Sometimes I just don’t understand Dexcom calibrations. For example, this evening my Dex is showing 74 with a flat line arrow. It asks for a calibration. My meter says 71. I input that and immediately my Dex alarms low and shows a reading of 56. Huh???
This happens often and makes me just want to stop putting in calibrations. Then there are times that the Dex is off from my meter. So the Dex says 100 and the meter says 150. I calibrate with 150 and the Dex goes to 110.
In general my Dex is pretty accurate. It’s the calibrations that throw it off. I think I once read someone here who said he doesn’t do calibrations when the Dex is running well. If you don’t do calibrations, the MM system quits working. But I think the Dex just keeps going on. So maybe I should quit calibrating???
Since I started typing the Dex has dropped to 53. Huh again???
sometimes we do drop fast and possibly not much time for arrow warnings? that said..... i have found dex to be reliable only when sugars are in normal range. if high or low, it seems way off from meter.
Mike W-So do you just ignore the messages to enter a calibration? How long has you gone without calibrating?
Several years ago when I was using the Medtronic system, I found calibrations worked best when the results between my sensor and meter were close. It was like petting it on the head and saying "good dog". But with Dex, close calibrations sometimes send it off on its own adventure.
My Dexcom is acting up so bad I don't really see the need to check my BG to calibrate it. They lied about the accuracy of it. I can't even trust the trending of it.
Thats exactly right, I just ignore it if its close. For instance I just checked using my meter. It was 195 and Dex reads 205. It has also been asking for me to calibrate since yesterday. As far as I'm concerned theres nothing to calibrate if its reading correctly. I don't remember how long I have gone in between calibrations but it seems to me to work better when I calibrate less not more. I was very unhappy with this system when I frist got it but lately I like it much more if I just let it do it's thing. Of course, everyone's results will vary.
I have been complaining to DEXCOM for a while about the erratic behavior with big differences with the BG meter. I spoke to someone at Dexcom who asked me to do an experiment:
Be sure to pinch the skin when inserting the device.
Calibrate when the device asks for a calibration.
Do NOT calibrate unless a reading is 20% or more off from the meter.
In addition, I also don't calibrate when the BG is rising or falling quickly or if it is below 80 or above about 250.
Following these suggestions has produced really excellent results on the last 5 sensors that I have inserted. It doesn't make much sense, but it seems to work.
In general I think I do those things, Jeff. But I’ll pay even more attention to all of your suggestions and make sure I’m doing them. Thanks for your input. I’m anxiously awaiting my Dex Gen4 and hope to get more consistency and accuracy with it.
I'M NOT SURE THAT THE GEN4 WILL MAKE A DIFFERENCE SINCE I BELIEVE THAT THE SENSOR IS THE SAME AS IT IS NOW. I THINK IT IS ONLY A NEW RECEIVER. IF IT IS A NEW SENSOR, THEN IT MAY MAKE A DIFFERENCE. I HOPE THAT'S THE CASE!
I KNOW THAT THE DEX CAN BE USED MORE THAN ONE WEEK BUT I ALSO HAVE FOUND THAT THE IRRITATION GETS REALLY BAD AFTER A WEEK (NOT THAT IT'S GOOD BEFORE). I GUESS YOU HAVE TO TAKE THE GOOD WITH THE BAD.
SORRY FOR THE CAPS ... I WAS TOO LAZY TO CHANGE MID WAY.
I agree with most of what Jeff has said here. The best place to get a good understanding is to read the manual. If the math and statistics is crazy - GOOD! The only thing I would add is to calibrate any time you dose insulin. This is a SAFETY issue, not a calibration deal. I also enter the carbs and insulin bolus for my pump in the 7+. It makes recall easier and provides dual documentation of crazy drifts and insulin responses.
Bottom line, read and follow the manual! Remember, the CGM is a tool and it needs to be used to our advantage.
That is what I was doing before and it really screwed things up. I agree that you should use a meter before you dose but with this new procedure I feel reasonably comfortable dosing right from Dex. Sounds crazy but so far, the results have been outstanding. Too many calibrations confuse the thing and you start to see big shifts. Anyway, that's my observation. Jeff
See above there have been changes to the sensor. Dexcom has always been rather mum about specific sensor info though so again not sure what exactly is different. I have upgraded from the Seven plus to the Gen4 so I have both types of sensors. The shape of the transmitter cradle looks the same so I don’t think that is why you CAN NOT switch sensors between systems. Dexcom strongly emphasized that and I’m not willing to potentially waste a sensor experimenting. When I pull my sensor I’ll try to put my old transmitter on it and see if it fits but I just started one so it’ll be a while.
All I remember the rep saying about the differences in the sensor is a smaller, stronger wire. It’s still platinum, and the Tylenol contraindication is still present but anecdotally the wacky numbers don’t last as long.
I was out of town for about 10 days and accidentally ripped out my last sensor a week ago. It's the first time in about 2 years that I've gone this long without a CGMS. I have really enjoyed this vacation and find I'm not anxious to insert another sensor.
I'm in a low-carb eating spell, and I actually think when I eat this way I don't need a CGMS. Although when I eat low carb I can have some highs when I "cheat", I find that I have very few severe lows. I'll dip into the high 50's, 60's and 70's, but I definitely avoid Himalayan peaks and valleys.
I'm tempted to wait for my Gen4 arrival to start CGMS again. I doubt I'll wait that long though because as Thanksgiving approaches, I suspect my low-carb eating will fall by the wayside. But maybe not.
I have definitely postponed my pump decision. Jeff, I think that I would hate some of the same things you hate about your Animas, and I'm just not ready to abandon my Revel. I think I'd like to see how I like the Dex Gen4 and confirm that's it's worth abandoning Minimed to get the Animas Vibe. And since my Revel is working fine and the Vibe is not on the market, the easiest and best thing is to do nothing.
I agree that doing nothing is often a wise decision. Personally, I would rather have the MM pump coupled with the DEXCOM CGMS. But we rarely get good choices. If I could get a new pump today, I would jump to the MM and stick with Dex. But, to be fair, I would want to look at the new Animus and see if they fixed the current insanities.
Unfortunately, I am now with a new ENDO who has a small office and no sales rep presence that I can detect. I am not sure how to get questions answered but I can always call and ask. I still have some time before my insurance will allow a new pump. By then, perhaps, the word will be out.
Jeff, I really hate carrying two devices. I’ve done it for two years and I just don’t have enough pockets for a pump, Dexcom, phone, and glucose tabs. I wear cargo type pants as much as I can, but I dislike all of the device bulges and basically feeling like my pants are going to pull down because of all the weight.
I feel that MM has done a great job with the pump integration, but the sensors are painful and inaccurate for me. The Enlite sensor will probably make the system work better for me, but I don’t think it will still be as good as Dexcom. Another reason to keep waiting.
Since I’m out of warranty a pump problem will force a decision, but right now it’s wait and see. A Tandem pump might come into play if they put an upgrade program in place for the eventual Tandem/Dex combo
