I said I would post more about using the new Guardian instead of my Dexcom Seven. Here it is.
I would say the “honeymoon” with this device is over. I had originally thought that by setting the low threshhold to 100, I could bypass the Guardian’s rather crappy performance on lows. So I have. And most of the time that is OK, I get a low warning that I am 100 or 95, and test and see that I am really in the 70s, so I treat if it’s dropping and forget about it. But that doesn’t always work. Today, for example, I was working and my “Low Predicted” alarm went off. It said I was 120 with one arrow down. I tested and got a 60. Quite the difference there.
Still, though, it caught it. So that’s not the most annoying thing.
The most annoying thing is when a sensor just flakes out and your readings either launch skyward or drop like a rock. Sure, my Dex has done this a handful of times in the 15 months I have had either the STS or the Seven. But I have been using the guardian a little over two weeks and it has happened 3 times.
The first time I was at work. It was the middle of the morning and I had been drifting down after breakfast when I suddenly got a predicted high warning at 170. I tested and was 125. A few minutes later Guardian said I was 190. Then 225, then 300 in the next half hour. I tested again. 122. I entered this value on the Guardian, which by now had me in 400+ range, and promptly got a CAL ERROR and a request for a new reading. Now, when Guardian thinks you have a CAL ERROR and asks for another reading, it doesn’t really mean it. If you give it that second reading you’re begging for a second cal error and a bad sensor. So instead you wait for your BG to level out if it was weird, and don’t give it a new reading for an hour or so.
So I waited. And waited. Ate lunch, went for a walk, tested two hours after lunch and was 170. OK, let’s tell Guardian. Cal Error. Bad Sensor. Since I’m in a study, I can’t just restart, I do need to change the sensor. Which is at home in the fridge. Big PITA.
The second time, I was in bed. It was not quite one in the morning, and I got a predicted low warning. I tested and was 130, right where I want to be at night. A few minutes later a high warning. Then a predicted high warning, then a bunch more high warnings and assorted beeps. I was never over 160 on the meter and pretty level. Again I tried a sync up, and got a cal error. Now it was also beeping for a “Meter BG Now” that I wasn’t going to give it. Needless to say, after that first alarm, I never fully got back to sleep. At 5:15 I finally got out of bed, flung the damn receiver into the closet and shut the door. I could still hear its muffled complaints in my 30 minutes of sleep before morning. I had to call in sick to work that day because I just couldn’t function.
At 9am I let Guardian out of his prison and let him Find Lost Sensor. He happily chugged along for the rest of the time with no problems.
Then a few days ago it happened again. Only this time Guardian thought I was low. I was 156. After an hour or so of bogus below-40 readings, that I refused to dignify by trying to sync up again, I locked Guardian in his closet and went downstairs. Several hours later he was paroled and again behaved himself.
So now I’m thinking that clunky software and carrying a goddam potato clipped to my belt might be a small price to pay for actually getting to use the darn sensor when I want to. If I’m at work when Guardian flakes out, how do I get him out of range for long enough to smack some sense into him? Ask a friend to keep an annoying beeping or vibrating device in their office for a few hours? Put him inside some kind of Faraday cage to block out the signals? Leave him in the ladies room with a “please don’t steal me” post-it note? Or just give up and go back to Dex, who flakes out every few months not every few days.
I’m done with this study in a week and a half. I find now that I’m looking forward to my old clunky but reliable Dex.