Keeping sensor in more than 7 days?

Hi – my husband isn’t much on computer social networks so I’m writing for him (plus I’m the nag about his diabetes). He’s been using the dexcom for about 6 months. I noticed some of you had noted keeping the sensor on for more than 7 days, but he said at day 7 he gets a message on his dexcom that it’s time to change the sensor and he things it turns off or something like that if he doesn’t change it. Does that sound accurate?

Yeah, you just restart it when it expires :slight_smile: Unless you get a “sensor failed” there’s no reason to remove it at 7 days… most of us find that if anything, the sensors are the MOST accurate between days 7-10 or so.

What your husband says is true. However, when the sensor ends, instead of removing the sensor and inserting a new one, he should just go to “start new sensor” on the Dexcom receiver. The system will think it’s a new sensor, so it will take the usual two hours to calibrate. Once it asks for the two startup BGs, he’ll be getting readings again.

I can usually get between 13-15 days per sensor.

The DexCom 7+ receiver automatically stops the sensor after 7 days. A sensor start including the 2 hour blackout period is required. A change of the sensor is not enforced. This means that you can restart the same sensor and thereby use the sensor for more than 7 days.

great, thanks for the information! I’m passing it on to him.

When I see “Change sensor soon” appear I click on “end sensor” which then causes “start new sensor to appear”.But of course it is still the original sensor that is restarting.

There is no benefit to restarting exactly after 7 days. I typically restart on day 6 during a time when my BG is expected to be stable.

thanks! good to know.

The warning to change the sensor that is displayed on the receiver screen is similar to an alarm clock going off. There are no signals from the sensor or the sending unit that initiate this message.
If the sensor is not removed your husband can “fool the system” by telling the receiver to start the sensor.

When a new sensor is installed, the body reacts to the new intruder by generating an immune defense. That immune reaction by the body is necessary for the sensor to operate. It takes the body 3 hours or so to accomplish this. That is the reason behind the start up routine involving a 3 hour wait.

Since an “old” sensor is already operating, the 3 hour wait is unnecessary. However, the receiver unit is programmed not to display sensor data for that start up period.

None the less, there are other considerations. Some members of this group experience rashes, discomfort or failure of the adhesive any of which can cause the user to remove the sensor. Also the sensors themselves have a variable life span. So if a user wishes to keep the sensor past the 7 days, he or she must be sensitive to signs that the sensor is coming to the end of its life. Usually the receiver reports an error, the ??? or flatlines and is unresponsive.

Today is day 14 for my current sensor. No irritations, adhesive still working and best of all the Dexcom readings have been extremely close to my AccuCheck Cpompact Plus meter. I may be able to start this sensor for the third time Monday or Tuesday.

I began using the DexCom in October 2009 and had lots of trouble with sensor life. During my starting period I experienced close to a 50 % failure rate. Luckily, the last two sensors have continued long past the seven day expected life.

Good Luck with the DexCom. Its a great help to many of us.


thank you so much for the response, this is a big help. Yes, he’s had some issues with the sensors failing but has worked through those. Right now we think there’s a problem with the receiver as the other night it started beeping non-stop, still working on that one!
Thanks again everyone for the replys.
Sandy (Dave’s wife!)

There’s another key sign that you’re getting near then end:

Instead of appearing as a sharp line, the 3-hour and 6-hour graphs begin to get drawn with a bit of “fuzziness”. This is caused by having lots of adjacent readings which jump up, jump down, jump up again…

And Glucose levels don’t do this. Glucose density is a “continuous function”, it changes smoothly from level to level over time. It can change quickly, and it can switch between “upwards” and downwards pretty fast – but it should never be shown with a lot of jumps in both directions.

I keep mine going for as long as it’s accurate. I’m on sensor my 20th and have never had a rash or infection and used each sensor up to and past 14 days. When i start to get serious disagreement between Dex and my meter, i do the replacement. We’re not supposed to dose ourselves based on Dexcom’s reading soley, so we’re all checking anyway. Dex just helps me head off those unexpected highs and low.

Wow, 15 days per sensor, that’s amazing and really good news for me. I’m trying to decide between DexCom and MM CGM (although I’m pretty convinced about DexCom). That’s not an easy choice for me, since I live in Portugal where the Dexcom is not yet available, we only have the MM option right now, but it’s way too expensive (295€ - USD 405 - a box of 4 sensors) and our insurance companies do not pay any of it, so I’ll have to pay for it 100% from my own. So if the DexCom sensors lasts for 15 days, I’ll only need 2 sensors per month rather then the 6 MM sensors, that usually lasts for 6 days top.