I've been using the Medtronic CGMS along with my MM 723 pump for a year. Sometimes when I get it calibrated just right, for a day or two I can get readings that closely match my finger stick readings. However, the CGM readings aren't consistently accurate enough to count on and I've followed others' advice to never bolus based on a CGM reading. I frequently or occasionally get CGM readings that vary widely (50-70 pts, but as much as 100) from finger stick readings and it's a big joke at work that everyone hears my (often inaccurate) low alarms. I test 6-8 times a day (whether or not I have a sensor in) and I can almost always feel lows at around 70-75. I'm thinking about discontinuing the CGM altogether. CGM users - any pros for continuing? Should I expect better results? Thanks for your comments - Dave
We have times when the cgm is spot on and times of variation. It helps identify trends for my daughter and warn of lows and highs. She doesn't feel the lows so I don't mind false low predictions--better safe than sorry. It really helps when treating highs. I use it more for letting me know we need to check that relying on the exact number.
Have you tried changing your low prediction rates? That could cut down on the number of alarms. Also check the expiration date....that could make a difference. And I think there are bad batches. I've used some sensors that were two to three months expired and had great calibration....others not expired that never could seem to catch up. And how long do you use it? We use three days, recharge and get three more out of it....often the second set of days sees better results.
As the mother of a T1 kid...I feel she needs to use the cgm 24/7. But I can see that as an adult who is low-aware maybe you don't need it all the time. Some adults I know only use it when they are seeing changes and want to look for trends. Maybe you could try that? Good luck! And hopefully, the Enlite will be out soon--more accurate/smaller. Medtronic will offer a Pathways plan to upgrade if your pump is under warranty.
I certainly understand your experiences, as mine have been similar. But, as many have said, it's really about understanding the trends, at least for now. Maybe in the future they'll get it down pat but not now.
I've only been using a CGM for about 3 months, but my cousin has been for a couple of years. She has this love/hate relationship with it. Probably also true for many. Anyhoo... she says her endo has recommended just using it for a week or thereabouts before coming to see him. Then they can get a fix on the trends she is experiencing, if there are changes in them, etc. I thought that was a pretty good idea..
My .02 anyway.
I only get allowed a CGM every so often so I'm not a pro (NHS so it's free to get them so that's acceptable), but my DSN (diabetic specialist nurse) always says ignore the readings and just go with the pattern and direction it's showing as it's not something you can use for trusted readings. Basically it's because it measures the glucose in the layer of fat it's been stuck into, as opposed to the BG meter which is reading what is in your blood. Namely, it's never going to be as accurate as a finger test.
I did like you with the alarm when I first got the thing and sheesh, barely got any sleep with the thing. Drove me up the wall so that got quickly turned off.
As for me, it's only of use when trying to work something out say over night or when I'm charging around at work and want to figure out what it's doing between finger tests if I'm feeling off or having a high that wasn't expected and figuring out if it's a rebound or basal or environmental/work load/stress issue.
I used MM CGMS for about 3 years (2008-2011), and then switched to Dexcom.
For me, the accuracy for MM CGMS varied, and depended a lot on the timing of the calibrations. I learned to use the 'ISIG' number to guide me on when to calibrate, and also inserted the sensor the night before, and started it in the morning. It worked best when I did 3 calibrations/day, 30-40 min before meals. I usually got 6-7 days, and day 2-6 tended to give more accurate results.
The key benefit for me when using MM CGMS was seeing the upward trend, and learning how quickly and high certain foods impacted my BG (as tested on meter, not sensor). As a result, I reduced portions/eliminated many types of foods and pre-bolused. Then I had less spikes, and then found MM CGMS was more accurate. So having CGMS resulted in changes in diet, which resulted in lower A1C. But yes, also had to put up with many false alarms !
If interested, here's a link to a comparison I did for MM CGMS vs Dexcom7+ after I had been using Dexcom for a year.
HI Megaminx, can you share how you insert the sensor the night before?
After inserting sensor, do you wait 20 minutes before attaching the transmitter, go to sleep, and in the morning link to the sensor, wait two hours then calibrate?
I used the MM for about a year and a half and it was frustratingly inaccurate. And as soon as it settled down a bit, it was time to change it. So I switched to the Dexcom. The Dex has been more accurate, although not 100%, and most of the time, I can depend on it to alarm accurately for highs and lows. But especially in the case of lows, I do check with my meter. Sometimes it gives false low alarms, and since I'm a little hypo unaware (can feel them in the 40's, but that's already TOO low!) it gives me a chance to catch hypos in the 60's and 70's before they get dangerous. I don't know if you'd have the chance to try the Dex, but I do like it.
I had similar experiences. The CGM is also very expensive, even with insurance. I think it makes more sense to test your glucose more often, instead. Maybe, someday, they'll come up with something better.
I too have this problem; if one more (no)help desk person tells me yet another elaborate calibration procedure, so I "don't upset the algorithm" I'll bloody well puke! After all, if my blood glucose was stable, I wouldn't need the damned thing, would I now?
Having said that, I must admit it has kept me out of the emergency room, for over a year.
I'm a pretty active old guy (long dstance runner, hiker, ocean sailor,boat builder, that sort of thing) so have come to just watch that 3 hour graph. I've desensitized those annoying alarms, so I get a little peace and quiet.Best results from sticking it into my backside, abdomen is worst. I restart and use sensors for 6 days ( afraid of possible infections if used for longer). I don't use those tegaderm thingys either. Just 2 pieces of 3M waterproof tape; one over the sensor/transmitter joint, the other halfway over the floppy end of the transmitter.
I calibrate about 3 or 4 times daily. I get up, calibrate, wait 15 mins, shoot up, wait 20 mins then eat breakfast. About midday- calibrate, wait 15, shoot up, wait as close as I can to 20 mins, then eat lunch. Dinner time- similar routine. Then calibrate before bed. Depending upon excercise levels; I may take on a few snacks along the way.
I am perservering with it because I plan to go on a 3 week, open ocean, single handed sailing trip, so I will have to depend on it.
Before I bought the Medtronics, I did try the Dexcom. I found it to be at least as innacurate, it took more 'vacations' and their help desk was less than forthright. Medtronics have been as helpful as they can, considering the erratic performance, and generous beyond their warranty obligations.
Hope that helps you, don't be bashful if you have any question.
I also find CGM helpful when travelling...