Troubleshooting highs

I have changed the cartridge twice (though at the time it started, I had been using the first cartridge for what I think was too long, so you might consider it only once)
I have changed the tubing twice (same situation applies)
I have changed the site three times. (all before they "should" need to be changed)
As far as I can tell... I am not sick.

What else can I check? Oh and my cartridges are not in any of the recalled lots (though I suppose there "could" still be something wrong with them... but I doubt it)

Any help much appreciated. Before Sunday, all problems seemed to just be about getting the basal and bolus amounts correct, and all could be easily explained, so I wasn't too concerned about those as things were "close enough" that I knew I could figure it out over time and all "mistakes" (basal rate, bad guestimates for carbs etc) were easily fixed.

I have been multiple dosing for the same highs over and over (and eventually give a shot) and currently have my basal (which occasionally made me a tad low if I didnt eat at my very predictable times) set to 150% of the normal. I get no errors other than the two that I know I caused (one occlusion and one for not following the correct load procedure).

Edited to Add

Also a shot will bring me down surprisingly quickly (by the usual amount of insulin for the high, hopefully "proving" that I am not sick). However, after the pen shot of humalog I stay down surprisingly long and even seem to continue to drop low, which makes me wonder if its possible for the basal function of the pump to be working but the bolus aspect be "broken"??? Which would seem unlikely to me... but I still know very little about this whole pumping deal

Hi Grumpychick! My son started on the t:slim in November and had a lot of these same issues. Highs we couldn’t explain that couldn’t be fixed with the pump were our biggest challenge. We were correcting every 2 hours and his numbers would barely budge and he wasn’t sick. The pump nurse told me the higher you are the harder it is to correct but we were using injections to correct constantly. We also had no alarms or warnings. We finally switched from a 90° infusion set to a slanted 30° set and miraculously things improved immediately. Have you thought about trying a different set? We had been using the Cleo and switched to Inset 30. I hope you get everything figured out soon!

I had not considered an angled set... though have a whole bunch of the regular insets... which worked perfectly for the first three weeks... even when trying to bring down a "big" high.

I'm going to try changing ~everything~ tonight one more time (cept for maybe the set as that was just put in last night and that's easily changed later if it appears changing just the cartridge and tubing alone dont work) and see if that works, if not I guess I'll call Tandem and see what their opinion on the matter is.

After 32 years with it, learning to pump is a big transition... but even with the lil hiccups I thought things were going pretty well. This however was not in my expectations.

Thanks though, at least it is one more thing for me to try... just not right now, as I don't have any other sets.

Have you tried using a new vial of insulin? I have had insulting go bad,even if the box is not expired,especially if exposed to extreme temperatures.
The higher the blood glucose the more insulin I need. It’s not the same sensitivity as when I correct for being 200 as when I am 300 or 400. It could also be a hormonal or stress related thing, too. That is harder to “diagnose” or eliminate by process of elimination.

Just some suggestions.

I use a new vial every time I change a cartridge (so I've used 2 new vials) and yeah, I know the higher it is the harder to bring down... but the prior three weeks it brought it down no problem, even if "really" high... past three days newp.

was 410 gave 8 units (twice my usual dosage to bring down that kinda number... brought me down to 375... then back up to 402... that's a lil too drastic to me... then gave 5 units with a pen... came down to normal, and then to low. So its something to do with the pump itself.. or at least my handling of it.

Since you have changed all of your consumables with out success it sounds like it could be either a set or a pump issue. Have you called tandem? They will get you a replacement pump in 24 hours.
Also might want to check with your set provider and try slant sets. I have a huge difference in my insulin needs if I use the Cleo straight sets vs a slant set. I need at least 30% more with the cleos.

Is this your first pump?

My first suspect would be the infusion set or the infusion site.

If you're using a site where you've been injecting insulin for 32 years you might have some scar tissue there that's impeding the insulin. Try a site where you never or rarely injected in the past and see if that changes anything.

As for the set, have you examined the cannula when you change sets? (the plastic tube that extends beneath your skin.) Check it for bends or kinks. If there are any it's an indication that you have a tough site (see above) or your technique for inserting the set needs some work.

Best of luck,


After 40 days on the pump we had to go back to MDI and put the pump back in the box until we could get different sets. It was a nightmare. The Cleo's worked pretty well for the 1st week and then everything went downhill and stayed there. As great as the pump can be the bad thing is that sometimes things are not right and there is NO obvious reason why. That's so frustrating! My son's correction is 1:100 and 2 units would bring him down 20 points :( I felt like all we ever did was correct. It seems since you've tried everything but different sets that may be your problem. Tandem was very nice when I spoke to them but since our pump came from a distributor that's where we had to get the slanted sets from. They did say that if the slanted didn't help to call them back and we'd figure it out so at least they were willing to help. They seemed as relieved as I was when the new sets worked. Good luck to you :)

Yes, my first pump. I'm currently using my stomach for sites right now, but my stomach had never been my first choice for shots anyway, so there shouldn't be very much scar tissue there... also for like a month prior to starting on the pump I made special effort to avoid both my stomach and my thighs for shots (didn't always, but tried) just so that my stomach and thigh sites could have at least a little time to heal as well.

It might be the sets. Unfortunate that they could work so well for three weeks and then decide that they are not compatible with my body anymore. Anyway, what I am trying for today is upping my basal by +/- 50% reducing my correction from 1:60 to 1:30 and also changing my I:C from 1:16 to 1:7. I'll see how that goes and then try ordering different sets when it comes time to (which is soon).

thanks everyone.


