Speed of Animas Ping bolus delivery (even when set to "slow) contributing to Skin Lumps?

I am experiencing the return of an old problem that caused me to have to take an extended/unwanted pump vacation several years ago. The problem of scars/fat deposits/lumps... I am careful to change my site every 48 - 36 hours; rotate site locations; prep skin properly...

I started to think that the bolus delivery rate was a big part of the problem even though I keep my pump delivery set to "slow".The only thing that seems to help is to use the pump to calculate the insulin that I need. I write that number down and then make little hatch marks to count off as I manually enter the bolus in smaller portions (0.25 u every 30 seconds or so), until I get the amount I want. Sometimes I will use a syringe to give the up front bolus as well.

I have tried most everything - like using combo bolus over 0.1 hrs ( I get an initial amount of 30 - 35% up front and then another ~3rd of the bolus at minute 3 and the remainder of the bolus at minute 6). For this to work, I might have to do more than one 0.1 hr combo bolus for a meal in order to keep the volume small.

This really seems to decrease the lump formation, but it is tedious and hard to manage at times - and requires a lot more focus in order to be safe in calculations.

I have learned that the T-slim delivers more slowly and that an extended/combo bolus is delivered continuously rather than every 3 min.

Would like to know if anyone has ideas had similar experiences, info or suggestions.

Appreciate any thought you might be able to offer -

I use the tslim, never had issues with pump bumps, like the micro delivery method. I think I get better control vs MDI, no other pump experience so can't compare.

Had to drop insulin dose by nearly 40% from MDI dosing when I switched

Have found that type of infusion set changes things for me in a big way. If I use a manual slant set, my insulin requirements are the lowest, if I use a auto straight set my needs are 30% higher, if I use a auto slant set its some where between. I also notice I got pump bumps with the auto sets and had my numbers go high by day 2-3 with the auto sets and that does not happen to me with manual slant sets.

Needless to say, I no longer use auto sets.

Don't know if this will help you any but might be something to consider.

I don't have any suggestions (I was going to suggest extended bolus but seems you've tried that). But with injections wouldn't you be delivering the insulin just as fast as with a pump?

Hi Jen,

The injected insulin goes in even faster, but it seems not to be a problem since it is done only once in the same spot.

I agree with you about getting better results on pump. I would only go back to MDI if I had no other choice. I only average ~1 injection a day when i want to take some of the burden off of my inset site due to a large bolus.

My doctor thinks it may be related to the set as well - I am meeting with my Animas rep this week to get some other sets to try.

I have seen some discussion on the D boards about auto sets and pump bumps. Seems the theory is that the sharp impact of an auto set causes tissue injury that a manual set does not cause. The injury leads the body to reactions that degrade absorption and causes the bumps, and may lead to scaring.

For me with the comfort short sets it can be a bit freaky to watch myself do an insertion and not actually feel it going in. Not saying that all are that way initially, but if you feel it as you start with a manual set you can move over a tiny bit and find a spot that does not hurt.