Just got CGMS and Paradigm 722

[MacDogg]

I guess I made some wrong assumptions as to how this whole thing works.
At 9:30 this morning I had the sensor inserted and I was educated on how it works and all these alarms. At 11:45 it beeped at me and needed the BG test to calibrate. I tested with the new meter, it appeared on the pump so I hit ACT and I received an invalid BG error. Nice. Called support and they had me put it in manually.
Now, two hours after I at lunch I feel like trash. The meter tells me the BG is 131 which would be great. I check with my meter, twice, and it tells me 274 and 272. I use the bolus wizard and get three units to fix that and I call support asking why the numbers are so far off.

What he tells me makes no sense and makes me wonder why I even changed from the Spirit to Paradigm. He told me the sensor should not be used in place of finger pricks because they will not be the same. The sensor should only be used for watching trends over periods of time.
I thought this whole CGMS setup was supposed to make finger pricks a thing of the past (except when calibrating twice a day). Luckily I didn't trust this thing from the start and brought my meter to work with me instead of leaving it at home since I would not be needing it until the next calibration in four hours.
So now I don't think I am going to use the sensors at all if it is going to be over 100 units off. How can you follow trends when the glucose levels are so different?? So far the meter says everything is perfect. My BG has gone from 83-144 in 5 hours. 144 isn't bad, I would take a small fix for that. But when my real level is over 100 points higher I can't trust it.

[Gordonm]

They are not perfect but with careful calibrations at the right time mine has been pretty accurate. The last couple of days it has been within 5% every time I check. You must calibrate when your BS is not rising or falling to quickly. The calibration number you put in calibrates for 20 minutes. So if your BS is rising or falling in the 20 minutes the calibration will be off. I try to calibrate first thing in the morning before any insulin or food and let it go for 20 minutes then eat and bolus. I next will usually calibrate in the afternoon and then around 9PM. I know this is not always going to work but I went through the exact same thing as you and was ready to throw the whole system out. I talked with the techs at MM many times and finally got a good one and he worked with me a few times until we got it correct. The key is to calibrate not to often and calibrate when BG is neither rising or falling to much. I used to test 10 to 12 times a day I now do it maybe 4 to 6 times with the CGMS. It is not designed to replace finger sticks, none of them are. It is for trends but I have gotten to trust it most of the time for some readings. If I have one that I feel is not right a quick finger stick confirms where I am.

[MacDogg]

Thanks for the info. I ate at 8am, plugged in the sensor at 9:30am and calibrated at 11:45, manually calibrated at 12:00 and then ate at 12:15. I was told there is a 'wetting' period of 15-20 minutes after the sensor is inserted and I waited to eat.

Maybe I will wait 30 minutes over the weekend and try to see if this thing will work a little better.

[It Ain't Over]

I went on the CGMS a month ago. Have found it to very good. What GordonM said is same for me. Still have to do finger sticks, but only 3-4 times per day instead of 10-12.
There is a lot to learn in order to get it to work for you instead of working against you. On of the most usefull sources I found was thread here in the monitering site called Pardigm CGMS. Liz wrote an excellent bit on how to set it up and calibrate it. Have found all of her advice to work out very nicely. You might want to read that and keep a copy with your instructions for the CGMS. I did and refer to them when I have a question.

[poodlebone]

The sensors can take some getting used to, so don't give up on them too easily. My very first sensor ended up not working at all, which was very frustrating.

1. You want to inset the sensor at an angle deeper than what Minimed recommends. I believe they say 45 degrees, but if you can go in deeper it's usually better.

2. The 10-15 minute wetting period is sometimes enough but I have had many sensors that just didn't work properly right away. The longer it gets wet before the first calibration, the better. Many people will insert the sensor at night, go without readings for that night, and start it in the morning. So, even if your readings are off at first they will often track better later.

3. Taping everything securely is crucial. I use a strip of tape (Hypafix) that I place over the plastic sensor hub right after insertion. It keeps is stable as I wait to attach the transmitter. Once the transmitter is attached I tape it all down well. I think Minimed provides IV3000 with the initial CGMS kit (but nothing after that) and I find those to be the worst. Tegaderm is somewhat better. Opsite Flexifix is a dressing that comes in a roll, in various widths, and is much better. The 4" wide is ideal for the sensors. I cut a 4" strip and that one piece holds very well. Hypafix is a cloth-like tape, similar to what's used in infusion sets, and I also use that a lot. It's not waterproof but once the transmitter is attached to the sensor it doesn't matter, as the seal between the two is watertight. I found I can only use Hypafix in the summer because moisture gets trapped under everything else, causing the tapes to peel and also causing irritation.