It may be too early to tell, but whatever the problem was appears to have resolved itself.

I gave a gargantuan bolus this morning and also adjusted my basal higher and actually ended up going a little low and had to drink something to keep it up (which is actually a good thing in this scenario as it helped prove the pump was working). I have since put back my regular profile and had lunch with my regular settings and all is well... if not a tad low. So I just hope this stays. Still not sure what the problem was to begin with, but at least it seems to have worked itself out.

Had a thought that was not raised by any one yet.
At the time of your problems did you check you infusion line to see if you might have been pumping intermittent air bubbles. I had this happen to me once early in my tslim days and realized that if I did not really tighten the leurlock hub that I could get little sections of air. It was not related to air in the cartridge but due to air getting in at the hub. Once I realized this I've made sure my hub is tight at site/tubing/cartridge change times and any other time I think of it.
I was thinking that my insulin was going bad, etc, etc until I noticed the air segments- it is not always so obvious- need to hold your line over a dark surface so the contrast is bigger. If you have low TDD amounts then this will cause a fairly big shift in BG numbers quickly.

I've been on the T-slim since September, and I wouldn't blame it on anything except the pump itself, especially after the cartridge recall. I have experienced multiple highs and lows, and the company told me I would "adjust." Needless to say, I haven't "adjusted." It is SOOO frustrating, and the limited 4-week return policy makes it even more so. Wish I could offer more encouragement, GrumpyChick!

Actually, my issues have worked out for the most part. It seems that for some reason my basal needs just increased significantly for no perceptible reason. After working on it for a while, things have for the most part leveled off quite a bit and I have set a new profile.

Don't get me wrong, being my first time pumping, my settings are sill not "perfect" (read: as good as they can be), but they have settled down enough that I can see this working, and is probably at least as good as I had on MDI... now its time to work on it getting significantly better than on MDI.

Sorry that you are having so much trouble. I assume you were on a different pump before? Or is this your first time too?

Hi. I'm kind of new here and have been having what sounds like the same problems. I started using the T:Slim in November 2014 and within 1 or 2 weeks started running increasingly higher. I was having such trouble bringing my BG down that it was scary. My 1st troubleshooting session with my endocrinologist marked a new lotion I was using as the culprit. Eliminating this lotion seemed to do the trick for a bit but within a few days, more high BGs...

Cut to almost 3 months later and there seems to be a pattern here: for 24 hours my BG will start to normalize i.e. it won't be AS high; past the 24-hr mark they climb way back UP. I had switched back to my Animas for a while thinking the new T:Slim was to blame for this odyssey of frustration but was having close to the same result - on the Animas my BG seems to stay a tad lower but not so much as to lay all the blame on the T:Slim pump itself.

So the other day I came home with a new bottle of Novolog from the pharmacy. I decided on my next changeout to use the new bottle instead. I am past 24 hours of using the new "clean" insulin and it would seem I am BACK to my normal range. I was so low last night I couldn't see straight so I had to dial down my basal rates just so I wouldn't dive too low overnight.

Do you or does anyone use the practice of sucking the unused insulin back OUT of the old cartridge and either: a) put it back in the insulin vial or b) mix this in with fresh insulin for the new cartridge? This is what I'm thinking: I referred to my new vial as "clean" insulin because my old vial has been mixed with unused insulin from used-up cartridges for almost a month now. I don't think it was a bad bottle or batch since the old vial is like my 2nd or 3rd bottle of Novolog since being on the T:Slim.

Does anyone here think there is some kind of contamination going on here? I store my insulin as recommended and there are no children or pets in my home to contaminate my meds.

I plan on calling the help line for Novo tomorrow to see if they have any record of similar complaints from patients.

I think I may be having the same issue with my insulin. It not old, Its probably only been 6 days since it's been open. Though tonight my bs level have been hovering around the 210-220 range. Nothings gone up or down as I've tempt for two hours, and changed the site twice. ><

I called t:slim's help line and troubleshooted. They stated that it could be a insulin degradation or another bad site. Though usually, with me, bad sites shoot my blood sugars up tremendously. So,my thinking is the insulin is faulty.

I do not mix the insulin or save the left overs.Mainly because of the health risk, also degration of the insulin itself.

Thanks for sharing. I was also told by my doc that my sites could have scar-tissue buildup but for this problem to arise seemingly all-of-a-sudden!? I wasn't convinced. I rotate my sites all the time

I understand that the practice of "recycling" unused insulin from pump cartridges is not recommended by the medical community but the T:Slim wastes a LOT of insulin which creates a problem for me with my pharmacy/health insurance. I get one bottle a month and if I run out then I have to then call my doctor & hope he understands or gets the message from his nurse.

What I'm wondering is WHY are we requiring MORE insulin for basal rates & boluses (I had to seriously overcompensate) while using the T:Slim with Novolog? My basal rate should be my basal rate no matter which pump it is or at least the variance should be negligible from pump to pump.

I saved my old bottle of Novolog just in case there's a chance of getting it tested to see exactly what the problem was. I'm currently NOT looking forward to going back on the T:Slim until I know for sure what the problem was.

I have only had my TSlim for around a month and my insulin resistance is pretty high my basal rate 4.5. I found myself at 320 after changing my set. I also had to switch from 6mm to 9mm sets. I had the small catheter fold over and it did not penetrate my skin.