Infusion set problems scaring new pumper back on MDI

Hi all, I’m a 63 year old T1 diagnosed 32 years ago who decided to try pumping. After five weeks I am forced to stop and reconsider.

I’ve done well on MDI for years so I have been waiting for a commercially available loop pump to make the jump to the pump. My endo suggested tSlim X2 with CIQ and I started using it mid September. It worked fairly well right out of the box with settings transferred from InPen. My numbers improved significantly and all the promises of pumping were coming true, until infusion set problems brought me to my knees.

I started with the Autosoft XC 90s. First one, Great! Second one I went to 450 mg/dl within 4 hours of insertion. It was a Friday night and I had no support, had no idea what was going on. I finally pulled it out and found that the cannula had folded over upon insertion. I fixed myself up with an injection and put another set in, being very careful with what I had already decided is a poorly designed auto inserter. This third set worked well. I decided that I would not eat a substantial quantity of carbs until a new set had proved itself. My logic seemed sound: if it is inserted and works no reason it won’t continue to work for the full 3 days. My fourth set worked great too, for the first day and a half. Then my sugars started climbing and correction boluses had little or no effect. I suffered in bewilderment for another 12 hours and pulled the thing out on the morning of the day 3. I smelled insulin and it was damp under the adhesive pad, a puddle almost. I queried my tandem trainer and the NP at my endo practice and they would not confirm that these types of sets can leak (that’s a whole other discussion). So I kept putting them in and went on vigils staying up late after insertions to try and determine if insulin was actually getting infused. Half the time I had to pull them out early and they smelled of insulin and/or were damp or wet. A two week nightmare. I finally found info on a website (I think it was that described “tunneling”. Bingo.

I switched to TruSteel 6mm, the logic being that the insulin will have nowhere to go but in me! I was back in dreamland for the first one or two of these steel sets. Then I started having pain at the infusion site when I did a bolus. Not terrible pain, but enough to say “ooo, what the heck”? I queried NP and trainer and they again came up stupid. The pain got more pronounced and I noticed swelling and tenderness where these steel sets has been placed. I called Tandem and it being Saturday (of course) they told me a clinical specialist would call me Monday. I tried one more set and the very first bolus hurt. I pulled it out on Sunday and went back on MDI. A nurse did call me the next day (this past Monday) and she diagnosed my problem as a nickel allergy. Evidently all stainless steel needles contain some nickel. No more steel, ever.

The Tandem nurse suggested I try VariSoft infusion set, 13mm. Upon discussing with endo, I find that these are usually a last resort for very skinny people. I’m 5 foot 6 inches 185 lbs - technically I am obese! The idea of stuffing these harpoons sideways into my already stressed out flesh is not appealing. There is a 9mm Autosoft XC but the nurse seemed to think this would not be good for me.

So I don’t know where to go from here. Last Sunday I was ready to give up the idea of pumping altogether, but after a few days back on MDI it feels like trading my 50 inch flatscreen for a 12 inch black and white TV.

I also really disliked having a tubed pump more than I expected. I’ve been looking at Omnipod 5 today and thinking of ditching the tSlim and trying it instead, after my infusion sites calm down. It has a 9mm plastic cannula inserted at an angle that goes in to a depth of 6mm. Maybe it won’t tunnel? Or maybe I am just a glutton for punishment?


This can happen if you pull up the cannula cover off and it pulls up the cannula too. To prevent this, always gently twist the cannula cover while removing cover. Inspect that the needle still extends above cannula before inserting.

Bent cannula usually means the needle point didn’t hit the skin first.


It was my first insertion after training and that very well may be what happened. I included the episode in my post because it scared the daylights out of me. First time in 30 years I had NO insulin in me and felt like I was going to die. I also had zero help or guidance. “Pull it out when in doubt” is something I heard first on this forum (like yesterday). I wish somebody had told me that earlier.


That sounds really tough @Aronld. I’m surprised that there aren’t more infusion set problems. Another part of the setup that is failure prone. I wish I could help you but I can’t. I am left wondering whether an additional training session might help straighten stuff out for you. I found my Tandem training session (which was in person with another diabetic pump user) to be very useful.

As for the tubing, it is a huge pain. My tubing will get caught on something about once a week.

When I was thinking about using a pump, I remember looking at a post where the person said: “I didn’t like the feeling of being attached to this machine. I feel better with the pen.” I can (sort of) understand that feeling, although I don’t share it.

I posted in another thread about getting caught in the middle of an argument between an older married couple - where the husband felt his diabetic wife should get a pump, and the wife was happy with pens and lantus. I had to extricate myself from this discussion, but I do feel that the patient’s preferences are paramount. I think that is also accepted medical practice. So, if you don’t like the pump, stick with the needles and a cgm will still give you better control if that’s what you want.


That is the only one that actually works well for me!

Also, what insulin are you using?

