Insulin On Board

[shiftzor]

I don't get this feature, currently got it set to 4 hour and it always causes more problems than it ever solves. I can think of a couple of instances where it was right but I ignored it anyway because its wrong 90% of the time :D. Problem is let’s say I am high at 2 hour mark even if I still have IOB I would ignore it and dose the full correction dose, returning to normal 2 hours later. There are exceptions to this, such as if I have eaten a high GL meal but these cases I usually leave it an hour and then correct if necessary. My question is am I using it right and does anyone else use it?

[sarahspins]

I currently have mine set to 2.5 hours (and my CDE is totally fine with it, didn't suggest it was too short). Sometimes I feel like that may be too long - I rarely see much action with Novolog past 2 hours, but I know that isn't the case for everyone (to be honest if I could set it for 2.25 hours I'd be thrilled). The good thing with the 2020/ping though, is that you can choose to ignore the IOB, or ignore about half of it (as I tend to do) or whatever you're comfortable with... since you just tell it the dose you want.

[notme]

I am just the opposite Sarah. I have mine set at six hours and it usually is pretty much right for me and the humalog I am using. I think you may need to alter your four hour duration, shiftzor. We are all different and have different responses to our insulin.

[sarahspins]

6 hours would have been about right for me with Humalog.. it behaved a lot more like Regular did than I had expected it to (it worked faster, but it sure hung around for a LONG time too). Novolog has always seemed to be in and out VERY fast for me. I see a tiny bit of action right away (within 10-15 minutes), then it peaks a little over an hour after injecting, and works for about an hour, that's it... I don't see much more effect.

I know everyone is different.. I'm actually considering trying Apidra to see if that will help with my site irritation and it will be interesting to see what the action seems like with that one.. I stopped using Humalog because of swelling and extreme itching/irritation, not because of the DIA, and now Novolog is causing just as much irritation for me.

[shiftzor]

I think you might be right about the duration. Problem is it’s impossible to really know how long insulin takes in me; however I am beginning to think 3 hours might be a better option though. It would be good if it worked more reliably because I do find it useful at times, like when I am playing sport. My post is more in frustration, I didn’t realise people used less than 4hours because having looked at the charts of insulin activity it seemed unlikely to be any shorter. I should know better than to be too scientific about these things. :D

[GretchO]

I shifted mine to 3 hours from 4 about a month ago (humalog) and have found this to be much better for me. Everyone's so different!

[Subby]

If spiked badly (I guess 4 mmol/l spike or more) I ignore between 1/3 and 2/3 of it (add the deduction back in). It seems this gets the best results for me down the track and rarely leads to a hypo if I think carefully about it. To me, it seems that the best accounting for this, is IR due to the spike/being high.

I have mine set at 4 hours (novorapid). I didn't have much luck on other settings - it led to big issues. Sometime I might revisit that.

[sarahspins]

I do think there is a tiny bit of a tail for me, but it's not enough, honestly, to worry about - everyone is different. I personally think that the 'curve' that the pumps use to calculate IOB is a little too gradual, no matter how long you set the DIA for.. in my case I just know there's much less working at 2 hours than it tells me. You can always change it to 3hrs for a while, and if you don't find yourself overcorrecting, then you'll know that works for you. When I had mine set to 3hrs, using the IOB I was having continual highs - when I got to where I was constantly overriding the IOB, I lowered it to 2.5hrs. Generally if the pump tells me I have less than 1u on board, I just ignore it, and add it to whatever bolus I'm taking.

[Russell A.]

I have mine set at four hours and pretty sure it is not accurate but do not put much value in that stat.

What I do find is when my post meal bg is over 200, if I eat again w/i four hours or do a correction, I have to at least double the normal amount to compinsate.

I basically pay no attention to the IOB and bolus according to my bg. I find the same thing at bedtime. If my bg is over 200 I must "juice" myself with a bolus, sometimes dual or square or else my bg is super high in the morning.

Anyone else agree with me or find the to be accurate?

Russell

[Mich]

Hi Shiftzor.

I use Novolog in my pump and have it set for 3 hours. I've tested every 15 minutes through two different 4 hour periods to decide that. After the two hour point, my blood glucose decrease really slows. At the 3.5 hour point, it's barely there at all. This is done with only normal moving around at home.

Llike most people I get more work out of my insulin (my usual 1:9 Insulin to Carb ratio is more like 1:12) with exercise, but the bolus working time remains the same.

Mich

[xMenace]

I agree with you Shiftzor. In fact I don't even use the wizard. It makes no sense for me to even consider IOB when I have a pp high. Yes I've taken insulin but I also consumed food to cover it. It should IMO be a totally written off dose and doesn't need to be considered. For those 10% of cases that are wrong, I suspect you had a high GI meal which have you more of a spike than expected, but these also tend to come down fast and hard in the 2 to 4 and even 6 hour marks.

I use Novolog in my pump and have it set for 3 hours. I've tested every 15 minutes through two different 4 hour periods to decide that. After the two hour point, my blood glucose decrease really slows. At the 3.5 hour point, it's barely there at all. This is done with only normal moving around at home.

A great test! Of course these types of calculations assume your basal rates are perfect. I know my basals are pretty good, but I still won't trust them completely when doing these tests. I suggest not only repeating them but also doing them at different times of the day. Once just isn't enough in this business.

[shiftzor]

A great test! Of course these types of calculations assume your basal rates are perfect. I know my basals are pretty good, but I still won't trust them completely when doing these tests. I suggest not only repeating them but also doing them at different times of the day. Once just isn't enough in this business.

That's another problem entirely. Even the finest insulin increments on the pump don't match a pancreas which will make a difference to post meal bgs.

IOB is a good idea in theory. Unfortunately its difficult to achieve in practice as it needs to be more scientific/accurate than just a guess based on an algorithm (a curved shape based on time).

[Mich]

You're correct, I doubt anyone trusts their pump to manage their diabetes. It's a tool. I'd rather have a pancreas ;) but it just wasn't in the cards.

For instance, the IOB is only the first layer I use when bolusing for a meal. It gives me an ok estimate of how much active insulin I have working.

Next I consider the glycemic index of what I'm eating.

Lastly I add a correction bolus for my pre-meal test. I add to that dose and do it before my meal if I'm high--another type of alogorythm we must consider of course is insulin resistance.

After all of that, I do my bolus.

I think managing diabetes has some things in common with herding cats.

For me, it's just never quite been an exact science. No matter how hard I try, there's always an element of surprise.:eek:

Mich

[Russell A.]

Lastly I add a correction bolus for my pre-meal test. I add to that dose and do it before my meal if I'm high--another type of alogorythm we must consider of course is insulin resistance.

After all of that, I do my bolus.

I think managing diabetes has some things in common with herding cats.

For me, it's just never quite been an exact science. No matter how hard I try, there's always an element of surprise.:eek:

Mich


I am with Mich!:D

It is a bit of guessing, estimating and using my crystal ball! LOL! Sometimes hit perfect other times I am off, mostly far off! LOL!

Love having D! Oh, all the joys:D

Russell

[Bethanne]

Hi Shiftzor.

I use Novolog in my pump and have it set for 3 hours. I've tested every 15 minutes through two different 4 hour periods to decide that. Mich

This is a great idea. I'm going to do this. I only recently started using my bolus wizard functions... sadly, I know. But I LOVE the Active Insulin function. I haven't overcorrected a hpyerglycemia in over a week because of it. :) I have found that on 4hours, my body will get to normal with the appropriate number of units/carb. Still, testing is a good idea.