Libre Sensor 2 - PLEASE BE CAREFUL - Recent Issues

[RobertJ]

Thanks @Westley. Your suggestion to change sensors in the morning is a good idea but that's what I already did with this one. I hate not knowing what actually happened but I don't what the answer is when the sensor and blood test kit disagree with each other so much.

I've had the sensor on about 24 hours now and I think it's accurate, so I guess I'll leave it on and trust it. It's just kind of horrible not knowing if I caused myself brain damage last night or not.

 

[In Response]

I've had the sensor on about 24 hours now and I think it's accurate, so I guess I'll leave it on and trust it.

Do you give the sensors time to bed in?
Many of us find that our bodies are not happy with an alien object inserted in our arms which can affect the readings from the sensor for up to 48 hours after the sensor is applied.
This is why it is common to insert a sensor a day before activating.

This is one of the oft mentioned limitations of CGMs. Yes, I mean all CGMs not just Libre.
If you are not aware of these limitations and so unable to take them into consideration, you could get very frustrated with the technology.

As for not knowing if you cause brain damage overnight, I think it is unlikely. People have celebrated 60 years with Type 1 diabetes. Most of those years were without CGMs or even finger prick meters.
I have had Type 1 for 20 years and only been using CGM in the last 4 years. Worrying about what damage I may or may not have done to myself in the first 16 years is not positive for my mental health. Likewise, worrying about the very occasional night when my CGM fails.
In fact, my body is pretty good at waking itself up when my levels get lower. CGMs are amazingly helpful but as they can fail, I believe it is very important not to lose hypo awareness.

 

[RoughcutAU]

@RobertJ I have had similar overnight as well. I trust my glucose monitor over my CGM anyday. I find (like alot of people) that that CGMs tend to over report lows and highs and are most accurate only within range. Also the 4 is the floor is a guide set for those on insulin/glucose reducing medication. Those without diabetes can have levels in the high 3s and not be considered hypoglycemic.

 

[Zinadane]

Well, we are all different and I read a lot of people complaining of libre inaccuracies and unreliabilities.
It confuses me tbh.
I was on Libre 2 for 18 months and now libre 3 for 6 months.
L2 was 90% reliable and 90% accurate (knowing its limitations of course)
L3 is 99% reliable and 95% accurate.
L3 is so small, I am basically not aware it is attached to me!
Upper inside arm placement (with cover patch) which tends to avoid compression lows in bed.
Perhaps I am just lucky!

 

[eventhorizon]

Well, we are all different and I read a lot of people complaining of libre inaccuracies and unreliabilities.
It confuses me tbh.
I was on Libre 2 for 18 months and now libre 3 for 6 months.
L2 was 90% reliable and 90% accurate (knowing its limitations of course)
L3 is 99% reliable and 95% accurate.
L3 is so small, I am basically not aware it is attached to me!
Upper inside arm placement (with cover patch) which tends to avoid compression lows in bed.
Perhaps I am just lucky!

I agree.
I've used the Libre 2 for a few years now. I can't remember the last time a sensor failed. I use it for all my boluses and basal adjustments. And when checked against a finger prick (rarely) it's nearly always within 10%. The only thing it might miss is a rapidly falling BGs into hypo territory.

 

[domoboy]

Hi all,

Glad to see all your comments, suggestions and other experiences.

To add to this, there is a freestyle support group on facebook for UK users with questions and issues. I believe there is currently a pinned post regarding a sudden influx of people experiencing the same issues over the last 3/4 weeks in terms of readings of 3.0 compared to finger pricks of 7/8/9/10/11 etc.

To update on my scenario, it took until Day 7 of my current sensor for it to become accurate (as in, how all my previous for the past 2 and a bit years have performed until the last 2 weeks) and was back within being spot on to 1.5 mmol out on readings. No idea why it's now suddenly working fine and as all my others until the last 3, or why it's taken 7 days to get to this point when mine have always been accurate within the first 24 hours or seemingly so in the past. But at least it's back to working and being accurate and not showing me as 3.2 when I was actually 9.2!

I'm due a sensor change in a few days... so I'll see how long the new one takes to bed in....

