Site smells like insulin? - update

My daughter has been using the Medtronic Mio sites for as long as she has been pumping, (4 years) and lately has only wanted to wear them on the back of her arm. So she has a site in the back of one arm and her Dexcom in the back of the other arm, and proudly flaunts her hardware. :slight_smile:

But we are noticing now that by the end of the three day site life, her sites start smelling strongly of insulin and her absorption rates go down. This is new for us, we have never noticed that smell before and sometimes have gotten longer out of sites, not intentionally of course, but sites have been known to be on longer without the smell or absorption issues.

Is it time to start switching sites more often? Is it the Mio’s? Or is this just the body getting good at building scar tissue in response to the sites? Is it her arms? She’s 11 now, and to think that she is going to have to wear a site for the rest of her life, it would stink if we are developing allergy issues or any other issue involving sites already.

If anyone has had similar issues can you let me know what you did?

Would it be practical to switch to a 2-day site change schedule?

It sounds like she might be building up scar tissue. You may want to try switching up her site locations more. The Dex doesn’t tend to cause too much scaring, but the pump can cause quite a bit. It’s better to use many locations on the body.

It is possible that she has over used the back of her arm. It may be scar tissue that is causing absorption issues.

It may be time to rotate to different sites

Another possibility is that she is getting what is sometimes called tunneling – movement of the cannula irritates the tissue and a tunnel forms around the cannula, then bolused insulin backs up along the tunnel to the surface, where you will smell it. Besides the suggestions above, another option is to limit the amount of bolus given at one time and extend the rest over, say, 30 minutes. You will need to experiment to find what amount prevents the back-up leak. I found 5U works well for me, but everyone will be different.


I suggest you get some Sure-T samples. Those sets were what prevented me from terminating many years of pumping with cannula-type sets. ST’s are so much less problematic, it isn’t funny.

Thanks all, we will try to rotate to another part of the body. Her tummy tends to rash up pretty quickly and fall off, so hopefully I can convince her to move to thighs or love handles. :slight_smile:

Tunneling also sounds interesting, for large doses of insulin we will certainly try giving the insulin more slowly.

We always do this for anything greater than 5 units. Extend over 30 minutes, 20% up front.
Between 3 and 5 units, sometimes we extend.

I figure there is no real downside and possible upside.

So I ended up calling Medtronic and they thought perhaps the 6 mm Mio canula isn’t deep enough anymore and they are going to send me some 9 mm samples. I can see this being the case for her belly, but her arm?

As well, we had been getting motor errors on our Minimed pump and I thought they were just related to empty reservoirs, but they wanted to replace our pump. The only problem is that our pump is out of warranty, but since we are part of a government program that pays for a new pump every 5 years, they have given us a new loaner pump to use for a year.

I guess we will see if either of these changes help!

Is it possible that the site on the back of the arm takes more physical abuse than other locations? Catching on clothing? Or door frames ? I found that too much bumping around leads to poor absorption and perhaps tunneling and for me also a possible site infection.