Minimed CGM Settings Advice Sought

Diabetes Technology Glucose Monitoring
#1

I recently received my new Minimed Revel CGM to compliment the 722 pump I've been using for the last 5 months. I've read through the literature that came with it and have an appointment with my outstanding CDE to get it up and running.

In order to ask intelligent questions during our session, I'd like to hear about the experiences of current users. Particularly what are your tips and tricks to make it as useful as possible. More specifically, what settings have been most useful to you, and why? I've read all about irritation with alarms - errant, unnoticed or annoying. After you got used to it, how did you set it up to integrate it into your lifestyle?

FWIW, I used the Dex when it first came out, but insurance considerations have mandated my change to the Medtronic system.

Thanks to all who contribute!

-Tom

#2

First you want to know about where they recomend you place the device(I use inner thigh), what you can cover it with (I use tagaderm), how long can you use it (6 days), how long to “wet” the device (20 mins), when and how often to calibrate (this is key) (I use before exercise, meal or bed when my BG is stable and hopefully in range), etc.

Then I think you need to determine is where you want your upper and lower limits set. IMO you need to have an aggressive upper limit. I started with mine at 200 and have worked it down to 135. An upper limit of 135 lets me know when I am trending up to limit my amount of time that I am too high.

My low limit is set at 81. I reached this number after playing with the settings for a little bit. I had the low limit at 80, but found that I was often alerted to a low when I was 60-66. I raised the CGM low limit to 81 and have found I am othen alerted at 66-72. The problem is I tend to drop quickly when I am low and I have raised the low limit to compensate for the lag in the device.

Lastly I think you need to know the limitations of the CGM (because it is not perfect). The CGM estimates your BG based on the estimate of your fingerstick. If you keep that line of thought, then you will likely test before treating based on the CGM readings.

#3

The CGM is great, but it is not perfect. It does wake me up at night, and sometimes starts buzzing when I am doing sales presentations - but it has helped me reduce my A1C.

I haven't put it anywhere but my lower abdomen yet.

The trainer will tell you that it lasts for 3 days. I have found that I can get another 2 days out of each one. On the third day, I tend to get really irratic results, so I only go 2 extra days. When it says that you need to replace the sensor, you just have to tell it you have put in a new one. It will then ask for your BG within 15 minutes. (not the 2 hours when you put in a fresh sensor) The battery will last for the 5 days without a problem. Don't tell the trainer you are planning to use it longer than they recommend.....

#4
#5

Congrats on the new sensor. I've been using the MM cgm for about 2 yrs. I was very frustrated in the the beginning because of the huge difference in the cgm numbers and the meter numbers. After a little (no really a lot) of tweaking, the cgm and I have learned to live together. Here's my two cents:
1. I put the sensor in at night (before bed) and do not turn it on until first thing the following morning. I find I get more accurate results that way, something about it "wetting" more or maybe the long period of inactivity and no food while I'm sleeping tend to give me more accuarate results.
2. I leave the sensor in for 6 days. My results are accurate for the full 6, but on day 7 they go hay-wire, experiment to see what works best for you. You can definitely get more than 3, and save yourself some pain and money.
3. Tape that sucker down. The adhesive on mm cgm is crap. I've had them fall off after 6 hours. I use the opsite flex-fix. I get the large roll and cut it to size. This stuff is wonderful and stays stuck for 6 days+.
4. I do not use my abdomen or butt for the sensor. I get horrible results there. I find that the back of my arms or my upper thigh works best. Don't be afraid to experiment. Your trainer will tell you stomach only, but what he/she doesn't know won't hurt them.
5. Insert at a sharper angle. The serter device goes in at about a 45 degree angle, but a 60 to 80 degree works better for me.
Having said all that my mm cgm and I have a love/hate relationship. As soon as the Animas/Dex vibe becomes available I plan to switch. My research tells me the Dex is more reliable and more user friendly. Post again to let us know what worked out and what didn't. Maybe your trainer will be full of good tips...mine wasn't.

#6

I have been using the CGM with the Revel for 2 months, before that I used the Paradigm CGM. I have worn sensors everywhere! My arms, legs, abdomen, and low back/hip. I found I didn't like it much on my legs, but I guess because womens clothes are snugger I felt like I always had something in my pants :/ I use the IV3000 that came with my kit, I have to use 2 pieces or else it starts curling up, I just line them up next to each other. It works great for me, I know a lot of people like the opsite flex fix but I have never tried it.

