Fiasp with Tandem t:slim X2

If you load your pump 20 percent humalog or novolog and 80 percent fiasp you will avoid the occlusions.

The additive they they put in to make it faster tends to stick to tubing and plastic.

So 20 percent it’s enough to grease the skids.

But of course the action will be a little slower. Not so much that you will notice it.

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Now that’s creative problem solving

This is good to know! Thanks, Timothy!

I’m completely out of the Fiasp loop now, but I’ll definitely spread the word if I hear of someone else dealing with this.

I’ve been waiting for their next update before I try my X2 again. Have they announced when it’d be released?

No, I don’t think so. I recently reached out to Tandem with some questions on this. I’ll post back on this thread if I hear anything like that when I talk to them.

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They keep saying they are about to release the new software that allows us to bolus from our phones etc but it keeps being pushed back.

I just want a better target BGL so I wouldn’t have to run sleep mode AND lie about my basal to get where I want. A longer extended bolus would be welcome too.

Back in the day (late 80’s) there was an engineer who managed a group which designed/developed chips. Supposedly when he saw a software schedule he once said

“But it’s software!??” :confused:
“Hey, how long could it possibly take? A few weeks? A month or two at the worst?”

It was filled with the FDA back in December. There’s not much Tandem can do at this point other than wait like the rest of us.

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Having the occlusion issues others found with Fiasp and the tslim X2. Takes about 1.25 days and 100 units of insulin and the bind up happens.

Tandem will not send a new pump for the issue. They basically read back a this isn’t our issue as Fiasp isn’t compatible with our product. So best of luck customer with doing something else.

After this thread I am now happy to looking into fixing it with mixed ratio and or alternative insulin options. Also looking at pumps that don’t have the potential in the first place to this problem.

I don’t think your pump needs to be replaced for that just change the set and the cartridge.

I have heard others mix 10% humalog w 90% fiasp and get a result that is pretty close to the same as 100% fiasp. And it doesn’t clog.
You can start with that and experiment with adding more humalog if you need more.

I have been using Fiasp in my X2 since shortly after it first came out. I have had maybe 2 occlusions since then, both completely unrelated to the insulin. I’m not sure what people are doing that is causing these issues with Fiasp. I certainly suggest people try it out in their pump, though after hearing people keep talking about Lyumjev I am interested in trying it.

Yes only novolog and humalog are officially supported in the X2, but it will not hurt anything. If you do get occlusions, you just have to change the set. Tandem won’t help with anything in regards to how things function with it, so it is something you need to feel comfortable figuring out…Which isn’t too hard.

All I have had to do is tweak my profile to account for the faster action time of Fiasp vs Humalog. Basically I just moved the basal rate changes to a little later than they were set and adjusted the bolus rates as I learned how it would react and what my sensitivity to it was like. I save it as a separate profile in case there is ever a circumstance where I have to use humalog for some odd reason.

Though I have heard of some circumstance when people were able to use Apidra, I would highly suggest avoiding it as one reason it works faster than novolog and humalog is that is lacks certain ingredients that those have that make them stable longer (if I recall correctly). I got occlusions after 1.5 days or less every time because it would start crystallizing in the tube and such.

It may sound odd but I actually prefer to feel it. That way I know it is actually going in and being absorbed properly. Always fighting with premature failures of my sites, either randomly starting to leak or the insulin not absorbing anymore, makes me paranoid when I can’t feel it.

No. It’s not. I called Tandem last night. Same exact scenario as this thread (wish I had consulted Tu Diabetes first). Tandem has given no indication to their Customer Support Team whether or not Fiasp is even on their radar – I asked specifically about this, and then lodged a recommendation to Tandem Support – not holding my breath…

It is super frustrating to know that post-meal highs are a thing of the past IF you use a fast-acting insulin like Fiasp.

ADD ON: I tried using Lumjyev and it is a no-go for me. Site burns and leaves a hard lump where the cannula went in. Not for me.

Sorry to hear that.

Lyumjev works for me. I’m not that sensitive to the burning or maybe I’ve convinced myself that I’m not.

