Stacking insulin.... anyone had this problem with the pod?

My daughter is receiving her Omnipod next week (woo hoo!), but her endo brought up a concern I wasn’t aware of. He said that we could try the pod, but it might not work because the chance of her having problems with lows is greater. His explanation was that when you eat a meal and give a correction, then a little while later bolus to eat again, that the Omnipod only takes into account the insulin given for correction and ignores what was given for the meal. So, if my daughter takes 10 units of insulin for her food and 3 units for a correction then blouses again in a couple hours for a snack the pod only considers the 3 units for correction and ignores 10 untits of insulin on board. Is that correct? Has anyone had a problem with this? Or is there a way to get around this so that you are not stacking insulin? I am assuming lots of parents with active kids give snacks in between meals and if it was that big of a problem they wouldn’t be on the pod, but my endo really disliked that feature so I thought I should ask how others handle it.

I’m going to disagree with Erika. The Pod only takes into account the insulin you’ve given as correction for the insulin on board. The theory behind this is that what you’re giving yourself at mealtimes is enough to cover the meal and nothing else. The only time I’ve run into problems with this is if I’m testing within a hour or two of eating. The pod will try to correct for that test even though my meal insulin is still working on any highs caused by that meal. It the ideal world you’ll get yourself more or less flat lined throughout the day and it won’t matter one bit. For now if I’m going to eat again soon after a previous meal I don’t bother to test before eating more, I just bolus for what I’m eating. I don’t think it’s a major cause for concern, it’s just something to be aware of as you’re figuring out how to use the Pod.

Nope the pod is all knowing. That has been one of the most useful features for my daughter to see where we are with the insulin on board. We have had many less lows because we can see what is still “in the works”. I’d be shocked if the pod doesn’t change things tremendously in a very positive way. Greg

It’s true that the pod takes this avenue with the Insulin on Board (IOB). The important thing to consider when eating an extended meal (or grazing through a meal like at a reunion, for example) is that you must count carbs accurately. If you counted right, it doesn’t matter that you have those 10 units on board (they will get utilized appropriately by what your daughter ate). The thing you have to be careful of is that your glucose may spike some w/ food intake (rise to something higher than you want, like 200-250) but if left alone, will come back down to the desired level when all your insulin is taken into the blood stream.
If you eat and bolus (like the 10 units you mention), and then test 1 hour later, your glucose may not be where you want it, but the pod thinks that all the insulin must have been used and you counted wrong (even if you did count right) so it will suggest a correction…just be weary of this if it’s been within 2-3 hours of your last bolus (this time will depend on your current insulin’s action time that you set…if this is set incorrect, your PDM’s brain will be calculating based on incorrect info, so it’s important that you get this right or your correction boluses, etc, will be off).

I think as long as you understand how the PDM is looking at your IOB, you’ll be fine. The technology can only be as smart as you allow it to be (by giving it the right info :slight_smile:

also if you just do a manual bolus w/ the pod (w/o giving it info like what your glucose is, or how many carbs you’re eating), it will also not calculate that amount into IOB. So be cautious if you do this for some reason…

Very helpful… thank you!

That makes sense to me… not sure why her endo was so concerned as this seems like a common sense way to avoid lows:-)

Sorry, but greg and Erika are definitely incorrect. IOB (Insulin On Board) is only used for non-meal boluses. This is different than at least one other pump but I agree with Rebecca that it is actually a more sensible strategy. When you tell the PDM about carb intake, it rightfully assumes all the insulin it calculates for that intake will (eventually) be used by the carbs. More carbs means you need more insulin, period.
In my opinion, an endo should be intimately familiar with this theory; from what I’ve read online it is a controversial subject and not all CDE’s and endo doctors agree; I can’t find the web reference now but the gist of what I read was that it is far from a closed subject and neither side is conclusively right or wrong.

Insulet made this a conscious decision in the design of the PDM software, and did not change it in teh 2nd generation PDM even though I’m pretty sure some people compained and asked them to. To me, that says they’ve given it all due consideration and their medical staff feels this is the right way for most patients.

By the way, in more than 1.5 years of using OmniPod I’ve never had an unexpected low BG because of this IOB strategy.

Great response, Bardford. Much more articulate than what I said, but I agree 100%. :slight_smile:

Hi Olivia,

Stacking insulin is a real issue and is a risk for all pumps. It is correct that the OmniPod calculates IOB for correction bolus’ only. It will NOT calculate IOB for a meal bolus. Other pumps will calculate IOB for any bolus given for either meal or correction.

I think that it is important to remember that although today’s insulin pumps are “smart” pumps, no matter what their features are, the user always has to use judgment when using them. There are many variables to take into account when processing a BG reading and I think it is usually prudent to stop and think a moment before delivering any bolus.

When Caleb began pumping we were counseled that you would not want the pump to calculate IOB for meals because if your IC ratio is correct and you counted your carbs right, you will need all that insulin for the food you ate. Theoretically that is correct.

However, there are times when even the best efforts result in an unexpected blood sugar and it is important to consider when the last bolus was delivered. For us, a low BG reading beyond an hour and a half but less than two hours has passed since the last bolus means we should compensate for IOB because most foods have worked their way through Caleb’s system at that point. But if Caleb were to experience a low within 45 minutes of being bolused and eating, a meal IOB would calculate an amount of insulin that would not be meaningful because for Caleb, the food has not hit his system completely. To rely upon a pump calculated IOB would result in feeding him too much or delivering less insulin than necessary and a high blood sugar would result.

