faulty Libre 2

[MBuck]

During a cruise trip last December my Libre 2 sensor didn't seem to work properly. My BG were high (according to my Libre2 readings) and properly caused by the holiday diets onboard. But the sensor at some point just gave out the word 'HIGH' with no reading. That lasted a couple of days. Unfortunately I didn't have the Accur-check meter with me to confirm the BG levels. The indication in the Libre2 made me quite worry about the amount of insulin I should inject.

I checked my BG with the meter after arrived home. Readings from the meter were about 5-6 units lower than the Libre2.

I reported that to the Abbott care centre, also emphasised my concerns of health and safety issues for users. The faulty readings could easily lead to a fatal insulin overdose episode. I also requested my local diabetes centre to make special note of the case to alert other patients. Unfortunately, their response appeared to be very causal, just made me feel guilty not taking the meter with me for holiday.

My Libre2 replacement worked well. Readings were corresponding to the meter. In fact, all the readings shown suddenly became reasonably satisfactory. It really was too good to believe! But only when I changed my Libre2, I then noticed the readings in my meter was often 3-4 units higher.

Have any of you had this experience before?

 

[Lucyr]

Unfortunately I didn't have the Accur-check meter with me to confirm the BG levels. The indication in the Libre2 made me quite worry about the amount of insulin I should inject.

Why on earth didn’t you have your bg meter? You should carry it at all times. You need to fingerprick to confirm any high or low libre readings before treating as it isn’t accurate at these levels. Additionally for holidays you should take enough glucose strips to solely fingerprick should all sensors fail.

 

[shaunoconnor]

100% lots of sensors are out by 1 or 2 mmol/l, I reckon 1 in 50 have the 4mmol/l error you describe. I trust the arrow and verify the number. I'd strongly avoid using the sensor to calculate insulin dosage. There are a few alternative apps for reading a libre sensor which include old school calibration from manually added blood test data.

 

[helli]

100% lots of sensors are out by 1 or 2 mmol/l

Not in my experience.
However, it is important to consider difference between finger pricks and CGM in terms of a percentage not an absolute. If your “true” (lab tested) BG was in double figures, it is very possible for the difference to be 1 or 2 mmol/l because the required standard requires BG meter to only be within 15% of a true BG.
This is not a fault of sensors.

If your true BG is 5 mmol/l, two meters could be more than 1 mmol/l apart yet still within the required range.

However, if you are finding your CGM always out by 1 or 2mmol/l, have you considered your finger prick meter is inaccurate?

 

[rebrascora]

I am sure Libre instructions specify that you should always check highs and lows with a finger prick meter reading before taking any action and particularly calculating an insulin correction dose. Libre simply is not reliable that far above range.
Many of us were obliged to do the Freestyle Libre Academy modules before we were prescribed the Libre, so that we had a reasonable understanding of it. It sounds like you are not well enough informed about how to use Libre and indeed how to keep yourself safe with the technology and insulin. Not taking your BG meter on holiday is a massive oversight.

 

[MBuck]

Thank you all for the comments. Both the Accur-check meter and Libre sensor are useful and accurate to certain extent. I think readings from the meter are more stable while the continuous development of the Libre could sometimes affect its accuracy. The episode I experienced was during the time Libre changed its duration from 14 days to 15 days.
Afterall, these appliances measure blood glucose in different way. The idea for posting my experience was simply to raise awareness.
All these bring back memory of my first time on insulin forty years odd ago. There wasn't any means to check BG before injection. My first glucose meter was huge. I had to purchase it and it was expensive. It seemed that I had fewer concerns then. Interesting.

 

[Merluza]

My experience with the Libre 2 is very confusing. @helli finds them as near perfect as you could wish but out of the last 10 I have applied I've had 5 failures within 24 hours. This doesn't make sense. I wonder if I am the problem but as far as I know I am applying them exactly as directed, and take great care to follow directions, but the outcomes I'm seeing aren't just inaccurate readings but sensors completely failing. I'm getting to be on quite friendly terms with my postman as he delivers replacements.

I've had more accurate results lately by applying the sensor quite high on my arm but this limits the area available and there is less fat in that part of my arm so I would expect the opposite. At the moment I'm taking some time off as now both arms need some recovery time. I probably need to discuss with at the clinic but that won't be until October. If anybody has any suggestions I'll be happy to hear them.

 

[Bruce Stephens]

If anybody has any suggestions I'll be happy to hear them.

Maybe consider Dexcom instead? Changing to Dexcom One+ would be cost-neutral so that shouldn't be an issue. Some people find Dexcoms work better for them than Libre (and some find the converse). There's a more limited set of supported smartphones, so that may be an issue. I think Dexcom One+ has a broader set of supported sites, too (Libre is only supported on the upper arms).

 

[Merluza]

I'll certainly discuss with the specialist in October. Useful as I find CGMs, when they work, I can't see me carrying on like this without significant improvement.

 

[Proud to be erratic]

@Merluza, I tolerated a wholly unreliable Libre during 2021, into '22. It became clear eventually to myself and my Consultant that I was incompatible with Libre 2. I tried the original 2 part Dex One, which was better - but not brilliant. I self-funded Dexcom G7 for a few months and the reliability of that was a complete revelation to me. It was also very obvious to my Consultant with my improved BG variability and 1st ever below 50 HbA1c. From that the Hospital provided and funded my G7.

Since your next consult is not until October perhaps you can get your GP to prescribe Dex One+ as a trial and see how that works out for 2+ months. Then in October you might have the basis of a business case to stay with Dex One+ or be provided with G7. I'm sure, @Merluza, there will be a decent solution out there for you. After 40+ yrs T1, you certainly qualify for special support!

 

[Merluza]

Thanks, at the moment I’m waiting to decide when to have another go, I have 5 libre 2s waiting for me.

 

[Proud to be erratic]

Thanks, at the moment I’m waiting to decide when to have another go, I have 5 libre 2s waiting for me.

Understood; that decision point isn't always obvious. The 5 x Libre 2s could wait, however, until you've tried Dex One+, at which point the DSN team will almost certainly take them off you if you decide to proceed with Dexcom. They are always happy to have spares to let other patients try CGM. Otherwise you might prefer to keep your Libres in reserve, while trialling Dexcom One+.