Does Narrowing the High/Low Alarm Range AND correcting Within a Narrow Range increase the accuracy of the cgms?

Replies to This Discussion

Permalink Reply by Jan on July 1, 2009 at 12:35pm

Sorry, Rick, I am bumping you back up into the "Expert" category, LOL. We called Dexcom tech support yesterday afternoon and she knew none of this, just told us to recalibrate. Dex was off night before last, so niece put it in her purse and walked away from it. After she got back from camp, we called Dex Rep, followed her advice and recalibrated. The fingerstick numbers and sensor numbers were VERY close, within 11 points, except for a few hours after dinner. Now it would lose her at points, but sensor did catch up to her BS at points even during that after dinner period. Was so accurate that at 4am, I decided time for sleep and went by the Dexcom reading of 96 one arrow down. I gave her 6 grams of juice, which should bring her BS up to 125 and unfortunately fell asleep before rechecking. She was 181 fingerstick at 8am, 170ish on the Dex. This is not her pattern, though she had times when she will go up in the morning from 4 thru. It is usually short lived. We have to hook up the Radio Shack wireless mike and in that case I should wake up. For school she can carry Dex in her small Coach bag which she takes with her everywhere. Pockets on jeans are too shallow so I sewed a jeans pocket with velcro that I saved down on the inside of her shorts and it works well. She does have bulges in her pockets between pump, Dex and Lifesavers. We left the low alarm on vibrate and turned off the high alarm (since she does not want to be bothered while acting). I told her if it beeped and she can't pull it out to eat sugar. She's okay with this. She has been between 100 and 150 from 12 noon until 3pm, when she was released from camp. Breakfast, she came down quickly, as she is in a rush and will only eat a yogurt before camp for breakfast. It is an acting camp, so they do dance moves, but off and on and are not running around like maniacs. Love, Love, Love the
Dexcom. As soon as Dex is integrated with a pump, I think she will really love it too. I like having a separate receiver, so I don't accidentally wake her up grabbing for the pump. She does not wake up usually for fingersticks, but I look at Dex at least every half hour, even 15 minutes sometimes. Put receiver on the dresser near the door beside her bed. She was completely unaware I was even checking. I do not expect such accuracy all the time, but even if it works this well a good deal of the time, I'm sold.

Permalink Reply by Jan on July 1, 2009 at 12:46pm

Rick, one more question on getting a good calibration for the high levels. She absolutely does and always has, spiked to 200, 250 after eating. If we prebolus, she may spike to 180, but DIA is four a a half hours, so you can see where that's going. Down. We are always feeding insulin around here. We will seek to get a low calibration point around 80 to 100. Should we seek to get the high calibration point around 200, not 160? This would be problematic because those are postprandial spikes and in flux. If I get the "high" calibration at hour 2 after eating, where it could be 200 at times, that is not a stable 200. So how do I get high readings? I certainly can't get them every day. I can get them at some point during a three day period. What should I do re getting the proper high calibration point? P.S. Sis did calibrate the 180 this morning.

Permalink Reply by Don on July 1, 2009 at 1:16pm

"But going UP, Dexcom has only ONE alarm. So, if it goes off at 120 mg/dL, after every single meal, that's "good" if it made you look at a sharp and unexpected rise. But here's the problem: If you KEEP going up, and the "correction"" dose which you chose to do never causes you to get under 120, then it it stays quiet: Just one alarm, as she floats up to 160, then back down to 130 from the "correction" takes effect, but if it starts to rise again, you won't get any notification -- not at 160, 200, 250, 300."

??? I thought Dex' snooze/re-alerts feature would allow tracking whether a correction dose has achieved your target??? Snooze it for 1 hour and Dex should re-alert that you are still above 120.

