- advertisement -

Medtronic 530g question regarding "active insulin" and bolus wizard.

Discussion in 'Parents of Children with Type 1' started by mmgirls, Feb 6, 2016.

  1. mmgirls

    mmgirls Approved members

    Joined:
    Nov 28, 2008
    Messages:
    6,030
    So we are trialing the 530g insulin pump/cgm with connect.

    I am wondering about how the pump reduces the suggested bolus when she has a low BG and IOB. Yesterday after school she had a good sized snack and went out to play, the pump alerted her of low BG and she decided she was hungry enough at that time to eat something else. I saw that the pump did a reverse correction for the low bg but it did not reduce the bolus by the amount of IOB/active insulin? it just twlls you IOB but does not reduce bolus ? or did we miss something while setting it up?

    Looking thru the books but have not found what I am looking for yet regarding the bolus calculations.
     
  2. kiwikid

    kiwikid Approved members

    Joined:
    Dec 29, 2005
    Messages:
    3,011
    With the Medtronic Paradigm pumps, all
    boluses (meal and correction) are taken into
    account when IOB is calculated. However, IOB
    is only deducted from correction boluses, so the
    full amount of IOB is not always deducted. For
    example, if the correction bolus is 3 units and
    there are 2 units of IOB, the full 2 units are
    deducted. But if the correction bolus is 1 unit,
    only 1 of the 2 units of IOB will be deducted. If
    the blood sugar is below target, no IOB will be
    deducted. In other words, IOB is never
    deducted from meal boluses, only correction
    boluses.
     
  3. mmgirls

    mmgirls Approved members

    Joined:
    Nov 28, 2008
    Messages:
    6,030
    HMM, I am not sure I like that. Yesterday I ran the Ping side by side of the 530g when I noticed a big difference in the suggested bolus and I told her to reduce the bolus because she was getting ready to go to a birthday party. SHe would have been low if we had not reduced by the IOB.

    Ok so how do you use or think about IOB then? what is your process if BG is low and you have IOB?
     
  4. kiwikid

    kiwikid Approved members

    Joined:
    Dec 29, 2005
    Messages:
    3,011
    That was a copy and paste from Gary Scheiner.. We trialled Medtronic and didn't like it..
     
  5. mmgirls

    mmgirls Approved members

    Joined:
    Nov 28, 2008
    Messages:
    6,030
    what was the biggest thing you didn't like?

    My daughter is liking it, but she has a friend with the pump so I think that is all that is.

    The CGM integration with the connect device is nice, but I am not sure its going to win me over. the look of the 640 looks so much nicer. And come on ANimas when are you going to come out with a new Ping remote that is fully functional?
     
  6. quiltinmom

    quiltinmom Approved members

    Joined:
    Jun 24, 2010
    Messages:
    1,189
    I want a meal bolused for regardless of iob, otherwise he will be high later from a meal not fully bolused for. If he is low, I will subtract a few carbs from the meal bolus, counting those carbs as low correcting carbs. If he was about to do something active, I would reduce the bolus amount (override the pump) or reduce basal.

    We almost never do manual boluses. If the iob is from a manual bolus, maybe it should be handled differently. Maybe someone else can comment on this. I assume it would be counted as iob and, if giving a correction, would be subtracted.

    I guess what I'm saying is that it depends what the iob was from and what caused the low. If he ate, then ate again an hour later, he would still have iob but if his I:c ratio is correct, he will need all of the second meal bolus, regardless of iob. If the first meal bolus was too much, causing a low, then you'd want to give some free carbs or reduce the second dose. If the low was exercise related I might do something different, depending on what was going on.

    Does the ping handle iob differently?

    You could call Medtronic and ask them. They *might* have someone there who can answer your question. :). (Nothing against Medtronic, it's just a technical question that I don't think they have as much practice answering.)
     
  7. kiwikid

    kiwikid Approved members

    Joined:
    Dec 29, 2005
    Messages:
    3,011
    My biggest dislike of the Medtronic pump was that we had the pump trainer here, we opened a brand new packet of batteries to get the pump set up and it wouldn't accept any of them as 'new' .. the pump trainer didn't really know what to do - said she hadn't come across that before but it stuck with me.
    Another thing I didn't like was the IOB calculation ( I dislike target ranges and have a target BG ) On Animas if you do a correction and you are outside your target range, then the pump will correct to the middle of your range .. On Medtronic I believe that the correction will correct to the the outside of your target range - which seems to be a bit odd.
     
