OK, so the honeymoon is over. There’s always that euphoria when you start using a new gadget or tool, and it always wears off over time. I’m still glad to have my new Dexcom — believe you me! — because it’s helped me out of a horrible motivational slump, and it’s made me realize how much of the time I had no idea what was happening with my BG levels.
So those are positives.
BUT… some of the aggravation of my early experiences living with CGM is back.
Overnight Nonsense
Who was it that said wearing a CGM overnight could be like having a newborn? Yup, the thing wails at you when it wants attention, regardless of your efforts or needs. I’ve had some nights where I’ve been stuffing the receiver in my underwear drawer (inside my new walk-in closet, with the door closed!) so I wouldn’t have to listen to it.
That started after one night last week where the thing beeped me awake with a 240 reading and two arrows going up, up!! I stumbled into the bathroom and did a fingerstick check: 140 mg/dL. WtF?
Later that very same night: Beeeeeeepppp! The screen showed me at 50 — OMG! But I didn’t even treat that false high earlier. Another stumble to the bathroom: checked in at 95. Grrrr.
Banished to the underwear drawer, you are!
The experts at Dexcom tell me this might be because the sensor was new, and accuracy is always “iffy” in the first 24 hours or so. Hmmm.
But last night, four days into another sensor, same thing: Beeeeeeeppppp! Screen shows me at 50! Stumble to the bathroom, and check in at a lovely 120 mg/dL. This seems to be an overnight pattern. Grrr.
Why am experiencing so many “off” readings overnight?! I’m wearing the sensor smack in the middle of my belly, and keeping the receiver right under my pillow (which makes for much unpleasantness when alarms go off).
I do not know. But it really isn’t doing me much good in the underwear drawer, is it?
Low-Carb Blues
I’ve also been on a Holy Mission to drop a few pounds after my post-remodel and post-holiday carb binge. I’ve been doing pretty darn well for several weeks now: completely off tortilla chips and granola bars, eating only tiny bits of carb in the form of a bit of nutty granola and some occasional apple slices. OK, and a few squares of dark chocolate after dinner some nights (which I dose for profusely).
Yet with all that low-carb goodness, I can’t say my numbers have been great. I still seem to spike sometimes after eating veggies with dip, or sunny-side-up eggs with a little coffee. Weird. And the CGM’s been slow to catch on to these spikes.
Shower Power?
I was shocked to learn from fellow D-bloggers Lee Ann Thill and Kelly Kunik recently that showering is known to mess with your BG levels. What? Just standing under water 
causes BG changes too? Can they make this control thing any more difficult?!
Anyway, I hadn’t really noticed it — or even considered the possibility — until I had the Dex. Now I do notice that I’m slow to come down after a shower. (Power of the shower, or power of suggestion?)
Some Dexcom folks have told me they suspect that showering or bathing may cause accuracy problems in certain batches of sensors. Uh-oh. They’ve asked me to monitor closely to see if I notice anything wonky after water contact.
Right now, the only thing really wonky is me. Every time something beeps in my vicinity I start frantically rummaging through my purse, to pull out not one, not two, but THREE gadgets I need to check: is it my pump? my CGM? my iPhone?
One or another of my three daughters often perks up with something like: “Mom, it’s just a truck backing up over there, see?”
“Oh right, thanks,” I sigh.
Then I get the eye-roll. But not before I’ve rolled my own eyes practically out of my head.
I know this is awkward, but I shower with a hand over the sensor. That reduces the issues with it getting washed away especially when it’s a week old and the adhesive is started to fade. Then when I get out of the shower, I try to pat dry the adhesive tap figuring it might help with longevity. Usually get 11-12 days out of a sensor, though last week I made it to 14!
I started my Dexcom on Sat. and I’m still enjoying the honeymoon. My accuracy has been good (not perfect) and I’ll have to watch out for the water/shower issues.
Are you still getting out for rides? If so, how’s the accuracy? I’m getting out on my bike again and I’m so looking forward to “instant” checks on the receiver so I don’t have to stop and test.
Good luck!