 

[domoboy]

I agree.
I've used the Libre 2 for a few years now. I can't remember the last time a sensor failed. I use it for all my boluses and basal adjustments. And when checked against a finger prick (rarely) it's nearly always within 10%. The only thing it might miss is a rapidly falling BGs into hypo territory.

Exactly the same great experience as me, up until a week or so ago

 

[domoboy]

@domoboy Great post, I have experienced similar with my Freestyle Libre sensors.

I have been using them for over a year now, I do find them very useful with their updates so get real time info of where my BG levels are. However, I have been slacking on using the finger pricking, as I should do it bit more, especially at night time. I tend to have a Hypo every other night around 2am-4am. As I am in bed, I just scan the sensor once it sends the alarm for the hypo, then I just grab my Lucozade or chocolate then fall back to sleep lol

Few weeks ago, I did see that the Libre was showing 2.8mmol, but when I used the finger prick, it showed 5.6mmol, I did not feel any symptoms as I do when going into a Hypo, so I did not take Hypo treatment, just wrote a note on the Libre app so I can refer back to it if needed.

I am trying to be good and use the finger prick at night when the sensor alerts me of a Hypo, so think best course would be to do the finger prick and go with the reading the machine tells us when having a hypo, instead of the sensor.

The sensors are a good addition and support in our T1 journey, but the finger prick will always provide us with the correct reading no matter during the day or night, especially if you are unsure or questioning the reading from the sensor.

Hope you have a wonderful holiday!!

100%.

In a way, I'm kind of glad it's happened as it has alerted me and promoted me to do more finger prick tests in the future, as you say, especially when low/high/questioning the reading as well as the odd random one to make sure it's working as expected!
/

 

[CheeseSeaker]

Occasionally they go wildly odd on readings, but mostly pretty reliable once calibrated in xDrip to give more accurate readings.

Worth noting there is a period of 'insertion trauma' with new sensors, where sticking them in causes swelling around the sensor and stops it reading as accurate (true for all CGM). I insert a day before switching on to reduce the impact, obviously not possible if the sensor has failed though (then calibrating in xDrip needs doing every day or so for the first 2-3 days wearing)

Had a look at the Dexcom One, and not tried yet, but reviews I see are 'about the same' for accuracy etc, so not too bothered to change to them yet.

Running Libres (1 and 2) for about 5 years now and couldn't be without a CGM

 

[Aaandyyy]

Interesting. I've ben T1 for 57 years now and loved the Libre sensor when put on them a couple years back.
That was until they updated it recently to send the information without the need to scan, since then it all appears to have gone to pot.
Reasonably stable for years and then as soon as the new sensors appeared "erratic" doesn't even come close to describing it.
Somethings not right somewhere Libre.

 

[ToxicWleper]

I retired about 6 years ago and decided to spend some of my pension on a Dexcom G6. It was life changing but very expensive! So, when the Libre 2 became FOC I decided to switch and, of course, now it’s become a CGM, happy days. However, in the 9 months I’ve been using the Libre 2 I’ve had to return three sensors as they were giving inaccurate readings or just didn’t work at all. A couple of months ago I noticed a lady wearing a Dexcom G6 and I asked her if she was aware of the Libre 2. She said she had started using the Libre 2 but it was so inaccurate that her GP had prescribed her the Dexcom G6 free of charge! Has anyone else had a similar experience?

 

[In Response]

@ToxicWieper - no CGMs are free of charge. The tax payer has to fund the NHS. I appreciate they are available on prescription and if we have diabetes not treated by diet alone, we are exempt from paying.
However, considering anything from the NHS as free of charge is not the case.
Thank you for returning your faulty sensors to Abbott. For some thinking of them as "free" means they do not care to return them or wastes them in other ways. Especially when the NHS has little money to throw away.

<Sorry. I will stand down from my soap box now.>

 

[Mike Watson]

Very interesting topic. I've used libŕe from the early days and have recently found them to be much more erratic (stopping early, not working after normal application, etc). I wonder if there is a production quality issue - demand must have shot up after they went on prescription. Of course, no-one could possibly comment...
I always take blood test kit when travelling and recently had to buy some contour strips in italy - much cheaper!

