Well, I had a rough start with my first sensor. but after the first day, things settled in and the rest of the week was pretty good and pretty in line with my glucose monitor.
yesterday, i did the stop/restart of my sensor. not as wacky as the first day of the sensor, but last night still getting alarms for being low and i wasn't! dex said i was 55, when my gm was at 96!
so this is day 8, and i'm hoping to get a lot more out of a sensor than a week. today hasn't been as bad as the first day of the sensor, but still not as accurate as yesterday. i calibrated when it first allowed me to do the first 2 bs #s. than i've calibrated two more times, one when i was higher, one when i was lower, to hopefully help it along. just took it again. dex says i'm 177, gm says i'm 138. way to much of a discrepancy for me!
i really want to make these last because they're so EXPENSIVE - just got my roll of flexifix tape and applied it around the sensor tape since it was starting to roll up on the edges. cut out area for the sensor as suggested in previous posts.
I typically can only manage about 8 days out of each sensor before I ??? and have to change it, but once in a while, I get lucky and get 10-12 days, and one time I got 15 days, but that's was only once. Most people seem to get a longer life out of them than I do; hopefully you're one of them. Dexcome told me to calibrate it ONLY when it's off by more than the 20/20 rule of If the meter shows 80 or less, the G4 should read +/- 20 points. If the meter shows above 80, the G4 should read+/- 20%. They warned NOT to calibrate outside of that (unless you need a calibration before bed to avoid it needing one in the middle of the night) to avoid misleading it from over calibration too.
I've gotten as many as 24 days before I needed to switch out sensors. I found the second and third restart does take less time to calibrate, to be closer if not spot-on, to my OmniPod BG monitor; it's hard to be patient waiting for it to adjust itself!
My problem came more with the adhesive not wanting to last as long as the sensor.
I place it directly over the transmitter, covering the Dexcom adhesive. I rarely get the ???. If it does happen, it's when it's getting close to the time for me to change sensors. The Tegaderm™ peels off of my skin nicely and off of the transmitter as well.
I get about three weeks out of a sensor, have it placed in the back of upper arm and alternate arms when I replace it. I have a fair amount of flubber there and do not tend to knock it. More importantly for after midnight readings, I do not lay on that spot when I sleep so no false lows due to tissue compression. I do have to calibrate frequently in the first two days following a sensor fake out, but that is the same as what I need to do with a fresh sensor, so for me no difference. And yes in the first 2 days I will not make a correction based on the Dex without double checking. Every time I do a FS I enter it on the dex, regardless of whether it is at the calibration time point or not. For me the more I calibrate it the better the accuracy gets. Once I get to the point that it is within 5 points on a regular basis then I drop down to entering the FS reading twice a day. Be sure your placement is not where you will sleep on it, stay hydrated at bedtime and enter all your FS BG's until you are sure of the readings.
Eventually you will get to the ??? or a point where it will not hold a calibration that you trust at which point you pull it and start over. Just be sure to give it a good day or two if you are in your second/third restart before you give up on it.
I have had some that I wanted to pull at the third restart that settled down after two days of frequent calibrations. It all depends on how you run - are lows your concern or highs? Do you run to extremes on a regular basis or do you know that you keep a fairly tight range?
The more wild swings in my BG the sooner my sensor fails.
I use the 2 3/8" by 2 3/4" versions both with my Dexcom and my Omnipod. Couldn't do this without them. For the Dexcom I do cut a hole in the middle for the sensor. Not sure if needed, but I feel better about it that way.
For the Omnipod, I put on the patch first, and the pod on top punching the canula right through the patch. Not sure If I'd try that on the Dexcom.
thanks everyone. the dex is doing much better again on the 2nd day of the restart. now sure why i get wacky numbers the first day, although it wasn't as bad as the 1st day of the new sensor. hoping it will last at least another week!
As to false lows at night, I found that it occurred when I slept on the sensor and compressed the transmitter/sensor between me and the mattress. There's a characteristic "V" in the BG trace line that dips 30-40 points and then returns when I roll off and decompress the sensor.
