Any advice on the issues we are having with the TSlim?

Hi all,

My son, age 11, was on the Cozmo for 4 years (LOVED IT) and the Medtronic Minimed for 4 years (wasn't wild on it.) He just recently started on the TSlim. Also we love the design, we are having some issues. This is only his first week but we are having enough issues that he wants to return back to his old pump.

1. When drawing the insulin into the syringe (before adding it to the cartridge) it is difficult to pull in without lots of air bubbles. The pressure is so great when drawing in the insulin, it's hard to not get huge amounts of air. Difficult to describe! :)

2. When filling the tubing we always see a lot of little air bubbles in the beginning of the tubing that just seem to hang out there and float around.

3. He has had more high blood sugars this week than he has had in his whole life. When we "correct" with the Tslim, it's like we have to correct over and over again for any response. For example, we did a fresh site change, his blood sugar was 350. He corrected (the correction factor is set up correctly) and it delivered 4 units of Apidra. He rechecked in 30 min and was still 350. So we corrected again with 3 more units. Rechecked 30 min later and was still 350. We never ever had this type of thing happen with our Medtronic Pump. This pattern has happened 3 times this week. One time we resorted to injections b/c we just got so frustrated.

4. We are using the Cleo sites for the first time. HATE THEM. We go through 2-3 sets each time in attempt to get them to stick. Very annoying. What sets are others using? Do the Medtronic Quick Sets work with the TSlim?

Thank you for any input on what might be going wrong here! I am not sure if it's the CLEO sets, the Apidra, air bubbles?

The syringe issue is a new one. I am assuming that you are drawing up air…injecting into vial…pulling out equal amount of insulin. I have slowly put insulin back into vial, the back out when noticing bubbles. As for trying to avoid bubbles after installing the cartridge. Slowly fill, slowly withdraw some insulin, slowly put it back in. Sounds time consuming when written; but it’s not so much. Hopefully this helps. I use insets by Animas. Love them. They also come in blue!

Oh, about the syringes, sounds like a bad batch, if it’s several. I did have one that seemed like it needed lubricating. It actually broke leaving that rubber stopper separated from the plunger. I usually move the plunger back and forth before use. Whoa, just noticed the mention of Apidra. People have been cooling their pumps by placing on gel packs during charging. Tandem does not advise Apidra in the t:slim. Your rep should have mentioned this.

ive used the cleo for years - try skin prep before you put it on

If you were using a longer or angled set before make sure you have the right cleo now. Also make sure you are not in scarred up or over used real estate for the site.
Try a correction with the cleo disconnected . does it deliver 4 units ?
if so then the pump and tubing are OK - the site may be in a bad area ...

I've only got a few weeks of experience, but here's my 2 cents:

1. Vials are sealed, right? So when you try to pull out 300 units all at once, you create a giant vacuum inside the vial and end up with bubbles inside the syringe. Injecting half a syringe full of air into the vial first makes it a lot easier to get the full 300 units out without a big bubble problem. Also, once your syringe LOOKS full, tap it a few times and (while still poked into the vial) push a few units back in to make sure if you have a bubble, it goes back into the vial. I don't usually see a bubble with my eyes, but I regularly push one back in when I do this. I think they get in between the needle part and the syringe, but I don't know how that happens.
Also helpful, once you're done filling the resevoir/cartridge, take the plunger out of the syringe and poke it back into the vial (right side up, hold it right side up for this part) so the vial can equalize pressure and the next round is easier to start.

2. I also have tiny bubbles in the first part of the tube, and I figure that as long as they stay there (and so far they seem to), they're a non-issue. If insulin can and does get past them, then they aren't in the way or turning into a bubble-bolus.

3. Apidra and Tandem don't get a long very well. There's a good article discussing this very thing on Diabetes Mine today. There's no great answer to why, and it doesn't happen with everyone, but in general, don't mix apidra with a t-slim. Novolog and Humalog both seem to fare much better.