I’ve noticed the shower thing, but I truly believe it has more to do with unhooking from my pump (even with a little pre-shower bolus) and getting up in the morning. My rise on the weekends is much lower and more smooth and the rise for workdays is much more steep and sticky – I think it has more to do with the adrenaline of shifting from rest to get-up-and-go than anything else!
Also, the first 24 hours with a sensor are always less than ideal – I try to change out as early in the morning as I can so I don’t have to deal with all the weirdness overnight!
Noticed those same trends when CGMing. Even when not using one and having no sensor in me, it’s clear that my BG rises and is slow to come down post-shower. The great Shower Power, indeed… but totally worth it when you get a “free” shower out of the deal!
It’s possible that I’m the only idiot who made this mistake, but remember not to calibrate the Dex *too* often (when it tells you and when it’s more than 20% off, according to the rep I spoke to). I was getting “phantom” highs when I exercised when I was feeding it practically every fingerstick I took.
I haven’t noticed any issues with showers/water/sweat contact, but I do sympathize on the first 24 hours issue. I pretty much never get through the first 24 hours of a sensor without wacky readings and a few (or MANY) hours of ???.
Why is all your testing stuff in the bathroom? Put a meter, strips, and lancet on your nightstand so at least you don’t have to get out of bed. Be sure it has a backlight and port light so you don’t have to turn on the light and wake your hubby. You can just leave it there for middle of the night checks.
I had the same sentiments exactly! It was beeping all the time and was highly inaccurate. It showed I was “low” when I was 150, and I never did end up getting low, was showing me really high high’s when there was none. Doctor wants me to buy one, after this trial run, and honestly I don’t knw if it is worth it. She told me that if I was dropping rapidly for like 20 minutes straight, that it will beep with a low, as in predicting what will happen, but when I got it, she told me it just checks it every 5 minutes, so It didn’t sound like she knew what she was talking about either. So I am still on the fence about buying one. I liked seeing the trends, but do I like it enough to have another thing attached to me? Idk.
LOL This was written so humorously
I take 3 minute showers every day and the last minute is cold (helps with circulation in the legs and keeps them lookin’ good!) but the cold also gets the metabolism up a little because the body works harder to keep warm, which in turn helps my blood sugars. Maybe that’s why I always get low in a pool or the ocean.
The Dex needs oxygen to get a reading. Hence if you’re lying on the Dex and cutting off the circulation, it won’t read correctly. When I was using a Dex, I started putting it downstairs overnight, and it was much more accurate without all those false lows.
However, if you’re type 1 and apt to go seriously low, it’s a serious problem. I think the Navigator, which is no longer available, didn’t require oxygen. Maybe people could get together and lobby Dex to use the other system.
you gotta get a meter next to you when you sleep! no more stumbling to the bathroom at least.
I have the medtronic CGm and I have the same problems. I always attach a new sensor in the morning so I can deal with all the issues while I am awake. Overall, even with it’s mistakes. I am so glad I have it.
Thx for feedback, everybody! @gretchen – I’m definitely not lying on top the Dex, so that can’t be the problem. @anne & @Denise – I do keep an emergency meter in my nightstand, but I absolutely HATE testing in bed. It’s all fumbly and bloody and awkward! I’d much rather stumble to the bathroom where I can do a quick test without wasting a bunch of strips.
Same problem, I have to choose my sites carefully to get good nighttime coverage. No need to put in the sock drawer, just go to the menu and use Shutdown. This turns off receiver (not sensor) and all of its alarm functions until morning when you want to turn it back on.
Whenever we put in a new sensor, we get ??? while he sleeps the first night. Just about every time. I’ve just grown to accept it.
We had lots of crazy readings and ??? when we first started using the Dex on our daughter. Discovered that it was the insertion method and location causing the problems. She’s a string bean 5 yr old so it’s difficult to find a fatty location! Make sure you are pinching up so that the sensor wire is only in skin/fat and not muscle. Look at the wire when you remove the sensor. If it is bent, you have a problem with your site/insertion method. BTW – you can always silence alarms if you want to.
I’ve been using the Dexcom continuously for almost three years. It’s an amazing tool, but certainly not perfect…I’ve seen everything you’ve described.