I don't feel like I need to "wet" the sensor with the revel as much as I did when I used the paradigm. I usually disconnect from my old sensor, charge it and while it's charging I insert a new sensor. That usually gives me enough time for any bleeding to subside. Luckily I haven't hit a serious bleeder! You're not supposed to start up a sensor if it's in that condition, I guess it messes with the data, it wants interstitial fluid not blood.

At first, I had no glucose alerts at all. I hate all the beeping this pump does. But after a few weeks when I got a better handle on my BG I have turned them on and adjusted them. I have a more generous range during the day, and tighter at night. 75-180 during the day and 65-140 at night. That helps me catch my BG if it's going higher due to DP. I used to set my low threshold to 80, but I found it beeped at me too much. I have actually reversed some of my hypo unawareness so I don't worry about the current low threshold.

I have never used the predictive alerts, I hate beeping and I would rather not be stressed out if my BG jumps from 100 to 120 for example, you will get arrows if you have a rate of change >10 mg/dl I think. As far as if I do go over my threshold, I set the reminder alarm for 2 hours high BG and 1 hour low BG, that gives me enough time usually to make a difference to bring it back into target.

I calibrate 4 times a day, and on the first day or two I try to vary the numbers a little. Suprisingly MM CGM works exellent for me between days 3 and 6 (I always restart at least once, and did it by accident 3 times, it still worked!) I don't eat much during the day and I think that is what helps it's accuracy. On my wild BG days, it can really get thrown off, especially if it's a new sensor. If you don't mind waking up in the middle of the night to do a random midnight BG check, I would start a sensor in the evening, like 5 or 6 pm, then you will get your first calibration at 7 or 8 - when you first start the sensor you have to calibrate again within the next 6 hours then it's required at minimum every 12 hours.

This is a complete science experiment! Once you get hooked up, all of these nuances will make more sense. I found it was a lot easier to get started with the Revel than the Paradigm but maybe it's because I already had experience. Good luck!

#7

This is a good list of things that will help you get the most out of your CGM.
http://www.insulinpumpforums.com//index.php?showtopic=2308

#8

Thanks for the insights. When the Dex came out it was a great thing and just like any tech advance, the passage of time highlights the shortcomings (14.4, anybody?).

It was good of you to reinforce the limitations and practical application of the device. Reading the product literature is one thing, hearing what is and is not important is much more useful. I really appreciate the time you invested in sharing your experience.

Thanks!!!

#9

I could have used the "wake up" two nights ago. Before bed I was at 86 and to be on the safe side I popped 2 glucose tabs. An hour later I woke up feeling ever so slightly hypo. I was at 46 and after treating I'd sailed down to 35 fifteen minutes later. I know that their will be false alarms now and then,but with as much as I am alone and inability to exhibit hypo symptoms I am convinced that it will help me to avoid trouble. My wife is on the road a lot and to avoid trouble - especially at night - I tend to keep it on the high side.

I hope that it will also help me to lower my A1C. That is the goal!

#10

Just curious about calibration times. It seems to me if basal rights are decent that the most likely time that the BG is stable is prior to a meal? It would also fit in with the idea of calibrating 3x/day. Is that on target or do you follow a different schedule. In other words, to me it seems that calibrating prior to a meal satisfies the need to get a BG to run the bolus properly and also to cal the sensor.

Great idea @ "daily SG totals. Hadn't thought of that one and sure would be interested in the data to mentally track progress.

Thanks also for the tip on insertion angle. My problem (some would object to my use of the term) is that I have very little subcutaneous body fat. Between that and what you said I wonder if the actual part of the sensor that samples interstitial fluid is on the tip or along the length of the portion inserted in the body. That information is elusive & I'll ask my CDE about it.

I really appreciate your comprehensive and thought provoking reply. It is exactly the kind of response I was hoping to get.

#11

Thanks for the tip on extended wetting. That makes a lot of sense. Thanks also for the tape tip. I looked into that particular brand and the comments and reviews are universally positive. I've had problems during the summer with infusion cannulas pulling out due to sweat neutralizing the adhesive.

Happily for me my CDE is a Type I so when she offers opinions I'm confidant that they are based not just on what is in a book but also are based on personal experience.

Just curious, but how do you insert it in the upper arm? I know some do that with the pump but I just can't figure out how to do it.

