Cgm vs blood reads...

[donnellysdogs]

Can anyone help on this?

I have a cgm dnd combo pump.

I have given the cgm a rest for a few weeks as I was getting frustrated with it and nobody from manufacturer gave a **** to help..

But, I have it.. So I thought give it one more go before returning it to the hospital..

What bothers me is the difference I get in the readings between blood and cgm.

Now I know there is a time lag... But my cgm does not follow behing my blood at all on occasions...

Overnight it has read constantly from
Midnight to 3am at 4.6 to 5.1.. But I have checked this against my meter as those readings are too low for me... My meter said I was 6.2 and 7.1.. When the cgm was giving me these lower readings...... Even now 2 hours later my cgm still only shows a reading of 5.9..

This was happening a few weeks ago.. It telling me I was hypo ish all night and yet my combo meter telling me I was in the 5's and 7's.

The cgm always telling me I am so much lower than my actual blood readings... And therefore my dsn snd consultant telling me off for too many lows... When I'm not sctually too low according to my blood snd meter..

I have tried to tell the manufacturer.. But they just sent out control solution.. And both cgm and meter fall within permitted allowances.

I have notified my HCP's but their response is still that my levels are too low.... Last night at 19.35 cgm said I was 3.4.... Blood said I was 5.5.....so I am being told consistently by Hcp's to raise my levels to get an hba1c of 8.......last hba was 6.6. But last night at cgm reading of 3.4 I wasnt feeling low.... Because my blood wasnt giving me a low...lowish I agree... But blood was still at 5.5... My c then took 2 hours before it gave a reading above 5....
My HCP's last told me to use the cgm only as a guide of my trends and that they would get the other cgm user who gets on so fantastically with it to ring me...
Nothing heard from Hcp or fellow cgm user...

The cgm rarely displays kevels consistent to blood readings... And certainly doesnt catch up...

I don't know what to do. I felt priveleged to have this funded cgm.. Especially when working and driving..
But I cant afford cgm to have such low (false??) value readings to my pump meter... I really dont know whether to persevere or to just hand it back in.

I have got hypo awareness, but due to my prev driving incident few years back and my ncteased driving and my job and hubbys hours etc I was privileged to get this funded...

However, now I am just costing my NHS people more money... As now it is funding bllod strips for me to test eroneously low readings on my cgm when I 'm not low on my blood!!

My questions..
Has anybody else using a cgm get such different values between blood and tissue readings?

My cgm isnt widely used.. Its a Navigator one...has anybody got the use of an Abbott Navigator cgm who can advise me?

I know I am a perfectionist... I know I like to achieve good levels.. But I want to do it at less cost to NHS and with some degree of accuracy and worry free.. But it does give me an idea whether my bloods are going higher or lower without me having to think for 2 hours.. I dont get hyper symptoms unless very high.... So for patterns it is reasonable. Whilst gardening in huge gardens it is also very handy that I dont have to walk ages, take off dirty gloves, find a tap, get to car, stop working etc... Meter testing can take me 15 minutes to get back to car.. Wash hands etc by which time.. If feeling low I have already gulped down sweets (and mud)....

Has anybody any advice.. Sorry its a rambling message, but having just had another night of cgm showing lowish readings and blood different I feel like ripping the cgm off...

 

[Spearmint]

Hi DD

We've used a Navigator before with varying results!

I borrowed one from the hospital for my daughter because i was struggling with lack of sleep trying to catch night hypos, i had to buy a pack of 6 sensors though myself!
We used it on and off from April to July this year.
I had to change the hypo setting overnight because it would always read her lower and constantly alarm, i did read somewhere that overnight your body temperature drops which causes the CGM to read lower than you are although i don't know how true that is!
During the day i found that it would be fairly accurate for the 1st day and then it would read her higher during the day.

 

[donnellysdogs]

I thought I read somewhere that it could give liwer readings at night.. But when I asked Abbott helpline they denied having any knowledge that the cgm would do that.

Today, I did a test just now pre eating and blood said 7.0. Cgm said 5.8 with a diagonal arrow downward.... If it said upward.. I would think.. Yep in 30 minutes it will read 7.0.. But it just doesnt..

Cgm Reading so low all the time makes it great to make sure I'm driving safe.. As when it says 5 or 6 I guarantee it's higher....

