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Every CGM fails

L

leaha

Member
Messages
10
Type of diabetes
Type 1
Treatment type
Insulin
I‘ve recently had every single one of my gcms fail or give me very wrong readings. I‘ve tried the freestyle libre 3 where the values were almost always off by 60-80 especially after the first fee days, which can be a very dangerous difference most times. Now I am again on dexcom g7 and it fails to show any readings every time after only two or three days. I have never had this problem in all the years since my diagnosis. I tried different sites but that didn‘t help either. Does anyone know what this could be, I‘m seriously struggling and constantly anxious about my values now.
 
Hi @leaha ,

Welcome to the forum.

When you say “almost always off by 60-80”. Is this higher than a meter test or lower?
 
Always lower, the gcm would say 102mg/dl when I am actually at 200 or more, or it would show that I am very low and I would be at 140.
 
leaha said:
Always lower, the gcm would say 102mg/dl when I am actually at 200 or more, or it would show that I am very low and I would be at 140.
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I used to find that dexcom would under read for the first 24 hours (it's been much better recently for some unknown reason) but you can calibrate it if it's still off after 24 hours....

Having said that if it's reading as far off as you describe above, I'm not sure that calibration will be possible.

Probably a stupid question, but are you sure your meter is accurate? eg are the strips in date?
 
But suprisngly the dexcom is very accurate the first day and the second as well. Then around the third it just stops showing readings every few minutes and if it does then they are wrong. The freestyle was always a bit off but less the first days as well. My stripes are in date and I wash my hands before and I change the needle…
 
Are you saying the Dexcom drops the readings to your phone app?
 
Oh no I didn’t, thank you for the advice! But wouldn’t that interfere with my current dexcom from the first day on an not just after the second/third day?
 
leaha said:
Oh no I didn’t, thank you for the advice! But wouldn’t that interfere with my current dexcom from the first day on an not just after the second/third day?
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My experience is using Libres. So a rescan sets it up where it left off if there is an issue mid use.
With Dexcom.. you should just need to input the transmitter code?

Another thing comes to mind.
I have used a Dex G6. I discovered the transmitter wasn’t snapped properly into the probe part. Which also caused intermittent connection issues.
 
I think I should switch back to libre 3 as well… have you experienced wrong values le no readings with the libre a lot? With the G7 it’s all in one piece so no more transmittor.
 
leaha said:
I think I should switch back to libre 3 as well… have you experienced wrong values le no readings with the libre a lot? With the G7 it’s all in one piece so no more transmittor.
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I use the Libre 2+.

The only time I experience wrong values is there can be a delay coming back up from a hypo.?
The Libre can still be suggesting I’m still low 15 or 20 minutes after the symptoms have gone & the meter confirms it too.
I believe that after treating a low. The brain gets priority & the interstitial fluid layer under the skin is the last in line?
 
Yes the dexcom also has quite a delay not only after a hypo. What I dislike about both Cgms is that when my blood sugar rises or drops very fast then they won’t show any readings, but I guess that is unavoidable cause they just can‘t keep up.
Do you think values can be false or not showing if after taking it off I notice skin rashes and/or bruises?
 
I think there is a safety feature with rapid moving numbers the algorithm shuts down till the readings get a baring on a settled number?
I’ve had sensors bleed a few times on fitting & I kept an eye on the numbers with the meter. The sensors been OK.
I can’t say I’ve had bruising or rashes. I tear mine off on removal..
 
leaha said:
Do you think values can be false or not showing if after taking it off I notice skin rashes and/or bruises?
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I had that problem with the original libre. After I became allergic to it it became completely inaccurate and I had to switch to dexcom.

I use cavilon cream with the dexcom so I have managed to avoid more than a very mild occasional rash.

As regards skin allergies, I would definitely recommend some form of barrier cream rather than progressing to a full on sever allergy.
 
Really? But adhesive irritation by itself shouldn'tnormally cause the G7 to repeatedly lose glucose readings, right? So I wouldn't assume the itching explains everything. But I would really hope that was it, cause I‘ve not been able to solve the problem and I won‘t have unlimited supply. Thank you for your comment! Do you put the barrier cream on right before changing the gcm to that spot?
 
I put the barrier cream on immediately before I apply the sensor. I can't remember whether the sensors just became inaccurate or also stopped reading altogether, as it was a long time ago, and also with the original libre sensor.

You may find this article by dexcom useful

Good luck
 
Hi Leaha - where exactly are you placing the sensors ? Positioning is quite important so be good to know exactly where on the body you are positioning them. G7 issues always need to be reported directly back to Dexcom too - so call their support number to explain the issues you're having, they may well just be bad sensors which is pretty common with the G7.
 
Hi, I mainly place them on the back of my arm, inner or outer side, but since I’ve had those problems I have tried placing the dexcom on my stomach but the same scenario occured and I also got a rash underneath which surely did not help. I already contacted dexcom support and they called but never actually confirmed if I would get replacements.
 
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