 

[wobbles]

BACKGROUND: I've been using the libre2 sensor on prescription for well over 2 years now with no issues (apart from two falling off, and one telling me it had malfunctioned a week into it's life). On the rare occasion I have calibrated my sensor with a finger prick it has been usually either spot on or within 0.5, even during periods of transition. Not even the 15-30 minute delay has caused any issues. My Diabetic team at the hospital (UK, been a T1 since the age of 7 and now nearing 30) advised finger pricking isn't really necessary even to calibrate, even when driving as the DVLA accept CGM machines as accurate now, it's only if you are in hypo or exhibit symptoms you must test which has never been the case for me as I get really good warning signs.

My sensor ran our on Friday night, so I replaced with a new one. For the last week my BS readings have improved on normal, especially overnight which I attributed to a change in Glargine.

On Sunday afternoon (yesterday) my Libre was showing me as 3.4. Odd I thought, I felt fine and usually once I go below 4.5 I start to get the feeling of dropping and get a bit sweaty and just general yuck feeling. Anyway, I had some glucose and some carbs and 30 minutes later my Libre was showing as LO... weird, I had a little bit more glucose and then 10 minutes later I was showing as 6.4.

Great, I thought. Here comes the bounce. I decided to test 15 minutes later so I could begin and gauge how much novorapid to microdose through the bounce and it was showing as 4.2.... 5 minutes after that? 3.6 again. At this point I finger pricked to show 11.4. I then decided to monitor over the next 5 hours and do regular finger pricks and Libre readings. I have enclosed these on the image.

In summary, these were off anywhere between approx 2.0 mmol and 11mmol. I removed the sensor, and put a new one on as it was clearly faulty. I even switched arm.

I then did the same with this monitor (but not written and recorded) about 12 hours after starting it and it was anything between 0.1 and 1.5 in difference to a finger prick. No issues with that, seemed the norm. Then this afternoon (just after 24 hours had gone) the same differences as the other Libre started to occur. These are also on the image attached. Please note these readings were only taken during periods of questionable readings from the Libre and purposefully was selective in the amount of insulin given to make sure it wasn't a very big delay being the cause of issue for the ''test'' and my readings are usually nice and settled and lower than the finger prick results!

My sensor then failed and said there was an error and I needed a new one. I also use Glimp every now and then so I've recorded the levels from that, as I was wanting to make sure it wasn't a Libre app issue, or me, or the sensors themselves.

I've contacted Libre who have sent out replacements, but i am perplexed and now have some serious trust issues! The cherry on the cake is I leave for a beach holiday on Friday and whilst I was going to take my finger prick with me, was looking forward to practically hands free monitoring from the poolside! Has anyone ever become immune to Libre sensors?

View attachment 63036View attachment 63037

UPDATE: The replacement sensors from Abbott have arrived. 2 hours in and I haven't left between 6.0 and 6.8 on my libre app, yet between 4 different finger prints I've ranged betwwn 8.5 - 10.7. Not looking promising. The auto CGM is also turned off for some reason on the app for this sensor and doesn't seem to be on, I will post an updated spreadsheet later with the disparity with this one.

Thanks so much for sharing this @domoboy

I also appreciate the help Libre sensors have given me in managing my Type 2 diabetes I’ve been diagnosed with since 2008.



The data has helped me in my current journey towards remission. I’ve been using them (buying them) for about 4 years or so.



The last 3 months my sensors have been pretty flawless but last week I had the same symptoms as you. Sensor reading was 5.4 when started (accurate) then with minutes 3.6 and then “LOW” and then within 24 hours stopped working. The new one stopped working on the very first scan.



I think Abbott quality control needs looking at as I have a high sensor failure rate in the last year or so (then improved 3 months ago until recent failures).

When I return the failed sensors I never get the results of their analysis of the root cause.



