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Approved for pump - which size please?

ChrisMaleType1

Well-Known Member
Messages
115
Location
North West England
Type of diabetes
Type 1
Treatment type
Insulin
Hi everyone, I've recently been approved for an insulin pump and it will probably be the medtronic one. I'm just wondering which size I should go for? There are two sizes, a 1.75 ml and a 3 ml. The dimensions are very similar for both, the only difference being the larger one is about 1.5 cm longer. I tend to eat a bit of chocolate in the evening and bolus for that so I take about 50 or so units of novorapid a day and currently my basal is 9 units. The manufacturer advice is to go for the larger pump if you take over 50 units a day. When I told the nurse how much insulin I was having each day she said definitely go for the bigger pump. She then said that I would have to change the resevoir every three days at the same time as changing the cannula. The thing is, I don't know if she was accounting for the fact that my insulin dosage is likely to go down - because I'm on a pump.

If I followed her advice and went for the larger pump could I just fill the resevoir to whatever level I wish (I know they also take the smaller resevoirs) to save throwing away any insulin. It's probable that a 3ml resevoir would last me 6 days or so so should I just change the resevoir when empty? If I went for the smaller pump, it's quite possible that it would last me three days - 60 or so units minus 20-25% (for being on a pump) times 3 equals about 140 units so perhaps I should go for that one?

If I want the smaller pump I'm going to have to call the nurse to ask her to change it (she might not be willing) so I'd really appreciate everyone's advice. Thanks very much.
 
Hi

If you are using about 50u per day on MDI, then on a pump you will need approx 20% less (sometimes slightly less) so that will give you about 40u per day. If you multiply that by 6 days = 240u. You will also have to add on some extra insulin to allow for the priming of the length of tube you are using (which can be used for about 6 days with no problems), a bit more insulin for priming either 2 or 3 infusion sets per week (this depends on whether you are using a set that needs to be replaced every 2 days or one that can be left for 3 days) and also you will have to allow for some spare insulin in the cartridge to flush out any air bubbles that might appear. So with this in mind, its probably better for you to have the larger pump that will hold 300u of insulin. You wont have to chuck insulin away as you will get to know exactly how much insulin you will need to draw up before it goes in the cartridge. It's better though to have too much than too little. I would imagine that you should be able to draw up about 280u of insulin with no problems and that will probably be ok to last you 6 days. Even if there is insulin still left in the cartridge at the end of 6 days, you can still carry on using it until its all gone. If you go for the smaller pump, then yes, you will have to fill the cartridge probably about twice per week instead of just once for the larger pump.

Hope this helps you decide.... Have you had a chance to actually see the larger pump and compare it to the smaller one?
 

Go for the bigger cartridge (300u) this will cover you for any increases in insulin needs when ill on not active.
Please also note you do not need to change the cartridge at the same time as the cannula. That's a dreadful waste of insulin and a cartridge.
There is also no reason not to use the cartridge for 6 days either. Many do and quite often for longer. I have been told insulin starts to degrade after the 6 day mark once put into a cartridge. Personally I haven't noticed it doing so. The analogues are licenced for 6 days in a pump anyway.
I use about 20 units a day total and fill my cartridge full (200 units) and replace when empty. I also did the same with my previous pump which had a 300u cartridge have never had a problem.
Happy pumping
Yes you can put what amount you want in the cartridge
 
Thanks for both replies, they're very helpful. I guess I'll probably stick with the 300 unit one. I've seen the bigger pump I think (and worn it for a few hours) and it really is quite small so I think I'd be happy with the bigger one. I'm getting it in a couple of months and I'm really looking forward to it. I'm getting it because I have too many hypos and that's because I like really tight control. I find it really difficult to do anything active without having a hypo so I think this is where the pump will help a lot. Cheers everyone.
 
Great news about the approval Christopher
 
Hi Christopher,

Good news re the pump. Let us know how you get on with it,

Lucy xxx :thumbup:
 
Interesting read this as I was told from the outset to change both the cartridge and cannula at the same time. I only fill the cartridge to cover the levels I'll use over 3 days so I'm not wasting inuslin - but I guess i am using double the amount of cartridges than you. I've got a Medtronic Minimed pump - would anyone know if I kept the same cartridge over 6 days and only changed the cannula would I go through the exact same options on my pump menu as I would normally?
 

