MM Sure-T and Insulin Pump Resevoir

I am wondering what I should do in this situation. I am using the MM Sure-T Infusion set and my trainer says I need to change the set Every 2 days instead of every 3 days like with the Mio infusion set. I currently fill my resevoirs to 3 ML per my trainer and I am seeing that after 2 days I still have over half the resevoir full of Insulin…Should I go ahead and change everything out OR, could I just change out the Infusion SITE keeping the tubing connected to the resevoir? I see on Medtronics site that they sell just the sites for those who have no problem with the tubing…Should I do this or just go ahead and change out everything…My supplies are covered 100% by insurance…Thoughts?

I just change the cannula, leaving the tubing on the pump and then bolus a .5 to fill the cannula. I only change the reservoir (cartridge) every 6 days.

Depending on whom you talk to, you will probably get one of three responses.

  1. Change everything.
    This is ostensibly the “safest” approach since you are starting fresh and eliminating any possibility of contamination no matter how minuscule that might be. It is what I would expect the health care folks and pump and insulin companies are likely to advise. No doubt they do this simply because it is safer for you and not at all because they don’t have to pay for anything and only want to make sure that they “aren’t blamed”. :smirk: (Yes, I’m a cynic.)
  2. Change the infusion site (i.e. the needle) but continue to use the same reservoir and tubing.
    I believe this is the approach you outlined in your post. The principle objection I can see to this approach is the possibilities of wear of the tubing or possibly air bubbles coming out of solution in the reservoir or tubing. In my personal opinion, that is a minor risk and something you could check for & correct. But it’s also a matter of personal preference.
    Some may worry about the potency of the insulin in the reservoir. But in my experience the insulin in the reservoir will not degrade significantly over a short period of only a few days at essentially room temperature. I would only be concerned if your insulin was somehow subjected to a much higher temperature for a period of time. I expect that you’d be aware of that if it happened and take it into consideration.
  3. Change the site and the tubing but continue to use the reservoir until it is empty.
    This is the approach I use. I have been told I’m making too much work for myself because I use the tubing of the new set and need to prime it from my partially used reservoir. But I view it as a personal preference. I don’t see enough of a benefit to prefer using the old tubing. I would rather just throw out the old tubing. Since I use the shortest tubing available for my set, I don’t lose as much insulin by throwing out the old tubing.
    I use one of my old reservoir plungers to fill the tubing from the partially used reservoir. I then use the “Fill Cannula” function of my Paradigm 723 pump to advance the pump’s plunger until I can see insulin drops coming from the business end of the infusion set. I don’t rewind until I use up the reservoir. Using “Fill Cannula” is slower & somewhat tedious, but I think it also gets more life out of a pump battery.

Why does your trainer say this? Have you experienced absorption or other problems if you wait for 3 days to change your site? Are you concerned about scar tissue? Personally I would let the site tell me whether or not it needed to be changed sooner than 3 days. If I’m having problems, I change it sooner. If not, I go the 3 days. But your mileage may differ.

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I have used MM pumps and Sure-T sets for 8 years, and have always changed after 3 days. No problems! I have scar tissue on my upper ab from 62 years of injections, before I started using a pump, so I don’t use that body part now. As long as I use body parts that do not have scar tissue, I have no problems with using sets for 3 days. None of my doctors have ever suggested I should change every 2 days.

change your set when you run out of insulin. No need to change after two days, unless you need to refill the reservoir. If I use an extraordinary amount of insulin from time to time, I will refill the reservoir and continue to use the same set if it hasn’t been more than 2 days. that is a rare thing for me to do, mind you.

Any trainer or doctor (or sane person) will tell you not to do this, but here’s what I do. I change the site when it stops absorbing properly. Seriously. I’ve left them in for as long as week (and as little as maybe a day). If I have a really good site, I will re-fill my cartridge if I run out of insulin. If I have a site that isn’t working right, but a full cartridge, I’ll just change the site (sometimes I just move the needle and use medical tape). I also keep my insulin in until I run out and have, as of yet, not had a problem with potency. I think it’s all personal preference. I understand the risks I run by leaving my site in so long. I’ve also talked to people who leave theirs in much longer. So, basically, I change things when they need changed and fill things when they need filled and kind of wing it. If you wanted to change everything out every two days, couldn’t you just put less insulin in your reservoir?

I’m also curious why your trainer said every two days. I use the Contact Detach (about the same thing, I think), and I was told 3 days by my CDE and ends.

Perhaps a holdover from when Sure-T’s were first put on the market, ostensibly for kids. Their immune systems apparently may reject the metal sets before 3 full days, so the recommendation was to change them every two days. The 2-day set change just kinda stuck as dogma.

@irrational_John laid out all the options except for the one I use :smile: Draw less insulin into the reservoir. I use about 24u/day, plus 10ml to fill the tubing, plus a one day margin is about 85ml for a 2 day run. I keep going with it until I run out of insulin.

My endo switched me to 2 days instead of 3 because I had a couple of cases of ‘tubing blocked’ messages that wouldn’t clear. Medtronic had me ship back one of the infusion sets to have the engineers make sure it wasn’t a manufacturing defect. I typically get 3 days out of my set without any issue, but every once in a while still get a ‘blocked’ error and need to change sites.

I do change everything, and I feel guilty about the waste. I feel 100% safe reusing the tubing between the reservoir and the steel needle, and I do that specifically to reduce waste when I go on holiday where I have to pack my supplies in and pack my waste out. I have reused the reservoir, but have a nagging worry about pushing old insulin back into the supply vial. I have also reused the steel needle when I pulled it out, but not specifically so I could extend the life of a set. I’ve used both Mastisol to get it to stick, and IV3000 tape patches.