However on a longterm basis... Its not good because like just now after I ate I needed to drive... So at 5.8 would have had 3 dolly mixtures to drive the 10 min journey... But at a real blood reading of 7.0.... My pump was saying to give me 0.1 correction!!! So I never know in reality where I am with it...well I do..... Much higher than it says!!! This isnt just day one.. It is every day.

It has made my life easier for driving long distances and working but harder because my HCP's believe the cgm readings and Abbott haven't been any help at all..

Truly frustrated, but glad to hear that someone else has used their cgm and also has a recollection of nights giving lower readings!! Thankyou..

Incidentally.. If an Abbott cgm was funded would you use it on a permanent basis from your experience with your daughter?

 

[zibi1]

Try the Dexcom, which has a superior technology and accuracy with respect to any other cgm on the market, especially the G4

 

[donnellysdogs]

Wish I couldtry dexcom.. But Abbott is what hospital have managed to get and I dont pay... It does sound ungrateful... But I'm not... I actually see the cgm as a fantastic piece of equipment and hope it really gets developed more, and that NICE will recognise it as a benefit to nhs.. Not a cost....

I just wish this one was more accurate... As it fails to come within the allowable tolerances for a lot of the time.

 

[Spearmint]

I thought I read somewhere that it could give liwer readings at night.. But when I asked Abbott helpline they denied having any knowledge that the cgm would do that.

Today, I did a test just now pre eating and blood said 7.0. Cgm said 5.8 with a diagonal arrow downward.... If it said upward.. I would think.. Yep in 30 minutes it will read 7.0.. But it just doesnt..

Truly frustrated, but glad to hear that someone else has used their cgm and also has a recollection of nights giving lower readings!! Thankyou..

Incidentally.. If an Abbott cgm was funded would you use it on a permanent basis from your experience with your daughter?

That doesn't surprise me! I found them very unhelpful when i rang to complain about 2 sensors failing, 1 failed after just 6 hours but they just blamed my daughter on moving around too much and being too rough???

I found the arrows fairly reliable and the overall pattern and trend was useful.

I couldn't believe that it read lower overnight as it was no use in picking up overnight hypos at all and i actually ended up with less sleep having it than not having it due to it constantly alarming!!

No i don't think i would use the navigator on a permanent basis, maybe every few months to get an overall pattern but i would have the alarms switched off!
I'm quite interested in the Dexcom CGM as the sensors last longer

 

[donnellysdogs]

Well today just to be sure I have done more tests during day... Which initially I didnt do.. As I was convinced the cgm wasn't too bad.. But tonight cgm has also been quiet.. No beeps.. Alarms etc so it must think I'm level and no arrows and it has kept at 5.9 and 6.0 for past two hours.. Just done pump and it says 8.3.

Just spoken to hubby and he thinks it is too inaccurate to continue.

I emailed Abbott and HCP's about the bad night levels with cgm .. Obviously all checkable.. My HCP sai she glad I taking up with Abbott. Requested Abbott to phone me.. This was after they sent the test control solution.. They have never phoned. I only have a mobile, so get charged to phone them.. Thats why I would like them to phone me and I dont honestly see why I should pay to phone them when our NHS already being stung hugely..

I shall wear for the remainder of this sensor life and then I think I will hand back..

Such a shame... As it could be a fantastic monitor it was for me so handy and gave me a lot of my working/social life back to prediabetes with the facility of the button checking and arrows etc. it has actually increased my awareness of hypers.. As I now can sense them due to getting chronic headaches! I also realise when I belueve it is inaccurate with lows!

Made me laugh the night before I started re-using it.. I had left the batteries in whilst I stopped using jt for a few weeks... And it chose 2am to start alarming.. And I couldnt remember where I had placed it... Which sock or knicker drawer.. So it alarmed 5 times and went off.. And then I had to wait for another 2 bursts of alarms before I could find it.. So it even had to wake me up at night when I wasnt even using it... I also 'stretched' the alarm settings and mutes for nights due to 'false' lows...

Such a real, real shame.

 

[donnellysdogs]

Well.. Latest update...
Have phoned and spoken to Abbott.. Navigator Cgm manufacturer...
Have tried everything they suggested...

And still todays results with only 6 hours to go of my last sensor... The following results.....I did not eat.. Or bolus at all for duration of these results....

