Freestyle Libre not working correctly

[quinners92]

Hi,

I recently bought the freestyle libre off abbot and set it up. I placed it slightly to the side of the back of my upper arm. I waited the hour and went to get my first reading. However when I did it told me it was 2.9. I did not feel like my Bg was low so I did a finger prick and it told me it was 7.0. This trend continued throughout the evening, everytime I checked it it told me I was low, whereas a finger prick told me a totally different reading. Since then the readings have become a bit closer, for example a finger prick told me it was 12.5 & the freestyle said 13.4 . I bought the freestyle as a way of leaving finger pricks at home but now I'm afraid to because the freestyle libre makes me feel that I can't trust it.
Has anyone experienced this issue? Or have i done something wrong?
Thanks

 

[DeejayR]

Hello. This is covered in numerous other threads on the Libre on this forum, so have a search. Persevere with yours ... it will probably settle down after a day or two.
http://www.diabetes.co.uk/forum/threads/free-style-libre.115203/

 

[AndBreathe]

Hi,

I recently bought the freestyle libre off abbot and set it up. I placed it slightly to the side of the back of my upper arm. I waited the hour and went to get my first reading. However when I did it told me it was 2.9. I did not feel like my Bg was low so I did a finger prick and it told me it was 7.0. This trend continued throughout the evening, everytime I checked it it told me I was low, whereas a finger prick told me a totally different reading. Since then the readings have become a bit closer, for example a finger prick told me it was 12.5 & the freestyle said 13.4 . I bought the freestyle as a way of leaving finger pricks at home but now I'm afraid to because the freestyle libre makes me feel that I can't trust it.
Has anyone experienced this issue? Or have i done something wrong?
Thanks

Welcome aboards, Quinners.

How long have you had that sensor on, and did you apply it, then activate it almost immediately, or wait a day or so?

 

[jessie]

Hi Quinners, I'm having a very similar problem and hoping it will settle down. Starting to read through the many threads on the subject for more advice! All the best.

Jessie.

 

[quinners92]

Welcome aboards, Quinners.

How long have you had that sensor on, and did you apply it, then activate it almost immediately, or wait a day or so?

I have had the sensor on about 28 hours now, I activated it immediately and was told on screen that I could get my first reading in an hour. I have just checked it against a finger print reading again there and there was just a 0.1 difference so I'm hoping its starting to settle. But I'm still concerned that it could just go AWOL again and I'll be totally off in my judgement if I don't have my finger prick with me

 

[Postleneo]

Hi there... Been using the Libre now for a few months. I also had the same issues initially however I started to put the sensor on two days prior to activating it and by doing that I get close readings from the first scan after activation. It's never exact but found it's usually around 1 mmol out. Maybe just takes a couple days to settle

 

[quinners92]

Hi Quinners, I'm having a very similar problem and hoping it will settle down. Starting to read through the many threads on the subject for more advice! All the best.

Jessie.

Hi Jessie,

Hopefully, because it's a costly product and it's definitely worth the money if it's working correctly but if I'm carrying around my finger pricker to verify the readings the whole time then it's certainly not worth it.

How long have you had yours on now? How long are you waiting for it to settle?

 

[AndBreathe]

Hi Jessie,

Hopefully, because it's a costly product and it's definitely worth the money if it's working correctly but if I'm carrying around my finger pricker to verify the readings the whole time then it's certainly not worth it.

How long have you had yours on now? How long are you waiting for it to settle?

Quinners, if you drive, you will still be bound to do some fingerprick testing, in order to comply with DVLA guidelines, irrespective of how closely your Libre and fingerprick tests marry up.

Currently, the DVLA do not accept Libre readings for driving.

 

[Energize]

I now apply a new sensor around 18-24 hours before the current sensor is due to expire. Then activate the new one once the old one has expired. By doing this, it seems I get more reliable results straight away.

As for being the same as your finger prick test, you are comparing blood glucose with interstitial fluid, so not unusual to have a difference. Also, if you were to test the same drop of blood on a number of different meters/test strips, you would get a variety of results.

As @AndBreathe has already said, you will still need to use blood and test strips to comply with DVLA regulations.

Also, the Libre is not advised to use re calculating doses of Insulin.

 

[Scott-C]

There's an article here https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903977/#B38 which says this:

"Despite the advances in the making of sensors with new and improved designs and materials, sensor insertion causes trauma to the insertion site. It can disrupt the tissue structure, provoking an inflammatory reaction that can consume glucose followed by a repair process. The interaction of the sensor with the traumatized microenvironment warrants the need for a waiting period for the sensor signal to stabilize, and that period varies depending on the sensor type."
​

The way I read that is that because glucose is being consumed by cells around the insertion site, glucose levels are in reality low at that site for a while, so the libre is reporting it correctly but gives the appearance that it is out when compared to blood from untraumatised sites. That's why a lot of libre users insert and then wait a while before activating, to give the repair process time to fix things and stop gobbling up all the glucose.

 

[jessie]

Hi Jessie,

Hopefully, because it's a costly product and it's definitely worth the money if it's working correctly but if I'm carrying around my finger pricker to verify the readings the whole time then it's certainly not worth it.

How long have you had yours on now? How long are you waiting for it to settle?

Hi again Quinners,

I'm new too (just started my second sensor) but from what I've been reading I'm feeling hopeful that things will settle down. When I apply my next one I'm going to wait a day or so before activating it as recommended. I guess its also a matter of getting used to things, as it's a big leap from finger pricking really. I still haven't got my head round having this 'thing' stuck in my arm, I find it a bit freaky!!

Jessie. x