A couple months ago when I first started using the CGMS the first two that I used worked great. Than the next few I used I started to not like it at all. I did not give up. Now after using it for a few months I seem to have had nothing but good luck with it. Honestly the days that I dont have one on I just dont few right without the CGMS. It has helped out a lot adjusting my settings and lowering my A1C by a lot.
Karen, You won’t get an infection from leaving the foreign object in too long? I do the same thing with my pump, I refill it and get an extra day or so from the same site, but sometimes it gets sore.
I hope I don’t Linda. Today I know it is there and my readings have not been as accurate, so perhaps it is time to change it, but I have not gotten a bad calibration error or sensor end.
I had a crazy day trying to work out my morning highs and I think that is when the sensor gets confused and I kept calibrating as it was not matching up to my meter, but my bgs were so out of control this a.m. with trying somthing new for my morning rises in bgs, which did not work.
Not sure yet if I am going to take sensor out. I really want to try my arm but I am scared.
Karen, I want to try it again, and I heard you get good readings with the arm, but I am scared of that too! Let me know about the site when you do take it out.
Linda and Karen,
I wear a Dexcom 7, which is supposed to be for 7 days, but everytime I wear it I have been able to get 14 days out of it with no soreness at the site.
Toni, Thanks so much, I had thought of extending the days of the sensor, but was afraid of infection. Thanks, I will try it but I’ll watch it closely.
My trainer told me it isn’t as likely to get infected as the pump site because it isn’t infusing anything. I hadn’t thought about it that way, but it makes a good point. I am on day 5 of my first sensor. I am thinking I am going to change it, but only because I am getting ready to change my pump site too. I figured I might as well do them both at once. 
I used a Minimed sensor once for 3 weeks once after I head Dr. Aaron Kowalski of the JDF talk about his experience & self-experiments with CGMS’s. The problem I have with doing that is the build-up of scar tissue about the sensor. I think eventually there is so much scar tissue that the sensor can no longer detect interstitial fluid. Later I’ve been swapping them about once a week.
I am not using a sensor now. I have taken the weekend off from using the sensor.
Cara, When you put a sensor in do you wait until after calibration before you eat anything?
There are variable temporal associations between plasma glucose and insterstitial glucose levels measured by current generation CGM’s. They are especially bad in measuring rapid glycemic shifts and often continue flowing in a direction opposed to rapidly-changing glucose values coming off a shift. In one such circumstances, you may be observing glucose levels of 40 mg. per dl. even after you’ve rebounded to 250. CGM’s offer values most consistent with glucose values when the values are changing least and are in steady state. Never intervene,e.g., wiith insulin, carbohtdrate or whatever without first taking a conventional blood glucose reading (even those devices at times fair poorly in regard to accuracy and consistency.
I generally get 10 to 14 days out of one sensor. I’m glad you kept trying. I think the benefits outweight the cons. My Dexcom really helps me keep better control and wakes me when I go low in the middle of the night.
A couple of thoughts cross my mind. I haveused the MM sensor for over a year now and it is frustrating. But here are a couple of ideas that might help.
First when I insert my sensor i never ask the pump to find it right away. I always wait at least tow hours and usually 4 or 5 hours before I ask the pump to find the sensor. I was haivng difficulty with it losing it during the start up and I hated that. Second I use the sensor on my upper leg. The abdominal area seemed way to schizophrenic for my taste.
Finally, I suggest lowering the alarm ranges until you get used to it. When I started I changed mine to 40 and 240 and have worked up and down form there. I hate false alarms, but setting it low will give you a chance to work on stuff before it goes live. I am testing now more than ever and the calibration is a hassle. But remember to only calibrate, if you can when you are relative stable. I mean sometimes, it cannot be helped, you have to claibrate when you do, but if you anticipate a little do when stable. One other thing, if the calibration gives you an error. Keep it in, turn it off and restart it in an hour or so. Remember when you tell the pump you have a new sensor, the pump does not know it has been in for some time.
Also help is ont he way, MM is testing the generation 2 CGM system. Lets hope for a quick release.
