Animas Ping - IOB and corrections

I am sharing what I have ‘figured out’ so far with this pump. If you know how to make it work better (more reliable), I am absolutely interested in hearing what you do with this pump to get it more reliable…

(As many here, I came from the Deltec Cozmo pump… This spoils me as that pump just worked… quite well if you ask me!)

In case it matters, I use Novolog. For the most part, I see the insulin effective for about 4 hours after bolusing.

Here’s a possible scenario that helps to explain what I am asking about:

5:00 pm BG check = 140
5:30 pm Dinner: pizza (total Carbs = 120g) (for me, this is a 20 U insulin bolus)
7:30 pm BG check = 210

Here’s where things get interesting… If I check my BG at 7:30pm (as shown above) and see that it is 210, I can’t trust the Animus ping meter IOB formula… It does not seem to consider that two hours have passed and the IOB has two remaining effective hours for me…

If I correct for the 210 BG, in two hours, I will end up severely low… several times low enough that I needed help getting back to normal.

The current remedy for this is to not trust the ‘correction’ process at all with this pump/meter combo.

Does anyone have success being able to use the eZBG menu on the meter and give a correction without crashing several hours later?

For the life of me, I don’t recall the Deltec giving me any troubles with the corrections given.

What you could do is based off the ezbg take what you normally would only cut it in half and see if that helps or prevents putting you as low as it usually would.

Link that was posted in the bottom of the other recent IOB thread that explains the difference between the way IOB is calculated for different pumps.

http://www.diatribe.us/issues/22/thinking-like-a-pancreas.php

It does not seem to consider that two hours have passed and the IOB has two remaining effective hours for me..

Have you changed the IOB duration?



I find pizza is very hard to judge in terms carbs, but are you positive your I:C ratio is correct? Do you combo bolus?



Have you thought about ways to keep from spiking that high during a meal (aside from carb/portion “control”)?

I echo Scott’s question. “It doesn’t take into account the IOB duration” probably means you haven’t set it for the 4 hours you want. For corrections, the IOB should be correct based on the DIA and the ISF you set into the pump.I also notice you said your bg was 140 1/2 hour before dinner. Did you add that bg in when you went to bolus? If so, it would have also suggested a correction bolus. If you start at 140 and eat pizza without a correction, it’s pretty much a guaranteed high!



I believe it is when you are doing a carb bolus that it doesn’t subtract the IOB. It does display it but it doesn’t subtract it, you need to do so if you wish. I’ll have to check to make sure, but I believe that is the difference between the EzBG and the EZCarb.



I agree with Scott that a combo bolus works better for pizza. Although, frankly for me, that much pizza wouldn’t work at all. I ate one piece of thin crust pizza last night with a salad for 43 carbs and even that needs a combo bolus. Some things just are too much carbs for me and I can’t predictably bolus for them. YMMV.

Thanks for the replies…

I checked my pump and confirmed my IOB-2 is “on” and set for a duration of 4 hours.

I also checked the Insulin to carb ratio and am currently set for the following:
12:00 AM 1 : 5U
9:30 AM 1 : 6U

I am not sure about the ISF… It is currently set as follows:
12:00 AM 1U : 15

I have used the combo bolus but do not normally use it.

ISF is how many points one unit of insulin drops your blood sugar. Mine is one unit drops me 45 points. So far, I just have one ISF, but I can see that I should make it different for different times of day.



I think combo bolus works very well for high carb high fat meals like pizza, but it took me some playing around with it to get my own formula: I use a 4.5 hour spread, and have my bolus set 40/60 (40% right away and then 60% spread out over the 4.5 hours). I also overbolus about one unit.



Kelly’s link to info about how IOB is calculated by various pumps is reposted above. It helps to read it, but it’s complicated, and for me what I do is just look at the recommendations and make my own decisions based on experience of what works for me.

How much IOB do you have at your 2 hour mark?

Me? I use a 3.5 hour DIA. When I was on MDI I just used 3 and calculated it in a linear manner. So if I did 3 units, at the 2 hour mark I had one unit left. Easy to figure! The Ping calculates it in an algorhythmic maner which means it considers less taken the first 1/2 hour, more taken in the second hour and then less after that, because it takes awhile for the insulin to start acting and then it has a “tail” where there is some smaller action at the end, it isn’t even. Kelly’s link gives the exact formula of how this works I believe.