Last night:
17.30 cgm 6 5. Pump 6.7 ....HOORAY!!!!
18.15 cgm 4.2. Pump 5.5
19.30 cgm 4.2. Pump 5.7
20.20 cgm 3.4. Pump 6.0 had to cjeck cos said I was low.... Yet on blood had raised
21.17 cgm 4.3. Pump 7.2
23.31 cgm 5.2. Pump 7.8

Then.....
03.27 cgm 4.0. Pump 6.3
6.46 Cgm 3.9. Pump 4.8
9.10 cgm 3.9. Pump 6.1
12.30 cgm 3.6. Pump 5.2
14.38 cgm 3.7 Pump 6.1
17.05 cgm 3.1. Pump 5.6

Now...... My hcp's last time they looked at my blood diary of cgm results told me off...

This was on 19 Nov 2012.....

I tried to tell them and Abbott that CGM reads low..

I have now been placed in position of having to return cgm to them..

Please can I ask felliw cgm users... And non cgm users...

My blood levels to my pump readings look **** good to me... **** for hypo's on cgm levels....

1) would you continue cgm use?
2) would you allow hcp's to keep threatening your driving licence and livelihood? What would you do?
3) would you go by cgm or bloods on a daily basis? My last hba1c was 6.6 and based on my cgm readings totally at that time I was told by my consultant that she wanted to see my hba1c at 8.0 .... All based on cgm readings at that time.

I have emailed consultant who has said she will norify dsn.
I keft message in dsn phone 3 days ago saying that with **** cgm readings (listing them) I wished to hand back cgm.. Could they contact me... Heard nothing..

Now I know Abbott and HCP's can read these messages... They are 100% accurate with my readings and thoughts.. But I would appreciate felliw pump/cgm users opinions... As currently I feel **** because I am being told off for having too low levels... ( and Nov told to decrease all basals 0.1... Which put my readings 14.26)... And constantly having mt driving licence and livelihood mentioned at leadt 3 times every meeting with ny dsn by her.....

This is really worrying me.. I have notified MHRA of cgm differences.. I have spoken to dsn, Abbott constantly but now I have had to call it a day with cgm because of consistent huge differences...

Any thoughts from anyone?

 

[VickiT11979]

I would find it really hard to give up funded CGM - but if it's inaccurate then there's little point in having it. I'm really surprised your HCPs are not trusting your well documented meter readings, as the party line for CGM from them (at least in my experience & in all the CGM literature) seems to be that it's less accurate than finger stick meters & the trends are more important than the actual values. They shouldn't be making veiled threats about your driving or advising changes to your treatment based solely on CGM!

I THINK that I'd hand it back if I were you, but it is a really big decision. Is there absolutely no chance your hospital would use another company for the CGM? I think Abbott works out the best value overall (I looked at the various setup & ongoing costs as I'm thinking of self funding), which might be why.

 

[donnellysdogs]

Have spoken to another cgm user from same hospital, but wont disclose fully the conversation as this forum open to everyone...

However, after speaking to person I know we have 2 huge differences in personality. I am anal about accuracy and costs to NHS... So wheras I report differences and get really wound up by them.. The ither user just changes the sensor ... The other user says 3(!!!!) were used last week.....now I get wound up by one sensor being inaccurate, let alone a 2nd and then doing a 3rd in a week...
I worry about costs to NHS and utmost is that unless these faults are fed back to the Company,NHS and MRSA this Company supplying the Navigators will never improve their products.

I spoke to Abbott ref inaccuracies at night on Navigator compared to the blood. The girl I spoke to stated that unless I got up and washed my hands each time I trsted my blood during the night that the results would be inaccurate and invalid to compare to the cgm. Now, I am sorry... I wash begore going to bed, i wash thoroughly with cleaning teeth etc. i test last thing before sleeping, and can further test another 3 times during the night... I have never got up and washed my hands unless I had a wee.....I have never been told to by any HCP.

Anyway, tomorrow I am going to try the Abbott Navigator again and try to be less anal.

The other cgm user does not record anything in blood diaries and only tests blood on the 5 set up blood tests. So to make it work for me I will have to abandon sone aspects and my morals will have to become less.

It is a good guide for daytime use 80% of the time and as the readings are always less than blood then they can give realisation back even more so to users of hypos and hypers...
I.e now I know that when I get a headache my levels on cgm will be showing as 8-9 .. On blood they will be 11.

The other user does not have any record book to record any details in, so the HCP's do not look at this, like they did mine. So I am going to stop recording my levels.

So I will see how the next 5 days go. One thing is for sure with the other user using 3 in a week and ne going to be less anal the costs to nhs will go up.

I get staggered at how good other cgms are getting 14 days.. When the Abbott Navigator barely gets 5 on a good sensor!!