Evening Sensor Changes w/ Medtronic 670G

Hi, everyone! I have been a Type 1 for 51 years, and got my first pump in 1992, but I have a question for the Medtronic 670G users. If your sensor gives up the e ghost early, or you manage to knock it out, do you go on and insert a new one in the evening? I’ve been trying to avoid that, since I don’t want to be awakened all night to do the initial calibration, the 3-hr one, and then the next 6-hr one. However, when I look at my infusion over night, I sometimes go a couple of hours with no insulin delivered at all. When I let it run in Manual Mode and wait to start a new sensor the next am, even though I’ve set my rate at 0.2u/hr, I still have a crash in the middle of the night, without fail. I have to stop those, but when I’m awakened all night for calibrations, it’s pretty tough to get up and get to work the next morning. What do you do??

Hi! I am using a 530G with Enlite sensors and am about to convert to the 670. I believe the Enlite and Guardian sensors work the same way. You don’t have to wait for the 6 hour alert to satisfy that calibration! After the initial calibration, you can calibrate any time within that 6 hour window! My healthcare provider taught me that trick when I first started using a CGM. It’s also listed on Medtronic’s website under “Calibrating Your Enlite Sensor”. The Guardian version says “within the first 6 hours” so I think it’s the same. Good luck!

With the 670g, my experience is that I have to calibrate at least 3 or 4 times to get to the 12 hour calibration interval. I always start my sensors first thing in the morning, and get to the 12 hour calibration interval on my final calibration of the day (usually between 8 and 10 pm). Starting a sensor in the evening would mean calibrating 2 or 3 times while I am sleeping, no matter how I plan the timing. So I don’t even think about putting myself through that nonsense.

Treva, I have two ideas that may help. Your basal rates may not be dialed in properly. I suggest talking to your doctor about when and how much to decrease your overnight basal. If you have decreased your active insulin time for auto mode, you may also be going low due to an evening meal bolus or correction bolus that is still dropping you even if your active insulin shows zero.

Thank you! I’ll check again w/ my MD. I appreciate your suggestions.

Unfortunately, the Guardian wants to target in more specifically than my Enlite did. It takes one at about 3 hours after the initial, and then one at 6. I have learned that I can do them early after I get them to the 12 hour mark, though, so that will still work. Thank you so much for your reply.