How to know how much insulin is still active?

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curlygirl

curlygirl

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Relationship to Diabetes
Type 1
Hi,
I am a bit confused as to how to work out how much insulin is still active at a given time. For example, if i had my bolus at 6pm say, and it was split over a multiwave of say 1.5units upfront and then 1 unit over the next 45 minutes, how long afterwards is the insulin that has gone in before tea still acting on my blood? I have been given 2 very different answers by my dsn at different points and am therefore a bit confused.

The main reason i am trying to work it out is so that at bedtime i can see if it is ok to go to sleep as it is only really the basal that is working on my blood or whether actually, the mealtime insulin is still having an effect and will, therefore, drop my sugars too much.

I was told that the peak time is approx one hour for novorapid and approx 3.5hours for finishing working, but i am not sure this is tallying with my experience at present.

Anyway if anyone has any answer to this question i would appreciate that. I am still working on lots of areas so maybe, when carb ratios and basal rates etc are sorted things will become clearer...
Thanks
Curlygirl
 
Hi, not sure what pump you're on? We have the Medtronic Veo, and you can set your own individual "duration of insulin action". My son's is set to 4 hours, although in practice I think 3-3.5 is more like it at certain times of day. The pump uses this to calculate "active insulin" at any given time, which it offsets against any correction bolus (although you can override this if you wish).

The problem is, it inevitably varies between individuals as to how quickly the insulin acts and how steep the curve is for using it up ( it's not linear - ie 4U is not spread equally over 4 hours, I think more like 75% of the insulin is "used up" in the first 2 hours). So it's not an exact science!

I do find dual wave boluses a confounded nuisance when they're needed for an evening meal, because you end up with "active insulin" well into the night, and this messes with any corrections that might be needed. I've taken to avoiding pasta for teatime, or to replacing the square part of a dual wave bolus with an increased temporary basal (which won't be counted in "active insulin"). But I'm getting up in the night to monitor his BG level, so can keep an eye on things.

Sorry if I've rambled on a bit! 😉
 
I think your DSN is a bit short on the duration of insulin as it's between 4 and 5 hours.
If you have set your pump up correctly it will tell you how much insulin is on board at any given time.
All pumps are capable of doing this as long as you have set the pump up correctly.
( Out with the manual quick 🙂 )
 
This is a classic example of it's never one size fits all unfortunately. After much trial and error, my active insulin (no or rapid) is set to 3 hrs and this works for me when it comes to having to make corrections based on the active insulin left according to my pump. I can't really comment on the multiwave option as I don't use it often but I can imagine that being quite difficult especially if your active insulin time isn't correct. Hope you work it out 🙂
 
A Medtronic veo tells you how much active insulin in the screen. Good luck 🙂
 
Thanks Redkite for sharing your experience - it is appreciated and it is interesting to hear from people with much more experience than i have - it is all so new, and very overwhelming at times still.

Pumper_Sue - thanks for your reply. I have had the book out, but can't find how to get this information. It is the accuchek insight pump and when bolusing for an early lunch say, there is a deduction made for insulin still active from breakfast etc, but i cannot see active insulin displayed anywhere other than this. If anyone who uses this pump does know how to do that it would be very helpful to know how...

Riri - thanks for replying, i appreciate you taking the time. I agree that using multiwaves is perhaps making it even more complicated to work out my own personal length of insulin activity, but the pump rep said i should use a multiwave for all meals, at least for now, so i am trying to do this.

Hobie - thanks for taking the time to reply, it is appreciated.

Curlygirl
 
Hi Curlygirl, I have the Vibe so can't direct you in the right direction. Can only suggest you go through each section on your handset as must be hidden there somewhere.
My pump shows it as IOB when I poke a button, so very technical :D
 
curlygirl said:
It is the accuchek insight pump and when bolusing for an early lunch say, there is a deduction made for insulin still active from breakfast etc, but i cannot see active insulin displayed anywhere other than this.
Click to expand...

Ah! That might explain things... Unless Roche have had a rethink with the Insight, your pump will *only* track the correction parts of any dose (this is what the Expert and Combo used to do)... Any insulin that is dosed against food is assumed to be working correctly with the carbs that are still being digested (slowly if you chose to use a combo bolus!) so they don't show in the Active Insulin calculation.

Have a dig around in the handset and see if you can find anything about Active Insulin?
 
Thanks everydayupsanddowns - perhaps this is the case with the insight then. Having had a look at the handset and the manual i still can't find any reference to active insulin. I am seeing the pump rep next week so it looks like i'll have to wait until then and ask her.

I was having another read through a couple of your posts about Artoo yesterday, particularly the one from a couple of months into pumping. They make for interesting reading and it is much appreciated that you write and share your thoughts on these things.

Curlygirl
 
Hi Curlygirl I don't know the answer to your question but if I wanted to find out whether it was my basal causing drops or my multiwave then I would do basal testing during the evening/night. I know that the guidance is not to eat anything or bolus within four hours (query 4 or 5 hours) but obviously this is difficult if it is for your evening meal. So personally I would go carb free for the evening meal so that I don't have to bolus and then see how my BGs act overnight - I know that this isn't perfect because for some people protein can put the BGs up but it might be better than other options. With regard to Insulin on Board I think that also depends on the individual because although for some people Novorapid may last e.g. three hours for others it may be five plus hours. I hope this helps. Apologies if it doesn't or if it has confused you.
 
If the Insight is the same as the Combo then you programme into the settings the duration of the bolus,let's say it's four hours. Therefore if you can't find the IOB displayed it will be four hours after the multiwave finished. So, for example if the multiwave was for 45 minutes and you bolused the multiwave at 7pm then the IOB would end 4 hours 45 minutes later.
 
Thank you for your reply AJLang - your time is appreciated. I am working my way round to the evening basal test. I was told to start with overnight, then morning etc so i haven't done an evening one yet. I had not thought of doing it with a carb and bolus free meal, i was thinking i would have to go from lunch one day through to breakfast the next, but i will have a think on the carb free ideas now.

I am calculating the approx end of the active insulin as you described e.g length of multiwave plus duration, it's just that i am not yet 100% sure of the duration for me, and i have been given several different figures as the length of duration. Hopefully time and experimenting should help me work it out.

Thanks again.

Curlygirl
 
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curlygirl said:
Thanks everydayupsanddowns - perhaps this is the case with the insight then. Having had a look at the handset and the manual i still can't find any reference to active insulin. I am seeing the pump rep next week so it looks like i'll have to wait until then and ask her.

I was having another read through a couple of your posts about Artoo yesterday, particularly the one from a couple of months into pumping. They make for interesting reading and it is much appreciated that you write and share your thoughts on these things.

Curlygirl
Click to expand...

Awwww thanks Curlygirl! You are too kind. Thanks for reading 🙂
 
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