T:Slim x2 suspension low issues

Good day all, just checking to see if anyone has experienced something similar to my experience. I have updated my T:slim x2 to the latest features which suspends delivery of insulin when low. On two occasions my insulin resumed delivery when I was low and Tandem Reps says that it will resume when the pump detects it is going back up. I have an issue with this design because this morning my level was 48mg. It did suspend but resumed delivery with it at that level, then 10 minutes later suspended again and the arrow and graphs were going down during that time. Luckily I felt this low while sleeping and I got up and addressed it immediately.

As far as I am concerned, it should never resume basal delivery until it is above the set low marker which in my case is 70mg. The Reps blew smoke my way this morning when I called again and I believe Tandem is really trying to push something that may be a problem. If anyone has experienced similar issues please illuminate as this may be a problem that is being hidden.

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Tandem has been pretty clear all along about how basil IQ works and what they state is correct. I would say there is probably an argument that could be made that if you are below 50, the pump should just suspend until you are above that threshold.

In my case if I was at 48, both my pump and phone would be going crazy with alarms, and I would get up and adress the issue.

The next new Tandem feature, Control IQ, will probably adress the issue.


There is no smoke.
As @Jim26 states, the rules for the Basal-IQ algorithm are exceedingly clear and simple. It certainly would be a stretch to say anything is hidden within this algorithm.

There is no configuration with Basal-IQ and there is no changing the rules. They are what they are. It works great for us. I do not think anybody is under the illusion that one solution, one approach or one algorithm is going to work for everybody.

If it does not work for you then it is only a tap of the screen to turn off the Basal-IQ. Perhaps the Control-IQ algorithm which is expected for a Q4 launch this year will work better.

If you have any questions on HOW the Basal-IQ operates, feel free to ask.

So are you saying your bg was 48 and it resumed? I would not use it then if it does that. I turn off my basal with a 25 minute temp rate when I am low and keep doing it until I stabilize, especially if it is a bad low in that range. I will try it if I ever get the G6 but if it does what you described I will not use it.

I agree it should not resume until 70 at least. They should change that.

The rules for Basal-IQ are published, very short and quite clear.

We have been using the Basal-IQ for about 9 months now and the Basal-IQ algorithm works unbelievably well for us. Certainly it is far better than we ever would have expected.

There will be no changes to Basal-IQ. It is what it is. There will be no revisions, no enhancements, no updates to the Basal-IQ algorithm.

Tandem is planning to launch the Control-IQ algorithm in Q4 this year. The Control-IQ algorithm is planned to have continued enhancements and revisions with a likely annual release.

It is great there are choices so if the Basal-IQ is not appropriate for somebody there are plenty of alternative options.

Do you work for tandem, is that how you know there will be no revisions? As I recall you sometimes seem to be defending things that are badly designed. It makes no sense to have basal start up again if your bg is that low. It was a bad decision made in the original design that should be changed imo.

I will not be engaging personally.

Let me know if you want to discuss the product on its technical capabilities.

Everything in life has room for improvements, via revision, enhancements, and or updates. Nothing man made is perfect and to believe otherwise is ignorant. I was hoping that my experience with my glucose being dangerously low and the pump suspending and then resuming maybe it might also help or maybe an update might help. I guess not, thanks Tim35.

I’ve only been using Basal-IQ for about a week and to say I’m impressed is an understatement. It’s a big step forward for me. I’ve gone into this understanding it’s limitations and I’m taking that into consideration. I don’t feel they were being evasive with me or overselling it’s capabilities.

I think the issue you discussed is a good and obvious one. I also know the people at Tandem are pretty sharp. A good percentage of them are T1D’s so I have to assume they also see the limitation/opportunity. I’m giving them the benefit of the doubt and assuming there’s a valid reason such an obvious feature isn’t in there. I’m personally thrilled with Basal-IQ’s current capabilities, even with it’s limitations, and looking forward to the new and improved items in their pipeline.

Good day Paytone, I am impressed with this extra feature they incorporated with this particular pump as well. But the suspension of basal should not resume when you are below their established 70mg low mark.

I know they state this in the Basal IQ tutorial that if the sensor detects the glucose rising it is going resume but mines never got over 70mg and it resumed delivery. Some don’t understand that this could be dangerous if you are a heavy sleeper for example, but I think it needs to be looked at. I’m just saying.

Another rule is that if pump has been suspended for 2 hrs in the last 2.5 hrs, it will resume.

I can think of possible reasons for resuming under the circumstances you describe. Of course, these are pure speculation. 1) Given the lag in CGM readings especially bG is changing rapidly, resuming when the bG starts going up, could be to mitigate any potential rebound. For some people, if it waited until the bG was over 70, counter-regulatory hormones may be kicking in and they end up chasing rebound highs. 2) It suspends the the CGM predicts the bG will fall below 70 in the next 1/2 hr (or is it an hr?). Resuming as soon it starts up will keep the bG steady without dropping too low.

I have found circumstances the Basal-IQ doesn’t help. Like if I bolus and forget to eat. I have a lot insulin on-board, and my bG is going down no matter what basal I have. Even if I’m below 50 yet. I eat glucose, resume insulin and set a temp basal of 0 for 30-60 minutes. Then I eat the meal I forgot, maybe waiting 10-15 minutes for the glucose to kick in. I may reduce the meal by 20-30 g of carbs.

Basal-IQ isn’t designed to resolve every low. It supposed to prevent lows under some circumstances. There will be situations where one will need to take additional action.

I didn’t realize that Basal-IQ was not getting updates. I think any revisions need to be cleared by the FDA. Perhaps it is just not practical for small improvements or an extra feature or two. So, hopefully, they will fold them in to the next release, Control-IQ.

I am looking into getting a tslim insulin pump/ integrated g5. I was on an animas vibe before I basically was forced to go with a medtronic 630. I had some experience being on a dexcom with my vibe. After switching to a minimed 630g and using their sensor for a few months I didn’t like it. First it only was a 6 day sensor but the 5th day accuracy was off. It was too expensive. I couldn’t restart the sensor and get another week out of it. Then when I saw that Tandem was coming to Canada after Animas disappeared I was thrilled. Now I am going to try and get out of my warranty for the 630. I have until February 2021. That seems like a long time if especially if the basal iq control comes before that time. Tandem is offering a one time payment of $1400 to go with their pump.

What province do you live in Dee - AB?

I live in Ontario. Canada is so strict when it comes to healthcare. We are always the last ones to get something new.

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I would say go for it! I had the Animas Vibe, now I have the X2 and using the Tandem X2 is almost like using my Animas but to the 3rd power. Plus with the Basal IQ gives me a little reassurance of low blood glucose. Try it, you should be ok.

Thankyou. I am just waiting on medtronic to email me my warranty confirmation letter. I don’t think they are going to move too fast! I am looking forward to getting updates for this pump rather than changing and learning a new system all over again. Tandem seems to be the more superior pump company now.

I have wanted this pump since it became a touchscreen. All the other features with it are just “the icing on the cake.” It may cost me 1400 bucks but that’s ok as we can use it towards our income tax return next year. With my disability tax credit we get back alot. In Feb. 2021 when my warranty expires the adp will pay for the Tandem pump.

Hi, Robert. I have a question for you. What is the lowest basal rate on the tslim? I am on .025 at 9pm and my sugar still seems to drop on the smallest amount.

Dee_Meloche, sorry about the late response @ work. You can go as low as .001. So flexibility is there.

Once it starts getting warmer I become really sensitive. It’s nice to know that there is more flexibility with this pump. I’m just waiting for Medtronic to email me my warranty letter.