  8. cdninct

    cdninct Approved members

    Joined:
    Jul 29, 2011
    Messages:
    888
    I don't know--it doesn't bother me. If he is low, his pump does a reverse correction, which works for me, and is all the thinking I really want it to do.

    The pump assumes that you bolused correctly, so all of the mealtime insulin will get used up sooner or later. Just because my son has IOB, say, 2 hours after eating, does not mean that he is heading low, just that the process of carb absorption and insulin use has not yet run its course. So in your case, it assumed that your daughter's body was still working on the snack she had had before going outside (which, at least for my son, would certainly be the case), and it left that IOB to do that work. It took care of the low with the reverse correction. If it both reverse-corrected and reduced the next bolus, that would be a double correction, to my way of thinking. K would wind up high.

    If ever something seems way off, I will manually adjust, but it almost always works just fine for my kid. I guess we all kind of adjust our thinking to our kids' pumps' logic, but Medtronic's way of "thinking" makes good sense to me!
     
  9. cdninct

    cdninct Approved members

    Joined:
    Jul 29, 2011
    Messages:
    888
    See, again, we're used to different pumps, so we are comfortable with different logic! I don't understand, why would you have a target range on your pump if you want it to correct to one particular number? What other purpose would a target range serve? If I wanted K's pump to always correct to 5.5, that is what I would program his Medtronic pump to do. As it is, I think it is set from 4.5-7.0, so it will attempt to bring him up to 4.5 from a low or down to 7.0 from a high. Works just fine for me!
     
  10. kiwikid

    kiwikid Approved members

    Joined:
    Dec 29, 2005
    Messages:
    3,011
    Bringing a low up to only the bottom of the target range wouldn't give us much leeway, I'd much rather it brought it up to the target..

    We didn't set a range on medtronic, we don't on Animas and we couldn't on Cozmo.. But its there as an option and many people don't realise the way different pumps work. We always correct to a target number.. pump trainers expect you to set a range though.. and obviously pump manufacturers do too.
     
    Last edited: Feb 7, 2016
  11. rgcainmd

    rgcainmd Approved members

    Joined:
    Feb 6, 2014
    Messages:
    1,374
    My comment is neither here nor there, as it's not about the Medtronic pump, but we always correct to a target number also (95), not a range...
     
  12. mmgirls

    mmgirls Approved members

    Joined:
    Nov 28, 2008
    Messages:
    6,030
    So it happened again today on a weekend, daughter had a snack and then went out and played basketball for a bit in the cold. She rang low and had a juice and went to have a snack. She was 74 and had 1.3 iob, Animas said to give .70 and Minmed said to give 1.9, we gave 1.2 and she skirted low the next hours to 88 at dinner. So I think Animas would have won out on that and Metronic, would have defiantly sent her low. I would say for we are not very aggressive, on I:C or ISF she is 10 years in and 75lbs. 1:15 and 66ISF. We have a target of 111 so not terrible high or low.

    I am just surprised by the difference, very similar to the issues we had with the Accu-check Combo pump and I think similar to people that went from the original pod to the newer smaller pod. At the time with the Accu-check, McKenna was too young to learn how to interpret IBM and change how we did things.

    McKenna is so used to plugging in numbers and letting the pump think. She does recognize when she has been running low and asks if she should bolus or times she is running high, but at 11 she is asking what she should do, wanting adult confirmation.

    I do believe part of our issue is Apidra, we have duration set at 3 hours but with small boluses, it is more like 2.5 and large 3.5. Which brings up the fact that I don't like that the 530 can only be changed by the hour.

    So far the CCM and predictive alarms and threshold suspend have been spot on. I am pleasantly surprised.

    I HATE not having a remote but it is completely age appropriate for her to be in more control. I love the ease of the connect unit, hate that it is is only.

