Easy to forget... Dexcom UI issue
So a little time after lunch today my Dexcom suddenly showed the big blood drop signal, indicating the need for a calibration. While it was a little strange since I had just calibrated it only about 7 hours before, I gave it one. It cleared the screen to the normal screen... but then the blood drop stayed there.
So I gave it another calibration. No go. The blood drop at the top right refused to move.
I called support. First of all, I want to note about Dexcom support: they really WANT to help. Some of them are better than others, surely, but they are NOT the typical call-center guys. In any case, the lady asked if I could upload data, which I couldn't because I didn't have the sync cable, but she did remind me something that I had forgotten:
If the Dexcom shows the big blood drop signal in the center of the screen, DO NOT automatically calibrate again. Instead, press "c" and see what the top right image shows. If it's showing "???", then calibrating will just mess things up.
Anyway, I got home, got my data synched, called and uploaded. I was speaking to Brad (who deserves a good word, he was great) from Dexcom support, and he offered to replace the sensor (thank you!). However, I refuse to believe all these uber-expensive sensors can go bad so frequently, so I delayed accepting (yeah, OK, I'm a dumb consumer), and asked what else could be done.
Then Brad said a couple of things which are worth repeating:
1) the data collected from the receiver includes additional information than just glucose values, that is not represented in the software. By looking at this data, Brad was able to tell that the sensor's sensitivity was being reported as too high - explaining the receiver's refusal to present readings.
2) he suggested I try another calibration and see what happens. It worked; everything went back to normal. Apparently all that was happening was that the heightened sensitivity was causing the software to not trust its own interpretations of the signals, and (this is my conjecture) it is designed to not show readings until things stabilize instead of potentially endangering the patient with false readings.
Oh, and the sensor isn't really bad or going bad. In fact, it appears that had I just pressed "c" when the blood drop showed and ignored the request, none of this would have occurred.
Brad also admitted (OK, I'm paraphrasing since he was far too professional to say all this) that most patients just don't care enough, they want to tear the sensor out and get a new one. I'm sure this is especially true in this case, as my sensor was about 5 1/2 days old, just below the free replacement threshold (that is, if it actually works 1 more day it will have "worked as advertised"). But I'm also pretty sure that these sort of "real world" troubleshooting events are worth their weight in gold to Dexcom, and in the end, to us as users. Thus, while it would have been wonderful to get a free sensor out of it, I'm really happy that we were able to troubleshoot this and get to the core of the issue, which is:
1) the user interface is confusing; the big blood drop signal should indicate one thing and one thing only, "do calibration". It's too much to remember that it might mean different things at different times.
2) the user in this case was a moron.
Something else which is really interesting and is a direct result of this system: I now occasionally compare CGMS, Onetouch Ultra, and Freestyle Flash. Right now I had an interesting sample:
Dexcom 172
Onetouch 216
Freestyle 248
(both the meters used the drop from the same prick)
How's that for variance? I know the Dexcom was "catching up" to a rising trend, and we already know it lags on those. But one would expect the meters to be closer. Fascinating stuff. And not the first time this happens, either.
So I gave it another calibration. No go. The blood drop at the top right refused to move.
I called support. First of all, I want to note about Dexcom support: they really WANT to help. Some of them are better than others, surely, but they are NOT the typical call-center guys. In any case, the lady asked if I could upload data, which I couldn't because I didn't have the sync cable, but she did remind me something that I had forgotten:
If the Dexcom shows the big blood drop signal in the center of the screen, DO NOT automatically calibrate again. Instead, press "c" and see what the top right image shows. If it's showing "???", then calibrating will just mess things up.
Anyway, I got home, got my data synched, called and uploaded. I was speaking to Brad (who deserves a good word, he was great) from Dexcom support, and he offered to replace the sensor (thank you!). However, I refuse to believe all these uber-expensive sensors can go bad so frequently, so I delayed accepting (yeah, OK, I'm a dumb consumer), and asked what else could be done.
Then Brad said a couple of things which are worth repeating:
1) the data collected from the receiver includes additional information than just glucose values, that is not represented in the software. By looking at this data, Brad was able to tell that the sensor's sensitivity was being reported as too high - explaining the receiver's refusal to present readings.
2) he suggested I try another calibration and see what happens. It worked; everything went back to normal. Apparently all that was happening was that the heightened sensitivity was causing the software to not trust its own interpretations of the signals, and (this is my conjecture) it is designed to not show readings until things stabilize instead of potentially endangering the patient with false readings.
Oh, and the sensor isn't really bad or going bad. In fact, it appears that had I just pressed "c" when the blood drop showed and ignored the request, none of this would have occurred.
Brad also admitted (OK, I'm paraphrasing since he was far too professional to say all this) that most patients just don't care enough, they want to tear the sensor out and get a new one. I'm sure this is especially true in this case, as my sensor was about 5 1/2 days old, just below the free replacement threshold (that is, if it actually works 1 more day it will have "worked as advertised"). But I'm also pretty sure that these sort of "real world" troubleshooting events are worth their weight in gold to Dexcom, and in the end, to us as users. Thus, while it would have been wonderful to get a free sensor out of it, I'm really happy that we were able to troubleshoot this and get to the core of the issue, which is:
1) the user interface is confusing; the big blood drop signal should indicate one thing and one thing only, "do calibration". It's too much to remember that it might mean different things at different times.
2) the user in this case was a moron.
Something else which is really interesting and is a direct result of this system: I now occasionally compare CGMS, Onetouch Ultra, and Freestyle Flash. Right now I had an interesting sample:
Dexcom 172
Onetouch 216
Freestyle 248
(both the meters used the drop from the same prick)
How's that for variance? I know the Dexcom was "catching up" to a rising trend, and we already know it lags on those. But one would expect the meters to be closer. Fascinating stuff. And not the first time this happens, either.
posted by Blinkered at 4:13 PM
2 Comments:
Interesting. This is the first time I've heard a suggestion about actually using the C button.
I do wish that Dexcom would start to use the web more and actually put some FAQs up on their web site. For example, last time I looked, there was no information about travelling with the Dexcom. Does the insert cause problems at airport security?
There's a lot they could put up there. But then again, that would mean we don't read each other's posts!
As for the differences in reading, see my Failure to Communicate picture. All of these devices give you readings that are +/- 20% of the real value. So I'd say that what you got are all acceptable readings.
Welcome to the wild and wacky world of diabetes blood glucose testing! (I think you already knew this.)
Very cool pic, Bernard. But note that your two meters were still pretty close; in my case, the OneTouch was right in the middle, 30 points of each of the others.
I agree that Dexcom is not web-friendly. I am hoping that blogs like mine and yours can help with education, because the benefits from this systems are fantastic.
And you're spot on with the wacky world comment. Thing is, with the Dexcom I am much more AWARE of just HOW wacky it really is.
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