On the other side, if Caleb has a high blood sugar at an hour and a half after a bolus, most times the IOB in his system is not working and I need to ignore and override any IOB the PDM has calculated from a previous correction. This is probably not the case for everyone. It is what I have learned over time is the case for Caleb.

I think the fact that OmniPod does not calculate IOB for meal bolus’ in and of itself does not preclude it as an effective insulin management tool, nor does it mean that you will inevitably stack insulin. It is important for the user to know how the IOB is calculated for any pump though, so that they can make appropriate decisions in their insulin delivery. Some people, because they have grown accustomed to the method of IOB in their pump (which includes meal boluses) find the fact that OmniPod does not include meal bolus’ as a deal breaker. I can understand that once you are used to a method and it is working for you that you would not want to change it. But to state outright that it will more likely result in lows I find to be misguiding. I also know of as many people who have switched and adapted to the IOB change without an issue.

The other thing to keep in mind is what you program into the pump as your insulin duration. We use two hours and that works for us. So if Caleb ate lunch, then 2 hours later checked his blood sugar and ate a snack, there would be no IOB calculated or theoretically in his system and he should only be bolused for the food that he is about to eat, and should have that entire bolus. Some people use longer insulin durations. When we were trained on the Pod, the trainer told us 3 hours - anything less would result in lows. She left the room and the CDE had us change it to 2 hours - anything longer would result in highs. Again, as long as you understand what the variables are, you should be able to work with them.

I think part of the decision to leave a new IOB system out of the 2nd gen. PDM would be that they would have to re-submit for FDA approval…which is a LOT more hoops to jump through, and delays in getting the new product out. That’s not a substantiated fact though, so I could be incorrect in what I’ve heard…

I agree with what Lorraine has stated. It’s about understanding the technology in order for it to be utilized in the best possible manner. No matter what pump you use, you need to understand how IOB is calculated. You also need to know that your insulin action, correction factor, insulin to carb ratio, basal rates throughout the day, etc, are all set appropriately. Once this is secure, then bolusing becomes much easier and much more accurate.

This all makes perfect sense; her endo had me concerned because he kept referring to it as a “quirk” with the Omnipod… like it was an unintentional defect. Having no familiarity with using a pump I figured it was best to put my question on this forum for people who actually do use it. My daughter has LOTS of nighttime lows (40’s-50’s) right now so I am so excited to get her on the pod.

Agreed, Lorraine (and others). The pod differs from the Minimed/Animas/Cozmo pumps in the way in which it calculates on board meal insulin, but all pumps have this issue. A smart pumper can work around it, either way. All pumps currently calculate on board correction insulin the same. I switched from doing it one way for nine years on other pumps and now do it the pod’s way. I find the pod’s way actually covers my food better most of the time.

If I take my bolus, wait the right amount of time, eat my meal, and then want to repeat the eating later (which I do frequently b/c I’m pregnant and starving all the time), I have to realistically consider how I’m responding to the last bolus taken. If it’s an hour later and my blood sugar is at or near my target 1-hour post-meal goal of 140, then it makes sense to give new insulin for a new food. If it’s an hour later and my blood sugar is 70, then the first bolus, as Lorraine mentioned, probably wasn’t accurate for one reason or another and I might choose to eat the snack without a bolus, since I know the insulin will continue to lower my BG for another 2 hours or so. Etc. If her ratios and targets are set accurately (which takes time), you’ll know whether or not to tweak those suggested bolus amounts. How long your DIA (duration of insulin activity) is will depend primarily on the insulin you use (Apidra’s DIA is shorter than Novolog and Humalog, for instance) and on her personal insulin sensitivity.

In time, all these tiny factors will be tweaked for optimal pump performance for your daughter. Do not fear the lows and highs as you proceed through the learning curve of pumping. Just treat, log, and learn. It’s the difference between using a computer and a typewriter. There’s a lot to process, but in the end, it’s so worth the change.

Great advice; your information on insulin durations is well stated too. I think it is wise to carefully consider the bolus and not just rely on what the pump suggests; I am asuming that is why Insulet put this feature on the Omnipod. It allows you to bolus for additional carbs eaten without being told that you can only take so much insulin because of IOB.

On another note, how long has Caleb been on his CGM? My daughter is resisting wanting another “thing” on her so I am not pushing it for now. Were you able to get good control prior to him using it?

Well said & I love the computer analogy:-)

Every time you bolus, the pod asks you if you want to use your bg to calculate the bolus. If not, you can just enter the carbs. This is what we do if my son ate within the past two hours. I always have him check, because if he is low, I want it to “reverse correct” and give him less insulin. If he is high, and it’s been less than two hours, we just have the pod ignore the bg.
Also, there is a way to see how the pod is calculating your dose. Once it has the dose figured out, you just push the ? button, and it will tell you how it figured it out. That way if you have other information that would affect the dose you can adjust it yourself.

Good to know!

I love this site…thanks, Natasha, I just learned a few more things about the OmniPod. I’ve got the “reverse correction” thing down; but wasn’t aware that you could see how the pod/PDM calculates my bolus.

Hi Olivia,

Great question and I am not even going to attempt to add as Eric, Bradford and Lorraine have more than covered it.

Question for everyone who has commented, what do all of you have your active insulin time set for? I just left it at 3hrs because that is what I had it on the minimed when I switched a couple of months ago.