    If we where 100% untethered I would hate how long a bolus takes, but an appreciating it right now because we have had more than a few sites that have tunneled back and we smell insulin. I really think the slow delivery will help with that.

    So many things to think about, no wonder I always tried a new system during breaks.
     
  13. mmgirls

    mmgirls Approved members

    Joined:
    Nov 28, 2008
    Messages:
    6,030
    So in my view a reverse correction gets you to your target bg. Our ratio is good on a normal day, but she can go all out in playing outside. So she can come in from playing ringing low sometimes especially if kids are out she just wants a juice boost, but since still active will stay lower or go low agsin. Days they are hanging out and not in the middle of something she wants a snack, and plugs everything in and boluses and go's back out.

    Now her A1c,, was sitting between 7 and 7.5 with very little effort. Both my girls have jumped up to since being here, will have a blood draw a1c, within moths to see if an office finger poke a1c, issue.

    Yes there are times that she ends up high after a bolus following a lower bg with iob. But I would say at least 3/4 of the time it stops another low and let's her go on to the next thing.

    Animas does a reverse correction and reduces suggested bolus by Iob. Since we strickly carb count using a scale I know our boluses are right, and I have always felt that if a correct bolus dropped her to a low with actively then the iob will also drop her if continuing the actively.

    I don't know how to easily change the way we do things it so natural what we do, and I have to figure this out.
     
  14. cdninct

    cdninct Approved members

    Joined:
    Jul 29, 2011
    Messages:
    888
    I guess it really is all in the thinking. Since we have only ever used Medtronic, it makes total sense to me! I look at your scenario and because that the low is a result of the activity and not the previous bolus or IOB, it seems to me that the pump has no business messing with the size of the next bolus based on IOB (but that it should, of course, do the reverse correction). I would assume my son will stay low or go lower because of the activity, and I would give him uncovered carbs to address that particular situation because unlike the pump I can analyze the problem and make a specific, rational decision. I wouldn't want the pump second-guessing what is going on with my kid, I suppose! Boluses are boluses, and corrections are corrections, and my Medtronic-centred logic is just fine with that!
     
  15. mmgirls

    mmgirls Approved members

    Joined:
    Nov 28, 2008
    Messages:
    6,030
    My issue is only when there is IOB from a previous bolus and activety, how many extra carbs that might be needed is dependant on how much IOB there is. I really don't see the difference between uncovered carbs and a reduced bolus from iob?
     
  16. cdninct

    cdninct Approved members

    Joined:
    Jul 29, 2011
    Messages:
    888
    See, to me, how many extra carbs he needs is not particularly dependent on IOB because that insulin is still allotted to handle the earlier carbs as it was intended to do. As long as I'm not second-guessing my carb counting and the IOB is not actually the cause of the problem, I disregard it.

    As for the difference between giving uncovered carbs and having the pump reduce the bolus from IOB, since that is an art and not a science I want to leave it up to me to factor in exercise and whatever other factors or trends I might want to consider rather than having the pump make an executive decision on me.
     
  17. Ali

    Ali Approved members

    Joined:
    Aug 1, 2006
    Messages:
    2,221
    So a grown up perspective. But, I really do not rely on my pumps numbers, because when I am trending low and eat some candy or drink some juice I do not bother to enter those carbs into my pump, I use my own knowledge of what I have eaten and what level of activity I have had in the last hour to figure out what to do. I do rely on it to figure out what amount of insulin I need for X amount of carbs at this BG level, but even then I always double check with did I just take a quick walk around the block, has my BG tended to run high or low all day, did I just eat some carbs cause I thought I might be going low? You can not just plug numbers in to any pump and go, you need to manage on your own, The pump just shortcuts come number crunching, the sensor just alerts but you still have to factor in what you have done and what you have seen trending.
     
  18. mmgirls

    mmgirls Approved members

    Joined:
    Nov 28, 2008
    Messages:
    6,030
    Well the sensor stopped working on the 5th day and unable to recover it. I love the connect device at night that texts me with predicted lows or highs and other alarms. Because my dad does not wake to the alarms at all unless close to wakeup.

    We are getting used to "thinking about IOB", and overall it is teaching us a new way of thinking. That's a good tjing, I think.
     

Share This Page

- advertisement -

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice