The First 24 hours on your Dexcom Sensor; Is Patience a Virtue?

i keep reading about others who claim that their sensors become more and more accurate over time. that some people even leave their sensors in for as long as 3 weeks and that they find that until the sensor goes a little haywire, the accuracy is great.

but how much patience do you need to get through that first days start up period? i will get gaps in my trend line, loss of direction arrows, ???, inaccurate BG #s, and on and on. i find myself getting so frustrated. i end up calling dexcom tech support and requesting a replacement sensor just so i can pull the dud one out and start all over again. am i supposed to wait it through that first day instead of taking it out prematurely? is there something i am doing wrong? it is in a comfortable site, no pain whatsoever. i actually don’t even feel that its in my body. but still, all the problems.

please help!!!

Kind of a hard one to answer–I haven’t actually seen all that much variability in the first 24 hours, with one exception a couple of weeks ago when I hit a capillary. After 48 hours it was still being crazy so I took a closer look and saw that there was blood under the sticky-tape. I have noticed that I have more “lost connection” episodes with the Bluetooth connection than I had with the G4 RF one.

How many sensors are you taking out after only a few days? If it’s most of them, then maybe try keeping one in for a week just to see what happens. My personal view is that as long as the trend on the Dexcom is accurate, I’m willing to put up with a fair bit of inaccuracy. I do find that the first couple of days of my sensors tend to be inaccurate, which can be annoying, but then they settle in and I actually find the second week gives the most accurate data (and the third week, but then it usually dies quite suddenly partway through).

excellent suggestion. thank you. as i am writing this now, and i don’t want to jinx myself, my sensor is up and running again w/ good accuracy. go figure :wink:

Lately my first 12-18 hours have been terrible. For example I started a new sensor yesterday. This morning my sensor said 230 and my meter said 128.

If I had as many problems with sensors as it sometimes appears you have, I think I would just quit. I been using Dexcom for over 3 years and I can count on one hand the number of “dud” sensors that I’ve had.

Not sure if it is body chemistry but something seems amiss. I’m sure your doing everything right but maybe there is some type of body chemistry that doesn’t mix with Dexcom. Maybe try Medtronic Elite and have better luck.

I find around a third of sensors are less accurate over the first 24 hours or so (i.e. they differ from a fingerstick by 20% or more). They almost always settle down by 24 h. I have been using the Dexcoms for 2 years now and have had 2 sensors only that were duds.

i have found the same w/ regard to accuracy. not for all of them, but this does happen. but, i have gone through a lot of duds which really pisses me off b/c i feel like a pin cushion and i hate having to boot up a new one and wait the two hours all over again.

thats a huge difference. do you end up running out of test strips b/c of this? do you just relax and let it go, knowing that it should settle down, or do you get anxious and want to rip it out and start over again w/ a new sensor?

I call the first 12-18 hours the “WTF” period. For me, they seem to start leveling out at about the 18 hour mark. Dexcom does say the first 24 hours can be crazy.

I find its slightly less than the first 24 hours, more like 16-18 hours… Even with the biocompatibility taken into account, a foreign body is invading your body and assaulting it when your inserting a sensor… Andt the body reacts a bit… Try this… Insert a sensor but don’t start it (morning is good for this)… untill before dinner… then calibrate… … I used to do this with the 7+… Or just let it ride… it will settle down and snap to after the next forced calibration… or if you do two in a 15 min gap… (if its the morning of the next day)

how does this work out? is this so that the body can get use to the “foreign body” entering your system? what do you do about the 2 blood drops asking for the calibration? do you just ignore them?

sorry to ask again, but did you mean that after i put in the new sensor, do i not press the “start sensor” button until later?

Daisy Mae

Yep… Insert the sensor, snap on the transmitter, but dont “start sensor” for a few hours…
Remember youll still need to wait 2 hours after you decide to start it because it will still require calibration but it may be a bit less wonky… (least I thought so)

thanks. i get it now. how long do you usually wait before you turn on the sensor? are you on the Dexcom, b/c thats what i use.

No, I always figure that the sensor will settle down and I would never rip out a sensor so early in its life. I probably test more at first than with a reliable sensor. The sensor is mostly fine now two days later. I use my sensors for about two weeks, sometimes a little more and sometimes a little less. I find that they continue to get more accurate through the first week and I usually have more consistency the second week.

do you ever find that after inserting a new sensor that you feel sore for a little while that first day? and then after that it’s as if nothing is there at all? also, where do you place your sensor that you get such consistent accuracy? i use my left thigh as that is where i have the most “meat,” and it is usually very accurate by dexcom standards.

I rarely use my thighs because I wear a lot of athletic wear that is made from synthetic fabrics. Mostly my athletic pants are synthetic fabrics and most of my shirts are cotton. Two winters ago I had a huge problem with out-of-range errors messages with my Dex. They replaced both the transmitter and the receiver and the problems persisted. At that point I was using a lot of leg sites. Finally I got a Dex Rep who asked what clothes I was wearing. She suggested that the problem might be static related and I should avoid synthetic fabrics. I spend winters in Arizona and Minnesota both of which tend to be extremely dry in the winter. Once I quit using leg sites, the problem went away and I truly believe it was related to static. I have heard of other athletes who have experienced the same problem.

I use the back of my arms for the most accurate results. I occasionally use my lower abdomen, but the results aren’t great and I tend to have allergic reactions there. I haven’t used my thighs in a long time. I am trying to use legs for pump sites just to have “virgin” territory.

If you’d like to read my blogpost about Dexcom and Static, this is the link:

i have heard such great things about using the back of the arm. comfort and accuracy. my thigh has been great b/c i have old age sagging skin there which seems perfect for placement (what irony!!! who’d have thought that sagging skin would have such an advantage) anyway, i wanted, now that its winter here in NYC, to try my upper arm. i have seen the Dex video on how to use a chair to put the sensor on. i think, though, that i would need my husband’s assistance…no big deal. do you find any problems with it rubbing against anything? are you able to rotate from left to right arms despite which side you sleep on? just curious.

I am careful to put the sensor on the back of the arm, not the inside where it might rub against something. As far as sleep goes, I am able for the most part to discipline myself to sleep on my other side knowing that two weeks later I’ll put the sensor on the other arm and sleep on the opposite side. That is why sometimes I do use my abdomen for a sensor so I can sleep on either side.

There are YouTube videos about inserting sensors on your arms, but I do it very differently from any video that I’ve ever seen. Some day I’ll have to make a video (probably not going to happen…).