beating my old sensor record, 35 days and counting... Options

[JohnG]

Sorry, but since this made me LOL, so I just had to post. I remember this very same string from a few years ago and hear I thought I invented that term. Perhaps I did. But the meaning for when I refer to it around people that are around me in real life and a few veterans here is something different.

I've always been easy to control. And that's probably due to a variety of different reasons. I very rarely am out of the target range and if I am, I don't stay there long. So when I speak of "flat-lining" I actually DO mean staying between 90 and 110 for hours, if not days in a row. To me, that just proves my bolus rates are nailed.

However, take away the insulin and I'll be above 300 in no time.

I specifically chose Minimed because the current CGMS system was under FDA approval when I decided to switch to pump therapy. I just was fortunate enough that it was approved during that initial "training" process. I made my own decision to make the time to take the time to learn the ins and out of pumping before I started CGMS. This was one of my sources during that time and after my transition into CGMS.

I use one sensor a week and have used expired sensors successfully. That's to cut down on my out of pocket costs and now that I'm taking Plavix, it cuts down on the brusing associated with sensor insertion. I save my belly exclusively for my infusion sets and my thighs for my sensors. I'm not very tall and because of the length of time of my Type I condition, my confidence in site patency is limited.

There is actually a group on TuDiabetes called flat-liners...

[Suemalonas]

I completely agree - thighs for sensors - stomach for infusion - switch legs every other week. Always replace CGMS after 6 days - the 7th is my day of rest - good sleep - etc. Nice cadence this way. Could I go longer with sensors? Yes - but frankly - they get a little skanky.

Your philosophy sounds like mine. We all have our different motivations and needs for doing what it is we do. We need to keep that in mind when participating in forums such as this one, which is one of the best I've come across (in my never humble opinion).

I'll check out the group that you mentioned subsequently to this response when I get a chance.

[aggie168]

I agree with routine, after my XX days run on one sensor. The last 3 are back to about one week of prime usage and then it goes south. Same box. So I am back to changing every weekend. Most of the time on Sunday. (IMG:style_emoticons/default/smile.gif)

[Maureen H.]

I always try to go 10-14 days with a sensor even if all the readings are not accurate. If the ISIG stays high, above 10, it usually corrects itself. I am now on about day 17 with this one and it is accurate again. I do shut off all the alerts at night. I decided my sleep is more important. I wake from time to time and look at the BG. If I sleep on the sensor I do get the false lows.

[gigem99]

I am currently on day 14, so later on today, I'm gonna have to try to peel the tape up and disconnect the xmitter to charge it.

It's interesting. In the latest issue of the ADA magazine - I think it's called Diabetes Forecast - they list various technologies, and the CGM is one they discuss. I was surprised: At the first of the article, they said there were 3. The three they listed were the Paradigm RT, Dexcom and Guardian. The Guardian, of course, is the standalone RT.

Anyway, they list various features and they said the RT xmitter can hold a charge for 14 days. They are clearly mistaken, so I may have to write a sternly worded letter to the editor (even though I'm almost positive I had one last longer than 7 days).

Tom

[Maureen H.]

I think the sensor can go 14 days but the pump makes you disconnect it after 7 fdays. I think you can disconnect the transmitter and then quickly reconnect it and it will run for another 7 days. i don't actually do this because I have two transmitters, like Liz, and I alternate them. The good part is I never have to wait for them to recharge. I put the new transmitter on after 7 days and of course wait the two hours to calibrate. My last one went 21 days but I pulled it because I saw a little redness.

[Linda B]

Anyway, they list various features and they said the RT xmitter can hold a charge for 14 days. They are clearly mistaken, so I may have to write a sternly worded letter to the editor (even though I'm almost positive I had one last longer than 7 days).

I think the sensor can go 14 days but the pump makes you disconnect it after 7 fdays. I think you can disconnect the transmitter and then quickly reconnect it and it will run for another 7 days.

The article is technically correct. The xmitter will hold a charge for 14 days, but the pump software sends a bogus 'weak signal' message after 7 days forcing us to disconnect and reconnect the transmitter. Most of us elect to recharge it at that point since it is disconnected, but technically that is not necessary. In fact, I recently was caught off guard when I got the dreaded weak signal away from home. I managed to disconnect and reconnect the transmitter without removing the tape, just moving it apart from the sensor under the tape. It started back up as expected with a 2 hour warm up. The only reason I tried this is I remembered John G writing about doing the same thing.

Linda B.

[JohnG]

I managed to disconnect and reconnect the transmitter without removing the tape, just moving it apart from the sensor under the tape. It started back up as expected with a 2 hour warm up.

I did this for awhile but it was unreliable and sometimes I would disturb the sensor and it would not give me the 6 blinks , I have two good transmitters now and
just carry my spare on the charger along with some pre-cut HypaFix. I hate it when I lose track of time and get handcuffed by a week signal alarm. It never
happens unless I'm right in the middle of doing something I need to get done or my BG is throwing and big tantrum.

[gigem99]

THIRTY DAYS IN THE HOLE!!!

OK, apologies to Humble Pie (IMG:style_emoticons/default/tongue.gif) .

Technically, I changed sensors after 31 days this morning, but the last 12 hours or so, the thing wasn't reading right at all. Early this a.m., I was due for a calibration. My sensor read about 125, but my fingerstick was over 400!! That's a separate issue - I had another kinked cannula on a Sil. I got a pretty nice picture of it and will upload it in the topic I started about that matter.

