Insulin ON Board question

We have stated using the advance features and my son who is 15 is getting used to using EZ Carb and EZ BG. About 4 hours ago he was at 91 and about 2 hours ago he took 2.6 units to cover a snack. He just tested and was at 175 and ate 27 carbs at a 10:1 ratio. Normally we would give him insulin of 2.7 units and one for correction for a total of 3.7 units of insulin.

Using EZ BG it showed insulin on board and showed a insulin correction of only .35 units needed when factored with BG.

However , about 5 minutes later when I when I went back to check the number it showed no IOB and suggested the correction I would have given him (1 unit) without the meter suggestion.

Can't figure out why it changed so quickly in such a short time. Any ideas anyone. Should he be following the meter / pump IOB suggestions??

Check where you have the “insulin on board” set at. if it was set at 2 hours it might have shown the .35 correction. A few minutes later (over 2 hours) it might show no IOB and recommend the full correction. the pump and the meter should be talking and giving the same # as long as they’re in range.

if he has 2.6 onboard 2 hours previous, there is no way it would normally all be gone in that 2 hour period…unless there was a weird fault in the meter (are you using one touch ping?), it is remotely possible that you may have just hit a wrong button or read the IOB wrong the first time. I have never had that problem, but have adjusted my insulin sensitivity because the bolus corrections for high BG were not bringing me down enough - I have gone from a 3.1:1 sensitivity to 2.8, and that has managed the highs very well…the meterand the pump are powerful comuting devices, and in particular the IOB, so I just cannot see how that could have happened. Then again, I get ‘pump not primed’ errors about every third time I chnge my infusion set, even if I have not chnaged cartridges or tubing!

What time do you have programmed in? I don’t have my son’s pump in front of me, but I think his is programmed for 3 hours (he’s almost 15 too). Our experience with IOB in 7 years of pumping is that many times we disregard what the pump says during the last hour to 1/2 hour of IOB. This is a case of pump not being as smart as the body - the pump programming assumes the body uses the 1/3 of the insulin per hour (or however it breaks down for your son). In reality, I’ve read it’s something more 50/30/20 (don’t quote me on that, but you get the pictuire- more insulin is used in first hour than it is in second or third).

For example, if it’s been 2.5 hours and he’s 180, he goes ahead and just boluses for the food and adds in his correction (or about a unit), and not what the pump says, because we know it’s not going to be enough,

I hope this makes sense!

The Ping does not use a linear IOB algorithm (which you suggest by saying it assumes using 1/3 per hour when set at 3 hours). In fact, it uses a curvilinear algorithm which does in fact take into account a “peak” insulin action. Some pumps, like the Omnipod do use simple linear algorithms though.

cool. We’re on an older version (had it 3 years) and before that a Cozmo. One of my biggest complaints was that - it seemed like with that all the info out there about insulin absorption rates that would be fairly easy to fix. Hmmm, I may fork over the upgrade money and consider. My son didn’t see a lot of benefit in upgrading (other than the improved screen). But I’m going to double check this first on his - I know for a fact that the Cozmo was and I always was complaining to the endo. We always got in the habit of “overriding” the pump suggesting and doing our own correction because we knew it just wasn’t enough.

Let me ask this - can you still program it for slower absorption rates - say 4 hours? When my son was younger the endo always had us set up for 4 hours. Now that he’s a teen we’re down to 3. Or is it preset???

That being said, I would still check how the absorption rate is set up on the pump. It might be set up incorrectly. (2 hours?) I would do some testing to verify his absorption rate. As another person said above, having all the insulin gone in 2 hours is just not right.

Yes, you can change the rate of absorption setting on your pump. I have my IOB set at 2.5 hours after some tweaking and working with my endo and Animas trainer.

I would call Animas and just chat with them (or perhaps your pump trainer). I have noticed little oddities like this over the years (just don’t question them as much anymore) and rely more on our “gut” instinct with corrections, because sometimes the pump suggestions seem a bit off (esp. in that last half hour of IOB). I know quite a few adults who don’t use the “smart” features because these little program glitches annoy them and after years of not having smart features, they feel they know their bodies better than the pump programing.

Thank you all - Well I just checked and the IOB duration is set to 3.5 hours. Not really sure what that means.
I think that is a factory setting. So is the amount of IOB that is indicated on the meter the amount left after the 3.5 hour mark??

If I understand your question, the IOB duration you have set up means that after 3.5 hours you (your son) has no more “active insulin” from the bolus. Now, is this the correct duration? You’ll need to test this to make sure. I just recently changed my son’s from 3.5 to 3. If you had a pump trainer, they may have set it up to that. With new pumpers they prefer to be conservative so that they don’t stack (or over-bolus). I’d check it out on the weekend - if you believe the basals are correct, then have him bolus for a meal/snack and test at set intervals (like 2.5 hours, 3 hours, 3.5 hours) to see if the insulin is still “active”

Good luck - nowadays with my teen we’re always changing basals/boluses every few months - growth spurts suck. But one day I hope soon he’ll stop growing.