Fried G5 sensor?

I started a Dex G5 sensor last week and only got 2 days out of it before it went haywire and had to be replaced. Called Dexcom and they will replace it, even though it expired 2 months ago. (Long story…thanks Edgepark !!). I have a theory about this sensor that I wanted to throw out there and see if anybody else had a similar experience.

This sensor was my travel spare, carried it around in a hard case (so the tabs would not get broken off) for about 5 weeks while travelling. The other spare I used on this trip worked fine and was also expired but was not exposed to any serious heat. However, the last week of travel was in New Jersey during a heat wave in the 90’s. I was able to take care of my insulin but frankly I forgot about this spare sensor and left it in an overheated van several times. I was busy with other things and became oblivious to Dexcom’s warnings to not expose the spare sensors to excessive heat (the label on the packaging says 77 degrees F max).

This particular sensor hurt (kind of a dull ache like a nail was stuck in my arm) for about 1 day after I inserted it. When I pulled off the fried sensor, there was blood on the base and my arm had a faint bruise about 2 inches in diameter.

So the possible reasons the sensor failed are (1) sensor was expired; (2) insertion site hit something weird inside my arm causing blood and bruising or (3) sensor was baked while travelling. What does everybody think based on your experience?

I don’t use my arm, but whenever I hit a blood vessel I usually end up with wonky behavior. So I’d vote for the blood and bruising.

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I’ve used some that were over 1 year past expiration without any problems.

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I’m inclined to agree with vanc. According to rumor, age alone doesn’t particularly hurt a sensor (maybe the useful lifetime is shortened a little, but not to 2 days.) I haven’t seen an experimental result about the performance of a sensor after baking. I suppose it could degrade the enzyme, but I’m still inclined to go with the damaged tissue interfering with the CGM.

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I hope my stockpile of sensors due to expire next month performs flawlessly. Hoping to make it into 2019 before I have to restock.

I’m still concerned about the baking this sensor experienced and will be more cautious the rest of summer.

Well, my expired ones were not baked…

So you are breaking new ground there.

I vote for the heat because I have used expired sensors with no problem, and I also find that when I happen to hit a blood vessel that the sensor tends to be more accurate.

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I would vote for this:

When EH hits a blood vessel or a muscle it’s spotty at best and dies sooner. Our house gets pretty hot lately (indoors probably at 90° F), and we’ve yet to have an issue. But a car is much hotter.

I now feel like we’ve got another challenge. :wink: @Eric what do you think?


I tried putting a sensor in a vein. It doesn’t work.

But I learned a new word when I did it - “hematoma”!


I know you’re into veins and such, but really @Eric sensors are not for veins! :stuck_out_tongue_winking_eye:

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