CGM Log (how long do they last, why do they fail)

[PhoebeC]

iphone, have used all libre, 2 and 2+ and now dexcom 6 with their related apps.

 

[helli]

If you don't suffer from comms failures, would you mind listing what phone you're using please?

I use a Pixel 7

Do you have many devices connected to your phone via Bluetooth?
This may also be something to consider as phone do not have endless number of Bluetooth receivers.

 

[Merluza]

I use an iPhone SE currently running on iOS 18.4 and being constantly nagged to update to 18.5. In the last few months I’ve had two sensors that have misbehaved for three days then given up and two that have died within twelve hours, one of them didn’t manage an hour. I’ve also had three that have seemed perfect and the latest one seems ok but is giving occasional odd readings. These are all Libre 2s. So out of eight sensors I had four needing replacement.

I had the idea that where you put them affects their performance, at least when you have one that works as intended. I always take care when applying them but it still seems to be down to luck rather than judgement as to how well it does. But to me they are very unreliable and if they have any quality control it doesn’t work. I’ve had so many failures that I expect it.

In your case it seems even more mysterious. Which phone are you using? I anssume it’s on their list but it seems the most likely reason for your problem. Of course it means buying a new phone to find out. I had to buy a new phone when I started using them. There was a recent update to the app that might be worth a try. I live in hope that the 2+ will be more reliable.

 

[rebrascora]

All I know is that I find the reader and the sensors VERY reliable. I only have a problem if one comes loose and now that I have a new arm strap I have solved that problem.

 

[Merluza]

Maybe using the reader is the answer.

 

[Skater P]

Had three Dexcom G7 all fail on my last sensor change, my CGM score when from close to perfect to about 50/50 in a day.
Issue was a looping filament (so the filament failed insertion)
All replaced by Dexcom
Having re-read the instructions veeery carefully I'm a little concerned about the SC fat requirement as I don't have much and it could get awful crowded.

 

[mashedupmatt]

My last one failed at 14.5 days and Abbott are still sending me a replacement so although it's a pain, they are very good at correcting any issues without any fuss

 

[Natalie123]

I'm using Libre 3+ with Pixel 8 Pro phone and Cams App (for HCL). I get the odd loss of connection but a quick turn the Bluetooth off and on again solves the problem. Apart from the very first one that seemed to be a bit dodgy, I've been really impressed with the libre 3, they have been much more accurate and almost always agree with finger prick tests (except when low, they don't show a rise after hypo treatment as quickly as a finger prick but that's what I expected anyway). Very prone to compression lows though. No failures yet. Hope I haven't spoken too soon!

Could you ask for a reader to use with your sensors? I used a reader with my old Libre 2 plus sensors and got on well with it.

 

[SimonP]

Thanks everyone 🙂

Maybe using the reader is the answer.

I do activate the sensors using the reader and even the reader can't see them when their Bluetooth has failed, so it's definitely a case of the sensor having failed (despite my flippant comment above about Bluetooth stacks.)

I use a Poco X3 Pro, which is close to one listed on the accredited list (the Poco X3 NFC iirc) and may indeed be exactly the same thing just with different regional branding. I don't know off-hand if there is any difference in the NFC chipset/aerial (for the single scan to link to Juggluco - given that the sensor appears to have failed rather than the issue being with the phone's Bluetooth.)

I use a Pixel 7

Do you have many devices connected to your phone via Bluetooth?
This may also be something to consider as phone do not have endless number of Bluetooth receivers.

Not many at any one time, though this won't cause a sensor failure just an intermittent drop out (which I used to see while cycling with lots of ANT+ devices talking, all of which happens in the same 2.4GHz band as Bluetooth - something has improved as I don't see this effect any more).

In any case it can't be interference as they randomly fail no matter where I am (the last one in France where I had nothing Bluetooth turned on at all in the house aside from my phone.)

Very odd indeed and immensely frustrating! 🙂.

I'll have to reach out to the Juggluco developer and confirm that it passively listens to the sensors and doesn't write to them at all, which is the only other failure mode I can think of unless there's something about where I live/work that cooks the sensors!

My current sensor's (5 days remaining) Bluetooth stopped working last night after I'd gone to bed and sleep but then started working about 8h later just after I got out of the shower this morning. I had planned to replace it anyway as the calibration was so far off (reading ~5mmol lower than actual fingerprick data) but as it was communicating I thought I'd give it another day (and avoid applying a new sensor then getting hot a sweaty immediately afterwards riding to work) and shortly after I arrived at work it decided to change calibration over the course of a couple of hours until it was and is fairly close to the actual numbers now. Interestingly there was no sensor error or massive jump in the value, the CGM value just stayed fairly flat as my BG moved to meet it.

Fwiw I confirmed that it had failed by using the LibreLink app and it couldn't see it either (this was an unusual one, I usually start the sensors with the reader before handing over to Juggluco, but was in France when I replaced this one and was travelling light.)