I'll warn you now, the remainder of this post is rather technical and unless you are an analytical type or a science type, you might find it boring. To me it represents pretty much all I've been able to think about for four days - so bear with me...
The purpose of basal insulin is to keep the blood sugar regulated when there's no food. Overnight, for example. A healthy pancreas will continuously regulate blood sugar by constantly excreting tiny amounts of insulin. People with diabetes need a basal insulin because their bodies don't excrete those tiny regular amounts, or don't excrete enough (in the case of a honeymooner like my Sarah). At night, Sarah needs a whole lot of basal (comparatively).
A few days ago (before testing began) Sarah's basal settings looked like this:
12:00 AM 0.400
4:30 AM 0.575
7:30 AM 0.350
10:00 AM 0.150
5:00 PM 0.325
10:00 PM 0.250
Notice that between 10am and 5pm, she only gets 0.15 units per hour, while during the night and early morning she gets more than triple that amount. Strangely, we know the nighttime basal is correct because it's the easiest one to test. All I have to do is stay up all night and test her hourly (which I did about a month ago), and now I look at her CGM each morning to confirm she's staying in range during the night.
We test basal by having Sarah go a long time during the day without food. For example, she ate breakfast this morning around 8:30. Generally insulin lasts up to 4 hours, and food is about the same. So both the breakfast and insulin she took with breakfast should have been used by by around 12:30. The test begins - and we test Sarah every hour. If her basal rate is perfect, her blood sugar will remain stable. Unfortunately, we did not achieve perfection...
Additionally, basal tests have to be aborted if Sarah's blood sugar goes below 80, and herein lies our problem - keeping her above 80 without food seems like an impossible challenge!
Day 1 - Thursday - Attempting to test late afternoon basal (4-8pm)
211 at lunch
84 at 4:05
75 at 4:49 - not happening...
Day 2 - Friday
85 at lunch
65 at 4:07 - definitely not happening...
Day 3 - Saturday
112 at lunch
81 at 2:05 - Nope, still not happening...
Day 4 - Sunday (today)
100 at breakfast
110 at 12:18
63 at 1:48 - + 16g. of carbs (no insulin - so I'm thinking we can rescue this one. If her cereal brings her up and she still has no insulin, maybe I'll learn something)
139 at 2:47 - looking good - Reduced basal to .05 per hour (practically 0!!!)
102 at 3:47 - Um, kind of an unexpected drop
67 at 4:53 - Well crap. Thinking maybe I should set her basal rate to suck the insulin back out of her at this point!!!
And here's a visual of our very failed test today...
|The range (green box) represents 80-200|
So now I'm thinking we're going to change her daytime basal to 0.025 per hour starting tomorrow. And we'll start testing again on Thursday because it's the first day she doesn't have classes in the afternoon which require her to be fed and happy...
And this is not an atypical day...