My son Spencer, has been on the Omni-Pod since November. He has four sites, arms, stomach that we use, so in reality, they come back to the sites every 12 days. For the last couple of Pod changes he has been going high (300-350) I tried adding 0.50 units, yet it seems to still go high. Any suggestions would be greatly appreciated. Thanks all!!!
I just tried this, after experimenting with an opened pod to see how to hold it to get any air-bubble next to the output port. It seemed to have the opposite effect to that desired:
23:09 BG 206 mg/dl
23:09 bolus 1.35IU (the old pod; that should have fixed the high BG)
23:16 Pod deactivated
23:19 Pod activated (basal .5 IU/hour)
01:02 BG 218 mg/dl (it woke me up)
01:02 bolus 1.20IU (that should have fixed it, again)
04:36 BG 200 mg/dl (woken up again)
04:36 bolus 1.50IU
07:48 BG 149 mg/dl
So it's finally getting back in line, and during the night I felt like I wasn't getting any basal dose (tingling in the my arms and legs). Over 8 hours I should have got 4IU of insulin and the original 1.35 IU should have corrected the high I had at the start. (That was probably failing to account for the sugar in two glasses of sweetish red wine; no carb information on wine bottles in the US!) Instead I had to bolus a total of 4IU just to stay steady.
This suggests I only got half the insulin I asked for over the night.
The previous pod (the one I had primed the "wrong" way) actually had less air in it that the first one I opened, but that's only after I'd used it three days so it really doesn't prove much.
John Bowler jbowler @ acm.org
we have found that if kennedy does one unit bolus with pod change, she hits around 200 at lunch, without the unit she's 300... next pod change we are going to try 1.5 units extra and she how she does, her rise occurs around 4 to 6 hours after the pod change ( with apidra) with humalog it took longer, 6 to 8 hours.
Best of luck and let us know what you find out with trial and error.
Hi mike, we had major frustration with this issue, but have finally fixed it, we bolus .5 pre pod change and 1.5 to 4 units post depending on jacobs blood sugar we tried temp basal increases with mixed results, i dont thing your sites are "tired" it seems like the pump needs to be primed so to speaks, this has made a major change in our overall happiness with omnipod and our quality of life! i'm sure you can related to that comment. one other thing i try to not have him eat at least an hour after a change, he changes it consistedly around 4 430 pm do the extra bolus and he has been great at dinner. this works for us. wishing you the best! amy
We change Spencer's around the same time 4:00/4:30 pm. I will try the .5 pre and start out at 1 unit post. Thanks
I leave the pod in its tray to inject the insulin into the pod then sit the pod in its tray on top of the PDM while it goes through the priming process. While it does that I cleanse the area and apply IV prep and Mastisol on the intended site before I ever take the pod out of its "cradle". I then remove the plastic end cap, peel the paper, and apply the pod. Do you "pinch up" with the thumb and middle finger while pressing down with the forefinger on the cannula end of the pod during the "start" procedure. One of the techs told me to do that. I then bolus 1.0 units, wait an hour and correct. Sometime I do a 10% temporary basal for an hour too.
We do the "pinch up" but we DO NOT push down, he is "extremely" lean & tall, Almost 5 ft. and just turned 8 in Dec., and when we pushed down while pinching up, He had so many occlusions. Now we only pinch up and "Thankfully" that has stopped the occlusions. We will try the pre/post bolus and see what happens.
I've discussed this problem with my endo who is T1 and uses a Medtronic pump. He's not aware of this pattern of highs with site changes in his own experience. One plausible explanation is that the site trauma with cannula insertion is less with the Omnipod, such that it requires more initial insulin in a subcutaneous depot to start getting diffusion into the blood system and reaching a "steady state" for basal delivery. Kids with much smaller basals and boluses would exhibit more of a problem. Insulin has a molecular weight of about 35,000 Da, which is way larger than salt ions, oxygen, glucose, water, etc. that diffuse much more readily. So it may reach the blood system in a timely fashion only if there is sufficient trauma, AND/OR there is considerable positive pressure buildup of insulin after a site change.
I wonder if standard pump users report this kind of problem? If so, it may be associated with certain types of infusions sets having gentler insertion, smaller diameter, shorter length, teflon not steel.
OK, I've cracked open 4 pods after use and consistently see an estimated 30-50 uL of air as a single bubble remaining. I also tried priming with the exit port corner up, tapping the pod to disodge bubbles before the priming started and it did not seem to help.
What this means is that the bubble must compress to the point where it equalizes with the backpressure of the infusion site. If the site has a backpressure of say just one atmosphere (and it is probably considerably more), then for a 50 uL bubble you would need to bolus + basal 2.5 U (1U=10uL) just to equilibrate with the site backpressure before any insulin started to infuse into the site. Barry Ginsberg has a paper touching on this problem with inuslin pens : The Kinetics of Insulin Administration by Insulin Pens
I thinks this is why the "high after pod change" is so widely reported in kids: they are so low-dose that accumulating enough intial bolus and basal to overcome the pressure of the bubble takes a long time.
One thing Omnipod could do is redesign the exit port so that it had a funnel shape that could catch the bubble when that corner is upright during priming. I took the insulin chamber apart and the exit hole is quite small and the surface around it flat.
In the meantime I think many people have hit upon the solution by doing a "compression bolus" of 0.5-several units after changing a pod. One could start doing this by starting at say 0.5 U after your next pod change, and if you still go high, try 1.0 U the next time, etc. And be aware of the occasional small bubble that might result in a too large compression bolus, so test early and often!
Please report back here on your results! Thanks.
hi mark! your comments made me smile, you must be an engineer, may be you could work for insulet and improve the product! honestly your comments make sense but i would never of put them so intellegently, my son wants to be an engineer someday! time will tell he is only 13 but i am impressed with his goals. hope you had a good easter! amy
wow! we experimented, starting at .5 units, and have found 1.5 units is just about right!! You should call support with your findings, I think if omnipod would acknowledge this and create process for implementation for finding the right amount, it would be really helpful... but then that dang fda, they will be watching, so I understand that could be a concern...
we have found for kennedy 1.5 units is just about right, and on apidra it seems that it's between four and six hours that we see the increase,
she is on about 25 units a day, split about 50/50 between basal and bolus, 70 pounds...