#12

Interesting thoughts on the predictive alerts. Given the lag between SG vs. BG the idea of using thresholds makes sense. It also seems that after crossing the low threshold setting alerts every 15 minutes makes sense as an adjunct to managing lows or keeping an eye on avoiding them in the 1st place with BG testing. Is that in the ballpark? or would your experience indicate that is a bit much?

Thanks a million!

#13

Great link. I ran through it and there is a lot of experience there and wisdom to be learned from. I really appreciate it!

#14

I keep my low alert on 60 as it would drive me bonkers any higher. I have the high at 130 as that's about where I wanna know about it. I'm totally fidgety and am always peeking at the sucker. I didn't like the (Chicago) CGM trainer quite as much as the pump trainer who was, while professional, a bit warmer but it may also be that I knew what I was doing. I try to keep an eye on the calibrations to go into them when it's 1) flat and 2) where it's supposed to be, 80-90, as if I calibrate high, it seems to then read high until it's recalibrated. That's w/ the 722 though.

#15

when I do the upper arm I have to get my hubby to help. He just holds and I pull everything out. I've tried to do the upper arm alone and I just had a bloody mess. If you don't have and extra pair of hands it probably won't work for you.
I also have very few "fatty" areas to insert into and I thing that's why my stomach doesn't work for me. Try the thigh. It's much less painful.

#16

In theory that would work, the reason I don't do that is because it can really lag longer than 15 minutes. Also the first time I had the CGM many years ago, my sensor was really acting up and was beeping at me every hour when I was trying to sleep even though my BG was normal. I know my settings are pretty lenient, if you are hypo unaware (which I used to be pretty bad at one point) I would set my low threshold higher - around 80 so that it's possible to get the cue to test your BG before you get too low. Luckily, my I:C and correction boluses are set pretty well, so I don't drop quickly often, now it's really only my basal that I am fooling with. I don't eat at regular intervals while I am working so that is the only time I fight lows and they are slower to occur and my hypo unawareness is much better.

I hope I answered your question a little, it's pretty much trial and error. Have you gotten the CGM yet?

#17

I received my CGM last week - just waiting to get an appointment with my CDE.

I have hypo unawareness and when I do figure it out based on symptoms my BG can be has high as 85 and as low as 45 before I figure it out.

In a perfect world, I wish I could crank up the alert volume - if there is ANY background noise I don't hear alarms. TO add to it, I have tinnitus which means without background noise the hissing I 'hear' constantly drives me batty. I have it on vibrate but for that to work I have to use the hard plastic holder and then position the pump directly over the point of my hip. Carrying it differently means that with neuropathy I might not notice that either.

I hope it doesn't sound like I am whining - the pump is a huge improvement over MDI and I hope the CGM adds to lowering my A1C.

Great tip on trying to find the "sweet spot" for alarms. Your advice has given me plenty to think about.

#18

I have found that it's not hard to notice the MM alarms, I wake up in the middle of the night because of them. The beeping gets louder and more irritating if you don't clear it, and even then if you don't hear it, it vibrates pretty good too. I can feel it with the regular belt clip on my hip.

Also, I remembered why I set my low alarms to only go off every hour, it's because they can still drop! I was 70 on SG but felt a little low, tested and was 65, ten minutes later alarm goes off! It stayed below my threshold for another hour when it beeped again at 65,it was probably because I had a slow acting carb. But the next time I tested it was 105.

The CGM helped me greatly with lowering my A1C, it was 7.2% in December and 2 weeks ago I had it tested and it was 6.2% and my control isn't great, I struggled with my insulin pooping out on me recently, crazy stress levels, illness. I can't wait to see what it will be in another 3 months. I hope I can get to 6% or lower.

#19

Those are great numbers compared to mine. Congratulations!!! If I can get my A1C to where yours is I will be very pleased indeed.

I called Minimed after testing my pump a bit. Even my dog couldn't hear the alarm. I spoke with them this afternoon & will get a replacement in the morning. Talk about service - what a deal. My current one looks like the "Visible Man" (you can see the innards) and the CSR even let me pick out a different color. I couldn't be more delighted with their service. Obviously mine had a defect and after some reflection it seemed that if I couldn't hear the alarm - especially at night, then the CGM was of little use.

All of these real-world experiences are incredibly helpful and everybody's hard earned insights are really valuable!