I just started, day2, but I can't get that jubilation that many others have posted here. I'm hanging in there and will certainly give it plenty of time but so far the readings are so unreliable it's been fairly useless, even the trends have been backwards. I have had a couple of the "???" display's but it came back on by itself, maybe I've just got a bad sensor.
I'm a former Navigator user, almost 2 years, so maybe I'm expecting performance similar to the Nav and maybe it's an apple orange comparrison, maybe it's not supposed to be as accurate as the Nav and I'm expecting too much.
Are there any other users who have first hand experience using both that could give me encouragement, or advice.
This is my first CGM and I started last week. I am having similar issues. Multiple sensors have failed. The third sensor that gave me a ??? started working 6 hours later because the technical support rep said it can ??? for up to 10 hours... seems odd to me. I am hanging in there as well and hoping for more consistency!
The Dexcom sensor takes a little while to warm up to you and your body. The techno speak in the book translates to this: the sensor generates a current based on the sugar in your body fluid - not blood. This is usually about 15 minutes off of the BG when changes are occurring. The computer in the receiver must learn - by you entering finger stick BGs - this much current equals this reading ( projected BG).
Suggestion - for at least the first 48 hours on a new sensor, do a finger stick BG (FSBG) every time you dose insulin. Also do a FSBG two to three hours after meals. Enter all of these FSBGs in the receiver. After 48 hours, you should be seeing good curves. Do not go with the numbers, go with the curves. Also, FSBGs with every insulin dose is the safest plan for giving yourself the correct dose.
I'm just approaching that first 48 hours and it is starting to fall into line with Bg. From the beginning I entered every FSBg in the Dex receiver, because with the Nav having its built in meter is where I stored all my data. So for record keeping I just kept entering each FS in the Dex, probably 50 times (not much sleep last night). I normally wouldn't do that many but I was wanting to learn the accuracy patterns. I noticed each time I entered a FSBG it adjusted the CMG value closer to the FS, with the Nav I had to go to a separate menu and do a forced recalibration. I'm getting a little more encouraged that I can build a trust relationship with this Dex.
It makes sense that the more FSBGs you enter the better the results will be. Many DexCom users noticed that the opposite holds true. I only enter FSBGs twice a day for the required calibration with the exception of situations where the dex is way off.
Franco, I had the same problems during my first month. Then I got many good hints from the more experienced group members here. I started having good accuracy in Feburary. Those hints are in some of the older discussions. It would be worth going back and reading some of those discussions.
Why did you stop using the Nav? I know the company was having some delays and problems, but I have a friend who is still using his. He must be getting supplies or he would not be able to do that.
The first 48 hours were over last night and just like others have said it's gets better, well it did! Overnight the readings really fell into line and I'm gaining more confidence in the numbers.
Richard, to your question of why I stopped using the Nav was that mine developed some black spots in the screen display. I was still able to use it but I phoned support about warranty replacement and they said they didn't have any idea of when I could get it replaced and they suggested they would buy mine back for $2000 in order to go buy a Dex or travel to Europe where the newer versions were available. Nav's are available all over Europe & Israel but not permitted by the US FDA (Abbotts explanation). I tried to get one outside the US but was getting much poorer glycemic control without CGM and I just couldn't wait any longer. Also my insurance had denied coverage for the last two years and I was paying cash, but my insurance changed and the new policy covered CGM. Since Navs aren't available in US, Dex was the only way to get a route through the insurance.
I'm going to give the Dex a good try but I still like the Nav better, there's a few advantages to the Dex over the Nav like much smaller transmitter, and a slightly easier cannula insertion. I'll wait to make judgment on the accuracy. The new Nav is supposed to have a 1 hour calibration instead of the 10 hour that my version had. The other thing I liked with the Nav, only because I had to pay cash for sensors, was that I consistently got 30 days from the sensor and the longer I left it in the more accurate it got, I once tried to see how long it would last and got 75 days before it fell off from a tape failure, who knows how long it might have worked. I think the technology is there for longer use but hey, where would the manufactures and distributors make their huge profits from the diabetic cash cow community! Don't get me wrong, I'm a huge supporter of free market innovation, that's what moves new research along, but something's wrong in this area. Enough said I know this is the wrong forum for this discussion.
Two weeks now and the accuracy is every bit as good as the Nav. Those first 48 hours were horrible but it fell into line and has been flawless since. I do still like the Nav better but the Dex is an acceptable trade off. It’s so nice to be back on CGM!
Franco, 75 days with a sensor while using the Nav? What was your skin condition when you removed the sensor? Was there any scar tissue or a large bump? I have a friend who is using a Nav, but he never uses it more than a week. I thought the Dex was supposed to give the longest sensor performance.
The skin after the 75 days was very clear, no redness or irritation of any kind. Remember the probe on the Nav is only 5mm and inserts at 90 degrees, at least half as long as the Dex. I've had more probe irritation with 2 or 3 week sensors than with the 75 day one. The skin around the probe had healed around the probe and it took a little tug to remove it. I had placed a layer of Opsite Flexi...under the sensor, I just poked the probe right through the Opsite. I think Opsite must be breathable and maybe even has some anti bacterial effectiveness. I could only get long sensor life on my upper leg, abdomen sites were hard to keep attached more than 3 weeks.
I'm now starting my 3rd week on the Dex and have found it to be very satisfactory. 2 weeks ago I would have said the Nav was superior but I've change my thinking. They both have pros and cons, I could go either way. My 2 years on the Nav were not covered by insurance and that super long sensor life made it affordable. My insurance just changed and CGM is now covered under my new policy so that makes the Dex affordable now.
