# Libre 2 readings



## Martin62 (Jun 11, 2021)

Hi All
Got the free trial libre 2 sensor and activated it yesterday,  I've noticed the readings are lower than my finger prick ones, I understand that this is because one uses blood and the other interstatial fluid, but when I got up today, I scanned it and it showed 3.2 , I immediately did a finger prick test which showed 6.7 , I don't see how I can trust the libre readings to calculate my bolus dose with such a difference,  scanned the libre 25 minutes after the finger prick test and its showing 5.4 and rising, still not caught up.
Not really impressed. 
Martin


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## helli (Jun 11, 2021)

When did you insert your sensor?
Most of us find it takes a few days for CGMs of any sort to "bed" in. In the meantime, our bodies try to reject it which affects the readings. 
It is very common to insert the sensor a day or two before activating it to overcome this problem. 

If it is in accurate after 48 hours, Abbott.

Libre is incredibly useful but only if you understand its limitations and know how to use the data that it provides. 
Unfortunately, Abbott are not great at advertising the limitations but there are many discussions about them on fora like this.


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## rebrascora (Jun 11, 2021)

Hi. 
Sorry to hear your Libre isn't giving you accurate readings. Some people find they need to apply the sensor a day or two before activating it to give the cells/tissue surrounding the sensor filament time to settle down and accept the foreign object in their midst. It is also possible that you were lying on the sensor prior to getting up and some compression was causing the low reading which can take time to catch up. Many of us find that our BG levels rise as soon as we put our feet on the floor and get out of bed and that means that the Libre will be lagging behind BG levels until 15 mins after that FOTF rise levels out. I usually inject fast acting insulin as soon as I wake up to cover that.

My body seems to cope with the intrusion fairly quickly so my readings will be reasonably accurate from the start but I do a few calibration checks  in the first 24 hours of activation and very occasionally thereafter. If my Libre is consistently reading 1mmol lower than my finger prick then I keep that in mind when bolusing. My last sensor was as much as 2 mmols low which was a bit frustrating as I had to double check quite a few alleged hypos which weren't but this new sensor is pretty well spot on. 

It is not a perfect system but once you get used to it, you learn to work around the deficiencies and the benefits far outweigh it's flaws for most of us. I would give it another day or two of checking with finger pricks to see if it comes into line and if not then hopefully it will be consistently out and you can factor that into your bolus calculations. If it is very wide of the mark then contact Abbott who will hopefully replace it. They are usually pretty good with their customer service.


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## Martin62 (Jun 11, 2021)

Thanks for the info, I've only had it on since yesterday evening, so will give it a couple of days to bed in , and check readings with finger pricks to see how it's going.
Not really worth me contacting Abbott, as I am only using the free trial one to evaluate if its for me or not .


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## trophywench (Jun 11, 2021)

Mate - be aware that Libre accuracy is much the same as insulin absorbency - it varies A Lot.  I've always had the prob with insulin absorbency even on jabs, sometimes I'd go Oh Sheet, thought I jabbed for my lunch but perhaps not? and this is much more noticeable pumping as it's sposed to be 'one jab' (ie insertion of new cannula) every 3 days, but I have to change mine every 2 to try and avoid creating any new rotten absorbency areas.  It is exceedingly tempting to 'just leave em a bit longer' when I get a crackingly well absorbing one.  I'm on day 3 with this one now .....

re Libre - I agree with the advice to see what happens tomorrow sort of thing, cos I have had that with mine - and I honestly think there is much more variance in people's skins than are dreamt of in the philosophy of all the medically qualified Horatios we deal with.


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## SB2015 (Jun 12, 2021)

I am another who found it useful to let the sensor settle for a day before i needed to activate it.  I focused more on the patterns rather than individual readings, but then I still had to do pin pricks to get info into my pump for bolus calcos.


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## helli (Jun 12, 2021)

Martin62 said:


> Not really worth me contacting Abbott, as I am only using the free trial one to evaluate if its for me or not .


Abbott will still replace it if it is faulty.
They want you to have a positive experience so you buy more.


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## Martin62 (Jun 13, 2021)

Well after being on for 4 days, I now get the message sensor not working,  replace sensor.
Not impressed,  glad I didn't pay £50 for it.
I'll stick to finger prick tests, cheaper and more accurate and reliable.


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## Paulbreen (Jun 13, 2021)

I’m using libre sensors for over 3 years and had very few problems and I’m thinking you messed up installing it, it’s likely from that message that the wick was not completely installed or the sensor has come loose, it might be worth another go and I’m sure Abbott will send you a new sensor to try if you contact them an let them know what happened


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## trophywench (Jun 13, 2021)

YES - I have heard on the grapevine that they are just as helpful replacing the free ones as when you've either paid for them or got them on prescription and they fail.


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## Martin62 (Jun 14, 2021)

Paulbreen said:


> I’m using libre sensors for over 3 years and had very few problems and I’m thinking you messed up installing it, it’s likely from that message that the wick was not completely installed or the sensor has come loose, it might be worth another go and I’m sure Abbott will send you a new sensor to try if you contact them an let them know what happened


No I installed it as advised and it certainly had not come loose as it was very firmly attached and was hard to remove, I got the message " your sensor has ended , please replace with new sensor " after only being activated for 4 days.
not fussed on replacing it, as just wanted to use the free trial to assess if it's something I want to use.
looking at all the complaints about faulty sensors on here and other forums, you must be one of the lucky ones to have few faults. I don't think Abbott should market a device with such a high failure rate, especially at the price they charge,but that's just my opinion and I understand that for a lot of people it's a great piece of kit, but not for me.


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## grovesy (Jun 14, 2021)

I am stuck the phone at the moment waiting to get through to a colleague handler, as I had one fail yesterday with 2 day to go that is not a problem. Though the new did not even last the hour for it to start without falling off. I had 2 this time last year that did this. 
I realised the 6 hours or so or so I was without one, I missed it.


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## everydayupsanddowns (Jun 14, 2021)

Martin62 said:


> Well after being on for 4 days, I now get the message sensor not working,  replace sensor.
> Not impressed,  glad I didn't pay £50 for it.
> I'll stick to finger prick tests, cheaper and more accurate and reliable.



Sounds like something went wrong with the insertion, or it was unfortunately a duff sensor.

Get it replaced and have another go.

Coincidentally my first Libre2 was a bit off too, it was replaced and the second and third were bang-on.


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