Making best use of the CGM data?

I'm interested in how others are contextualizing the data you get from your CGM. We never had enough success with the minimed system to actually benefit, but with the G4 we've got this flood of data, which, while great for acting on the fly, isn't information rich enough to help me make changes.

All I can see doing is keeping a detailed log of events, including meals and sports practice and all that, but I'm just loath to...

What tricks or tips have you long time users, or highly motivated newbies got to share?

Thanks.

 

We just started on Wednesday and I'm interested in this question as well. Is there a way to integrate the data from her Omnipod with the G4? We currently use diabetes partner for her Omnipod data but they don't support the G4.

 

I hope to hear some good tips too.
I print out the daily strips (under glucose trends) so I can visualize the patterns. I also like the hourly stats. We are beginning to emerge from he honeymoon stage and entering growth spurts so we have been changing basals every 3-4 weeks for a while now. These in connection with our carelink data help me figure it out.
(I do wonder why under patterns it always says "no significant patterns detected" - when there are- do others get info here or is it a tool for clinicians?)

 

There are several things I do, I am not sure how well they would work with the Dexcom since I only ever used the 7+ for a significant period of time. I am not entirely sure what info the G4 offers on the actual device so you may have to download it to get this info.

1. Most nights right before I go to bed I look at the SD and the average BG. I aim for a standard deviation of under 40 and an average BG between 110 and 140. Any higher or lower means I am having sustained out of range blood sugars. If the standard deviation is below 25 and the sensor average is below 120 then I typically skip the next few steps.

2. I look at the 12 hour screen and see how long after each hash mark (which means a bolus) it took for me to come into range. If it takes more then 2 hours or requires a correction to get into range (70-120) I mark that down. To get the info on boluses you would either have to enter it into the Dexcom or look at Maddie's pump.

3. I look at the 24 hour screen as a whole. I mark down any time period where I was above 140 or below 70 for more then half an hour. If this happens for a few consecutive days I adjust my basal rates by .05 units an hour for the 2 hours before the problem.

4. I keep track of exercise in my head. I always set temp basals for that. I just glance at the 12 hour screen to see how that went. I also like to look for delayed lows from exercise in the 2-5 am time period on the graph.

I think if I was just starting out with a CGM I would work on dealing with exercise lows first just because I find those the most concerning from a safety standpoint. I would then deal with carb ratios and finally basals. You may have a very different experience with this then me but I find my basal needs vary so much day to day that I am nearly always using temp basals. I think if you work out the lows and meals/corrections first it gets easier to worry about basals.

Also, I know the method I posted above looks somewhat complicated. But it has become totally instinctive for me at this point and I spend maybe 3-4 minutes a day looking at the data and in exchange for that time I have significantly reduced the time I spend dealing with lows.

I am so happy you guys are having a better experience with the Dexcom! Good luck with it!

 

Thank you Meg for this info! We are starting the process of getting a CGM mainly for the purposes you described and because she is becoming hypo unaware. I too was wondering "How do I handle the info it gives me."

 

Thanks Meg :cwds:

Very helpful, both for what we might do and how we might be thinking about what we might do.

I appreciate you taking the time

 

on the G4 bolus marks aren't shown on the actual reading screen. You have to download this info (if you've entered it).

 

I think one of the best things you can do is to teach Maddie how to use the data in real time. (Easier said than done with a 15 year old. ) I now know how to tell if a meal bolus is going to "work" or not just by looking at the CGM graph about an hour after that bolus. So I'm able to head off a high or a low much faster and with much less insulin (for highs) than if I didn't have the CGM. I also correct much more aggressively than I would otherwise, knowing that I can "catch" any resulting low with some juice or whatever if necessary.

We don't log or chart or download anything. We mainly react to the graph. Not on a minute by minute or hour by hour basis or anything. But a quick glance every so often actually makes D less invasive overall for us.

 

for me, the "on the fly" info has been far more helpful than any historic data I get from downloading. This is the exact opposite of what I felt with MM. With that, I felt that overall trend was more useful and so I spent more time looking for patterns of Bg. I do still look a little bit at the downloads though not anywhere near what I did before, because what I've seen is that today holds very little info that is useful tomorrow.

But the graphs that I do tend to use I use to see how food boluses are working, and I can get a really good feel for when we need to increase boluses. I look the 'glucose' trend report with a single day selected to see when rises happen at night (You know that if you highlight a portion of the graph you can enhance the time view?) And I can look at the big picture to see if this week is better than last week.

