Pump occlusions - anyone had better luck with Tslim

So I have been battling with pump blockages on my medtronic 640G. I’m just wondering whether anyone has had better luck with the Tslims in terms of pump not blocking up?

After a lot of trial and error, i think there is scarring under the skin over time that are causing my pump to block up. I’m not sure whether Tslim infusion sets are any better but I’m due for a pump renewal so I don’t know whether I should continue with medtronic given that I’m getting problems, or try the Tslim.

I’ve been pumping for 8 years now and have only been on medtronic pumps so I don’t know whether there anything thats any better. Here in australia the major players are medtronic and tslim. We don’t have the omnipods.

Are you getting error nessages of blockage, or just unexpected high or unexpected bgs.

The infusion sets for Tslim are essentially the same. Have you tried the steel sets (Sure-Ts) ? Sometimes this is better absorption, and the needle can be moved around with same set. Medtronic might send you samples to try.

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Hi MM1,
Its the Insulin flow blocked error message. When its blocked, my blood sugar is often high by the time it notifies me that it’s blocked.

I’ve tried the sureTs too based on some suggestions on this forum. Still get blockages and doesn’t last as long as the mios.

I think that a lot of the blockages are caused by scarring. Before I insert a new set I feel around the area to make sure there are no hard areas under the skin. I also use a lot of different areas on my stomach but some areas are better then others.

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Since it’s not a new pump and this seems to be a new problem, yeah, that seems the likely culprit. In which case as @MM1 says, trying Sure-T infusion sets is probably the way to go, and MT are pretty good about sending you a few sets to try out. It would be good to eliminate the pump as the source of the problem so you can make the decision whether to switch to T-Slim based on other factors.

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I already had the pump replaced so its not a pump problem. I’ve also tried the sureTs and they too block up. When i feel my skin before inserting, the area seems healthy. Not hard not scared on the surface either.

The other areas besides the tummy for some reason gives me irritation and turns red after a day. Doesn’t happen on the tummy area so thats where I have been inserting. But i rotate everytime I do a site change.

Irritation makes me ask, are you using Fiasp by any chance? I pump with it and don’t have any problems, but I have heard that it’s sometimes an issue. I think it’s slightly higher viscosity, and some people find it inflames the dermis, which can be a cause of occlusions if it’s bad enough.

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Nope not using Fiasp. Although I’ve tried skin prep if its the same thing??? It doesn’t make a difference to the irritation though, with or without it is the same.

The irritation is quite bad. Starts of itchy then by the time I take it off, the area is pink and there is usually a noticeable hole in the insertion site which doesn’t go away until a few days later. There is mild to medium pain sometimes.

So yeah, those are all signs of inflammation obviously, and excess inflammation is definitely on the list of things that can cause occlusions. So that seems to narrow the focus to figuring out what’s causing the inflammation. Stainless steel sets are usually the first alternative, but you say you’ve already tried them.

Seems like a telling detail that it’s not an issue with belly locations, just your legs. I know areas can change how they respond after years and years with this stuff. Some of my old-favorite locations have become avoidance zones because they’re now painful to use, even though not particularly scarred. One possibility would be to consider a tubless pump (Omnipod) next time because they are easier to locate on “virgin” areas that are hard to use with a tubed one. Lower back, back of the arm etc. I’ve tried those locations with a tubed pump but they are too awkward and prone to yankouts. Not really attracted to Omnipod for various reasons, but I’ve kept it in mind against the prospect of waning real estate.

[Edited after re-reading your last post]

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One of the disadvantages of tubed pumping vs MDI is all those sweet-spot locations you used to inject into no problem are harder if not impossible to use with infusion sets. Even the ones that hurt you could still reach, and so keep them in the rotation just to maximize the available territory and minimize the effects. Those charts they give you of the human body with all those recommended injection zones—more than half them are not really available anymore, which is a major problem with pumping as the years go by. But from everything I’ve read about Omnipods, well… I dunno, some people are thrilled with them, but there seem to be a lot of problems as well, not least of which: occlusions.

Which are infuriating and seriously depressing. I tried the (now defunct) Assante Snap pump when it existed and loved much about it, but it used an optical occlusion sensor that was just way too reactive. It might seem trivial to outsiders, but we’re not talking about some annoying medication you finish with after a time, you’re CONNECTED to this thing 24/7, like part of your body, and when it’s firing off these alarms at any random time of day including stupid-o’clock in the night, and you’re ATTACHED to it in a way you can’t avoid, it’s a serious emotional as well as physiological matter. I coined a term for this syndrome, “Diabetic Claustrophobia,” largely because of the occlusion alarms with the Snap pump. In that case they did switch me to angled steel insets and that actually fixed the problem, though only shortly before the company cratered.

Holy crap–angled sets! Have you tried those? The theory is that they don’t go as deep into the dermal layers, which basically avoids scar tissue, and are able to deliver insulin without nearly so much inflammation response. That’s what I was told when I tried them and it did work. The Snap was really occlusion-sensitive but this fixed the problem.

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I came here to comment regarding inflammation, something I suffer chronically myself so is always at the forefront of my mind, but just saw the @DrBB beat me to it. I’ve noticed that when my flare-ups are worst, the immune response that causes the inflammation also kills my infusion sites faster. I can only get two days max, often one, from a site then. I’d ask your doctor to check for inflammatory markers like CRP (c-reactive protein).

