My rule is if gone for 4 or more hours, take meter. I notice there is a lag on the trend line for rapid raise and drops. I'm not so concerned with the actual number and I am with the trend arrow. Any arrow other than flat gets my attention and I review the trend line and adjust according. Since I pump, I can play with my basal rates and adjust on the fly. I imagine that QQMary is using pens, so adjustment is more difficult. In summary, I would give up my pump before I give up the G4; although I would probably exercise my 2nd amendment rights before giving up my pump :D
My new OmniPod is in a box at home. My training session is next week. The Dex convinced me to get a pump - couldn't wait any longer for the integration between the Dex & OmniPod. Once I get settled with the pump, I'll probably look to get the G4.
Dexcom told me not to calibrate too often. Most people I've spoken to say to calibrate as little as possible. Also, with the G4 you are not supposed to calibrate if you're showing double up or down arrows. This is different from the Seven.
Yesterday I had to call Dexcom because the sensor was way off from my meter. They of course are replacing the defective sensor but the tech also mentioned that if the sensor is really off by a lot that I should calibrate in 10 minute increments. This will help the sensor get more in line unless of course it is a defective sensor in which case no amount of calibrating is going to help it.
I never inject or correct without actually doing a fingerstick but I don't always enter this result in to the Dex, especially if they are very close anyway.
Interesting the rep said that; completely opposite from what they told me, both in person and from Tech Support.
When I met my Dexcom rep this past Tuesday that was my first question:
"I test 10-11 times a day, should I calibrate each time?"
and she said "definitely not. Twice a day, and when you start a new sensor I would try to calibrate a low (~80) and a high (maybe 1 hour after a meal) if you can"
I was surprised as well!
I forgot that my rep also mentioned that you can calibrate if the values differ by more than 20%.
The first day or 2, the sensor can be off more, particularly during the high/low ranges. This is because it doesn't have enough history of the calibrations.
I tend to do MORE calibrations on the first 2 days, especially when it's higher or lower than what it should be. Or if I see that it is rising quickly, and I check my BG and know that it is not, then I'll enter a calibration and often the rise on Dexcom will correct itself within 10-15 min.
If it continues to be off, then you might try to do 3 calibrations within 10-15 minutes, as sometimes that will help it get back on track.
Some sensors are better than others, and some locations are better than others.
If it went to LOW, and then just stopped itself, you should contact Dexcom support, as they may replace the sensor. Typically you would get an error or ??? if the receiver is unable to communicate with the sensor. Possibly static caused it to shut down, and may be the cause of incorrect readings ?
I'm sorry to say, but after many attempts with two different Minimed CGMS sensors and then the Dexcom, I've had to accept that these devices just don't "work" with my interstitial fluids. I have tried working with their support teams and calculated all the algorithms before calibrating, but my values are still usually wildly off of what the reality is, which is ultimately useless for me. If I can't trust them even within 20% variance, it's pointless. I hope there will be new technology around the bend to help those of us (and apparently there are many) whose personal chemistry does not jive with the CGM technology. I can only hope my insurance company would approve a different system, since they've already bit the bullet on three systems for me.