But, on the fly, so much more helpful.

 

We are participating in a study, so we are given tips on how to handle certain scenarios. It's referred to as "Trend Adjustment." For example if we have up arrows and it's time to correct we are encouraged to increase dose by 20%, angled arrow, 10% and if it's going in the opposite direction, decrease by those amounts.

Now, this is impossible for my 11 year old to do, but I am trying it. While it's a little time consuming to do the extra math when we are out and busy, I do find that taking that extra moment really does make a big difference in how her body reacts to the increase or decrease in insulin.

 

that's good info to know.

 

I do that as well - i learned it after trial and error, but if I see those up arrows, esp at bedtime, i know its going to take a bit more for him to come down since he will be rising until that correction starts to take effect. Glad you mentioned it.

 

The % increase for a rise makes perfect sense. Did they give you any parameters for time and # point at which to implement this? Our biggest problem is, and has always been, pre-bolusing and I'm seeing that in the post meal spikes but I'm still working out when best to attack a spike and at what point to begin to intervene. I suppose I should start pushing the spike check back to 90 min or even an hour...

 

We were actually told to do something very similar at our MM training. I'm actually more aggressive than that, but it comes with experience.

As for how to tell when a meal bolus/correction is going to work or not, I think it's trial and error. For us, on the MM system, any time we see double arrows, we are going to need to correct, and probably big, so I go ahead and blast some more insulin in there, no matter where we are after the meal bolus. And we've frankly learned that if we see a meal spike above 160 or so on the CGM, we've probably underbolused the meal, and he'll need more to return to pre-meal BG.

 

They want us to do it only at a correction dose, making sure that there are 3 hours in between last correction. This is where it gets tricky for us, because around the 3 hour time, it's a holding steady arrow. I will admit, I did do it at 2.5 hours the other day and there were no ill effects. I took into consideration her number, what she had been doing and would be doing after the meal and what she would be eating. And honestly, we haven't done anything with the down arrows because if she's going to eat, those downs (for us at least) will level off, or rise then level off. I may use it after one of her dance classes that is pretty intense.

 

It always comes back to this ^^

Perhaps one of the most challenging thing about setting guidelines is the role of all those extenuating circumstances, i.e., does she has lax, did she run, did she get school lunch, did she have PE right after lunch, where are we in the cycle, is the moon full

 

Pre-bolusing has been our biggest benefit from trend management. In our case, peak bg occurs at 1:45 after a meal. By trying out different times for pre-bolusing, we have been able to shave the peak. The other benefit is when we see bg creep up after 3 hrs post-bolus. Then we know we made a mistake in carb counting and are able to react. Then there are the ad hoc benefits like, for example, knowing that a night snack can be very costly.

 

One thing I also like to do when making corrections is to account for the additional increase in blood sugar before the insulin will take effect.
For example, current blood sugar is 210, it takes 25 minutes for apidra to have a measurable effect for me, so I scroll back 25 minutes and see my bg was 170 so I rose 40 points in 25 minutes and presumably will rise another 40 points in the next 25 minutes so I correct for a 250 instead of a 210. I would not do this without a CGM but with it I know I will catch any lows this causes before they become problems.

I probably have 10-15 "tricks" like this I use that I will type out here at some point. The reason I didn't bring them up before is because I still remember being 15 quite well (sometimes not too fondly ). Maddie has just started using the Dexcom and I personally in her shoes would not want to be overloaded with additional things I had to do in addition to actually wearing the CGM. My suggestion which could be a completely horrible idea would be to focus at first on things you could do without requiring Maddie to do anything else but talk through your reasoning behind them (ex: adjust carb ratios with cgm data) with her. At some point you may want to add things like this but I would try to make the cgm as unintrusive as possible right now. This is coming from someone who spent the majority of high school wanting to "lose" my transmitter somewhere at the bottom of the Atlantic Ocean . I love it now and can't imagine life without it but had my parents/endo not been very careful with how it was introduced I may have been turned away from it forever.

Dexcom people: Can you scroll back on the G4? I remember not being able to on the 7+ but I am not sure if that changed. That would effect the feasibility of my first suggestion.

 

That's a good caution, Meg - I hear you. Thanks

Yes, you can scroll back 24 hours in various increments.

 

On the Dexcom Gen 4 receiver you can still only view the graph for the past 24 hours not the precise values like you can with Medtronic.