Who uses a pump AND glucose sensors from Medtronics?

[tygr1]

I've just started with the real-time glucose sensors and I must say that I'm not impressed thus far. It seems that all my sensor readings are way off what my meter readings are. Also, the sensor readings seem to fall way behind my meter readings.

Anyone else using this therapy notice the same problems? Does the sensor\transmitter work well for you?

I'm wondering if it's just me.

[Subby]

Can you give some examples of what "way off" is, and what your expectations are?

I've used it once, and found it accurate enough to be very handy at revealing my trends. It was generally in a range of 1 - 2.5 mmol/l (18 - 45 mg/dl) of what my tester told me.

If it was much less accurate it would have lost its use... but as it was it did perform a valuable function for me. I would have loved to keep using it to see if other sensors were more accurate but alas, it was on loan.

So let us know more specifically your experience? I know there are a couple of very helpful members who use this on a regular basis, I am sure they will pipe in.

[sarahspins]

All current CGMS technologies have a bit of a delay - this is as much as 20 minutes from what your fingerstick readings say... so if you eat something, you won't notice a change on the CGM until a while later.

Some also suspect that CGMS numbers are slower to come up from lows than fingerstick readings are.. I haven't personally noticed this myself though.

I am wearing a Dexcom system though... so my experience may be different, but when my levels are steady it's really accurate. It seems to lose the ability to read what is going on when my BG is high, or changing quickly, which on some level negates the appeal of having it on all the time, but on the flip side of that, I've been able to iron out my overnight basal issues very well.

That said, since everyone's body chemistry is slightly different.. there are some people who have great success with the MM real-time system and others who have nothing but problems. How and when you are calibrating can be a huge component of that.. or you could be doing everything "right" and still not have it work well for you.

It's also more useful for seeing trends rather than something you can rely on for accurate at a glance #'s... while I've found that my Dexcom is for the most part really accurate, when it's been "off" it's been off enough that I wouldn't be comfortable relying on anything it tells me to calculate an insulin dose... I always comfirm highs or lows with a fingerstick, and test before eating as well.

[tygr1]

Well, yesterday I was seeing a constant 60-80 mg\dl difference in the readings if my blood sugar was a little high (140-180) and less difference (20-40) if they were normal.

I try to keep my BGs very tight and think that relying on the sensor may not work out for me. Maybe I was just chasing it yesterday and not giving things enough time to settle down.

I will probably keep at it as I really WANT it to work for me.

Edit to say; I wouldn't consider using it yet to make boluses OR to attempt raising my BG. Ideally though, that's what I hope for from it. Maybe not eh?

[tygr1]

OK, I just checked my after breakfast BG and I saw a 157 with my meter and a 141 with the sensor...hooray!

I inserted a new sensor this morning just to see if that helped and apparently it did. If this keeps up, Ill be pleased.

Still closely watching.

[GretchO]

I use both a MM pump and CGMS. I absolutely love mine. I find them to be accurate for me - there are, of course, periods when they're kinda wonky but overall I find them to be fairly accurate.

The angle of insertion is important. I think you're instructed to use a 45 degree angle, I do more of a 60 degree angle.

Also, taping the whole shebang down prevents the sensor cannula from moving around too much once it's inserted. I find I have more inaccurate readings if I don't have the sensor/transmitter firmly taped down.

I insert my sensor in the evening before bed, attach the transmitter, tape everything down and then let it "get wet" over night. In the morning when I get up, I start the new sensor and generally find it starts up pretty accurately (and quickly).

[poodlebone]

I've been using a MM pump for 4+ years and the CGMS for the past 16 months and love it. It does take some getting used to but once you learn all of the tricks it can help a lot. I suggest taking a look at this thread (http://www.diabetesforums.com/forum/monitoring/42815-paradigm-cgms.html) posted here on the forum.

Basically, you want to keep the sensor very stable (tape, tape, tape!), insert at a deep enough angle (MM says 45 degrees, closer to 60 is even better),let it get good & wet before you do the first calibration (longer than MM recommends will be better), calibrate when your BG is stable, and understand the lag time in the readings. The readings will differ most during times of rapid change: exercise, a bolus kicking in or food digesting & hitting your system. If I test during a walk, an hour after eating or an hour after doing a correction for a high BG I can expect the two numbers to be off (meter vs. sensor). Two hours or so after a meal or correction, or testing 30 minutes or so after exercise gives me much closer numbers.

Also, some sensors just don't seem to yield good results. It could be due to poor insertion or insertion into a spot that wasn't ideal. If you don't know about checking your isigm take a look at the thread I linked to above.