▶ Reply to This

Permalink Reply by Jan on July 1, 2009 at 2:34pm

Yes, I did think this too. But Dexcom tech support told me point blank NOT to set the high alarm at 140 if she very often goes above 140 because the alarms are too annoying and they would be going off all the time. Regarding calibrating the Dex, you want a lower reading near 80 or 100 and you want a high reading near 200 if she does normally have 200 or above numbers. If you normally do not rise above 140, then that is what you should set your high calibration at. Regarding alarms, we set it to 160 so we can have a "heads up" on highs after dinner and especially overnight, we want to catch the highs early. However, DN is not used to the alarms yet and is getting annoyed so we turned low alarm to vibrate and turned off the high when she is away from us. She eats at noon so does a fingerstick then and we pick her up early afternoon. She almost always has good numbers until 6 p.m. I just put the Dex near her at home and go check when I need to for now. At bedtime, when I need to hear the alarms, I'll turn it back on.

▶ Reply to This

Permalink Reply by Rickst29 on July 1, 2009 at 4:46pm

Don you may be right-- I've not yet tried using that feature at all.

▶ Reply to This

Permalink Reply by Don on July 1, 2009 at 4:52pm

Well, if it does have re-alert feature, the danger is in over-alerting and over-annoying. I could see Jan setting the high alert at 160 with a 2 hour re-alert at night, maybe 1 hour during day. The manual says you can set the re-alert as soon as 30 minutes later but that is not enough time for a correction bolus to work and probably just going to annoy her niece.

▶ Reply to This

Permalink Reply by Jan on July 1, 2009 at 10:03pm

To answer the alarm question, on the Dex 7 Plus you can set the alarms to go off every half hour for the highs. But it only vibrates, then two short beeps, so easy to miss. Need the wireless mike setup to hear.

▶ Reply to This

Permalink Reply by Rickst29 on July 1, 2009 at 5:19pm

Jan, the last two posts are "nested" too deep for further replies.

Some Dexcom support people know as much as I do. BUT, they can't actually "bring up" any suggestions which the FDA hasn't approved. Independent end-users, like me, have vastly more freedom to state opinions.

For jeans, and maybe shorts too, I recommend that she forget about using pockets: The new-style Dexcom clip works really great on any fashionable belt; you don't have to keep digging it out and stuffing it back. And far more important for a young teen: the clip avoids ruining a sexy profile with ugly pocket "bulges".

You could try calibrating highs the curve BEGINS to level off, approaching a peak value shown on the Dexcom-- bG has ALREADY peaked, and the "bit lower" meter measurement might be a decently balanced match for the "still not all the way up to max" ISF-based Dexcom value. I don't do this, of course: for me, Dexcom and bG are extremely close during periods of moderately falling bG, and I don't have the kind of wild spikes which you're dealing with.

I still think that the long DIA would be much better addressed by modifying the meal content. You haven't found an insulin formula which can handle those rapid onset, carb-heavy meals, The insulin is insufficient after one hour, AND it keeps biting her in the a** 3 hours later. It sounds to me like the best way to get off this "roller coaster" is to change the meals, rather than play increasingly risky games with longer and longer pre-bolus timing attempts.

Just my opinion, of course.

▶ Reply to This

Permalink Reply by Jan on July 1, 2009 at 10:09pm

She's pretty good about limiting herself food wise, if she is high, and there is a lot of junk food she does not touch. But she loves carbs, loves veggies and fruits and does not really like meat. Breakfast and lunch, she eats 30, 40 and under. Afternoon snack, 50 or 60, it is the dinner meal which is troublesome. I may have to experiment and try to keep it closer to 50, maybe give her her dessert snack later on. She loves pasta; conincidentally, if I give her that gluten free Quinoa pasta (which we do all the time now) she drops like a rock. Gave her 20 extra grams of fruit and pasta and she was still dropping. Once I figure out this one, she will be able to eat a lot of pasta, which she loves. P.S. We have noted this with Quinoa and have always given 20 extra grams with a little fruit up front, plus checked at one and a half hour mark, then covered part of the insulin. But without the cgms, we did not know she was dropping to 55 and then coming back up. That was really a big surprise.

▶ Reply to This

• First
• Previous
• Next
• Last