I heard that there is a return period for pumps. See if you’re in it. I think it’s 30 days for regular insurance based on what I heard. I’m not sure about Medicare.

The insulin part is one annoyance with Tandem. I did love the Basal IQ and refused to upgrade to Control IQ as my in range number are usually at 80% and a1c numbers are near normal ranging from 5.7-5.9.

I’m at the end of my Tandem warranty, so I’m working through the remainder of my sets and will switch back to the Omnipod. I used to wear one before their closed loop system. I just picked up my Omnipod 5 set over the weekend. It will collect dust while I’m working through these X2 supplies. I hope I can hit the same numbers or better with the O5.

Good luck to you.

You can still use whatever insulin you want in the pumps, even if it’s not approved, if your doctor writes it you can try it. I used humalog in my pump before it was approved

I like the algorithm of control iq. It gets me 95% most of the time, and even 100% some of the time. I would be open to trying the pods again but the way the cannula is 90 degrees or nothing, made me give up on them because the cannula will hit muscle and bend and occlude, if I can get one that allows for angled insertion I would try it

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To me this would make the MOBI the perfect compromise. That’s if it ever gets approved and released. :face_with_spiral_eyes:

Actually… that is EXACTLY what ended up happening! Now using Fiasp and back to pretty postprandial blood sugars! :tada:

ADDING ON: I also had an issue with TSlim and Fiasp with pump saying occlusion for boluses when insulin levels were low (50 units and lower). Searched this forum, JDRF forum and Reddit forum & found the solution and occlusions no longer happen. – For full details see higher up in this thread. Quick lowdown: remove ALL AIR from cartridge using empty syringe (the one you use to load the cartridge), then proceed as normal… Don’t know why this works; don’t really care. I’m just glad Fiasp is usable now in my TSlim pump! – Someone on Reddit suggested it might be related to viscosity, which makes sense.

You k ow weirdly I get bent cannulas even inserting on an angle, and even places where I have plenty of fat.this is happening more as I get older. I really love my tslim, but I stupidly ran out of infusion sets. I thought I ordered them and I forgot then the sent them to my old address, so now I am on MDI while. Weirdly I need to bolus more though, my average meal on a pump is 6 units, now it’s 8 I wait, and surprisingly I’m staying in range pretty well. Maybe I need to increase my Lantus, but I’m going to ride this out a while till my infusion sets come. also realize that I microdose a lot on a pump, where it’s too much trouble on MDI, so I pass on snacks more. I might have discovered while I’m little by little gaining weight over the past 2 years

Ugh. I came here awhile ago because of the occlusion alarms, which have disappeared after employing the air removal method for the cartridge described in this thread. BUT the algorithm-thing is real. I have noticed that the Tandem pump algorithm is slightly off with the Fiasp and I have to do more adjustments to boluses or food intake. The Fiasp is noticably faster and has solved post-meal highs but with the Tandem algorithm to bring down high BGs, signals get crossed because of how rapidly Fiasp works. – I am so sad to see Tandem not trying to adjust their algorithm to be more atuned to what BGs are actually doing as the Control IQ is working.

I was looking at this discussion because I’ve been trying to determine what the advantages of the insulin analog varients were, and how I might be able to use them if I needed different results than I have been getting -given the equipment available today.

From the very sparse data available, it appears that the makers of these products are reluctant to disclose objective statistical numbers regarding onset times. The published response curves are without vertical axes, based on pure glucose loads with a limited number of test subjects. Some “short” products seem to have faster initial rises than others.

What all short term insulin products share is for the same pure glucose load, over a 6 hour period, they all produce similar outcomes in test subjects. That is the first criteria the FDA uses for approval.

The second criteria is effects when used as directed. The FDA cares about new safety-related side effects, ones than those of the previously approved products. Hypoglycemia from an overdose of insulin is not a side-effect of a product intended to lower blood glucose. It is only a concern of the FDA if its effect is very non-linear with dose compared to approved products and requires special precautions.

If I were a test subject laying on a bed in a clinic all the time and being fed glucose, I don’t think that would care what kind of insulin I was being given. But that is nothing like my life.

