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Realtime CGM MM question

Discussion in 'Parents of Children with Type 1' started by PAULEEN, Nov 17, 2008.

  1. PAULEEN

    PAULEEN Approved members

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    Hi All, I have a question for those who are using the CGM...We started yesterday I don't feel we had much training time as the trainer only stayed for 45 minutes and didn't explain too much :eek: Of course, I know where to to go when I really need the experts help CWD :D Anyway, I think I'm a little overwhelmed by yet one more thing to have to know. First, I know that there can be a 20 % difference from the finger stick to the sensor but it seems to feel way off for me. My son had a count of 60 earlier tonight and feeling he was going low (had the wobbles). The CGM said his count was 100 when we did the finger stick he was 60 and went down to 53 :eek: before he started to go up. The lowest the CGM read was 80 and never even gave us the down arrows - and that was 20 minutes after the low and we were reading 120 with his finger stick. So, what are we doing wrong?! I am so frustrated with this. We have calibrated it they way we were told and have been putting his count into the pump and sending it to the sensor each time and it still seems to be running a lot higher than he actually is. Any advice? I feel that we are wasting our time with this and keep hoping that it will begin to work and get better...I am afraid of using the little space we have on him for sites for this device (he is very thin) especially if we are wasting time. My son thinks that it is cool and I had to go over with him many times that because it says it is reading his count that it is not doing it correctly and he still has to use his BG monitor to take a finger stick. He is almost a teen and doesn't want to hear that, but after tonight I am hoping that he now sees it is not correct. Any advice anyone has is appreciated. Thanks.
     
  2. Abby-Dabby-Doo

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    Are you calibrating close to the time of eating? Are you calibrating when there are arrows present?
    What do you have the low alarms set at? We have Abby's set at 100. With the CGMS being 5 to 15 minutes of the actual blood sugar at times (especially when the blood sugar is moving rapidly) she can be a 100 but 15 minutes later she can be in the 60's. When she alarms, 9 times out of 10 she's below a 80. That's why we have the low alarm set at 100.

    Please remember this device has a learning curve, it's not going to be perfect overnight. Just like switching from shots to the pump or switching types of insulin such as NPH to Lantus it takes some patience. It does get better with time.
    My daughter is very skinny, but we've managed to move her pump sites around.
    Good luck
     
    Last edited: Nov 17, 2008
  3. Wendyb

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    This is a good question and I think several more experienced MM cgm folks will chime in. We are new to the MM CGM and I am having similar problems with this second sensor. It has varied from being 50 pts off to being exactly right. Sometimes I don't see the down arrows either. I do recall that you may not see the down arrows unless your son's BG is dropping rapidly enough to get them. I can tell you that our last sensor (the first one) was much more accurate. It amazed me continually for the entire 7 days that we used it. The only thing I did differently with the second sensor is that I did not inject it in as deeply as the first. The first one went in at at least 60 degrees at the recommendation of the trainer who watched me do it. This one I purposefully put in right at 45 degrees (with the serter's legs firmly planted) to avoid any additional pain from hitting muscle (which really made no difference) . I'm wondering if with a more shallow insertion if it is not getting enough fluid around it and this is causing the accuracy problems. However, that said, this second sensor is trending correctly and is still useful to me in terms of adjusting basals. Others have said that accuracy improves after the first 24 hours of so. Be aware that you do not have to callibrate with each BG check. We calibrate ours only about 2-3 times per day---when I know he is very even. Be sure and read Darryl's callibration tips that he has put on a sticky in the CGM forum. I think both of our techniques will improve with time.
     
  4. hawkeyegirl

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    This makes me think that you're calibrating every time you're checking his blood sugar. If so, that's your problem. You should only calibrate when he's really, really stable - probably no more than 4 times a day at most.

    My other advice to you is to give it time. It probably took us a month to get the hang of it, and we're STILL learning. Darryl on this board has some really good tips that are linked to in his signature. I'd check those out.
     
  5. Flutterby

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    are you updating the sensor each time you do a finger poke? If you are, don't do that anymore:D To many updates leaves room for calibration errors.. we calibrate every 12 hours, no more (except for the first day). Remeber, the sensor is about 10/15 minutes behind a finger poke. If Kaylee alarms at 90, most likely she's in the 60s by the finger poke.. if his levels are changing rapidly then you'll most likely see a bigger difference between the sensor and the meter reading.. there is definitely a learning curve to the cgms.. you'll get to know how it runs for him..
     
  6. PAULEEN

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    Thank you all for your advice. Yes, I guess we are (were) calibrating it every figer stick. So this might be the problem. As I said, I don't feel that we had enough training or information about this and felt very rushed. We are still on the same sensor that the trainer inserted, and plan to keep it in as long as we can hopefully until Fri or Sat. So I am hoping it will get better . Thanks again. I will keep you all updated as we go along.
     
  7. hawkeyegirl

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    Pauline, if I were you, I would think about restarting this sensor. I'm afraid that with all the bad calibrations, you're just going to continue to be frustrated if you don't. It's super easy to do, and you don't need to insert a new sensor. You just go to Sensor>Sensor Start>New Sensor. You will get a Meter BG Now in a couple of minutes, and have to do another calibration within 6 hours. After that, you only have to do one every 12 hours.

