't it, I thought I must be getting flu first one, and that was why my BG was stupid!  LOL

We'll get there ... it might take time, but we'll get there .... !!!


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