How is Day 1 for everyone with new G4 sensor?

Our very first sensor last month was spot on from day 1. Our 2nd sensor Day 1 was AWFUL. Called tech. support and they said do the 3 calibrations 15 min. apart. It didn't help much. I didn't want to insert a new one, so we waited a few more hours and it seemed to finally get in sync. After Day 1 it was very accurate the rest of the time.

Yesterday at 4:00 I inserted my son's 3rd sensor and AGAIN Day 1 has been WAY off. I did the 3 calibrations 15 min. apart this morning and am waiting a few more hours to see if the readings get better. Should I put in a new sensor or just wait again to see what happens?? Do most of you get crazy readings the first 24 hours?

Lori - Kyle's mom

My readings are always spot on from day one (10-15 points st most in terms of variability) and there are a few ideas you might want to try to get the sensor to acclimate on day one. Day one of the sensor is usually where I do a finger stick at three different glucose levels to acclimate the sensor algorithm in the first 24 hours. This usually does the trick for me and the next 12 days are pretty much spot on. Hope that helps in your case.

Day one for me has been awful from the very first sensor. The first one buzzed incessantly either high or low and I got no sleep. The second one was way off as well. It didn't matter how many times I calibrated it, but once it has "marinated" in the interstitial fluid for a while it is very accurate. Even in the literature it says the day 1 results are only 71% accurate. I can say I don't get anywhere close to that.
The trainer and my CDE both said set the alerts to very high, like 300-400 and very low to 60 the first day and then adjust afterwards. Otherwise you get no sleep and that is really tough to deal with.

I would wait. In my experience (at least with the dexcom seven+) it takes about a day to settle in but is pretty accurate after that. It's worth the wait to not waste a sensor, in my opinion.

spoke to Jesse last night. He's loving the new sensor... says its better than his Navigator... wow.. he's been using the same sensor for 3 weeks now...

So, morning, afternoon & eve. or closer in time than that??
Thanks. :)

I slept with my son last night (on the floor) because it was SO off I didn't want
it waking him up, but I wanted to do a finger check just in case. At 2 a.m. the CGM was reading 269 and when I tested him he was at 144 - GEEZ!! But, that's what happened on Day 1 with the last sensor too. I just hate to "wait it out" if it isn't going to get better. Well, we'll wait it out until this evening ... that'll be +24 hours.

Thanks, Clare. :)

If this is a consistent thing, do you think it would help to insert the sensor 24 hours before activating it. (Insert it before deactivating the old one?) Just a thought I had.

I was glad we waited it out with the last sensor. After we made it through Day 1 it was spot on for 8-9 days before we replaced it. AWESOME! :) But, this one seems to be taking a bit longer to settle in. Thanks for your quick response.

So he would be wearing 2 - just one without the transmitter? Can you do that? Wouldn't "stuff" get into the open sensor without the transmitter in it? Wonder if that would help OR if the calibrations are really what help sync it. Hmmmm ...

Same thing happened to me, the first reading after the 2 hours calibration time was 243 and fingerstick was 143 so I didn't worry about it and I certainly didn't correct for it with any insulin.

I wouldn’t do that. Every sensor I’ve ever used, across multiple brands, has a period at the beginning where it’s not very good. The G4 is better than any previously in that regard, but there is no way to avoid the need to fine-tune calibration. The initial 3hr calibration and its adjustment therafter is a process that requires both sensor data and interpretation of that data; the interpretation occurs in the receiver. So even if you were to pre-insert a new sensor a day early, it would still require the receiver’s “attention” for the same amount of time, and you’d shorten the new sensor’s reliable life by a day for no reason.

In general i consider high accuracy on day 1 to be an unexpected gift if I get it, but it usually doesn’t happen, you shouldn’t rely on it, and I always make sure to test bg a lot (8-10x) on day 1 to lock the sensor in ASAP.

That makes sense & along the lines of what I was thinking too. So, do you enter/calibrate ALL of your test results on day 1 to help sync it?

I disagree that "it would still require the receiver's "attention" for the same amount of time".

Compare the 1st day of the 2nd week with the 1st day of the 1st week. My experience without exception is that the 1st day of the 2nd week is much better than the 1st day of the 1st week.

I didn't have your Day-1 problem. (On my first Sensor, stil in use at day 11, I had only a "first two hours" problem - a less unstable startup than I had on 7+ Sensors).

But if you want to make a cover for an extended warm-up, while the Transmitter is still in use on the other Sensor, here are two possible ways:

Way #1 - Much Less Hard, but equally hard work with every new Sensor: Make a sort of "shower cover" with a non-sticky middle section of "cover" over the actual Sensor. Here's how:

Step 1A: Using an alcohol wipe, Clean fingers, scissors handle, an area of counter, and the outside of your box of Glad "Press-N-Seal". Let alcohol dry off everything.
Step 1B):Then cut a large piece of "Press-N-Seal', set it down with the sticky side up on a clean counter. This peice needs to be really huge, bigger than the Dexcom adhesive pad by 1/2 inch all around.
Step 1C: Now cut a smaller, Sensor-sized piece (slightly bigger than the Sensor pad area) and it sticky-side-down on the middle of the sticky-side up piece.

You now have a large donut-shaped Press-n-Seal, which isn't sticky above the Sensor and Pad, but IS sticky in a ring around the outside.

Or Way #2, Much harder to make the "cover", but EASY JOB upon inserting a Sensor. I'd do this one (but I'm pretty good at whittling and grinding things out of plastic):

Go to a plastics store (an actual fabricator, not a "big-box hardware" place. Have them either make a couple of small 3D rectangle of the approximate Sensor size (cheap), or have them completely fabricate a pastic "Sensor Blank" (Quite expensive.) If you got the rectangles, as I would, then you take them home and trim to Sensor shape yourself. (You got two or 3 recatngles, in case you mess up the first one or two tries). Then - use this "Sensor Blank" as the cover, preventing stuff whacking at the "flap" or getting inside the Sensor mounting area.

If possible often with the original dex 7+ I would insert a sensor before bed, and not start it untill the next morning.. even justgiving it a few hours to settle out before starting the sensor (more than starting the sensor and waiting) seems to help it a bit... Some people it seems the body reacts a bit to the trauma of the sensor insertion.. but as always YDMV

Mine has been pretty spot on so far, day 1 to well, I'm on day 15 right now. I just tested for dinner and it was 2 points off from both of my meters :D

I do however cover it up in the shower. I know it says that it's waterproof, but my first one died in the shower and since I have been gun shy about trying it again. So I usually just put a paper towel covered by some medical tape over it while I enjoy my cleaning time :D

Well, glad we waited. It took more than 24 hours, but we are within 10-12 points off last night and today. Hoping it will even get better today (like our last one did). My son has been sick and that 24 hours seems like forever. Funny how fast we learned to love (and rely) on it. Can't imagine not having one now. Thanks to everyone for their input. We may try inserting the sensor and waiting two hours before starting it up to see if that helps any (and not start it right after a meal if we can). :)

First one I used was way off. The calibration thing didn't help at all. Second sensor was spot on but I only got 8 days before the ??? kicked in.

I tend to do so but, if available, entering bg values when level (“straight across” arrow) seems to get the device to accuracy more quickly. Sometimes you just don’t have that kind of day though, and I still make sure to enter most if not all of the values on the first day.