4. Calibrate when your BG is stable. You also do not have to wait until the pump asks for a meter BG. You can calibrate when it's convenient for you. MM says to calibrate 2-4 times a day so you can spread those out to make sure you won't be asked to calibrate in the middle of the night, or 1 hour after a meal or when you're driving home from work.

5. Don't change the sensor every 3 days. After 72 hours you will get a Sesnor End message. Just go into the sensor menu and choose Start New Sensor. Within 5 minutes it will ask for a calibration and you can start all over again and go for another 3 days. You can do it again after day 6, but the transmitter times out after 7 days so you'd only get another day, at most, from that last restart. You can carefully peel up the dressing, remove the transmitter and recharge it. You must make sure that you do not pull or move the sensor at all. If you do, it's not worth trying to restart it. Just pull it out and insert a new one. Taping the sensor hub when you first insert it helps to keep it in place when removing the dressing.

6. Before calibrating, check your isig (on the Sensor Status screen). Divide your meter BG by the isig and that's your calibration factor. The calibration factor must fall between 1.5 & 20 or else you will get a CAL ERROR. If it's too close to either end you may still get an error. If you get an error with a brand new sensor, just leave it alone and wait a few hours and try again. It may not be wet enough. Letting it sit usually brings the isig up.

I just had a sensor that lasted 34 days and would have kept going but I managed to pull it out the last time I went to recharge the transmitter. It tracked wonderfully the entire time. The one I put in after that only lasted 5 1/2 days. Not sure what went wrong with that one. Sometimes they just die.

[GretchO]

WOW...34 days, that's amazing! I lose track of how long I have them in now, but I know for sure I've never had one in that long. (I love Flexifix, waaaaay better than IV3000).

[MacDogg]

Thank you all for the useful information. I have come to find out that this is in fact pretty good and I jumped the gun at being mad. I am a tech wizard and when things don't work the way I want them or the way they are supposed to I get bent too fast!! :)

After the first night, which was full of alarms, I turned the low BG level off. I had it set to 70 and it was going off every 30 minutes it seemed. I need to recalculate how low is too low and turn that setting back on. After that first 24 hours most of the BG meter results have been within 10% of the sensor except a few times so that makes me feel good about it.

My sensor ended today while at lunch and I was just going to wait until I got home to change it. Is leaving the sensor in for more than three days ok? I have no data to say yes but I will soon find out. I just restarted it so I'll see how it goes.

I'll look for that info from Liz and see how it can help me. All the real world information I can get will be great.
Thanks for those 6 tips, poodlebone. I did tape the sensor to me, on both sides, since I run. I didn't want that thing falling off and being lost. No idea how much that would cost me to replace!

[poodlebone]

My sensor ended today while at lunch and I was just going to wait until I got home to change it. Is leaving the sensor in for more than three days ok? I have no data to say yes but I will soon find out. I just restarted it so I'll see how it goes.

Almost everyone uses the sensors for more than 3 days. When the sensor ends, you can just go into the Sensor menu and choose Start New Sensor. Within 5 minutes it will ask for a BG calibration. You will then have to do a second one within 6 hours, then every 12 hours. Just like when you first started the sensor, but without that 2 hour warmup time since the sensor is already fully wet and the transmitter has not been removed.

Some people will let the sensor run through 2 cycles and change it, so every 6 days. Some people will start it for a third cycle but it will only work for one more day, since the transmitter times out after 7 days (7 days from when you first attached it to the sensor). Many people will then remove the dressing, remove the transmitter, recharge it, attach it to the same sensor, tape it down and start all over. Since the transmitter has been removed you will have that two hour waiting period before you can calibrate.

Personally, I use a sensor for as long as possible. I find that once it's really good & wet it is much more accurate. As long as the sensor is tracking well and doesn't hurt or itch, I will keep removing & recharging the transmitter every 6-7 days. My record was 34 days on one sensor and the site was very clean when I removed it. Just a tiny red pinprick, the same as if the sensor had only been in for a few days. My infusion set sites are generally worse looking after only 3 days.

I did tape the sensor to me, on both sides, since I run. I didn't want that thing falling off and being lost. No idea how much that would cost me to replace!

I think it's $650 to replace that little transmitter!!