For a Type 2 these sensors are super useful but honestly are a “nice to have”. I do worry about my Type 1 colleagues though that rely on the accuracy for their treatment…

 

[z123]

Stopped using the Libre2 - I just never got sufficient confidence in readings to dose insulin and had a run of about 4 sensors failing to give sensible readings or failing early. I think its' either my body reacting to something about the sensor or the sensor reacting to something in my body ... Abbott sent replacement sensors but just would not discuss or provide any further information ... I still have 3 replacement sensors in their boxes which I will not be using

Hi Jonathan
Sorry to hear that you will not be using the sensors anymore but if you have 3 maybe you could give them to someone else to use as they only have a short shelf life.

 

[Kaz1066]

Hi, I'm a type 2 on insulin and meds and I have recently been put on the Freestyle Libre2 for my glucose monitoring.
I tend to have the opposite problem to a lot of you that have commented in that my levels tend to always be high. However, when I queried with my diabetic nurse regarding the differences in the readings of my sensor and my FP, I was told that it is normal because they measure different fluids.
The sensor measures interstitial fluid around muscle cells just under the skin whereas the FP measures capillary blood.
I was just advised that if my sensor alarm went off for high (over 18mmols) to do a FP.
Anyhow, I just thought I'd comment because no one on the thread had mentioned about the difference in the way the CGM works compared to finger pricking.

 

[Wilsapp]

BACKGROUND: I've been using the libre2 sensor on prescription for well over 2 years now with no issues (apart from two falling off, and one telling me it had malfunctioned a week into it's life). On the rare occasion I have calibrated my sensor with a finger prick it has been usually either spot on or within 0.5, even during periods of transition. Not even the 15-30 minute delay has caused any issues. My Diabetic team at the hospital (UK, been a T1 since the age of 7 and now nearing 30) advised finger pricking isn't really necessary even to calibrate, even when driving as the DVLA accept CGM machines as accurate now, it's only if you are in hypo or exhibit symptoms you must test which has never been the case for me as I get really good warning signs.

My sensor ran our on Friday night, so I replaced with a new one. For the last week my BS readings have improved on normal, especially overnight which I attributed to a change in Glargine.

On Sunday afternoon (yesterday) my Libre was showing me as 3.4. Odd I thought, I felt fine and usually once I go below 4.5 I start to get the feeling of dropping and get a bit sweaty and just general yuck feeling. Anyway, I had some glucose and some carbs and 30 minutes later my Libre was showing as LO... weird, I had a little bit more glucose and then 10 minutes later I was showing as 6.4.

Great, I thought. Here comes the bounce. I decided to test 15 minutes later so I could begin and gauge how much novorapid to microdose through the bounce and it was showing as 4.2.... 5 minutes after that? 3.6 again. At this point I finger pricked to show 11.4. I then decided to monitor over the next 5 hours and do regular finger pricks and Libre readings. I have enclosed these on the image.

In summary, these were off anywhere between approx 2.0 mmol and 11mmol. I removed the sensor, and put a new one on as it was clearly faulty. I even switched arm.

I then did the same with this monitor (but not written and recorded) about 12 hours after starting it and it was anything between 0.1 and 1.5 in difference to a finger prick. No issues with that, seemed the norm. Then this afternoon (just after 24 hours had gone) the same differences as the other Libre started to occur. These are also on the image attached. Please note these readings were only taken during periods of questionable readings from the Libre and purposefully was selective in the amount of insulin given to make sure it wasn't a very big delay being the cause of issue for the ''test'' and my readings are usually nice and settled and lower than the finger prick results!

My sensor then failed and said there was an error and I needed a new one. I also use Glimp every now and then so I've recorded the levels from that, as I was wanting to make sure it wasn't a Libre app issue, or me, or the sensors themselves.

I've contacted Libre who have sent out replacements, but i am perplexed and now have some serious trust issues! The cherry on the cake is I leave for a beach holiday on Friday and whilst I was going to take my finger prick with me, was looking forward to practically hands free monitoring from the poolside! Has anyone ever become immune to Libre sensors?

View attachment 63036View attachment 63037

UPDATE: The replacement sensors from Abbott have arrived. 2 hours in and I haven't left between 6.0 and 6.8 on my libre app, yet between 4 different finger prints I've ranged betwwn 8.5 - 10.7. Not looking promising. The auto CGM is also turned off for some reason on the app for this sensor and doesn't seem to be on, I will post an updated spreadsheet later with the disparity with this one.