3. Although I understand being so high is frustrating, waiting only 30 minutes for a correction check isn't very long, most sources I've read say to wait at least an hour, although some of that used to be in order to prevent stacking corrections, but the other part is that insulin just doesn't work that fast in general. On a related note, it can depend on what caused the high... if its from 4 hours of missed basal due to a bad site, and assuming a 3 hour active insulin time, then it will be 3 hours AFTER plugging back in that the time-lag from all the missed insulin is over. Frustrating, yes. Lastly and most unfairly, you know your glucometer only has to be within 20% to be considered accurate? That means a reading of 350 could really be 420, and a second reading of 350 could really be 290. Not helpful, but keep in mind that especially on the higher end, numbers are not very accurate.
That its happened 3 times in the last week though, thats suspicious. Although might be very closely and directly related to....

4. Infusion sets! There's a billion different kinds out there, so if you have one you hate, get a different kind. Curses to MM for their "proprietary connection" system, you can substitute almost any other brand, EXCEPT theirs. Here's a good comparison chart between brands: (any that have a "luer lock" connection will work).
Most supply companies will let you exchange unused sets, and many will send samples too so you can try a few out before ordering a whole box.
I personally really like the cleo sets, I think sticking the tape first and then stabbing the needle is much friendlier than shooting the tape and needle together, and at least for me, it seems to make a more stable insertion because the tape is already stuck to me. My common problem is that things stick too much, and I get a big rash though, so maybe that I like these means they are a little less sticky? If they worked for everybody though, there wouldn't be so many options! If you still can't find any that stick, you can look into skin prep and similar "tape helping" stuff (skin prep, mastisol, etc).

My guess, having just gone through my own "adjustment period" (new pump, new tools, new sets) is that the high BGs are a combination of problems, and with more time and tricks up your sleeve (sticky stuff for sets, air in the vial) some of them might go away and you'll be fine. Talk with your endo/physician/CDE about Apidra though, and call your supply company about new sets. And, always call Tandem and report problems even if you don't know what caused them, because if they don't know what we're getting stuck on and stuck with, they can't improve the next version or issue better advice.

Lastly, there's no law that says you have to struggle through with a new pump if the old one still works. I didn't get a long with my MM system, so I was very happy to upgrade, and for me the first few weeks of trial and error were well worth it, but if it isn't working for you, there's no reason to force the issue.

Good luck!

Another suggestion is to switch to another box of cartridges with a different "Lot" number. I had issues with a "bad" lot of cartridges and changed to another box and the issue was resolved. I called Tandem and they gladly replaced the box with the issues.

I had problems with the Cleo infusion sets and switched to the Inset (used with Animas) and love them (they are similar to the MM Mio infusion sets). They stick really well, haven't had one come off yet!

When beginning to fill the tubing, there seems to always be tiny bubbles coming out of the cartridge into the pigtail (small tubing leading up to the Luer lock) and collect in the luer lock connection. Just when they reach the next portion of the tubing I give the luer lock connection a flick with my finger to make the bubbles go into the tubing so I can prime them out of the tubing before I connect the infusion site. My tubing usually remains bubble free after that.

I also had a situation when waking up at 400+, I had noticed that when I disconnected from the infusion site, there was a large gap of insulin just before the infusion clip (used to clip into the infusion site). I checked the tubing and found the luer lock connection leaking insulin. This has happened to me twice so now I check the connection first.

I was having difficulties for the first few months and Tandem worked with me all the way through. The customer support was very dedicated. I would report all the issues you are having to them so that they are aware of them and can assist you through the transition.

The insets (Animas) manufactured by Unomedical, actually have an all-in-one inserter. This is the infusion set that I use.

Hello and welcome.

I agree with the others that 30 minutes isn't that long of a time to wait before doing a correction. I too was not a fan of the cleo's and went back to the Animas insets.Since doing that, I've gotten rid of all my problems and all i swell here. Did you go to the training with the educator? My educator brought to my dr's attention that it might be better to change my correction factor. We did that and I've been pretty awesome since. I agree with Janice and would say try switching to Novolog and trying that out. I've had great success but it's because I've had novolog before. If your little man has never used it, it may be a different switch. But for sure get rid of the Cleos

Try drawing the insulin in more slowly. This will prevent the bubbles. Also if you inject air into the insulin vial and then just let the insulin fill the cartridge by the pressure, it will fill with no bubbles, you just need to be more patient because it takes about 30 sec to fill this way. I think the fill needle is too small. I have had the same trouble with the MM cartridges. The Animas however has a nice big fill needle where I never had trouble with bubbles.

