Dexcom G6 with Tandem t:slim pump

[Dee L]

My son was diagnosed T1D about 20 months ago, aged 24. He has been using a Dexcom G6 with a Tandem t:slim pump for 12 months and is achieving very good GMI figures and time in range. However, we dread the 10 day cycle of changing the Dexcom sensor. For the first 36 hours of a new sensor he gets erratic changes in levels, exacerbated by the pump trying to correct them. It really does seem to behave like a random number generator! Does anyone else have the same experience with the Dexcom G6 and, if so, how do you manage it?
Thanks for any advice!

 

[EllieM]

Don't have the issue with the pump, but do find the G6 inaccurate on first day. Would it help to insert the new sensor a day early to give it time to bed on, and then change the transmitter over after that 24 hours...

Don't know if it will help, but it might be worth a try...

 

[Dee L]

Thanks Ellie for your reply. Attaching the sensor a day early is certainly worth a try! Is this something you (or anyone else!) have done, and did it make a difference?

 

[EllieM]

Thanks Ellie for your reply. Attaching the sensor a day early is certainly worth a try! Is this something you (or anyone else!) have done, and did it make a difference?

I haven't done it (though did consider it) but I have read that people do it with their libres. Since the issue is supposedly caused by the body reacting to the sensot (or so I was told by dexcom support) you'd think it might work? The other thing to try is repeated calibration, but dexcom support told me this is a very bad idea...

And have you tried asking dexcom support for advice? Their CS folk are dexcom users themselves, so normally pretty clued up. (At least where I live).

 

[Dee L]

Thanks again. I'll talk to him to see if this is something he wants to try. We have been in touch with Dexcom (UK) support on this, and another issue, but we were rather less impressed by their responses than you have been! Let's hope the G7, when it's (eventually!) approved by Tandem, will improve the situation.
I'll be sure to post an update if there is any improvement, or otherwise!

 

[Juicyj]

Yes agree to applying the sensor a day early to bed it in - also where are you placing the sensors ?

My experience is just the first 12 hours are slightly off, the chart zig zags a bit, as long as it's not an exercise day or day of great exertion I can ride this fine, but my best advice is to keep calibrating against a BG meter every couple of hours until the readings are more finely tuned.

 

[Hopeful34]

I also apply the sensor early, but have only needed to calibrate a couple once in 6 months use. 1 calibration seems to steady it for me, but we're all different.

 

[Dee L]

Yes agree to applying the sensor a day early to bed it in - also where are you placing the sensors ?

My experience is just the first 12 hours are slightly off, the chart zig zags a bit, as long as it's not an exercise day or day of great exertion I can ride this fine, but my best advice is to keep calibrating against a BG meter every couple of hours until the readings are more finely tuned.

Thanks that is really helpful. He applies the sensor to his abdomen. There is a sensor change on Friday, so I think he is going to rty this approach!

 

[Dee L]

I also apply the sensor early, but have only needed to calibrate a couple once in 6 months use. 1 calibration seems to steady it for me, but we're all different.

We have calibrated when we know it is likely(!?) to have similar readings from a BG meter and the sensor. All Dexcom's information says that this is unnecessary, but we'd agree with you and @Juicyj, that it does seem steady things for a period.
Thank you for your help, fingers crossed that we have a smoother changeover this week!

 

[Hopeful34]

Maybe he could consider trying his arm, as some people find it works better for them.

 

[Dee L]

Maybe he could consider trying his arm, as some people find it works better for them.

Thanks. He used to have the Libre 2 prior to the pump and he had the sensor on his arm which worked well. I guess we have just been following the Dexcom and Tandem guidance on the sensor position. Part of our worry is that if the connection is not as good to the pump then we may have to change the sensor early. However, this would be less of an issue if we can improve the first day variability of the Dexcom G6!

 

[Hopeful34]

I'm a bit puzzled by this, as the back of the upper arm is one of the sites approved by Dexcom for the G6.