I have noticed that the past year or so of inserters tend to get a little ‘cockeyed’ when you pull them back.
I had a number of bent cannulas.
I started being VERY careful with how I went about insertions. I would check to make sure the goofy insertion tool was actually even from side to side before I used it. I was also careful to pull off the little sheath carefully.

I have problems with almost all other infusion sets other than the 9mm 90 XC. 6’1" 200 lbs for reference.


I was using Novolog in the pump which I used for years on MDI until switching to Fiasp about a year ago.

If you can, please elaborate on problems you had with infusion sets? They seem like the weakest piece of the rather complex puzzle of pumping.

Also, how much do you bolus at meal time? I found a few threads about leaking/tunneling and the solution was to bolus less than five units at a time or worse, bolus with pen and use pump for basal only. I typically bolus 10-15 for a meal.


Fiasp has issues in the tandem pumps.
I had to switch to Lyumjev to get around the issues that Fiasp caused, and tunneling was among one of the issues, including having the infusion sets fail sometimes as early as a day and a half in!
I didn’t have issues with Novolog with the Tandem pumps.

The bolus size is more of an issue with Fiasp and tandem. I haven’t had that issue with larger boluses using Novolog or Lyumjev.
With Lyumjev I can give even larger boluses without issue.

As for my issues with the infusion set itself, I found that I would have them bend on insertion, or make it feel like that sucker went in sideways! Most of it was basically the way the cheap plastic pulls back and locks into place. And how it releases when you squeeze it. I make sure that it pulls back SQUARELY and is evenly locked back. Then have a firm but stable hold when squeezing it to release it. Once I got a better understanding of how I should do it better, I got MUCH better results.
Again though, they didn’t use to be so finicky like this! I think the tandem specific stuff just isn’t as good as the older style setups, even though they are very similar.


I did not use Fiasp in the pump. Only Novo. I wish it was that simple !

I used to feel guilty throwing the big fat Dexcom inserters in trash but after using these Tandem devices I appreciate the design.

When you have an issue with larger boluses is that leaking we are talking about ?

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With Fiasp, the larger boluses would sometimes leak.


I used pens for years. I’m using a t-slim X2 now with Autosoft 90s. They work fine for me, though I DO have to change them every 2 days or BGs start rising. I also use Fiasp for boluses if convenient and if I need at least 1unit to bolus. So sometimes I’ll bolus the whole & half units, and then anything additional the pump suggests I’ll take that amount via pump. I stopped pumping at one point for a few months & then we were going to take a trip & I knew I wanted to use the pump :slight_smile: I just use Walmart insulin syringes (w 6 mm needles) when I bolus w Fiasp. I like being able to turn off my basal w temp rate if my bg starts heading too low.


I’m 72 years old, 6 feet tall and 225 pounds. I’ve been using a Tandem t:slim X2 with Autosoft XC 6mm inserted in my abdomen (on one side, the other side is where I have the Dexcom G6 transmitter). I rotate through about 12 locations in roughly a 3x4 grid. I use each site for just under 3 days with U-100 and 5 days with U-200 Humalog.

There’s an Autosoft 90 infusion set but I don’t like them as well as the Autosoft XC. I also tried XC 9mm but had more bleeding so I went back to 6mm.

I’ve never had a problem with cannula folding over. The only infusion set issues I’ve had is when one gets pulled out (and that has happens maybe once or twice a year). I wear my t:slim x2 in a leather pouch on my belt and the tubing rarely gets in the way.

If you have any questions, let me know. I think if you can get the infusion set insertion technique perfected, you will be happy with the results from pumping.


If you are bothered by tubing, trying the Omnipod sounds like a good idea. But I do want to defend the VariSoft – it also comes in 17mm, which (and its Medtronic and Animas clones) I’ve been using since the late 1990s. Fewer things can go wrong. Yes, that introducer needle is, um, quite impressive, but not much of it goes into you – though I did have a used one in my luggage once that wasn’t properly secured and quite impressively skewered my thumb as I unpacked, but that was my fault and no lasting harm.


