Dex operation

I inadvertently put this in the comment wall. I don’t know what the wall is for, having just seen it recently.

I just watched the dex video on this page, for the second time after viewing it a few months ago. I finally know enough to ask a couple questions. When I did the 1 week trial some months ago, I had two consecutive early morning (while sleeping) alarms. I treated myself both times with sugar pkts I had at bedside. Both times the darned thing kept beeping every few minutes because we know it takes a while for the BG to rise after treatment. That really interrupted my sleep two days. Does this mean I have to go through the menu and do a “shut off” in order to prevent the 2nd, 3rd, etc alarm beeps? That, too, would awaken me!
Second: we all know that our meters can be up to 20% off +/-. So it seems to me you could be entering a 20% error into the dex when you calibrate it. The dex I had was very much in line with my 1 touch. But it makes me wonder which was wrong during the 10% time the two were off. Was it the dex or the meter?!

I would appreciate thoughts on either of these issues, preferably both.

It sounds like you don’t have the snooze set on your low alarm. You can customize the duration that the alarms will realert for highs and lows. I have my lows set for 30 minutes and my highs for 2 hours. The snooze will cancel though if you cross back into your target range during the snooze cycle. So if you’re hovering right at the alarm threshhold you’ll also get repeat alarms as you cross back and forth across your target.

Here’s my philosophy about the variance in meters/cgms etc. It doesn’t matter. None if this is very precise but it is all we’ve got. As long as you understand that every time you do a fingerstick you’re pretty much just getting a ballpark number then all is good. What I do find helpful is to watch trends over time and to try to compare the numbers I’m getting now with numbers I’ve gotten in the past. That’s why I try to test with the same meter as much as possible. I try to be consistent with my technique in terms of fingerpokes, drop size, etc. If in doubt, I’ll wash my hands and retest and compare readings. If my use of my meter and cgms is somewhat consistent then my readings are going to be consistent with each other over time and the numbers can be used for pump settings. So that addresses my take on meters and accuracy.

I’m not sure what you’re asking about the dex vs the meter and which was off? If it was only 10% difference I would assume neither was. It also takes a little while to figure out how sensors behave and what a good sensor looks like and what a ditzy one is. Also usually the first 12 to 24 hours are not as reliable. I’d just give it time and if you have any doubts don’t hesitate to call dexcom that’s what they’re there for.

On the first question, there is a “Snooze” feature on the receiver that you can adjust. Note that you need to acknowledge a low sugar alert by pressing the OK button on your receiver when you get the initial alert.

On the second question, whenever I am doing calibration and the Dex and One Touch are off by a meaningful amount, I usually retest with the One Touch to see if the One Touch readings are consistent. If you enter a calibration entry for the Dex that is significantly different from the Dex’s current reading, you might be prompted to enter an additional calibration, or worst case you can get an ERR1 (I think that is it) message that you will have to clear after an hour.

I always hit the OK button, but it still binged again in 15 minutes. I did not know about a snooze button so I will check into that.
On the 10%, that was the percentage that the cgm and meter differed significantly, like a hundred points etc. Not a 10% difference in one set of readings.
Good point on checking with the meter a second time when there is a wide difference. Duh!!

Thanks for the comments and suggestions. Oh, and I do think that companies should have the accuracy worked out better by now. There are too many lab tests with finger sticks, etc that do have proven accurate results for the diabetes products to still have such a wide “acceptable” variance in results. Sloppy tech work, in my opinion.