Dexcom G7 warmup period query

[CathyFP]

Hi,
I’ve just put on my second G7 sensor. I inserted it about 6 hours before the first was due to expire as with previously with Libre2 I found that if I put the next sensor on early without activating it, it would be more accurate at the start.

When I came to pair the new G7 with the app (about 6 hours after I had inserted it) I found that it started to work straight away and did not show the warm up screen. Have I stumbled on a way to avoid the warm up period? Is this a correct and an ok way to swap sensors. Did it not need the warm up as I had already been wearing it for a few hours?

Any ideas G7 users ?

Thanks

 

[rebrascora]

I may be wrong, but I am not sure you can give the G7 any extra "bedding in time" like you can the Libre as L believe it starts it's warm up as soon as you apply it, so you will likely have lost a bit of time off it's lifespan by applying it early.
Hopefully others who use the G7 can confirm that. I am pretty sure @Proud to be erratic is one such member.

 

[CathyFP]

The graph even shows 2 lines presumably 1 for each sensor , which I didn’t think was possible?

 

[CathyFP]

Found a podcast which suggests you can swap G7s in this way to avoid having a warm up period without sensor readings. Interesting .

 

[everydayupsanddowns]

Just tagging @Proud to be erratic and @Inka who I think also use G7, in case they have any insights

 

[Inka]

The G7 ‘knows’ when it’s been inserted so the 30 min countdown starts from then. Yes, if you put it on earlier, leaving the old one on, then Start the new one after the 30 mins it will give readings straightaway. I don’t usually bother as a) by the time you’ve inserted it, paired it, put the inserter and box somewhere, it’s only got 20 mins or so warm up left anyway. I prefer to save my minutes and make sure I’m using the sensor for every minute of its life. It’s pretty much accurate from the get-go unlike the Libre @CathyFP

Edited to add, I wouldn’t put the new sensor on that early. You’re just wasting the minutes. If you really can’t cope with 20 or 30 mins without readings, then insert it 40 mins early or similar. It’s really nothing like the Libre so don’t carry across Libre tricks as the G7 is very different, and doesn’t need any tricks really anyway.

 

[Proud to be erratic]

I agree with all of the above. Because I have a Receiver and a phone app, I often fit my new sensor as the old one times out but keep the old one running at least until the 30 mins start up has finished, with my Receiver giving me readings from the old sensor. At the very least I find it interesting and reassuring to take 3 readings from rhe old, the new sensors and a finger prick; this allows me to establish if the new sensor is already close to finger prick. Sometimes I just leave the old sensor talking to my Receiver for the full 12 hours overrun that the G7 permits. I like to try and change sensor mid to late evening so it's getting the overnight fasting period to fully settle down (which it doesn't really need but I still have the baggage from Libre bedding down routines!).

Occasionally the new sensor is a small amount adrift from a finger prick and if I'm in a very steady BG state, with no bolus on board then I'll use the calibrate function. I perhaps need to calibrate every +/- 8 sensors. The G7 is terrific for me.

 

[Inka]

Yes, I try to use as much of the 12hr grace period as I can. I like having the flexibility of choosing a time of day that suits me to change sensors. Totally agree with the terrificness of the G7 - it’s amazing

 

[sninge]

I always give my g7 10-12 hrs to bed in and I do that during the 12 hr grace period of my last sensor. I connect the new sensor to my phone and keep the one in grace period connected to my pump. I do this because for me, like libre 1&2 & g6 I get erratic readings for the first 12 ish hrs and if they were connected to my tslim then I would be getting insulin I didn't require or not enough depending on what the inaccurate readings said.
I also start mine in the evening so it gets to settle in with calm blood sugar overnight and I was also advised by Dexcom not to calibrate for first 24 hrs. I find after 10-12 hrs the new sensor is close to perfect but always erratic to start but as I have had this with all sensors it is clearly me that is the problem there! The bonus to this is obviously no time without readings!

 

[CathyFP]

The G7 ‘knows’ when it’s been inserted so the 30 min countdown starts from then. Yes, if you put it on earlier, leaving the old one on, then Start the new one after the 30 mins it will give readings straightaway. I don’t usually bother as a) by the time you’ve inserted it, paired it, put the inserter and box somewhere, it’s only got 20 mins or so warm up left anyway. I prefer to save my minutes and make sure I’m using the sensor for every minute of its life. It’s pretty much accurate from the get-go unlike the Libre @CathyFP

Edited to add, I wouldn’t put the new sensor on that early. You’re just wasting the minutes. If you really can’t cope with 20 or 30 mins without readings, then insert it 40 mins early or similar. It’s really nothing like the Libre so don’t carry across Libre tricks as the G7 is very different, and doesn’t need any tricks really anyway.

This is all good news thanks @Inka

 

[CathyFP]

I will try out different ways of managing the G7 change. I am seeing some strange figures in the first few hours of a new sensor and was wondering when to use ‘Calibrate’?

 

[Inka]

They advise not calibrating it for the first day or two in case it’s settling @CathyFP but occasionally I’ve calibrated it on the first day. I find I often had to calibrate it back though - ie if I’d left it, it would have centred in on the correct blood sugar anyway. So,I agree with the advice to leave it early on. Most sensors I don’t have to calibrate at all.

 

[Mini Gem]

I always give my g7 10-12 hrs to bed in and I do that during the 12 hr grace period of my last sensor. I connect the new sensor to my phone and keep the one in grace period connected to my pump. I do this because for me, like libre 1&2 & g6 I get erratic readings for the first 12 ish hrs and if they were connected to my tslim then I would be getting insulin I didn't require or not enough depending on what the inaccurate readings said.
I also start mine in the evening so it gets to settle in with calm blood sugar overnight and I was also advised by Dexcom not to calibrate for first 24 hrs. I find after 10-12 hrs the new sensor is close to perfect but always erratic to start but as I have had this with all sensors it is clearly me that is the problem there! The bonus to this is obviously no time without readings!

Hi I'm intrigued by this as also want to do a 12 hr ish pre soak due to low readings when a new sensor is applied.

My issue is recently I put a new sensor on and started it on my phone and completely forgot to start on my pump (t slim) just because I was busy! So about 1.5hrs later I tried to start and pair it to pump and it just would not work and had failure straight away.

So I assumed I couldn't do a presoak. As when it leaves the inserter it activates and I assumed it then only had a certain window to pair. But it looks like I am wrong as it seems to work for you...

So you start it on the phone and leave it sometime and it still manages to pair from the pump?

 

[sninge]

I have had a couple of g7 fail to pair but it has been a problem with the sensor and Dexcom has replaced them. Apparently there are 2 different bluetooth gadgets in them, one talks to phone and one to pump (so ive been told on phone to Dexcom ) which explains why sometimes it fails on phone and sometimes on tslim. They always say that I ' should ' pair pump first but are happy when I explain I need to presoak because of erratic readings. If it fails to connect to pump I now call tslim first and they talk me through a reset with the pump which usually works and if it doesn't then Dexcom will replace the sensor. I also now remove the old sensor and put it in the bin in a different room to me before I pair the new sensor to the pump, I don't know if it helps but in my head it does!!!

 

[Chelseagirl]

It’s quite normal to see two traces on the graph as the G7 sensor has a memory in it. Don’t know how long though. Once it is connected up it downloads the measurements that it has taken since insertion. Also it’s a good way to see how accurate it has been so far too, always assuming that the old sensor was showing a reasonably correct reading.