[lark 27]

When I got my paradigm with cgms I had a false hope that it would be reliable enough to free me from 10-13 fingersticks a day. It's not. With that said, I still love it! Seeing the trends is wonderful even if it's not as precise as I would like. I find that the CGMS does not do well with precision on lows and highs, but it still shows a trend somewhat lower or highter. There is definitely the 20 minute delay for me---especially if working out where my BG might drop quickly. One thing the cgms has really helped with is identifying spikes that in the past I would have missed. I'll glance at the CGMS and note that it reads 120 when I had been 100 an hour prior. Then i might do a BG test and find I'm actually at 140-150 and I can treat properly for that. The other big boon from the sensor is being able to really fine-tune my basals.

I would say that I've gotten somewhat better at calibrating since I started (making sure to calibrate when my BG is stable), so I hope you might have increased success as well.

Of course there are also times where a particular sensor just does really poorly (but sometimes where one does really well).

[Gordonm]

THe CGMS system is not meant to replace finger sticks. It is not a blood monitor and was never designed to be. It shows trends. Do Ido less finger sticks with it? Yes I do. It has been a real eye opener for me and has shed some light on how certain foods react for me.

Another important thing is when you calibrate and how often. you can't calibrate when your BS is rising or lowering fairly rapidly. The sensor calibrates over a 20 minute span averaging the readings it is taking. So if you are on your way up or down it trys to calibrate the last 4 or 5 reading together. This will make it very inaccurate. I went through a bunch of sensors and a lot of phone calls with Medtronic before finally getting it dialed in correctly. It still can be off some but overall it has been pretty good recently. Don't give up on it and the folks at MM want it to work for you. Call them as often as you like. It may seem like you are pestering them but the yhave helped me a lot.

[xMenace]

I don't use one, but my MM rep said in a presentation I atended once that

- don't calibrate more than 3 times a day
- insert at 90 degrees. people cheat on the 45 degree recommendation and often don't get them all imbedded correctly.

[tygr1]

Wow! Thanks soo much for all the help and guidance. The thread poodlebone linked me to was also extremely helpful. Thanks for that.

I'm sure it's just a learning curve that I'll get through.

[It Ain't Over]

I am on day 19 of my first sensor with the new CGMS. I hope the rest work this well. Stays consistantly within five points of the meter, except for when bg's are going up or down. Then it still tells me the trends but not the exact reading. The meter readings and the sensor readings come back into sync once the bg's have been stable for a short time.
I read the thread Poodlebone refered to and the minimed literature before setting it up. I would credit Liz with the best information. In fact I showed her best paragraph (printed) to the minimed trainer/ rep and she said very accurate and she even picked up on a few points.
The trainer told me what xMenace noted.It will work better if inserted at 90 degrees. She also said the sensor is 9 mm long but the 2 mm nearest the skin layer send almost all the information. That would explain why it becomes so important to keep it taped in place tightly.

[Don C.]

I had the same bad results as you did tygr1. Tried it when I first got my pump and then gave up. The number it kicked out had no relation to reality. Might hae a stable 140 reading on my blood glucose meter and the CGMS might give 240.

[duck]

I've been using a MM pump for 4+ years and the CGMS for the past 16 months and love it. It does take some getting used to but once you learn all of the tricks it can help a lot. I suggest taking a look at this thread (http://www.diabetesforums.com/forum/monitoring/42815-paradigm-cgms.html) posted here on the forum.

Basically, you want to keep the sensor very stable (tape, tape, tape!), insert at a deep enough angle (MM says 45 degrees, closer to 60 is even better),let it get good & wet before you do the first calibration (longer than MM recommends will be better), calibrate when your BG is stable, and understand the lag time in the readings. The readings will differ most during times of rapid change: exercise, a bolus kicking in or food digesting & hitting your system. If I test during a walk, an hour after eating or an hour after doing a correction for a high BG I can expect the two numbers to be off (meter vs. sensor). Two hours or so after a meal or correction, or testing 30 minutes or so after exercise gives me much closer numbers.

Also, some sensors just don't seem to yield good results. It could be due to poor insertion or insertion into a spot that wasn't ideal. If you don't know about checking your isigm take a look at the thread I linked to above.

That part is critical for me...If I am climbing rapidly or descending quickly, my sensor is **** for the duration.

Though, I recently "rebooted" a sensor that seemed to be off (I told the 722 that I was starting a new sensor, when in fact it was a day old), while I was stable, and it acted much happier afterward.