Last night my Dex woke me at 4.30am with a low alert, saying my bg was 3.1 (55). I didn’t feel hypo so I checked and my meter said 18.7 (336)!!! I put this reading in and the Dex said Sensor error. As it was 4.30 in the morning and I didn’t know where the manual was, I stopped the sensor. I have restarted it this morning, just waiting for the two hour warm up to complete.
Did you wash your hands before the test? My first thought when I read your message was…there must be something on your hands. But if you did and you got that kind of number I would do what you did, stop the sensor and restart it. Then if you continue to get readings like that call Dex they might replace the sensor.
Did it give a sensor error 1? Those you can usually recover from, basically any time a fingerstick is more than a certain amount “off” from what dex thinks, it throws that error.
I have restarted sensors for a variety of reasons… usually I don’t give up until it’s totally failed
I’ll be interested to hear how this turns out. I would probably have done the same thing in addition to re-checking the meter on my other hand. I wouldn’t have made a correction before being very sure of which way I needed to do.
The sensor didn’t restart. I just got ??? after the startup period so I have ripped it out.
I am really disappointed with my Dex if I am honest. I can’t seem to get it to last more than 7 days, I can’t keep it stuck down no matter what I try - Skin Tac, tegaderm - and i don’t really trust the results after 4 days, because some of them can be out by 3mmol (50ish).
I had great hopes of this helping me get over my fear of hypos but it has been a real let down and I don’t know whether to bother at all.
(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?
I would have performed a second finger stick test to check the first. If the two finger sticks were close, then I would have tested the meter/strip combination against a known standard test fluid. If the tests with the standard fluids indicated the meter was accurate, then I would take insulin. I would then question why the sensor was behaving this way. For instance was this a new sensor that was not stablized, or an old sensor at the end of its life, or was I sleeping on the sensor and disturbing it, etc. Did you consume food prior to going to sleep? Did you inject adiquate amounts of insulin. In other words, if your BG was in fact very high, can you think back for a reason it happened. It is important to develop an awareness for all the possible relationships within that senario. Food takes a while to pass through the digestive track. Fast acting insulin may offset BG for a few hours while your body may continue to produce BG for hours therafter. So to recap: 1. it could be a single bad meter reading, especially if your food consumption did not warrant the high BG. 2. Could be a bad Dex sensor which needs to be replaced. 3, Could be bad strips or a malfunction of your meter. I would not just assume the Dex was off. However, if after all the other tests pointed to a defective sensor, I would replace the sensor. If the sensor was installed less than 7 days, I would ask for a replacement from DexCom. With respect to getting the sensor to stay stuck, I SCRUB the area where the sensor is to go very virgorously with several alcohol prep pads and let the site air dry before placing the sensor on my skin. The standard DexCom adhesive will stick to my skin thereafter for at least two weeks. If I do not scrub the site very well before placing the sensor it does not stay as long. By scrub, I mean rubbing back and forth with pressure for a minute or two. My skin gets pink from the rubbing.
Any time I get a material divergence between Dexcom and my One Touch (either direction) I always re-test. In your case, I would have washed my hands and did another fingerstick before entering it into the Dex. Here is a YouTube I did when I had a false One Touch reading above 300.
Here was my commentary: “My One Touch Ultra meter gave a blood glucose reading of 334 at 10:40 a.m., less than an hour after a 99 reading at 9:46 a.m. I didn’t think the 334 reading was correct so I checked my blood glucose again at 10:51 a.m. and the result was 117. If I had given myself insulin based on the 334 reading I could have gone into insulin shock! Be careful if you get a high reading on your meter - always retest!”
Thanks Kevin, I left out the most important thing!.
Always, ALWAYS suspect a “high” meter reading; wash up and confirm it.