The principles I use for my tech, insulin and bolus decisions are well known:

The “best fit” of an infused insulin bolus:

  • delivers enough, early enough to slow BG rise
  • prevents the BG from rising out of the linear response range into the hyoerglycemic nonlinear range of “glucose intolerance” or dropping into hypoglycemia duirg iut working period.
  • matchs the peak of the insulin delivery to the peak of carb absorption.
  • matches all the food converted to glucoise by digestion within it working period.
  • accounts for the delay between infusion and onset of absorption.
  • produces the lowest deviation from average.

My observations from 40 years of using insulin are:

  1. To get the highest degree of control over post-prandial glucose with any insulin, its delivery has to be matched to my rate of food conversion to blood glucose.
  2. An insulin with a fixed absorption profile and cannot closely match my wide variation in food composition and conversion to glucose from mea toi meal without adjusting rate of delivery.
  3. Fixed premeal boluses, at a fixed interval before eating, are not a close match.
  4. Pre- or post meal bolus whose interval depends on the approximate CH/L/P/F mix of the meal or not, may be a closer match if and when the estimate of the meal composition is accurate, and there are no other factors.
  5. There is a “depot effect” with infusion. Rather than a steady steam of insulin being conveyed to the bloodstream, it may be held within the interstitial layer, stored and/or delayed and delayed for a short but unpredictable period of time. This effect is used intentionally by long term insulin products, where a short delay variation isn’t critical.

As an engineer I know that any product with a known absorption profile and onset delay time (ODT) could be matched to this by controlling the infusion rate and initiation time (Ti), but without known, accurate BG measurements AND a close estimate of BG at (Ti + ODT), the result will be suboptimal.

As a PWD I know that no matter how hard I try, I won’t get perfect results every time. There are too many variables. Maybe in the future I’ll have a “robodoc” that tracks all my activity, my stress hormones, and my actual BG 24x7, not today.

What does this have to do with my choice of an insulin with my insulin pump?

ODT is more important than relative onset curve and will vary between sites and with a site over time. To know ODT I need to somehow monitor the effect after each meal to determine how well the last bolus is working.

If I know ODT, I can control that variable and bolus size, I can make an educated guess on an average delivery rate for the kind of meal I’m about to eat, and closely estimate the net carbs.

Unless I don’t learn or use that information, the onset curve doesn’t matter to me as a pump user. I can infuse FIASP a little faster or slower, earlier or later to match Novolog, or vice-versa, by using a 30 minute extended bolus and adjusting the percentage initial bolus.

If I don’t use the information available, I’d be totally at the mercy of a (first gen ) hybrid closed loop system.

I’ve seen how poorily it reacts if I don’t get food estimates right, if I don’t bolus at a reasonable to me before a meal. I’vee seen how my TDD varues when I do. If I were dependent on a HC worker, unable to oversee and provide the intelligence to manage the system, I’d rather go back to scheduled MDI than stay on a HCL pump. Staying alive and out of ERs is more important than keeping my GMI and SD low.

When it comes health, I don’t want to be an explorer or a pioneer, but a developer who benefits from from the knowledge of the pioneers. To me FIASP has several practical disadvantages over Humalog or Novolog.

  1. The pump I use has not been clinically tested with FIASP.
  2. Reported higher “infusion set” occulsion rates than Humalog. I chose Novolog over Humalog because of its reported slightly lower rate over 72 hours in clinical trials.

I’ve never experienced an “insulin set” occulsion. I have had bad infusion sites, and resolved them by relocating the steel cannula to another site. The ability to
do this was one reason I switched to steel from plastic cannulas.

With my pump being one part of an dynamic interactive system, high quality monitoring of what is happening is more important than the insulin being used.

So I decided that I will use whatever insulin product has been tested by the maker of whatever pump I’m using, and has the lowest cost to my insurer. I will validate every CGM sensor before relying on it. And I will use an realtime reporting/anaylsis app like Xdrip+ that lets me set multiple level alerts to let me know within my target range where I am.