Dexcom Glucose Monitor Common Questions Part 1
I see a lot of questions about the Dexcom CGMS in blog comments around the internet. I’m hardly an expert, having only had mine (Seven PLUS) since last fall (some people have been using them for 5+ years, since the very first model), but I’ve had my share of incidents/experiences with it that I think might be helpful, so I’m going to share my Dexcom knowledge, in the hopes that others with questions about the system can find lots of answers in one place. I will answer them over 2 posts, starting with general use questions, and then moving onto more detailed info, and then add more if people post questions in the comments section.
Does it hurt to put in/is it uncomfortable to wear?
What about airports/airplanes?
Where do you keep the receiver?
Now that you have a CGM, how often do you finger stick?
How long does the battery last?
Remember, I do not work for/represent Dexcom in ANY capacity. I’m just sharing my own experiences/observations. As always, nothing in this blog should be viewed as medical advice.
Obviously, this is a common question, and everyone will have different things to consider when trying to answer it (COST being probably the biggest). I waited to get mine until my insurance (Anthem BlueCross) would cover it (well, cover it to the extent that they cover anything- we all have our own %s). After having had it for the time that I have, I think if my insurance stopped covering it tomorrow (don’t read this Anthem!) I would keep buying the sensors, and give up something else to pay for them. I really feel like it makes that much of a difference in how well I manage my blood sugar. Testing 2 hours after a meal, as I used to, is fine. But I used to test myself then, and see a number <180, and think “ok fine.” With the Dexcom, I learned that my blood sugar could have been up at 220 (or higher) during that 2 hours, before coming back down into the ADA “ok” range. You learn a lot more about what different foods do to you over different time periods with the Dexcom, and you can have graphs of all that info on your computer to show your doctor. My A1c went down .6% in my first 3 months on my Dexcom.
The other area where it has made the biggest difference in is preventing hypos. I had frequent lows in the middle of the night, and I think getting woken up by low blood sugar is one of the worst feelings there is. I would sometimes compensate by trying to go to bed with a higher blood sugar (~150) than I really wanted to have. And that didn’t even always work. With the Dexcom, I know not only what my blood sugar number is when I go to bed (I still always use a finger stick to calibrate before I go to sleep) but I know which direction it’s heading, and roughly how fast. That usually allows me to take some kind of action to prevent an overnight low. If for some reason I’m unable, my alarm will wake me up before I actually feel low, so I can treat without that shaking/panicking feeling. It’s tough to put a price on that (but of course we are all accustomed to putting prices on things we would rather not).
So is it worth it? For me, definitely. Managing your diabetes well is all about managing your blood sugar, and managing your blood sugar is all about knowing how different foods/moods/times/activities etc affect you. The only way to really get that information is by testing, and the more you test, the better the information you have will be. Before I had the Dexcom, I tested around 6 times a day. With the Dexcom, I now “test” 288 times a day.
**I know that most people with CGMs already had pumps. I don’t use a pump, so for people deciding whether they really want to wear one more thing stuck in them, I can’t offer any specific advice.
Does it hurt to put in/is it uncomfortable to wear?
Putting in the sensors is no picnic, but it’s not that bad either. It hurts for about 3-5 seconds, then it’s over. I try to do it quickly. I have read some people saying they get good results by icing the area before they put the sensor in. This may work, but I would caution against having ANY moisture on the skin when applying the adhesive. It will definitely affect the life of the adhesive, and, as I will discuss, that can cost you money.
I do not experience any discomfort when wearing my Dexcom sensors. In fact, I don’t notice them at all. The exception to this is when the adhesive starts to come unstuck. See tomorrow’s post on ways to prevent/deal with this.
Is it really waterproof?
I can answer this with an unequivocal “Yes”. I surf frequently, and wear a wetsuit when I do. I’m often in the water for over an hour at a time, and my abdomen, where I wear my Dexcom sensors, is usually submerged for much of the time. In addition, my wetsuit, is, well, wet, and in contact with the sensor/transmitter. The only time I’ve ever had an issue with my sensor failing due to moisture is when the transmitter was only partially clipped in. Double check that and you should be fine.
***This only refers to the sensor/transmitter while it’s on your body. The receiver is NOT waterproof, and I do not use it while I’m surfing.***
What about airports/airplanes?
I have never had an issue with my sensor/transmitter at airports (and I fly quite often). I send the receiver through the x-ray. I have yet to have an “enhanced” screening/pat down, so I don’t know what the reaction would be, and I have also not been through one of those new body scanners so I can’t comment on that.
When I’m on a plane, I keep my receiver on. I know it’s an electronic device, and maybe I should turn it off for takeoff and landing, but it makes a loud beep when you turn it back on, and I know from my days at a job where I traveled entirely on private planes that commercial airline restrictions on electronic devices have more to do with keeping your attention than with their interfering with the plane’s instruments (we used to stay on our cell phones until the altitude made us drop the call- with the full blessing of both the pilot and the owner of the plane). Besides, the transmitter does not have any switches of any kind, so it’s always “on”. When you’re inactive (like on an airplane) your blood sugar does not always behave the same, and it’s important to keep an eye on it.
Where do you keep the receiver?
I am not a “belt-clip” person. Not for phones, not for my CGM. So I don’t use the clip case that comes with the Dexcom. There are trade-offs here. One: pocket bulk. Keys, a Blackberry, a Dexcom receiver, a cardholder, and cash. It can be a lot, especially when dressing up (what looks OK in baggy shorts is not the same as what looks OK in a fitted suit). Two: equipment damage. While my Blackberry has a case/screen protector, my Dexcom is naked. As a result, it is pretty scratched up (and, as I wrote about previously, has a rogue hair inside the display). The upside to the pocket method is that, unlike Bob at joyofdiabetes and Kelly at Diabetesaliciousness, I have never had my receiver fly off my clothing and land in the toilet. Like I said, a trade-off. You choose.
When I’m sleeping, I just throw the receiver on top of the comforter. No, it never stays there, but it usually doesn’t go too far. I am either very lucky or very unlucky (time will tell) that my wife is utterly impervious to its alarms, so I don’t worry too much about where it ends up, as long as it stays in range.
When I shower, I close the toilet and set the receiver on top. It tends to maintain the connection (but if you have another flat surface closer to the shower, go with that).
Now that you have a CGM, how often do you finger stick?
Every time you put in a new sensor, you have to enter 2 finger stick readings to calibrate it. It will beep twice a day to ask for more calibrations, but I do more than that, especially in the early days of a new sensor to make sure it’s working optimally. I corroborate every high/low on my glucometer, and will usually still test before meals, just to be safe (although once when without a glucometer due to boneheaddness, I went over 36 hours without calibrating. When I finally checked, my Dexcom was within 10 mg/dl of my finger stick).
How long does the battery last?
Dexcom says that it lasts 3 days but mine seems to last longer than that. Still, whenever it drops into 2 bars, I try to recharge it, just be safe (since it does not take disposables).
