Saturday, April 21, 2018

Using 3M Micropore tape as a barrier for Dexcom sensors

Being a member of the Dexcom and Libre rash facebook group means I see quite a few posts, and fairly horrendous pictures of the awful damage being done to people's skin by reaction to the Dexcom and Libre adhesives.  We used to have these same issues with George, and it used to make my stomach churn when we would see the suffering it caused him.

I see many posts with people suggesting things like

  • tegaderm (we tried this, it worked for a short while, then he became allergic to it)
  • opsite flexifit (same as tegaderm)
  • Compeed or other hydrocolloid dressings
  • Stin-tac
  • Anti-histamine spray
  • Barrier creams

or combinations of all of them.  Many of the preparations people go through are really involved, time-consuming and require expensive products.  Our setup takes about 2 minutes preparation (mostly of the Dexcom).  It will take you longer to read this post.

A while ago, I was at the pharmacy getting some supplies, and I discussed the issue with the pharmacist.  She recommended I try the Micropore tape.  I have to admit I was very skeptical.  She said "it's hypoallergenic".  I was like whatever.

So anyway, we tried it.  It was pretty odd.  Firstly, it's paper-based.  I thought it wouldn't stick well to skin.  I was wrong.  I thought he would still react to it.  Wrong again.

In fact we've never looked back.  This is now over 2 years on, and we usually get about 2  1/2 weeks of sensor life.  We think this is pretty good for a 7 yr old active boy.  He also loves to soak in the bath, and it's a trial trying to get him to keep his arm out of the water.

So, I thought I'd do a bit of a demonstration of the use of the product.  I couldn't find anyone who wanted to video it, so you'll have to put up with one-handed stills sorry.

Preparing the Dexcom sensor

One of the main issues is that the tape is in a roll, and there's no non-stick barrier between the layers of tape - nothing to peel off to expose the adhesive.  What this means is that you need to do a little preparation to work with it.  Since you're going to stick a dexcom sensor on the back of the tape, and you need a good clean wrinkle-free adhesion.

This is what we use.

the roll of tape (top left), some flixonase, a tegaderm (sacrificial), the dexcom, and a rockadex cover that goes over the top.

Step 1, prepare the tape.  First, we open the tegaderm, peel off the non-stick, throw away (!) the tegaderm dressing itself, and keep the non-stick.  Put this on the bench.


Then stick it down with the micropore tape.  Make sure to put the tape on the same side of the tegaderm non-stick that you peeled the tegaderm off.


Tip.  Micropore tape is a real pain to find the end of the tape and peel it off.  Make sure you fold 1/4" or so of tape over on the end.  It will save you 10 minutes (seriously) next time.

OK, peel the non-stick off the dexcom.



and stick it onto the tape


OK, peel the whole shebang off the bench (or whatever surface you're working on)


Get your trusty scissors and trim around the edge of the dexcom.



You're done!  Now for the arm.  We find the tegaderm non-stick comes off the sensor pretty well.  You don't want to be sticking things on and pulling them off many times, as you don't want to wear the adhesive off the tape, or it will not stick as well.  We haven't tried using other things than tegaderm yet for sacrificial non-stick, as we purchased a large box of them several years ago (we used to use it for a barrier, but now can't so we have no use for them).  Maybe grease-proof paper might work.  Each tegaderm probably costs as much as a whole roll of the tape (yes, it's really cheap).

The arm.  

This is the old (now pretty much dead sensor).  We have a rockadex on top (rock-tape).  We replace those weekly (peel off carefully and put another one on - no other prep).  He tends to make them come up at the corners, so eventually they aren't holding enough on.



This is what it's like once pulled off (normally it's unblemished, not even a wee patch of weeping around the filament hole)


And what you've all been waiting for - his arm.  This sensor was on about 17 days.  Photo is taken about 1min after removal.  We haven't even given it a wipe yet with a warm facecloth, after 17 days there's a bit of dead skin needs to be washed off.


OK, so normal application pretty much. A warm wet facecloth to wash the arm, then a couple of squirts of flixonase which I smear around with my grubby finger, then we dry the arm with a tea-towel. I suspect the flixonase does basically nothing, and we have tried it a couple of times without it (didn't seem to make much difference).

Peel off the non-stick


Insert it.  I usually hold it on for around 30s around the edges to make sure it's stuck.


probably should clean off that residual rockadex adhesive from the previous sensor (nearly 3 weeks ago).  Stick on the rockadex and we're done!



More notes on the micropore

We know a few surgeons, and I've actually discussed the Micropore tape before with them, and they both said they really love it and use it for covering surgical stitches.  The main benefits over the other proposed solutions I've seen are:

1. It lets your skin breathe underneath
2. No latex
3. No irritation or skin reaction 
4. It doesn't stretch, so neither does your skin stretch away from the filament hole.  I'm sure this is another reason why plastic surgeons use it.
5. Insanely cheap.  you can buy a whole roll of this (lasts a year) for the cost of 1 compeed (e..g on eBay you can get a pack of 6 rolls of 2" x 10yd for under $10 USD).

You can also use it to tape down over the top.  If we run out of rockadexes I do this, just get 2 strips of it, and cut a space for the transmitter.

Some insertion tips:

I've also read horror stories of people who manage to sever the filament on insertion.

The key to pain-free insertion is "the pinch".  It's called a pinch, but it's more of a pull. What you're trying to do is pull the subcutaneous tissue away from the underlying muscle.  If you pinch (squeeze) too hard, it hurts when you jam an inserter needle into the compressed tissue, so you need to be gentle in the pressure, but pull the tissue enough away from the arm to avoid muscle (which also hurts a lot).

The amount of force required on the actual white inserter pluger is MINUSCULE.  I use only the tip of my finger.  

Cheers