I often see posts asking how to keep continuous and flash glucose sensors on for more than a week. As I pay full retail price for my CGM (it is not easy to get a CGM subsidy in Australia), I try to get every last bit of performance out of them before throwing them away.
My record so far for a Dexcom G5 was seven weeks and I gave up at that point because the sensor wound had healed enough that it was no longer registering the spikes; the line just slowly rose and fell in a dampened response to the glucose levels.
These days I change the sensor in the first weekend of the month, getting around four weeks per sensor.
Here is how I do it.
I bought a bottle of this on eBay but you can also buy wipes with the same name that do the job. The very first thing I do is apply it, using the sponge applicator, to the area where the sensor is going to sit.
To wipe off any excess, simply use Methylated Spirits (Denatured Alcohol).
Prepare the Sensor, Rocktape and Opsite
While the Skin Tac dries and gets sticky, I prepare the other components. Firstly, I take sensor out of its packet ready for application, then I prepare the RockTape.
I use the Rocktape to keep the sensor’s sticky material in place. The white gauze that comes with the Dexcom is good for about one week so the Skin Tac and Rocktape help extend this.
I cut a little rectangle out of the Rocktape for the transmitter to fit through and keep the rectangle for later.
I also cut off the corners of the main piece of Rocktape and this stops it from peeling away from the skin as readily.
With the Skin Tac now nice and sticky, I apply the sensor, attach the transmitter, and start the soak-in period on the receiving app.
If the transmitter looks a little unusual, I use a modified G5 transmitter with a rechargeable battery attached to replace the embedded batteries. It is a little experimental but it has saved me a fortune in new transmitters.
Next I put on the RockTape on top of the gauze.
This is a transparent, breathable covering which sits on the skin. There are cheaper alternatives in the market though so do shop around. The idea is to cover the sensor and Rocktape completely to help prevent the sensor getting knocked out by leaning or bumping into things.
The rectangle of Rocktape we reserved sits in the middle of the Opsite to stop the Opsite getting stuck to the transmitter. The adhesive attaches very strongly to the resin on the transmitter making it difficult to remove when we want to change the dressing.
We now apply the Opsite to the sensor, keeping the backing on the Rocktape rectangle and we have a secure sensor with its own Rocktape camouflage. With the backing on the Rocktape still in place, the dressing comes away easily when we want to replace it.
Once a week I check for peeling and, if it is coming away, I reapply the Rocktape and Opsite, removing the old dressing by peeling sidways to or away from the transmitter to minimize the risk of dislodging.