Rick Phillips
Along the lines you mentioned…I do a couple things that could be categorized by sane people (ha ha) as fluky to insure the sensor has reached a reasonable level of stability - before giving the sensor a blood sugar callibration. 1st thing I do is insert a new sensor the day before while the “old” sensor is still in, working, and connected to the transmitter (Minilink). Then in the morning I pull the old sensor, recharge the transmitter (doesn’t take long), connect the recharged transmitter to the new sensor, and start the 2 hr callibration period. At the end of the callibration period, when the pump lcd displays METER BG NOW I ignore it (e.g., don’t give it a blood sugar value), but monitor Sensor ISIG values (hit ESC 4 times) for awhile and enter a callibration blood sugar only when I feel the sensor is stable. From that point on I usually find things work pretty well.
Having said all the above…it’s insane we need to resort to doing all of these kinda gyrations to get a sensor stablized. So I for one can’t wait until the generation 2 CGM system arrives (whenever that is)!!!
You still have to prick your finger at least twice a day to calibrate it. They say to still check as you would before using the CGMS. The start up cost is $999 for reader and the sensors are about $35 a piece. My insurance covered most of it. I absolutely love mine. I used to have lows that would just knowck me out within a few minutes. I set my alert for 80 and I have always been able to catch them before they become a problem. I was lucky enough to get to try both the mnimed and the dexcom and found that they were both equally as accurate. I went with minimed becaue that’s what my insurance would pay for and I wear a minimed pump.
I’m glad it is working out for you despite the initial hurdles. Having used mine for a few months now, I can say there are times it is frustratingly inaccurate with regards to my specific blood glucose number, but it is always accurate in showing me trends. Even if it is off by 50 points, I still find it helpful to know in which direction my number is moving and how quickly.
Only once have I seen extremely distant values on the CGM- I think it said 160 and I was at 330 when I tested and realized I had been jacked up for the last few hours. Most of the time it is very accurate or at least “accurate enough”, and I feel nervous when I don’t have it working even for a few hours.
I love being woken up to fix hyperglycemia, although my wife probably doesn’t appreciate the fact that she usually hears my pump alarm at 3 AM before I do.
The only thing about the Medtronic CGM that absolutely crushes my soul is that hollow spear you insert it with, the thing Medtronic calls a “needle”. A needle is what is on the end of my Symlin pen or perhaps my infusion set. They should describe it accurately, like this:
“A large, hollow, very sharp nail that enters with the grace of an angry bee’s stinger and provides an additional 5 to 10 seconds of throbbing, intense pain.”
That said, I’m not sure what hurts worse- the CGM or a 120mcg Symlin injection.
I love diabetes.
Dear Oneless.
How are you enjoying the symlin ?
I can’t live without it. It is as important to me as insulin now.
Version 2 is due out in 2010 or so. It is supposed to be more potent and require less frequent dosing, along with being geared more towards reversing obesity. It already has remarkable weight-loss properties, so 2.0 should be epic.
In the minimed store online there is a product called “Unisolve.” It gets anything sticky off of anything. Much better than alcohol or GooGone.
Yea, I know what you mean. I have the Dexcom and it’s generally pretty good. I’ve had it for about a month and it seems to be more accurate the longer I keep it in. I’ve been letting it go 2 weeks. Just checked it and it was 80 pts. off but I just inserted a new one last night, other times it will only be 2 pts. off. I just use it for trends. Try it for a bit longer and see if it gets better.
If you are getting sensor errors or very out of line readings you have a ‘bad’ sensor. Call MM and they will send you a replacement at no cost. I actually had an entire lot of bad sensors; 20 in all that had to be replaced. If you happen to have lot C110 start calling for replacements
However, once you get on a good sensor you need to make sure that you calibrate when your BG is in the normal range and stable. For many people this is early in the morning before eating and in the late afternoon/evening before dinner. If you are in good control in general anytime 2-3 hours after a meal should be just fine though.
Never calibrate with high (160+) or low (75-) readings or when the reading on your CGM has changed by more than 5mg/dl in the past 15 min.
Also, understand that to catch highs and lows before they become nasty you need to set your alarms tight. I use 150 for the high alarm and 75 for the low. That means, with the ~15 delay between the CGM and real BG levels you can catch highs before they get above ~~170 and lows before they reach ~~65. The more stable you are the tighter you can set the alarms and the tighter you set the alarms the more in control you can be
Finally, when you insert the sensor you may want to do it at a MUCH steeper angle than the 45dec that MM officially recommends. I insert them at ~75/80dec and they work MUCH better and don’t hurt as much.