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Dexcom and Desperation.

For a few weeks, I had a tough run with the Dexcom.  Out of the five sensors I'd used in the last three weeks, three of them had gone kaput on me.  And by "kaput," I mean that I'd put in a new sensor after Las Vegas and it instantly gave me "???" instead of blood sugar results.  I've seen the triple question marks before, but usually the sensor synchs back up and rights itself.

Dexcom tossing "???"

But this time, the question marks hung out for ages.   Like hours, and then when it would finally ask me to calibrate, it would work for about 45 minutes ("work" being a loose term here, because it had numbers that were over 180 points off from my actual blood sugar) and then the SENSOR FAILED error would come ringing up.  Stupid error. 

Dexcom sensor - FAILED!

I thought it was just the one sensor, but it happened three different times in three different weeks.  Using the Dexcom, it seems, has helped me get my A1C act together, and since becoming pregnant, the Dex has helped bail me out of many, many unpredictable low blood sugars.  (Lows plagued me during the course of the first semester, relentlessly.  50s, 40s, and 30s coming to stay for a visit without calling first.  No symptoms, no warning, and no predictable time frame.  Without the Dexcom, I wouldn’t have woken up in time for those lows, and I don’t like to think about how far I could have dropped while sleeping.  Whoops, digression.  Sorry about that!)  

So I called my contacts at Dexcom, because they are aware of my pregnancy and how paranoid I’ve become about things lately.  (Actually, I emailed them at 2 in the morning because when the third sensor in a row kicked out on me, I flaked.  I sent them one of those “Sorry I’m a lunatic, but …” emails, and thankfully they got back to me early the next day.)

After a few email threads, Dexcom decided to FedEx out new sensors and help get me back on track.  And for some reason, these worked.  I’d heard from the Twitter crew and from some comments here on SUM that there appeared to be a certain batch of sensors that just weren’t cutting it.  I don’t have the “official word” on what the deal actually was, but I do know that a certain box of sensors just weren’t working right.  And now that I’m cracked into a new box, things appear to be working okay now.  

Which is a relief, because the Dex caught a 29 mg/dl as I was getting ready to leave the house the other day.  

“Holy shit, I’m 29?”  

Chris wasn’t home at the time, so I panicked a little bit.  Not a single symptom was on board, and I was freaking out.  I tested again to make sure, as I drank grape juice straight from the carton.  Yup, 31 mg/dl.  Dexcom was blaring its head off.  

Weird things happen when you’re low and don’t realize it.  Like you find yourself sitting at the kitchen counter, eating a whole bowl of Puffins cereal in one gulp.  Chris came home as I was inhaling carbs.

“Are you okay?”  

“Yeah.  I’m 29.  No symptoms.  This sucks.  I seem fine, don’t I?”

“You do.  You seem completely fine.”  The Dexcom went off again.

“Good thing that’s working again.  Did you have juice?”

“Drank it. I’m eating the whole box of Puffins now.”  Grinned through a mouthful of carby goodness.

When it works, it works.

I’ve been wearing the Dexcom on and off for two years now, but almost 24/7 for the past six months.  And not having it on, or having its integrity compromised through technical failure, etc. makes me feel absolutely naked.  It’s not a cure, it’s not a guarantee for tighter blood sugar control, but it’s the safety net I was hoping for, and now that my basal rates, insulin:carb ratios, and blood sugar trends seem to be unpredictable during these months of pregnancy, I’m leaning on it more now than ever before.

[Dexcom disclosure]


I'm right there with you sister. I was just talking about this with myself (hah) in the shower this morning. When Dex works he REALLY WORKS, but when he doesn't I get really ticked! I'm on my second failed sensor in 4 days, but the good folks at Dexcom always come through and make it all better!

I definitely believe in the "flawed" batch syndrome. When I have a bad sensor, the chances of the next one being bad are definitely higher than usual.

It can be really frustrating to work through 2 or 3 bad ones, but I just keep hoping to get past it and get back to a good one. On the plus side, I think I've never had more than 4 bad ones in a row.

gah. i want one. insurance company HATES ME.

My first order was full of those failed sensors. 1 out of the four worked. Thankfully dexcom seems to be on top of things, they sent me new sensors immediately. Now if my current order will get here before friday I'll be golden.