    We usually calibrate first thing in the morning, once before lunch or supper, and then once after he goes to sleep for the night. Those are his most stable times, and we have pretty good luck that way. I think if you change your calibration practices, you'll have much better luck. I'm furious on your behalf that your trainer didn't tell you about this. It's THE most important thing to do in order to get good readings.
     
  8. PAULEEN

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    Thank you Karla, I think you are right. I will restart it now. I did not know I could restart it without using another sensor. Thank you.
     
  9. hawkeyegirl

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    No problem! We're all in this together! :)

    Frankly, I think the people on this forum know a lot more about the CGMS than Medtronic does. I've learned WAY more about it from this board than I did from the "official" training we got. :rolleyes:

    ETA: Just so you know, the sensors are programmed to end after 72 hours. It will beep and say SENSOR END. To get around that and keep the same sensor in for a while longer, you do the same thing to restart it that I posted above.
     
  10. thebestnest5

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    CGM is not a plug in and use right away device. The learning curve is steep and not the same as fingerstick BG.:cwds: We started in June '07 and I felt quite comfortable with CGM by October '07. I am not saying it was awful for 4 months, but it takes times to really learn how to use this new technology accurately and to it's fullest. (I also had a newborn baby just a few days after Liv started the sensor.)

    Accurate calibrations are key to accurate CGM--and a large part of the learning curve. One inaccurate calibration wreaks havoc for the next 4 calibrations; it stays in the "memory" that long.

    If you were calibrating with every fingerstick, then that was definitely the problem. Restarting was good advice and will reset the memory.
     
  11. PixieStix

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    I would really encourage you to use the first couple sensors as learning tools, if you manage to select a good site, do the insertion, keep it securely taped on, have an ISIG, figure out a calibration routine, evaluate/validate alarms--you are doing great!

    Many of the other posters have already warned you about calibrations--be sure to turn off the connection b/t the MM meter/pump if you have it on, otherwise you definitely will be calibrating w/ every check. I also would encourage you to calibrate thru the sensor menu rather than in conjunction w/ the bolus wizard so you don't accidently calibrate w/ a bolus.

    The lag time b/t fingerstick/sensor reading is about 15 minutes, so when you catch the low and he is on his way up, the sensor will lag behind. I do find that very low lows and very high highs seem to take longer for the sensor to catch back up w/.

    The greatest value of the CGM is the trends and the alarms. It will not prevent you from having lows/highs. I am not sure what your trainer had you set the alarms at--90 for the low setting and 200 for the high is typical. When he alarms at these settings he might have passed by those readings 15 minutes before and already be symptomatic.

    Hopefully your trainer will f/up with you again but you can learn so much from the posters here. Try hard not to get frustrated--it is so invaluable once you are past the learning curve.
     
  12. Darryl

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    Please read my post below (in my signature) "CGMS Calibration".

    With a new sensor, it sometimes is accurate from the first cal, other times it might take a couple
    of cals over a 12 hour period to become really accurate. You'll know once you get a few BG checks
    that match the CGM reading that the calibration is working well, and from there you should continue
    to get good cal's for 7 days if you follow the guidelines in my CGMS calibration post.

    Once you get your calibration worked out:

    If BG dips below 80, then recovers, that the CGMS might not track the actual BG accurately to the
    lowest level. What's most important is that when it drops below 90 (or some target that works for
    you), that you eat some carbs. That will avoid the low getting to be a problem.
     
  13. PAULEEN

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    THANK YOU to all of you! We did restart last night and only have calibrated it once at 2AM it seems to be pretty close to his BG number only being about 10 pts off. We changed our alarms the trainer had no high set and the low set for 70. We quickly figured out by all of your advice by time it went off at 70 he could really be low :eek: I agree with everyone here, you all are the experts and the Minimed people sometimes don't have a clue - which is very frightening! You all are my saviors! Thanks Darryl, you have helped me to understand this device better - You should work for the CGM people :) We will be calibrating again at lunch and see what happens. Thanks again to ALL of you. Karla- Thank you for the advice about the restart and about what to do when the senser wants to be changed. Have a great day everyone! I'm off to work.
     
  14. OSUMom

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    I agree - I don't think 45 minutes was adequate with the MM rep. You'll receive excellent help from the experience of the parents here (the hands-on experts) :D, but I would also encourage you to try to set up a second appointment with the MM rep also.
     
  15. Janimal

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    I get the best results by putting the sensor in at night, plugging the minilink onto the sensor, but waiting until first BG check in the morning to start the sensor in the pump. The routine is weak up, turn the sensor on in the pump menu & check BG. It alarms for a meter BG usually within a couple of minutes. This gives the sensor plenty of time to get settled before giving any data. The first 12 hours were not that accurate anyway so I do not feel I am missing anything. It helps to calibrate on the low end of normal. Seems to make it more sensitive to lows. This being said, I do not rely on the sensor to inform me on lows. It just does not pick them up fast enough. I really count on it to let me know about general direction, warn highs and discover trends.
     

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