By the time I got up, the sensor was reading 215, and my fingerstick showed 245, so I probably could have gone a little longer with it, but I'm off today, and I like to change out during off-days so I don't have to mess with it at work.

Anyway, I put the sensor in on Jan 27, so I got almost all the way through Feb on it - which is what I was hoping for. I think I've finally used up about all the glucose oxidase, though, so it was time to take it out.

One of the interesting things is that the sensor electrode is bent opposite of how it usually is. You know how upon removal, the sensor usually has a slight bend inward? Well, this one had the same kind of bend, only outward.

Tom

[mommyphbr80]

Yes. It's on day 44, I think. If it still works on Monday, when I'll have to change the transmitter, I do think I'll pull it. It's on my left leg and since I have to keep the pump close to it, I've also been using my left side for infusion sets and I want to give it a break.

I am a new user of CGMS (about a month) and was skeptical about using a sensor for more than 7 days, but currently I am almost on day 14. My only concern is that my ISIG numbers are generally between 20 and 40. Is this an issue that I need to be worried about? My last bs was 80 and my ISIG was 25.38. I want to make sure that this thing is still working correctly. I too am finding that keeping my pump on the one side is slightly annoying though (the sensor is on my left thigh) as I used to move my pump back and forth on my sides every three days.

Any advice to my above question o the sensor ISIG would be great.

Way to go on your sensor record!

Jessica

[Liz]

I am a new user of CGMS (about a month) and was skeptical about using a sensor for more than 7 days, but currently I am almost on day 14. My only concern is that my ISIG numbers are generally between 20 and 40. Is this an issue that I need to be worried about? My last bs was 80 and my ISIG was 25.38. I want to make sure that this thing is still working correctly. I too am finding that keeping my pump on the one side is slightly annoying though (the sensor is on my left thigh) as I used to move my pump back and forth on my sides every three days.

Any advice to my above question o the sensor ISIG would be great.

Way to go on your sensor record!

Jessica

Jessica, I wouldn't worry about the isig. You calibration factor is excellent with that BG & isig! Calibration factor is your meter BG divided by isig - 3.15!! When I start a new sensor my calibration factor is usually between 4 - 6. The lower it is, the better the sensor seems to be. As time passes the isig will usually start climbing and the CF will start rising as well. Once the CF hits 10, I know I don't have much life left in the sensor. I have had some sensors that had a CF around 5 for several weeks and those were always my most reliable.

The calibration factor has to be between 2 & 18 (I think) in order to successfully calibrate the sensor. If it's out of range you'll get a calibration error.

[bkh]

Hi, Liz. My sensor isig is dropping (not climbing) as the sensor gets old. (These are the old-style Sof-Sensors). When my blood sugar is close to 100 mg/dL a great sensor will give an isig around 20. A pretty good sensor gives around 14. A weak sensor around 8. When the sensor is nearing the end of its life (typically around day 8 or 9 for me) the isig drops rapidly: maybe 9 in the morning, 7 mid-day, and 4.5 in the evening. That rapid drop (given blood glucose near 100) is what tells me it's time to plan a sensor change.

I prefer to watch the isig rather than calibration factor so that I can still use the CGM even if more than 12 hours pass since the last calibration. Sometimes it happens that it's just not convenient to calibrate as the 12-hour deadline is approaching, but if I know what isig indicates a good blood glucose for this sensor, today, I can continue to use the isig even if the pump shuts off the BG display when the 12-hour deadline passes. (For accuracy in sensor glucose readings I only calibrate when BG is between 80 and 120, but accuracy is a different topic that others have discussed at length on these boards.)

[Liz]

Hi, Liz. My sensor isig is dropping (not climbing) as the sensor gets old. (These are the old-style Sof-Sensors). When my blood sugar is close to 100 mg/dL a great sensor will give an isig around 20. A pretty good sensor gives around 14. A weak sensor around 8. When the sensor is nearing the end of its life (typically around day 8 or 9 for me) the isig drops rapidly: maybe 9 in the morning, 7 mid-day, and 4.5 in the evening. That rapid drop (given blood glucose near 100) is what tells me it's time to plan a sensor change.

I prefer to watch the isig rather than calibration factor so that I can still use the CGM even if more than 12 hours pass since the last calibration. Sometimes it happens that it's just not convenient to calibrate as the 12-hour deadline is approaching, but if I know what isig indicates a good blood glucose for this sensor, today, I can continue to use the isig even if the pump shuts off the BG display when the 12-hour deadline passes. (For accuracy in sensor glucose readings I only calibrate when BG is between 80 and 120, but accuracy is a different topic that others have discussed at length on these boards.)

Yes, as a sensor ages the isig will usually drop and that means the calibration factor will increase. I pay attention to both isig & the calibration factor. They go hand in hand and for me, one isn't better than the other. I can have an isig of 7.23 which may not sound great, but if my BG is 39 it's a very good isig! If my BG is 109, it's not. The only time I pay attention to just the isig is if I've got a new sensor inserted and I want to wait for a good time to calibrate. I've found that I need to let a sensor sit for at least 6 hours before turning it on and doing the initial calibration. If I wait the minimum 2 hours only, I see my isig going up and down and my sensor readings are worthless. A steady isig means it's a good time to calibrate. And yes, it is also good if you miss the calibration. I know the Dexcom will continue to give readings even if a calibration is due and I wish MM did the same, but I understand why they don't. I just wish that there wasn't a 15 minute delay once you do enter a late calibration.