(1) Skin Tac and Tegaderm aren’t working, so get something else !!! My preferred under-coating, Skin-Prep, is NOT an adhesive product. (So please try it, per my instructions with drying help from the hair dryer) But yes; if the adhesive pad has peeling up by more than 1/8 of an inch anywhere, you need to toss the Sensor. The pad’s gonna be sliding around, and that slides the wire, and it that causes bad values.
(2) And if it’s a nighttime reading, and you might have “squished” the Sensor against the mattress, then the ISF and capillary blood doesn’t flow properly: Glucose gets “used up” and doesn’t get refreshed, both in the vicinity of the Sensor and right inside it. In this case, never trust a “low” reading, it could be utterly, totally, bogus. (Although, in this case, the Sensor might not be truly “failed”. If you’re not sure about your sleeping position, you have to do a finger poke. And DO NOT enter that finger poke as a calibration! A slept-on Sensor will need about 1/2 hour of morning activity, showering and dressing and making the coffee, etc., before you can be sure that local ISF has been freshened from blood and fully freshened inside the Sensor.)
(3) Back on day 4: Any set of “???” after day 2 which doesn’t recover IMMEDIATELY after a bG entry (and wasn’t a “sleeping position error” of the kind in #2), is a “failed Sensor” in my book. Toss the Sensor don’t give it a chance to mislead you into a mistake, or sit there for a bunch more hours, hoping to get numbers you can trust – Software has already declared, emphatically, that this Sensor is throwing out numbers which CAN’T be trusted. To the extent that future numbers “seem” OK, you’re just getting lucky with a random number generator: You fed it a bunch of near-normal calibrations, so it keeps showing a near-normal graph, but it’s GIGO. (Garbage In, Garbage Out.)
After just a few hours, the only time your should see “???” is when your Sensor voltage (ISF Glucose) is rising or falling into a new level which has not yet been calibrated. (For example, when I’ve started a Sensor at a reading of 80 mg/dL, I’ll often get “???” after a snack, at a reading of 140-160 mg/dL, without Dexcom sounding an alarm at 140. But a calibration at that level “snaps it” right back into operation.
The same thing can happen on a first fall; So, If I started out at 150, it might go “???” if I drop hard and it hasn’t been calibrated near my low-alarm level yet. (In such a case, I try to quickly push a new Sensor all the way down to 80-ish, doing fresh fingerpokes each half hour and entering all of them as calibrations.)
(4) Dee, what sites have you tried? And also, when does your “30 days” trial period end?