I too have had MANY problems with my Dexcom ("Dexter") for WEEKS. One sensor after another, I kept seeing "???". Tech support kept telling me to wait it out - so I did, for 22 hours until I finally called back and said "see, I told you, you were wrong - they're BROKEN". I even had one sensor give me "???" before it even finished the 2 hour warm up period. I am hoping these problems get fixed and we're back up and running and able to trust the "dexters" of the world. I feel your pain.

I just blogged about this yesterday. I'm with Tammy - when it works, it's a godsend, when it fails, I want to throw it across the room. Fingers crossed on your new batch!

I wish I felt half as confident in my MM CGM. It only catches lows AFTER I've treated them.

Oh, and right now? It's saying I'm at 68. I'm at 186.

When they're good, they're very, very good. When they're bad, they effing suck.

I am also jealous of the CGM. Glad you were able to get new sensors. And, I LOVE puffins. :)

I too have been having problems with sensors. I have had three fail in a row. I too wonder about the bad batch.

I thought (foolishly) i would only use Dex 2weeks/month. Now, I feel out of touch when I'm in the shower and Dex is on my dresser not getting a signal. I've only had one failed sensor out of 12. I record the lot and serial #s along with implant date, restart date, and in some cases second restart date. Not sure why; I guess i think Dexcom will have some brillant use for my data. So far they haven't asked for it. All in all, Dex has saved me from quite a few unexpected lows. Well worth the hassle. Once calibrated, i can forget it for almost two weeks and rely on the trends it sends me. I don't trust any absolute # to dose myself with though. I always use my meter. I love my technology!

I actually started using an insulin pump 13 years ago as part of a minimed study to determine whether or not pumps helped pregnant women avoid truly disastrous lows that used to be much more common in the first trimester (think morning sickness + MDI/insulin injected = low . Demands for nutrition from the baby + a 24 hour basal insulin on board = low). Now, pumps are a given for pregnant women. Hopefully CGMS will become the standard during pregnancy as well, and insurance companies will be quicker to cover it.

I am going through the same thing. I had two sensors go bad after working so-so for 12-18 hours after installation. Maybe yours and mine are from the same lot. Dexcom is really nice about sending new ones to replace the bad ones though.

I just started on the DexCom 5 days ago and I'm already pretty certain that we're in a codependent relationship. When times are good, they will be very good. When times are bad, they will be VERY bad. When Dex wrongs me, I'll take it as a personal affront to the trust we've built. When I try to squeeze every last minute out of a sensor, Dex will see me as the self-centered cheapskate that I am. And when I forget to charge the little data monster, we'll have conversations about my ability to commit. But we'll always come back to one another.

I had a batch of bad MM sensors and now I have one that seems to not stop working! So weird. Hang in there!

Totally know what you mean about relying on that thing. The Dex is FANTASTIC - when it works. I'd even venture to say its the best management tool I have ever had for diabetes - WHEN it works. When it doesn't work, and you get those numbers 180 off your real BG, and then you start doubting all the readings, it totally adds another layer of stuff to worry about and check on - and I hate that feeling! Glad to hear the new sensors seem to be tracking.

Oh gosh, When I was pregnant I hovered right around 60-70 A LOT of the time and felt just fine. It helped for my nice 5.6 a1c at the end of the pregnancy. But it really sucked when I wound up at 21 a few more times than I was comfortable with and had no symptoms until I was coming back up (of course with pregnancy the rebounds can come quicker than normal too, which makes for a cruddy day...). Glad you have Dexcom! I hope our insurance will cover that soon, I'd really like to try it.

A little birdie told me that they apparently tried a new manufacturer for the sensors and that's when the problems started happening. As soon as they isolated the issue they switched back to the old manufacturer, but it was too late--too many sensors had already shipped. We had 3 months worth of them. They were great about sending new sensors out though, always have been.

I want one, too, Sarah Jane! My insurance company won't cover unless I've had "documented" lows, or hypo unawareness, or times when people have had to help me.

I'd like to know what they think single people living alone should do if they don't have anyone to help.

Unfortunately, not as lucky as some people in terms of coverage and supplies...

I have the MM sensor and have had some issues with bad sensors as well. I was hesitant about wearing it but now that I do I too feel "naked" without it and forget I don't have it on. It def. has its days where it works well and others it doesn't and lows are def. not its best suit--it often tells me after the fact but helps prevent highs and overall it is better than nothing!

