I'm probably jinxing myself by posting this, but my current sensor is probably the best-performing sensor I've ever had in the 3 years I've been using Dexcom. But this sensor started out as a candidate for the "Call Dexcom and get a replacement" category.
I started this sensor almost two weeks ago. For the first 20 minutes or so after initial calibration it worked OK, but then it went into 4+ hours of ??? with no sign of recovery. Instead of killing it and calling Dexcom, I decided to "Stop Sensor" and go through another two-hour calibration just to see if that would work.
Sure enough, that re-start was the start of a perfect 7 days of performance. I am now into 5 days of a second week with the same sensor, and it continues to perform perfectly...no "misses" or weird nighttime fake lows (you know those...your sensor wakes you up with some reading in the 40's but you feel fine and sure enough fingersticks are normal). Everything has been amazingly accurate.
This was a sensor that I was ready to peel off and throw away, and now I am hopeful to get a full two weeks or so from it.
Just thought I'd post this. In my 3+ years on Dexcom, I've had good results and bad (more good than bad, for sure) but I've never had such unexpected strong performance from such an early poor performer.
I have had to eliminate the ??? in the same way a couple of times. My sensors are good for an average of two weeks. The accuracy is usually very poor on the 14'th or 15'th day.
I'm fairly new to the Dexcom, so please forgive my naivete', if that's what this is. But I thought the sensors were only intended to be used for 1 week? When it tells you to change the sensor soon, do you just restart it then? If so, is that really safe and ok? What about potential infection at the site (like an insulin pump site will show)? The little wire is still viewed by the body as a "foreign" object. Has anyone really received an official ok from a Dexcom rep, techie, or dr to do this 2nd week restart? Or are your sensors really lasting that long without a change sensor alarm? How do you manage with the 3 months' supply they send you with pretty tight expiration dates? At 2 weeks apiece, that really doubles the time they would last, doesn't it? And then they could be expired.
I'm so frustrated with my Dexcom I could throw it out. (smile) It keeps giving me values that are false - huge variations both higher and lower by 100 points or more, and it makes a huge difference as to what I do if it's 152 or 252. I have talked to Dexcom numerous times and followed every protocol and tip I have learned from them and here. Is re-initating a sensor a second time immediately after the first time usually worth it for accuracy reasons, then, in your experience? So much wasted time and effort in this since I started in March. It makes me feel like a medical robot (juggling from pump, cgm, medications for immune suppression, dr visits, etc.) - and struggling to keep a tiny bit of my humanity inbetween, rather than how I have always viewed my 44 years of diabetes - a human being first who happens to have diabetes. Well, thanks for listening.
Interesting, Richard, I find that the longer mine are in the more accurate they become. I average 2 weeks or so as well, and have occasionally gotten a couple of days short of 3 weeks.
Yes, the sensors were only approved by the FDA for seven days. But many have had success keeping the sensor inserted at the end of the seven day period and restarting it (like it is a new sensor) and trying to get more days use out of it. Alternatively, you can "stop" a sensor at any time and "start sensor" with that sensor which starts a two hour calibration period. That is what I did with my sensor after 4+ hours of ??? readings.
I have never heard any complaints about infection. After a week, though, the original tape will lose tackiness, so what I always do is add some Opsite Flexifix tape to the sensor site after a few days. That way at the end of the original seven day period there is no problem with the Dexcom tape failing.
My experience with "extra" time beyond the seven days is hit or miss. Sometimes I can get a full extra week. Sometimes just a few days...then accuracy goes downhill. You'll know when it is time to replace it....accuracy and performance will get pretty bad. Also, sometimes I like to remove the tape/sensor just to have the relief of nothing attached to my skin...in those cases I've removed a good sensor even when it was performing.
Good luck with the Dexcom. It is far from perfect, but it is better than nothing, at least to me. I am 30 years T1 and have been using the Dex for 3+ years, and have had many "bad" sensors over that period, which Dexcom has always replaced with a call.
Susan, scar tissue can occur with a pump because something is entering your body at the site location. The infusion can cause scar tissue there if the site is not changed every 3 days. With a Dexcom sensor there is not anything entering the body, so scar tissue will not occur. I use my sensors an average of two weeks and there has never been a problem. I also had very poor accuracy when I started using my Dexcom, but I learned so many helpful things in the Dexcom User's Group here. You can go to back pages and look at older discussions. There you can pick up valuable info. Some people disregard the times that are not accurate and just look at the trends. That can be very useful.
I have used sensors that expired more than a year earlier, and they worked well, with no problems. Friends have told me the same thing. Of course Dexcom will not tell you that you can use expired sensors, and they will not tell you to use a sensor more than 7 days. Selling sensors is how they make their money!
Interestingly I was just thinking yesterday that my current sensor is the most accurate one I've ever had. It's almost spooky how accurate the sensor is - within 2-5 of finger sticks. To me there is an element on "luck of the draw" and I don't believe it has to do with variability with the sensor. The latter is made in a controlled environment under exacting standards. I truly believe the accuracy has more to do with the particular tissue and intersitial fluid dynamics at the insertion site. Our bodies are far more variable than the sensor wire and it's chemical coating so I blame our bodies for reading variability. I'm feeling great about Dexcom with my current sensor and hope my next insertion hits pay dirt in terms of good tissue and gives me the same super accurate readings.
Yeah, two sensors ago I had one that was "spook accurate" as well (I remember the first time that my fingerstick matched my Dex). However, my last one conked out on day 9 when I have pretty consistently been getting good accuracy through day 13-14. It really is the luck of the draw that I would attribute more to variation in insertion/site/etc. rather than the sensor itself.
It seems as if my sensors have different personalities. Sometimes you get the studious and serious sensor, which is very reliable and keeps you aware of what's really going on. Other times you get the wild and crazy sensor that overreacts to highs and lows. Or the one I fear the most: the Joker. This sensor likes to wake you up with false readings. Or it likes to report highs when you are low and lows when you are high. The Joker just laughs at you as you scramble to double-check with a finger stick. What other personalities do you see in your sensor?
