Why I (almost) never downloaded my Dexcom CGM
We all know CGM should more properly be called PCGM—for Pseudo Continuous Glucose Monitoring. There’s nothing continuous about it at all. It checks every five minutes. I guess someone at Dex decided it would be more honest to make graphs that plot only bona fide readings. But the result is a statistically proper scatter plot that’s fucking impossible to read.
Med-T software engineers went the fill-in-the gap route—connecting the dots to create smooth trace lines (albeit often with insanely steep slopes and valleys). To me, at least, these are much easier to read.
Hmmm…. Wait a minute. That’s not really an accurate statement. Because you don’t really “read” a CGM download. Not the way you read me, or a book, or a magazine, or your iPad.
You “read” it more like a radiologist “reads” an X-Ray. It’s visual, yes, but in many ways more visceral than cognitive. More interpretive than intellectual.
You need to “see” the ebb and flow of your body’s glucose rhythms—not so much as think about them. Perhaps it’s more akin to art than science. When I look at a Dex download I see Picasso. When I look at CareLink I see Monet. I have nothing against Mr. Picasso, I just find Mr. Monet easier on the eye, that’s all.
To me, the whole point of downloading a CGM is to give me the big picture of the little things that are happening in my body. I need a clean look. Yes I need other info too: what was my basal? When did I bolus? But I like the clean trace lines that let me focus my mind’s eye on the real story—what are the trends?
And I find trend spotting on Dex software so difficult I’ve given up trying. Med-T connects the dots. If some dots get lost in the real world, the seashell stores them. That doesn’t help you in Real-Time if you lose telemetry, but the historic data is there for you later.
Lost Dex data goes to the Bermuda Triangle. When I download the Dex of my youngest, bounciest peds patient, I have to get out a sharpie to connect all the gaps to try and get a clear picture of just what the hell is going on. (Just try doing that with a Picasso at the Louvre!)
I’ve also made some basal adjustments straight from Sentry, too. After the third morning of opening my eyes and starring at his six hour screen—my personal favorite—I recognized the three-AM dip. Tweaking the basal an hour up-stream flattened it out. I’ve never really been able to do that off a pump or Guardian or Dex monitor before, the screens are too small and too low res for that.
As for color—I get Dex’s intent. The thought, no doubt was to make it easier to follow one day. There are times that might be nice, but the combination of both a riot of color and a riot of shapes creates a visual jumble that nauseates me. CareLink looks clean by comparison. Overly clinical, perhaps, but in a comfy and Star-treky way.
When I look at my Dex downloads I see chaos.
When I look at my Med-T downloads I see problems.
Problems I can fix. Chaos? Not so much so.
No pump alarms today.