Last night I applied a Zio XT cardiac monitor to my chest; I’ll be wearing it for the next two weeks to check for potential arrhythmias. If you’ve ever used Cologuard, the whole system is handled in a similar fashion: your doctor orders the device, it gets shipped from the manufacturer to your house with very clear instructions on how to use it, you send it back to the manufacturer when you’re done, and they analyze the results and send your doctor a report.
The application instructions were clear, but somewhat sadistic:
shave the left side of your chest.
sand your skin with the included piece of 400-grit sandpaper. Forty strokes: ten vertical, ten horizontal, and ten on each diagonal.
thoroughly wipe down the application area with the FOUR included alcohol wipes.
stick the monitor to your chest.
Step #3 hurts as much as you might imagine, coming directly after step #2. And I definitely understand the need for step #3: this thing has to stick to you reliably for two weeks, so you gotta get rid of every last bit of skin oil. But why the hell did I need step #2?
A new survey shows that something as easy and simple as proper skin preparation prior to electrode placement can significantly reduce ECG artifact in most electrode situations by lowering patient skin impedance… The ideal skin preparation technique for the application of disposable ECG electrodes includes removing part of the stratum corneum to allow electrical signals to travel back to the electrode.
As the outermost layer of the epidermis, the stratum corneum is the first line of defense for the body, serving an essential role as a protective skin barrier against the external environment. The stratum corneum aids in hydration and water retention, which prevents cracking of the skin, and is made up of corneocytes, which are anucleated keratinocytes that have reached the final stage of keratinocyte differentiation. Corneocytes retain keratin filaments within a filaggrin matrix, and the cornified lipid envelope replaces the keratinocyte plasma membrane. These flat cells organize in a brick and mortar formation within a lipid-rich extracellular matrix.
No worries here. It’s just that repeatedly scrubbing your skin with alcohol wipes immediately after having scraped and scraped and scraped it with sandpaper was quite painful.
The outermost layer of epidermal tissue is the layer that flakes away. I’m thinking that sticking the device to the outermost layer is going to cause the connection to fail because the skin that it is attached to is going to flake away. Even though it sounds like some kind of medieval torture, the sand papering off of that layer of skin is going to make a more stable and long lasting connection to your body.
Over the course of two weeks, even the good & fresh skin in that area will get old, ragged, and slough. Best to clear it out so you’ve got all brand new fresh stuff to stick to.
I might suggest waiting a few minutes between steps 2 & 3 though.
Would it have helped? I mean if the purpose of that stratum corneum is to protect against the external environment, and I’ve scuffed it away, it’s not going to regenerate enough to keep out the alcohol in such a short time, right?
If you sanded to the point anything was bleeding even slightly and maybe invisibly, letting that coagulate would help. If the skin was just red and upset, waiting a few minutes for that flushing to calm down some might help. After that though, I agree you’re right that any healing or drying out of the new outer layer is far slower than just a few minutes.
I suppose my bottom line is a few minutes’ wait is in the “Cant’ hurt; might help.” category. Some folks’ approach to a hard-to-remove band-aid is just to yank it off now and get it over with. Others’ is to go through an elaborate ritual trying to soften the glue first to prevent the ouchy. I’m a Door #2 kinda guy myself. YMMV.
If I ever get one of those monitors I’ll try that and share the results here.
Since I think the OP was answered, may I just add how glad I am that the use procedures for Cologuard aren’t all the same as those for the Zio patch
I wore my last Zio patch a couple years ago. The pain from the process you describe finally died down last month. Yeah. It’s memorable and surprising.
I would have assumed either adhesion or transmission was the rationale, but I probably would have leaned toward adhesion, partly because some people are asked to wear the monitor for 7, 14, or even 21d.
I have to wonder if the skin impedance doesn’t ‘recover’ over that much time, marginally degrading the data over the latter portion of the ‘test.’
I wear a medical patch that i change weekly, and yes, by the end if the week the outer layer of skin is often sloughing off, and the patch adhesion gets weaker. I suspect abrading the skin helps keep it on for more than a week.
I had to wear a cardiac monitor once last year, might have been for two weeks, but I didn’t have to sand my chest. It was applied in the doctor’s office in fact, and after a few hours the bloody thing would not stick on properly. I found that very wide paper adhesive tape put across it and on my chest would keep it in place. I was very glad to finish that test and get the thing off of me. Fortunately the problem it was testing was temporary and I look forward to never having to do that again.
I had to wear a monitor for a week a couple of years ago. No sandpapering, and no alcohol wash that I remember. I pointed out that I cycle for exercise so I was going to get properly sweaty for a fairly prolonged period four or five times during the week - so do you want to give me some more pads as spares, as they’re not likely to stay in place the full week? They gave me a handful of spares and sent me away - and I didn’t use a single one of them.
I’m looking at the header at the top of this thread where it lists the subject, and then below that it says “Factual Question,” and then next to that it lists an apparently auto-generated descriptor, “fashion-clothing.” A swing and a miss.
I had to wear a monitor (different kind) back in the spring for a few weeks. No sandpapering. They applied the first time and in the box they gave me were extra adhesive things. The adhesive burned the hell out of my chest, though (as did the monitor itself from the battery). Had to wear it as they were checking for A Fib. A few months later they put in a cardiac loop just in case. That will stay in for years.
High 5. I’m wearing one right now and for the next 30 days. I have the Philips MCOT. Did you have an actual piece of sandpaper or are you exaggerating? Mine came with a rough, stiff piece of foam to scratch before putting it on.
Imagine a circle of sandpaper 2" in diameter, and a circle of tough-but-flexible plastic. The two circles are stacked and glued together on one half of their surface area. you grab the unglued part of the plastic to use as a handle to drag the sandpaper across your skin. So it was a bit of an assembly, but the important part was, yes, sandpaper.