I shouldn't complain b/c I have a MM.....but it blows. In addition to the sensors constantly failing it isn't remotely accurate. I can't count how many times I've woken up to a "low" alert when I'm actually high. I wish MM technology would catch up with Dex already!

I went through a similar issue with failed sensors a few months back. But they've been rock solid ever since.

Don't you hate lows where you're convinced that you're not. I'd test three times and admit that I'm too low to know that I'm feeling low. Glad Dexie saved you there.

This happened to me with my MM CGMS, but on a much larger inaccuracy scale. Such a pain. Such a headache. And minimed didn't do anything about it. I don't think they believed me. But in general this happens pretty often with MM. A HUGE reason why I called Dexcom yesterday to see if I can get switch!!!! Come on insurance!!!!!!!

With all it's imperfections, I agree that you do come to rely on the information that DexCom provides. It can be maddening when it doesn't work right, but it has helped out in many ways. Probably the biggest benefit is when Caleb is separated from me. It gives us all a little more comfort and thus him a little more freedom.

I may be one of the few, but I dumped the Dex7+ and have switched to the Nav.I have had nothing but problems with the Dex and cant use it anymore. I'm not saying it is a bad product, only that it does not work for me. In the recent past I had 5 sensors in a row fail within 3 hours of insertion. I have had multiple times when I would get a high alert and acknowledge it only to have the receiver reinitialize itself. Support told me it was a sensor issue, the district manager told me it was a receiver issue. They replaced the receiver and I still had reinitialization issues. I also found that more often than not, the accuracy was way off. I had one time for example where the Dex said I was 308 and multiple finger sticks showed I was at 83. Just a bit more than I can tollerate, so I'm going to have a go with the Navigator.

Hey Kerri, during both of my pregnancies I would get into the 20's and 30's and still be FULLY functional and not have symptoms. It was so scary! However, after delivery the hypo symptoms came back (with the exception of night time hypos, still don't wake up from those, thank God for Dex!) Just curious as if any other women noticed this too??

Sorry about your sensor Kerri. I just wanted to say that my MM does well when I do well. I see several people who are not happy but most of the time that is due to error in calibrating and not with sensors. At least that is what I have found. MM follows my own BS perfectly as long as I do it the right way. However, it is hard to find a time when I am not trending higher or lower so I can understand why others have trouble. MM has always been helpful with this issue. Good luck! I still can't believe that I had three babies without a CGMS or much diabetic help. You are so fortunate to have all this support.

1) I think your Freudian slip about trimesters/semesters is kinda funny.

2) Ditto what everyone else says. (Some variant on: "When it's good, it's good; when it's bad, it sucks big time.")

3) I've actually tried to do 1 week on Dex, 1 week off because I find that being on the Dex makes me even more absurdly lazy in the logbook department. I've been trying to clamor my way back onto the logbook wagon, and the Dex doesn't help on this front.

4) I like the blue skin for your Dex -- I haven't seen these before.

I wear the MM, and usually have quite good results, except when I get the occasional bad sensor. Then I am scared, and can't figure out how I lasted with Type I for 35 years before getting my CGMS. My tip to the MM CGMS-ers is this: set your LOW alarm for 100; set your HIGH alarm for 150. It will then catch at least 95% of your lows and all of your highs, unless you have a bad sensor.

I am in the midst of making a decision on what CMG to get - MM or navigator or Dexcom. I am fortunate that they are all covered, but reading this makes me wonder if it's worth it. Are failed sensors just a matter of fact? The reason I am getting one is because I can no longer sense my lows. So if they don't find the low's what's the point? What are you setting as your low number for an alert?

How do you know when to change your sensor?

I use a MM pump with CGMS, and the CGMS does not work as well as I would like. The alarm is the volume of a mouse, and have been woken up 3 times in the last week by somebody shaking me, only to find a SIRENING noise in the background and a fingerstick of 10mg/dL.

MM, you suck. Sorry.

Yeah, I had a similar experience Emma - waking up in the hospital and being told I was seizing while my MM CGMS said I was 96 (I am typically totally fine down into the 30s, so to be seizing I must've been in the teens or lower). The MM, for me, was terrible about catching lows, I would frequently be 40 with the Paradigm saying I was 100, and my wife had the same complaint about sound - the thing was just loud enough to be heard over background noise when you're awake, but nowhere near loud enough to wake you up.

Of course, right now I'm seeing the dreaded ??? from the Dex and irritated with that, but when it's working at all, for me it's a lot more accurate.

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