I am only in my second week of using the t:slim but what I have seen so far has been a great experience for me. I am not having a problem with air bubbles and the other posters have given good advice for solving that problem. In addition to pulling the plunger back with the amount of insulin you will draw out of the vial, I would add that when you fill the cartridge, make sure the t:slim is standing up. This is mentioned in the manual and I think this helps the pump eliminate the bubbles that may be in the cartridge. I also fill the cartridge very slowly. So far, no problems with bubbles.

The highs you have are worrisome, indeed. When I saw you were using Aprida red flags went up! Go to the Tandem site and read their findings. They don't recommend using that insulin with the t:slim. I use Humalog and find it is working just fine. I have cut back on the amount I use for a correction bolus. I was going low after making a correction. I may end up reducing my basals as well during certain times of the day. I am seeing the tendency for lows on occasion and I think the micro-delivery of insulin on this pump is also much more accurate as well. Where I was probably compensating with the inaccurate and antiquated plunger system of the Ping (and MiniMed) before, now that is not necessary.

If you try all this advice contained in the post and still have problems, make an appointment with a Tandem rep. There has got to be something simple to remedy the situation.

Like I said, I have only been using the pump for a couple of weeks but I find it a great improvement over the Ping. This thing is so easy to use and program. Having the insulin on board information on the home screen is worth a million bucks to me. I'm not missing all the excess button presses to perform simple tasks. Tandem has done their research and has done it right.

Did you figure your problems on the T:Slim? Was it the sets or the insulin?
Are you still using T:Slim or did you go back to Minimed?

No issues at all anymore with T-slim! We changed to Humalog insulin and we use MIO insertion sets, and everything has been working perfectly!

So you were using Apidra? Are you using Insets or Mios?
Are bubbles in the tubing easy to prevent?


We are using Unimed? Insets (guess they are the same thing as MIOs?) No issues what so ever. We did also change from Apidra to Humalog, so not sure what solved our issues but so far so good. That being said, our pump did break last week. Just out of the blue, so Tandem sent us a new one. Hope that was a fluke as we've only had the pump for 5 months.

We are using Unimed Insets, and they work great.

In reply to myself - one more mote - when you say you are having trouble with the cleos sticking- do you mean the set sticking to you when you insert it ? Meaning getting the inserter to release from the set ? if so many years ago I got a box of cleos that wouldn't release for anything, a Smiths medical rep back when they existed told me that if you use your finger to loosen one corner of the set from the inserter BEFORE you try to apply the set peeling it back after you apply will be MUCH easier. So every time now I simply look at the set when I uncap it and at the 3:00 position from the little remover tag I stick my finger to the edge of the set adhesive and pull it up a little- doesn't take much - then when I insert the set I just roll it away from the skin on that side and it comes right off - easy - no drama... doing that and using skin prep keeps them on in Texas heat. In the summer I cut a small piece of hyapix - fold it in half then cut a triangle out of the folded edge . when I open it I have a diamond shaped hole in the hypafix that goes over the cleo to help hold it on. Its stays on thru 3 days of scuba diving to 100ft, water skiiing anything I can throw at it .... hope this helps

HI there - Today is my first day wearing the t-slim! I practiced loading it 5 times with saline, no bubbles. Then when I put in the insulin....bubbles! It doesn't seem to be blocking the flow at all. I called 1-800-Tandem and they also told me to keep the cartridge upright and then tap it, which helps get any bubbles to the top so that they could be primed out.

I have to second your post (although I know awhile ago) on the Cleos. I hate them too! I just realized that Medtronic makes the quick-set (which I was using prior) with a luer lock now, so I might go that route because I know I have had success with it. I called Animas to try to get some samples of insets but thy would not send me any without a prescription. Maybe I'll ask my tandem rep for one.

Yup. I've had good luck with the insets, too. And you can get them in 90 degree needles or 30 degree. They both have very easy to use inserters and luer locks.

It has been some time since you posted your problems with the t:slim. Are they resolved?