Accounting for IOB during bolus - Tslim

I could have swore it will prompt me when I bolus whether I want to factor in my IOB when bolusing. If i press the tick, it will adjust for it and if i press the cross, it will disregard it. But today (and occasionally) when I bolus, it doesn’t give me the option and will just account for it. Is there a condition as to when it prompts and when it doesn’t

@tedos:

While I am running Control-IQ, I think that ihe bolus wizard in C-IQ ALWAYS factors in IOB when it is determining a bolus. At least that’s the way it looks to me …

John

1 Like

I’m on basal IQ version, and when i enter the bolus wizard it gives me this screen. But earlier this morning, this didn’t come up.

@tedos, odds are very high, that if the ‘advisory’ did not present on the screen, then your sensor was reporting your target number, for sake of discussion I’ll say 6.5mmol.
You can experiment by selecting the [ X], & manually enter a BG number.
In my case, if the BG entry is lower (6.2mmol) than target = 6.5, I get your reduce bolus notification. If BG entry is higher (6.6mmol), I get the over target notification, add correction bolus.
Only when BG = Target = 6.5, is there no warning advisory, & can proceed to enter desired Carbs.

No, it was not the target number or the same number as the sensor

Hmmm… well that is curious.
Logically, there are only 3 cases: below target ( reduce bolus); above target (add correction bolus) ; on Target = no action, calc for carbs only.
It is software controlled… I always 2nd guess that stuff! :slight_smile:

Next time you notice this, take a look at the calculation screen. One of my initial pet peeves when I first got the the pump was that it would occasionally grey out and ignore IOB and whatever the correction value was.

I never did figure out why, and haven’t noticed it in a long time. In fact I had tech support all in a tizzy about it, until a manager finally called me back quoting something from the manual… Which I promptly forgot and could never find myself.

I think I saw it most often when I was trying to pre-bolus a small amount, then sit down and test and calculate my final dose at the table. It’s line it assumed the recent bolus was for food not yet digested, so IOB was irrelevant at the moment.

I don’t really see this anymore. So either Control-IQ rendered away with it, or the pump trained me to behave the way it likes.

1 Like

@Robyn_H, I think the pump grays out in Calculation when you are below Range. It will also say N/A sometimes when your IOB is higher than it feels will take care of the BG. I may be slightly off on this but I have noticed that before as well. IOB has always been problematic for me with the CIQ because I always took IOB into account when on MDI as well as with my Animas Ping. Control IQ changes the IOB depending upon the maneuver it was currently undertaking and the amount varies up and down so frequently and without reason (to me) that I don’t take it into account for corrections anymore.

1 Like

I appreciate your consensus and venturing a guess, but I don’t think this is right. I have definitely seen this happen when I was in range, and I’ve seen the correction value highlighted in red with parentheses around it to indicate a negative value. Maybe it’s part of a larger set of qualifiers, though?

And just an FYI, Control-IQ adjusts insulin on board based on whether it has given you extra insulin or withheld any. It might seem odd and a new trick to adjust to, but it should be a more accurate indicator of how much extra insulin is left (that which is not used for basal requirements) to act upon your BG than just guessing based on time elapsed since your last bolus. I’d highly suggest trying to trust that IOB display, unless your settings are off in such a way that would render it inaccurate.

From the Tandem manual:

3 Likes

Side question - Does that mean on control IQ you can’t manual bolus or do a manual correction with an insulin pen?

Ah thanks @Laddie, that explains it then.

Not a consensus nor a guess. It is my experience. I have never seen anything in the Calculation highlighted in red, except the current IOB, nor in parentheses. I read only on the pump and don’t have any other app on a cell phone. Where do you see this?

You can always do a manual bolus on a Tandem pump by selecting the Units number on top and keying in whatever you want to bolus.

Yes but not with an insulin pen because it won’t add to the IOB? The reason why I ask is sometimes i inject via the insulin pen on the day I change my infusion set and find that the bolus delivered (using the pump) isn’t making much impact - just to give it a bit more time to settle and absorb. It just sounds like with control IQ, this won’t work anymore. It may be able to sense a falling BG and compensate for that but it won’t know the true IOB.

I have heard some say they also do pump bolus after disconnecting infusion set, just to record it. Just remember to reconnect !!!

1 Like

Oh yeah, that’ll work. Just wasting insulin but better than nothing if there is no other option

I can’t remember the last time I did an injection, and pens weren’t out yet when I started pumping.

(Oh, now I remember, it was when my last Medtronic pump failed, I was out of town 2 years ago. Did first dose of Lantus!
Medtronic overnighted replacement within 12 hours!)

1 Like