Erratic Freestyle Libre2 sensor displays

[Alan Playford]

Hi all.
I was diagnosed last year with diabetes type 3C after a routine blood test had dangerously high A1C levels ad after pancreatitis the previous year.
I had been called in to the hospital urgently that night, spent a few days in hospital, and they diagnosed type 3C which looks as if it had been undiagnosed for 18 months or so, with a collapse some months earlier inclding a brief blackout and confusion for about 20 minutes being attributed to a TIA (mini-stroke). However, all TIA tests passed with flying colours, but my recently new-found knowledge about diabetes leads me to believe it was actually a hypo?!
Anyway, being extremely needle-phobic, the hospital diabetes team tried to minimise any needle activity by only prescribing twice daily mixed (fast and slow acting) Hamulin M3 insulin pens and a Freestyle Libre2 arm sensor with the phone app to avoid the nasty pin pricks as much as possible.

The Libre generally works well, although in the last 6 months I've had to get replacements 3 times for "faulty" sensors.
My latest one missed some data this morning, and wouldn't fill it in even after re-scanning.

But a more worrying trend to me is the failure of the Libre2 to continuously report glucose levels, especially when a sudden high increase or low decrease occurs?
They frequently seem to report a couple of interval readings, then lose the signal completely even if the phone is next to the sensor?!
A re-scan sometimes works, but also very often states I have to wait 10 minutes and try again - all at the very time when I need those readings to ensure they don't go even higher or lower!
I also find that sometimes successive readings show an increase or decrease of at least 1 mmol/DL, which seems excessive from one minute to the next, even for my bodily system functions?

Do others find this, or is just me?
Needless to say, I will be replacing this latest sensor as it appears untrustworthy!
Thanks in advance for any insights and comments!

 

[Deleted member 527103]

But a more worrying trend to me is the failure of the Libre2 to continuously report glucose levels, especially when a sudden high increase or low decrease occurs?
They frequently seem to report a couple of interval readings, then lose the signal completely even if the phone is next to the sensor?!
A re-scan sometimes works, but also very often states I have to wait 10 minutes and try again - all at the very time when I need those readings to ensure they don't go even higher or lower!

It is recommended to check all highs and lows with finger pricks and not rely on Libre.

There are a couple of reasons for this
- Libre (and all other CGMs) are designed to be most accurate when at "normal" levels (typically between about 4 and 9 mmol/l). Outside of this range, Libre can exaggerate highs and lows resulting in overtreatment.
- CGMs (including Libre) do not read BG. They read Interstitial fluid. A change in BG will be reflected in a change in Interstitial fluid readings (ISR) after about 15 minutes. However, Libre accommodates this delay: as part of the algorithm to convert ISR to BG, it will extrapolate the current trend. This works most of the time, except when your BG is changing fast or changing direction. This is when it is likely to report "try again in 10 minutes." Sometimes, you may see a high reading which is later overwritten - this is when the algorithm will correct its prediction.

There are other limitations in CGMs which, sadly, DSNs and manufacturers rarely share. The key additional ones are "insertion trauma" and "compression lows". These are mentioned again and again on the forum so, I assume, most people are familiar with them.

The important message is Libre does not remove the need to check with fingerpricks.

 

[mariavontrapp]

My sensors only lose contact from my phone if I have left the room for a while. When I come back it usually rights itself in a few minutes

 

[Alan Playford]

My sensors only lose contact from my phone if I have left the room for a while. When I come back it usually rights itself in a few minutes

Oh, same here!
Even sometimes loses the connection when I'm still sitting next to it, though! And that's worrying?!

 

[barrym]

Hi all.
I was diagnosed last year with diabetes type 3C after a routine blood test had dangerously high A1C levels ad after pancreatitis the previous year.
I had been called in to the hospital urgently that night, spent a few days in hospital, and they diagnosed type 3C which looks as if it had been undiagnosed for 18 months or so, with a collapse some months earlier inclding a brief blackout and confusion for about 20 minutes being attributed to a TIA (mini-stroke). However, all TIA tests passed with flying colours, but my recently new-found knowledge about diabetes leads me to believe it was actually a hypo?!
Anyway, being extremely needle-phobic, the hospital diabetes team tried to minimise any needle activity by only prescribing twice daily mixed (fast and slow acting) Hamulin M3 insulin pens and a Freestyle Libre2 arm sensor with the phone app to avoid the nasty pin pricks as much as possible.

The Libre generally works well, although in the last 6 months I've had to get replacements 3 times for "faulty" sensors.
My latest one missed some data this morning, and wouldn't fill it in even after re-scanning.

But a more worrying trend to me is the failure of the Libre2 to continuously report glucose levels, especially when a sudden high increase or low decrease occurs?
They frequently seem to report a couple of interval readings, then lose the signal completely even if the phone is next to the sensor?!
A re-scan sometimes works, but also very often states I have to wait 10 minutes and try again - all at the very time when I need those readings to ensure they don't go even higher or lower!
I also find that sometimes successive readings show an increase or decrease of at least 1 mmol/DL, which seems excessive from one minute to the next, even for my bodily system functions?

Do others find this, or is just me?
Needless to say, I will be replacing this latest sensor as it appears untrustworthy!
Thanks in advance for any insights and comments!

That is behaving as designed. If your BG is changing quickly the app decides not to calculate a trend value so dispalys — where the current BG should be. If you scan, it tells you to wait, as you have seen. If it can’t accurately predict it will not store any value for you to pick up with a scan.

As far as I remember a signal loss is highlighted with a red dot on the hamburger icon. The sensor will still be recording and the scan will collect up to 8 hours worth.