 

[Juicyj]

I would agree with trying the bingo wing on the arm too - there's a good amount of soft tissue and easy to apply as well as approved - all my sensors are sited there with little issue.

 

[Dee L]

I'm a bit puzzled by this, as the back of the upper arm is one of the sites approved by Dexcom for the G6.

Hi @Hopeful34 and @Juicyj, this is what the Tandem t:Slim pump manual says in respect of the Dexcom G6 integration:

DO NOT insert the sensor in sites other than the
abdomen (belly) or upper buttocks (for ages 6–
17 only). Other sites have not been studied and
are not approved. Use in other sites might cause
sensor glucose readings to be inaccurate and
could result in you missing severe hypoglycemia
(low BG) or hyperglycemia (high BG) events.

Are you using the Dexcom with a Tandem t:Slim pump too? Whether the advice will change with the Dexcom G7 will be interesting to see!

 

[Hopeful34]

Yes I'm using tslim control IQ with Dexcom G6. Can't seem to find the page you're referring to in my user guide. What's the page number pls. Are you from the USA?

 

[Dee L]

Yes I'm using tslim control IQ with Dexcom G6. Can't seem to find the page you're referring to in my user guide. What's the page number pls. Are you from the USA?

No we are in the U.K. The text I copied is on P162, Section 17.1 and it is the fifth Warning heading.

 

[Juicyj]

Hello Dee, thanks for posting this. I think the advice hasn't been updated in a while, advice from Dexcom suggests otherwise. I have used the back of my arms for over 4 years now - no issues except to watch areas on which I sleep as this can cause compression lows, that's why the back of the arm rather than side is best:

Where can I insert my G6 sensor?

Dexcom G6 sensors may be inserted on the abdomen, the back of the upper arm (indicated for patients age 2 years and older) or the upper buttocks (ages 2-17 years).

www.dexcom.com

 

[Dee L]

Hello Dee, thanks for posting this. I think the advice hasn't been updated in a while, advice from Dexcom suggests otherwise. I have used the back of my arms for over 4 years now - no issues except to watch areas on which I sleep as this can cause compression lows, that's why the back of the arm rather than side is best:

Where can I insert my G6 sensor?

Dexcom G6 sensors may be inserted on the abdomen, the back of the upper arm (indicated for patients age 2 years and older) or the upper buttocks (ages 2-17 years).

www.dexcom.com

Hi @Juicyj, thanks. Is that advice from Dexcom for pump connections too? We are going to test applying the Dexcom with a gap before changing over the transmitter tomorrow. Then my son says that he mght try the back of his arm as a separate exercise in 10 days time.

 

[ElenaP]

No we are in the U.K. The text I copied is on P162, Section 17.1 and it is the fifth Warning heading.

Hi @Hopeful34 and @Juicyj, this is what the Tandem t:Slim pump manual says in respect of the Dexcom G6 integration:

DO NOT insert the sensor in sites other than the
abdomen (belly) or upper buttocks (for ages 6–
17 only). Other sites have not been studied and
are not approved. Use in other sites might cause
sensor glucose readings to be inaccurate and
could result in you missing severe hypoglycemia
(low BG) or hyperglycemia (high BG) events.

Are you using the Dexcom with a Tandem t:Slim pump too? Whether the advice will change with the Dexcom G7 will be interesting to see!

What I find confusing is that this guidance refers to children but, in you first post, you said 'My son was diagnosed T1D about 20 months ago, aged 24'. Is this a mistake?

 

[Juicyj]

Hi @Juicyj, thanks. Is that advice from Dexcom for pump connections too? We are going to test applying the Dexcom with a gap before changing over the transmitter tomorrow. Then my son says that he mght try the back of his arm as a separate exercise in 10 days time.

This guidance is purely for the use of the Dexcom sensor, pump connection advice would be provided by Tandem.

Good luck with the next sensor - please feed back here how he gets on as it helps other people who follow/read this thread.