I’ve had spurious nighttime lows most often when I’m sleeping on my side and the the sensor also is on the side facing the mattress. It’s worst when the sensor is between my body and the mattress…I’m guessing, but I think that any pressure interferes with the movement of fluid around the sensor wire and allows the enzymes on the wire to deplete the local glucose levels. The problem is bad enough that I almost always insert the sensor on my left side…I sleep on my right.
The too-frequent calibration problem seems to have been fixed in the Seven Plus. The algorithm is secret, but, from my discussions with Dexcom, appears to take into account both the frequency of calibration and glucose trend line. The original Seven would get totally messed up if you calibrated it while your glucose values were moving around. The Seven Plus is much better.
I usually get two weeks use out of each sensor; ten days at the very minimum. When the tape begins to peel, I take an IV3000 dressing, slice it lengthwise, and use half to hold down the upper side of the sensor. Without it, the stream of water in the shower gets between the sensor dressing and the skin and quickly works it free. The IV3000 lasts a shower or two and then I replace it with a fresh piece. If I realy need to hold the sensor in place and keep it dry and clean (think swimming, hiking, camping, etc.), I’ll take a 3M Tegaderm dressing, which is roughly 4×5″ and stick an IV3000 in the middle, adhesive to adhesive. That leaves a sticky ring around the outside and a non-sticky center. I then just stick the whole thing over the Dexcom sensor. It’s not pretty, but it works.
Lastly, until this thing gets bullet-proof accurate, I’d never use it to calculate dosing. The trend information, though, is invaluable. Being able to see how different foods affect BG levels over time has allowed me to tune insulin dosage to a degree that I never could before. Even with the occasional bizarreness, it’s wonderful.
Hi Amy: I just started the Dexcom, and am only on my second sensor. I have found it to be amazingly accurate! I had used the Medtronic Guardian two years ago, and experienced the problems that you are describing, but the Dexcom has been a completely different and better experience. My main problem is how I react to all this information. I am trying to learn to “observe” and not react. I hope things improve for you, Amy.
I use Masisol and the adhesive lasts as long as the Dexcom sensor (two weeks). I swab it on with a q- tip before inserting the sensor and it works just fine.
HELP – I heard about a diabetic supply company http://www.diabeticcare.com I just wanted to know if anyone has ever used this site and what they think about it. From what I can see they look good but I want some input. Thanks
I’ve used the Dexcom for almost 3 years and have seen many of the issues others have described above. I must be weird however, because I go “low” during a shower provided I am around 100 before I start my shower – go figure that one out. I’ve also found that 3M makes a tan colored tape that can easily be cut into narrow strips to put over the Dexcom adhesive. I’ve been lucky in that I often get 14 – 30 days out of my sensors. Since I am self funded that part is appreciated. Sure wish Medicare would see fit to help out with paying for part of the CGMS.
When I had my Dexcom 7 plus I used Glad Press ‘n Seal to cover the sensor for most of my shower (I took it off just to wash there at the end) and I didn’t have any trouble. I can’t conclude that this helps accuracy issues, but it is pretty simple to try.
The operating temperature of a sensor will absolutely effect the signal output. Significantly. Since skin temperature rarely fluctuates drastically or quickly, this is a factor that most won’t ever take in to account. A hot tub, a dip in to cold water, a shower- etc will cause you sensor to go up or down, depending. Remember that your sensor is carrying out a complex electrochemical reaction very close to the surface of your skin. Estimate 5% change per degree change in skin temperature. That’s on the high side, but not by much.
I’ve had my Dexcom for about 3 weeks so I have a couple of questions.
Today is the second time I’ve gotten ??? The first time I called Dexcom, they asked a few questions told me to remove it and sent me a new one. Today it’s 4 hours after insertion and I’m getting ??? WTH? Any chance it will recover from ??? without me having to change it again?
Also, some of you are saying you’re getting your sensors to stay in for 10 – 14 days. What’s the trick? Mine shuts down after 7 days.
Nonetheless, I do like observing my trends. I’ve gotten to the point while I’m sleeping, unless it alarms low, I don’t get up to check
I too am new at this cam. I just started my second week and changed my sensor. I thought that I had to change after 7 days. That is what my diabetes educator told me and sordid the deacon as the time approached. So, I too would like to hear more about how you are making yours last longer.