Hi. I am new here and tried T-slim for only a month, but just due to claustrophobia feeling I couldn’t shake and due to awful settings given at the start that were so so conservative. Looking back, I now think I could go back to that again if I thought it would be optimum for me. But I have also thought to go back to mdi if I can’t get my Omnipod 5 working better than me on mdi (been on since November, save for a 2 or 3 day so-called pump vacation (read, fiasco due to dexcom, not mdi or pump). I, too, to have been told by Omnipod that I may have tunneling issues due to my activity levels, but they can be addressed and some overlay suggestions, and physical remedies that I will probably try. I think if your insurance allows it, or you can afford it, you may want to try the Omnipod. But I do respect the opinions you heard above about which infusion set needle thing to use. I did not like that plastic contraption in the Omnipod it’s just so simple to put in. I don’t think it would hurt you at all to give it a try. It is that regular plasticky cannula and I’ve had them get bent somehow and I’ve had bleeding and insulin pooling. But I’ve also had them work well. You might be like me and need to ask for a prescription that allows enough insulin and pods to change it every two days. I have somebody that can be thickheaded and likes to learn by experience and to try everything. And I can get impatient and screwup because I didn’t wait it out but I say why not try it if you have a chance and then you may long for the t- slim and the way it’s algorithm works, or you may love Omnipod (And their customer support has been very helpful to me, though I’ve read horror stories. And they will replace pods but you have to talk to them a good long time. I finally got the other day to where I just said I don’t feel like spending all this time. I just want to give you the numbers on the pod and they let me get by with that. And some of the customer support people at the higher level that I’ve called me back or actually not just type one diabetic spot even LADA type ones like myself. I felt like I hit the lottery with that call back). I guess to me the privilege of having choices is the most freeing thing. I hate to just be constrained and even my nurse practitioner told me I could always go back on shots, so I just like having choice and you might also. And I think these pumps require us to stay on top of them a lot as we learn to use them, and be aware of the things that might happen like you experienced. And I had never thought until I just read on this great website and forum about using injections from your pen when in doubt. They really think out of the box here. And that thing about changing it when you have doubts is exactly right. I am truly inspired by the people here in the moderators, helping to give us good information and alternate routes. We may not have thought of. So I guess I did just wanna comment and wish you the best in the fact that you did dive in and try to make this work, suggests that you are ready for such a change or at least to experiment and see if it’s right for you. I know you’ve had terrible difficulties and it’s irritating, but I do think that’s part of the learning curve of any of these technologies and sometimes we’re working to get around how they’re supposed to work. Also, I think you should use your own judgment and try every type of infusion set just to see and take the information of the people here using those things. But if you have a chance to try Omnipod, I think you will feel good for having explored more broadly and deeply and then you will land on how to do you the best way. Hang in there! And good luck with whatever you do.


Your reply was MOST helpful. I just wanted someone to tell me they were able to pump a couple of hundred units of U100 through a single infusion set without significant problems. Thank-you.

Time for an update. I am successfully pumping with the Tandem tSlim using Auto Soft 30 infusion sets. How did I get there:

Rather than try Omnipod5, I got a new training session from Tandem with a new (better) trainer and a six week extension of the trial period. Trainer suggested AutoSoft 30 if I didn’t want to retry the 90s. I find these sets easier to use, and the little window on the set that allows you to see the cannula actually going into your body is very reassuring.

Since I restarted on November 12 22 I have only pulled out ONE infusion set early. There was no dampness or insulin odor so it was probably just random insulin resistance or whatever. It took me a while to get over paranoia of them not working.

This pump allows me to do significantly better than MDI. It requires a lot of work and attention but it’s worth it. The only way I could come close on MDI wold be to leave a bread crumb trail, a daily litter, of dozens of pen needles (and NEVER sleep).



I don’t think I would be doing nearly this well without the Control IQ. I never tried a “dumb” pump because I knew I would have gotten fed up trying to find an “ideal” profile, or set of profiles, and gone back on MDI. My metabolic rhythm and response to insulin is constantly changing and these algorithms buffer those changes. The Sleep function (which I believe is based on the older algorithm Basal IQ) is very nimble.

Thanks to everyone who responded to my original post, especially @bsmorgan !


Congrats for sticking with something you thought would help and finding the right combination!

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Thanks so much @aronid for letting us know the (current) resolution to your issue. That’s a very impressive change in BG.

Like many folks around here, I am a big fan of Control-IQ, and am glad that you were able to get things worked out so you could also take advantage.

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I’d like to add, for any new initiates that read this thread that are having similar problems: Keep trying different infusion sets until one works for you, or you run out of alternatives… then consider trying a different pump with different sets. When I complained recently to a tandem rep about the t-lock connector “locking” users out of leveraging 3rd party sets, she claimed they were working on an adapter dongle, probably t-lock → luer.

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I agree 100%, Arnold. This is one of the issue I have with patch pumps. If I understand correctly there are no options to the infusion cannulas. If I am wrong someone correct me, please.

Yes you have got to keep trying different infusion sets, absolutely.

However it gives me pause when you say that because Omnipod5 has just a single choice of set/cannula and you appear to be having problems with it. That is a major reason I decided to stick with tSlim and not switch to Omnipod5 after my disastrous initial attempt at pumping - it gives you choices.

The other reason is that I will be on Medicare soon, and Omnipod 5 is only covered under Medicare part D (pharmacy). Part D has hefty coinsurance and high out of pocket maximum. Probably cost me thousands of dollars a year more than tSlim, because tSlim is covered under Medicare Part B (durable hardware), which with the right Medicare Supplement or Advantage plan is practically free.

And yes, getting a good rep on the phone at any of these companies is like winning the lottery.