In short: How to extend sensorlife with current Replace Sensor warning?
Hi all, with interest I am following this thread.
Looking for a bit of advice.
My sensor (6+ days) is giving me a Replace Sensor message. I noticed that the values were getting off, the last 2 hours.
I’d like to extend the sensor life if possible. How?
What I did:
I did a restart sensor as existing sensor (same error message as result) and then I did a restart as new sensor (same error as result). I did not physically disconnect the transmitter before starting as new sensor, since battery level of transmitter is still >70% (and I am at work without charger).
ISIG history still producing values, but not giving Glucose values.
What options do I have left to try?
Thanks for replies.
You didn’t mention it, but I am wondering if you are outside the U.S. and are using a Medtronic MiniMed 640G & Guardian Link 2 transmitter. If this is true then your options may be limited.
There have been anecdotal observations that the Guardian transmitter includes more sensor diagnostics than the older MiniLink transmitter (still) used in the U.S. Your error message might be a consequence of that new hardware and so it might not be possible to work around it. (It also may not be a good idea to do that even if you could.)
Out of curiousity, what ISIG does the sensor report for a given meter BG reading? I am wondering just how viable it may still be.
I mention this because the Replace Sensor message is not one I think I have seen. I am more familiar with the error message below in the context of a MiniMed 530G (551/751) or Revel (523/723) pump.
REASON: You may receive this alert after you receive two Cal Errors in a row, without the Cal Errors, or when initializing your glucose sensor.
ACTION: If the alert resulted from two Cal Errors in a row, replace the glucose sensor.
If the alert happened without two Cal Errors, use the transmitter’s tester to make sure your transmitter is working properly.
If you received this alert during initialization, you may be able to resolve this alert without replacing your glucose sensor. Call the 24-Hour HelpLine at 1.800.646.4633, option 1 for further assistance.
Yes, I am outside US on minimed 640g and guardian 2.
ISIG values after the error are between 25-35. Quite steady, even higher than the first set of 6 days. Linked BG value in screenshot is 16,6 mmol/l (288 mg/dl). Maybe one last try after a recharge of the transmitter.
You need to physically disconnect the transmitter from the sensor, otherwise the transmitter will pick up the fact that you haven’t atually changed the sensor.
I always extend mine past 6 days (I usually get aroung 10-12 days) however if I receive a “change sensor” error past the 6 day mark I will always swap it out.
You can’t learn anything (much) from an isolated Enlite ISIG value. An ISIG has no meaning unless you pair it with the BG the ISIG corresponds to.
Suppose you see that your ISIG is 25. Well, if your ISIG is 25 when your BG is 5.0 mmol/l (90 mg/dl) that is outstanding. But if your ISIG is 25 for a BG of 18.0 mmol/l (324 mg/dl) I would question the health of that sensor and keep an eye on it for possible future failure.
Of course, if your ISIG value is unexpectedly low, say less than 5, then I’d also think the sensor was bad … or that perhaps you were about to pass out from a hypo.
If that is true then I think the 640G is working differently than the previous Medtronic CGM’s.
I can always start a sensor as NEW with my Paradigm pump and I believe this can also be done with the MiniMed 530G. The main reason for recharging after 6 days for the pumps before the 640G is because the transmitter battery won’t last longer than 6 or 7 days. So you have to pull the transmitter and recharge to use the sensor longer.
But, regardless of why you pull a CGM transmitter, doing so always resets it. The reset clears any internal sensor status the transmitter may have been keeping. This is why you need to do another 2 hour WARM-UP sensor initialization after recharging the transmitter battery.
On the chance someone reads this. If you are holding your phone and pump in the same hand or the pump is withing 30cm of the pump, your pump will not be able to, or may not be able to, speak to the transmitter due to RF cycling and, as such will show the error SG value not found. Just move your phone (or other offending RF signaling device ) away.