Hi

I regularly get woken up in the night by LibreLink (and Xdrip+) alarms telling me I'm low but a fingerprick test says I'm not. The apps may say 3.6 and the fingerprick

 

[R T Donkin]

BACKGROUND: I've been using the libre2 sensor on prescription for well over 2 years now with no issues (apart from two falling off, and one telling me it had malfunctioned a week into it's life). On the rare occasion I have calibrated my sensor with a finger prick it has been usually either spot on or within 0.5, even during periods of transition. Not even the 15-30 minute delay has caused any issues. My Diabetic team at the hospital (UK, been a T1 since the age of 7 and now nearing 30) advised finger pricking isn't really necessary even to calibrate, even when driving as the DVLA accept CGM machines as accurate now, it's only if you are in hypo or exhibit symptoms you must test which has never been the case for me as I get really good warning signs.

My sensor ran our on Friday night, so I replaced with a new one. For the last week my BS readings have improved on normal, especially overnight which I attributed to a change in Glargine.

On Sunday afternoon (yesterday) my Libre was showing me as 3.4. Odd I thought, I felt fine and usually once I go below 4.5 I start to get the feeling of dropping and get a bit sweaty and just general yuck feeling. Anyway, I had some glucose and some carbs and 30 minutes later my Libre was showing as LO... weird, I had a little bit more glucose and then 10 minutes later I was showing as 6.4.

Great, I thought. Here comes the bounce. I decided to test 15 minutes later so I could begin and gauge how much novorapid to microdose through the bounce and it was showing as 4.2.... 5 minutes after that? 3.6 again. At this point I finger pricked to show 11.4. I then decided to monitor over the next 5 hours and do regular finger pricks and Libre readings. I have enclosed these on the image.

In summary, these were off anywhere between approx 2.0 mmol and 11mmol. I removed the sensor, and put a new one on as it was clearly faulty. I even switched arm.

I then did the same with this monitor (but not written and recorded) about 12 hours after starting it and it was anything between 0.1 and 1.5 in difference to a finger prick. No issues with that, seemed the norm. Then this afternoon (just after 24 hours had gone) the same differences as the other Libre started to occur. These are also on the image attached. Please note these readings were only taken during periods of questionable readings from the Libre and purposefully was selective in the amount of insulin given to make sure it wasn't a very big delay being the cause of issue for the ''test'' and my readings are usually nice and settled and lower than the finger prick results!

My sensor then failed and said there was an error and I needed a new one. I also use Glimp every now and then so I've recorded the levels from that, as I was wanting to make sure it wasn't a Libre app issue, or me, or the sensors themselves.

I've contacted Libre who have sent out replacements, but i am perplexed and now have some serious trust issues! The cherry on the cake is I leave for a beach holiday on Friday and whilst I was going to take my finger prick with me, was looking forward to practically hands free monitoring from the poolside! Has anyone ever become immune to Libre sensors?

View attachment 63036View attachment 63037

UPDATE: The replacement sensors from Abbott have arrived. 2 hours in and I haven't left between 6.0 and 6.8 on my libre app, yet between 4 different finger prints I've ranged betwwn 8.5 - 10.7. Not looking promising. The auto CGM is also turned off for some reason on the app for this sensor and doesn't seem to be on, I will post an updated spreadsheet later with the disparity with this one.

This happens to me a couple of times a year. I just use a stick test to cross compare every 15 min and if the error persists I always believe the stick test reading and change the sensor.

 

[R T Donkin]

This happens to me a couple of times a year. I just use a stick test to cross compare every 15 min and if the error persists I always believe the stick test reading and change the sensor.

 

[In Response]

Hi

I regularly get woken up in the night by LibreLink (and Xdrip+) alarms telling me I'm low but a fingerprick test says I'm not. The apps may say 3.6 and the fingerprick

Sounds like compression lows. You may want to review where you place your sensor so you don't lie on it when you are asleep.
This is a known (and often described) problem with all CGMs. Libre users may experience it more often because it is only approved to wear on the arm.