If that is your problem, I highly doubt a different pump will matter, since all the infusion sets come from the same place. The things that help me is a prescription anti-inflammatory, Celebrex (celacoxib). I also take an over-the-counter enzyme blend of nattokinase and serrapeptase that digest the proteins in scar tissue. I absolutely love the Doctor’s Best brand called Natto-Serra. I’m not affiliated with them by any means, on fact, I think the supplement is recommended for heart health or something entirely different. I went looking for it after stumbling upon the enzymes in my research. I swear that stuff is my miracle, I would give up every prescription I take (okay not the insulin) before I’d give up the Natto-Sera. Granted, I mostly love it because it gives me movent back, but there is a distinct improvement to my infusion sites and how quickly they heal/recover, too. https://www.amazon.com/gp/aw/d/B00DBEVTDE?psc=1&ref=ppx_pop_mob_b_asin_title

As much as I love my Tandem pump, I don’t know if you would appreciate the difference in occlusion alarms. Earlier version of the X2 have been criticized for too many occlusion alarms. They replaced my most recent X2 because of occlusion alarms. It wasn’t that big if a deal, but I was most definitely getting them more often. I called tech support, mostly because I was sick and crabby and feeling less tolerant. It alarmed over the phone during one of the troubleshooting steps, and I was told that since they did a software patch, there should be zero instances of occlusion alarms anymore without a definitive blockage. I had to wait an extra day for replacement, because he had to go through the CDE-authorized replacement warranty loophole, since the pump never threw an error code indicating malfunction, but still had an occlusion-free replacement in two days. That said, the X2 is great at detecting real occlusions. You won’t be 400 when it finally decides there’s a problem. It will give an occlusion alarm early, which I think most people will ignore at first, hoping it works out it’s problem in it’s own. However, if there is a real occlusion (and you didn’t act on it when first indicated :slight_smile: ) Control-IQ will ramp up your insulin you keep you from going too high. After a little while, you’ll get another alert where Control-IQ tells you it’s failing to keep you in range, check your infusion set. That’s when I know the site is really toast and needs changed (sometimes I’m hoping it’s just a bad sugar day before then). So you might dislike that the X2 gives you just as many or more occlusion alarms, or you might appreciate that you’re getting them before you’re 400 and can act sooner.


A big problem is that those alarms are usually the LOUDEST ones in the device repertoire because actual occlusions are the top of the list for serious faults. So when you’re getting lots of false ones and you’re sitting at your desk at work and your workmates know you’re T1 and use a pump, it gets to be really problematic and not a little embarrassing as they come rushing in to make sure you’re ok.

I speak from experience.

Most definitely. Thankfully, the most recent update for the X2s let you set the volume/vibration for EVERYTHING, even alarms (their definition of serious problem, vs. minor alerts). I think the more serious things will involuntarily alarm eventually if you don’t respond to them, though. I got an auto-off alarm, when it should have just vibrated, after I exceeded my 15 hour limit of no-activity, while I was disconnected and didn’t notice. I don’t know how long it was vibrating before it started to shriek instead. LOL

Just a thought…do you use a barrier tape? My skin reacts to the adhesive on the back of the quicksets and becomes seriously inflamed. I use either Tegaderm or IV3000 patches first, and then insert the site through those. Since I’ve been using barrier tapes (past 16 years), I’ve only had one occlusion which caused a no-delivery message.


Be sure that your pump is set so that bolus speed is set to standard. If it is set to quick the medtronic pump will return far more delivery errors.

Go to options

delivery settings
go to the very bottom of the list and select bolus speed

Then make sure it is on standard. In most cases this will stop the issue.


I am a Medtronic ambassador. My opinions are my own. They did not pay me to say nice things. OK, they sent me a shirt and a cup but even I am more expensive than that.

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Thanks but the thing is those sites don’t block up, they just give me irritation. The site that doesn’t give me irritation (ie tummy) is the one that blocks up :sweat_smile:

And Omnipod isn’t an option. Its not available here in Australia :frowning:

Do the meds and supplements you are taking have any side effects? I’ll like to stay away from extra medication if possible.

I didn’t know that. So is it actually the same thing but branded differently? My mio infusion sets actually has the medtronic branding on them. Are you saying that even if i switch pump manufacturers, the infusion sets are still the same?

haha no win win. Do the tandem pump have an interface with the mobile phone so you can bolus from your iphone?

Ah yes I should try that. I was supposed to try that but it escaped my mind. Thanks for reminding me.

Yeah mine is always on standard. The quick delivery is painful sometimes so I leave on standard.

Not exactly the easiest thing to ascertain, but this seems to be the original manufacturer that works with the various pump makers:

My impression is that the each type of inset is going to be functionally identical across the different OEM brands; the difference is really between the types themselves.

As I said in my tl;dr post above, when I had the too-many-occlusions problem with the erstwhile Snap pump, they recommended using steel, angled insets. They did an abdominal inspection and drew my attention to signs of scar tissue that I’d never have noticed. I was kinda skeptical, but the angled sets absolutely did solve the problem.

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