Last year, about six months after diagnosis, w e were riding out cold after cold, stomach bug after stomach bug, ear infections, bronchitis, you name it. 1 1/2 year-old Luke picked up all the usual toddler ailments at daycare, but – as the nurses at Children’s blithely put it – we *just* had to manage his blood sugar along with it. We were living on our pump’s temp basal, sliding up and down through endless nights that left both of us heading off to work exhausted. (Luckily, Luke was starting to sleep through the finger sticks and fiddling with his pump.) We considered a month without an ER visit a good month, and I started to whimper at the next new cough or runny nose.
So, despite reluctance to slap another device on our son, we decided to trial a Dexcom CGM – and were hooked. To say it was like Dorothy stepping out into Technicolor might be overstating things a bit, but not much. Instead of trying to fly a plane by turning on the radar for a split second every couple of hours, we now had a roughly functional (if not entirely reliable or accurate) radar 24 hours a day.
I love data – the more, the better – so it was not surprising that I fell hard for this new device. And, like so many men I dated before my husband, the Dex often shut down unpredictably, leaving me swearing at it in one breath and begging it to come back online in the next. But, a year later, here we are, coming up on Valentine’s day and yet another cold – but so much more manageable than last year’s cold season, thanks to the Dex.
A short summary of what we’ve learned:
- Insertion: Seems less painful than a set change (based on Luke’s reaction), and the inserter makes placement fairly easy.
- Adhesion: We use Tagaderm over the adhesive to keep it on – but now avoid putting Tagaderm over the sensor, because the trapped moisture causes more frequent ??? (WTF marks).
- Accuracy: It usually takes a day for readings to settle down and become reasonably accurate. The Dex is pretty accurate in the 100s and lower (more than Medtronic’s CGM, from what I’ve heard), less so in the high 200 and above. Sensors often last 10-14 days (it’s not officially recommended, but the trick is to stop and then restart the sensor at the end of the first week-long period), and they become erratic in their final days as well.
- Alarms: There are plenty of alarms, and you can truly drive yourself crazy by having them all on. We’ve chosen to set just 3:
- High alarm at 200-240 (depending on the situation or time of day)
- Low alarm at 100, because depending on the margin of error and fall rate, actual blood sugar might be well below 100 by the time the alarm goes off
- Double arrows straight down (falling more than 3 points/minute), because no matter how high he is when this goes off, blood sugar can very quickly fall below 100.
- Check the alarms on a new receiver to make sure they’re working during actual use! We’ve had new replacement receivers show up with just the vibrate but no alarm working, and we’ve had alarms that worked when toggling back and forth between alarm settings but were silent during actual blood sugar drops below 100. Not good.
- Monitoring: One of the Dex’s limitations is its 5 foot transmission radius. During the day, we tuck the Dex into one of Luke’s pockets (lucky he’s a boy with endless pairs of cargo pants – I don’t know how we’d handle this with a girl), but nights are a little more challenging. A baby monitor solution would be great (for older kids’ privacy as well as younger kids’ safety) – Medtronic is openly working on one, and I’ve heard Dexcom is as well. People have come up with all sorts of makeshift solutions involving karaoke mikes and baby monitors. Setting the Dex right next to the microphone on our baby monitor has worked for us – and, incredibly, we can also get the Dex to pick up from one room or one floor away from Luke, provided it’s in a direct line with his body.
- Rugged the Dex is not (see Christopher Angell’s “Don’t Fear Diabetes” post on waterproofing a Dex – I wish!). We routinely had receivers or their alarms fail on us after just a few weeks, to the bafflement of Dex tech support. We have had
89 fail on us in one year. Finally one tech specialist mentioned that static electricity can cause the receiver to fail. You wouldn’t think static electricity would be an issue in rainy Seattle, but to protect against that possibility and general jostling, we got a skin for the receiver, and – knock on wood, this one has been with us a record 3 months (the warranty is 1 year).
- Calibration: Reading all the posts out there on the best times to calibrate the various CGMs blew my mind – do it during rising blood sugar, falling blood sugar, level only, twice a day, every hour, etc. Fortunately, Dex startup calibration does truly seem to work no matter what the blood sugar trend, and calibrating every time we check blood sugar seems to work fine.
- Acetaminophen – apparently causes artificially high readings on the Dex. We’ve never tested this – just moved to ibuprofin.
A few of the same questions generally come up when people ask about whether the Dex has changed our diabetes management:
- What are the biggest benefits?
- At the risk of sounding like a company shill – peace of mind. We don’t entirely rely on the Dex to catch every high or low, but it’s far better than trying to do that via finger sticks – especially at night.
- Having the blood sugar trend to provide context for the reading we just took. 100 straight up is very different from 100 straight down.
- We can see colds, stomach bugs, and set failures coming and prepare rather than being sideswiped by highs or lows already on their way to being real problems. Since Luke’s diabetes vocabulary as a toddler is generally limited to “Owie” and “No,” this really helped. He now says “beep beep!” when going low, sometimes before the Dex goes off. 🙂
- Basal adjustments are much easier, since we can see exactly when blood sugar starts trending up or down outside of BG readings.
- As a result of all of this, his A1C dropped nearly a full point in three months. Granted, we’re just 1 1/2 years out from diagnosis and are still getting things right, but having the Dex makes us much more comfortable with keeping his BG closer to target (have heard the same from other parents using CGMs).
- Do we do fewer or more finger sticks now? I think it averages out – we really just do more targeted testing now. If blood sugar is level and we’re out and about, I’m happy to skip a check and throw in a few free carbs for a drift below 100m but a sharp or unexpected high or low will send us for the glucose meter.
- How do we rotate sites, given that Luke’s also on a pump? This still isn’t easy, even with Luke becoming a very good-sized 2 1/2 year old. We reserve legs and butt for sets, the back of the upper arms and hips for the Dex sensor, use Unisolve to help peel off old sensors, and rub emu oil on the sites to help them heal. (We used to use the butt as well, but after a diaper blowout infected a site, we crossed that off the list.)
Some very useful online resources I’ve run across r.e. the Dex:
- Children With Diabetes has (as with all topics) an active, wide-ranging Continuous Glucose Sensing forum.
- Gary Scheiner (“Thinking Like a Pancreas” author) has an extensive post on Downsizing the Downsides of CGM Use, including links to resources for getting insurance coverage.
- In “This is Caleb,” Lorraine chronicles their experiences using a Dex over several years – really useful posts and videos in here.
- diaTribe covers future plans for the Dexcom, including where things are at with FDA approval and future integration with the Omnipod and Animus.
diaTribe is also giving away a Dexcom – entry is open till March 5.
- A shameless plug for a JDRF article about Luke’s pump and Dex use: Little Boy, Big Technology. Kara did a great job of capturing the impact those devices have had on our struggle to manage diabetes in a toddler (the article got a bit mangled in being posted to the web, so there are a few odd gaps).
With CGM technology providing half the technology for the artificial pancreas, you can only hope it will continue to evolve!