Dexcom Trial

I usually don't do much blogging about my diabetes, so this post is very different from my others.  Beware of the diabetic lingo!

Anyway, I finally just finished doing something I've been wanting to do for a while:  try out a Continuous Glucose Monitoring System (CGMS).  CGMS's approximate one's blood sugar every minute or so (time period depends on the model), but since the method CGMS's use to approximate blood sugar is not quite as accurate as a normal blood glucose test, some normal blood glucose tests are still neccessary to calibrate the CGMS and to verify unsavory blood sugar results before treating them.  CGMS's are useful for predicting high and low blood sugars, though, and they show trends very well on pretty little graphs so one can see the effects of one's eating, bolusing, and exercising habits on one's blood sugar.

After I mentioned to my endocrinologist that I wanted a trial, she reccomended I go to a local Inova branch, where the insulin pump/CGMS trainer would set me up with a loaner.  The trainer, who also trained me on my very first insulin pump trial about seven years ago, was very helpful and friendly.  She inserted the sensor, and it barely hurt—no more than a good infusion site insertion, I'm happy to report.  Since she wasn't allowed to loan out the Navigator (the CGMS I want) because it is so new, I got hooked up to a Dexcom Seven, just to let me see what using a CGMS is like in general.  I had thankfully already accepted the fact that I would feel like even more of a cyborg than usual, so with that hurdle out of the way, I was ready to give this a good shot.

The Dexcom Seven CGMS I used, shortly after pulling out the sensor.

The first twenty-four hours were only moderately accurate.  After the initial calibration, the Dexcom showed me trends pretty well.  To turn the Dexcom's reported numbers into my actual blood sugar readings, however, one would have to add about 30 mg/dL to each one.  It kept vibrating and beeping at me to tell me that I was below 40 mg/dL when I was between 70 and 80 mg/dL.  It kept that up for a couple of hours, at which point I was almost in tears.  I wanted to bring my blood sugar up so I could go to sleep without going low during the night, so I was eating some carbs to bring my BG up, but I was pretty scared that the Dexcom would keep me up all night, telling me I was low.  Argh.

Eventually, my numbers came up, I went to sleep, and life was good.  The Dexcom started looking like it was getting more useful and accurate readings around 2 or 3 PM the next day, and as long as I calibrated it when my blood sugar was relatively stable, it stayed about as accurate as it could be (there is a bit of a delay between traditional blood sugar tests and CGMS readings).  It caught several lows and highs during the nights of the week I used it, which was very useful.  Really, no diabetic likes waking up low at 3 AM.  Or waking up to the alarm clock each morning, testing, seeing a low result, and wondering how long they had been that low; that's just plain scary sometimes!  Thank you, Dexcom, for sparing me of that for a week.

On the con side, those late-night lows were annoying, and since the Dexcom alarms every 15 minutes if one's blood sugar is still below target, sometimes I got to sit around for a while to make sure my blood sugar was stable and high enough for me to sleep.  Better than waking up extremely low and discombobulated at the normal time, though.

Today, when I had to take the Dexcom off to give it back to Inova, I was kind of sad.  This device had been my constant companion for a week, watching my blood sugars even when I normally would not.  Watching the trends has been enlightening, and I'm sure I will do things a bit differently in my bolusing now.  I am even more certain now that I want to get my own CGMS.  I am fairly sure my parents' insurance will pay for it (Thank you!).  Now I just need to get started with that lovely pile of paperwork.  But for the safety factor I have appreciated for the past week, I think it will be worth the hand cramps of signing my name a few gillion times.