Thursday, September 07, 2006

DexCom is BACK!

It was great to receive my NEW DexCom receiver in the mail, I almost felt naked without the trend data the past couple of days. Nice job, DexCom with the one day service delivery, got a new one as I have in the past with pumps that needed to be replaced.

I've switched sides today; the new sensor is on my left instead of my right side, but no noticeable differences: DexCom is still tracking my fingerstick tests rather well.

Interestingly enough, I'm reminded of how inaccurate fingerstick meters are: when I calibrated the DexCom this morning (with 2 successive fingersticks), the Ultra read 181 on one finger of my left hand, and 207 on one finger of the right hand, a 26 point difference! I've also experienced 40 POINT DIFFERENCES from successive fingerstick tests on fingers of different hands. Kind of makes you wonder about folks complaining about a 20 point difference between a CGMS reading and their fingerstick reading from their trusty blood glucose meter. It's important to remember that cheap home test meters don't have the accuracy of lab instruments, and that when it comes to CGMS, trend analysis is key, in addition to the single point value given by the CGMS and the blood glucose meter.

4 comments:

Scott K. Johnson said...

Very good point here Gary!

GaryK said...

Scott, are you a CGMS user? I've found that if my BG is 300, and the DexCom is off my already 'off' ultra meter by 20 points, it doesn't make much of a difference to me in terms of treating the high in the short term.

On the low end, if my ultra reads 60, and the Dex is 20% off from the 60, say a (range of 48 to 72), I'm still going to treat the low the same way.

I'm getting away from trying to treat the single point value, and looking more closely at the trends.

As an example, before I drive, I test. With single point testing, if the Ultra measured 100, I would consider that safe to drive. If I see '100' on the DexCom and a steep downward slope, I treat with some glucose tablets. If it's an upward slope I don't bother, the same if it were relatively flat.

This has worked well so far.

Scott K. Johnson said...

Hi Gary,

No, I'm not a CGMS user. Just a bit out of my reach financially right now.

It is very tempting technology now, and I'm sure we'll see some really great advances in the next few years.

It sounds like you have taken the right approach with it, as you are correct - our frame of mind will have to focus on things other than just that single data point.

Gary said...

Yeah, CGMS sure has its quirks. I've gotten 3,7,8,2, and now running on my 4th day of the current sensor.

As an engineer formerly working in high tech, I was used to buggy products and so learned how to set my expectations, particularly with first generation products.

The CGMS is buggy, but a lot better than NO CGMS.