Hi

'
It's a safety precaution Riri so that the pump company can cover themselves if people get problems with what might appear to be down to insulin 'going off'. There is no real need though to change cartridges every 3 days unless the weather is really baking hot but even then, insulin is still ok to be used. People just have to be guided by what their bg levels start to be. Also though,..... it is thought that insulins like Humalog and Apidra will have a tendancy to cristalise in the tube if insulin is being used for longer than 3 days. The only insulin that I know of that doesn't have this tendancy is Novorapid so that is probably why so many pump companies favour it. Loads of people use Humalog and Apidra in pumps and although they might have started to change cartridges and tubes every 3 days, I dont think that they have carried on doing this unless they have experienced problems. So... leave changing the cartridge until 6 days and just change the cannula. The procedure - priming etc will be exactly the same as before.
 

here you go this is for humalog http://pi.lilly.com/us/humalog-pen-pi.pdf
Continuous Subcutaneous Infusion Pump
Change the HUMALOG in the reservoir at least every 7 days, change the infusion set, and the infusion set insertion site at least every 3 days. HUMALOG must not be mixed or diluted when used in an external insulin infusion pump. (2.3)

Novolog http://www.novolog.com/insulindiabetes/novologpump.aspx

Apidra http://products.sanofi.us/apidra/apidra.pdf Pump use change the apidra every 48 hours in the pump cartridge/reservoir.

Hope that puts your mind at rest
My PCT insist that a cartridge be used for 6 days and will only permit the ording of this amount of cartridges.
 
I use Apidra which is only licensed for 48 hour use, in the winter it's fine for the 6-7 days usually use a reservoir for but I have found that it doesn't seem to last quite so well in very hot weather (+30)

(I wish I could get it through to my 'pump nurse' that I normally only change the reservoir every 6-7 days. After 4.5 years I have so many boxes of reservoirs that I'm quite embarrassed about it )
 
phoenix said:
(I wish I could get it through to my 'pump nurse' that I normally only change the reservoir every 6-7 days. After 4.5 years I have so many boxes of reservoirs that I'm quite embarrassed about it )
Click to expand...

Perhaps a novel Christmas pressie for your pump nurse Phoenix? :lol:
 
Thanks or your advice. I will look to swapping cartridges every 6 days from now on and monitor things.
 
I use humalog insulin and in over 4 years of pumping I've never experienced it crystallizing in the tubing, I fill my cartridge up 300ml, and that takes me almost a month to use.. So plenty of tube/infusion set changes..

I've only had one cartridge go off on me, but that's because I kinda of baked it, when sitting out on a rather hot sunny day and hadn't realised that my pump was in direct sunlight, was rather hot to touch when I realised!

I was never told to change my cartridge when I changes infusion sets, nor was I advised that I should fill more than 6 days worth of insulin into the cartridge.. So always filled it up full, change when it's empty.

I have the Combo pump, and my tenderlink infusion sets come in two different sets, either the complete version, infusion set and tubing, or just with the infusion set.. And you use the full set, every other time, so tubing changed every 6 days.. But on occasions I have used the same tubing for 9 days without problems, 12 days started to hit problems due to the tubing creasing too much near the pump connector, restricting flow.
 
I get through 200u in about 2.5 days so it works out well for me. I'm either changing it before breakfast or before dinner so i have an immediate bolus to confirm that there are no problems with the new canula.

not sure why the waste of insulin is a worry though? You have to prime the thing anyway and thats not a waste...

also, don't forget that after 3 days the insulin binds to the plastic in the cartridge so is less effective anyway
 

Hiya,
you will find that the insulin can be used for 6 days as has been tested and approved to do so.
 
CarbsRok said:
Hiya,
you will find that the insulin can be used for 6 days as has been tested and approved to do so.
Click to expand...

Can you link me to proof of this please? My consultant is adamant on this point....

Kinda academic for me as i'd only get 4 days out of a 300u anyway but i'd like to understand why doctors fib about stuff like this?
 

Here you go viewtopic.php?f=14&t=31773 if you read down the page you will see the links to the time insulin can be used.
Perhaps your consultant hasn't kept up to date so is just going by the old recomendations
 

Thanks for that. I think we may be talking cross-purposes though. I've not been told to change every 3 days because the insulin is no longer usable. The reason to change has been linked to the insulin binding to the plastics in the cartridge, rather than the insulin 'going off'

I wouldnt't call my consultant out of date - far from it as he is a leaing research fellow at Liverpool University.

Has anyone else been told about this binding problem?
 
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