When first diagnosed, I was given three hard, numeric references for insulin. Not fluffy relative terms but absolute. rules. I like those. There's no room for interpretation. They just are what they are.
The first was a carb ratio. I would take 1U for every carb exchange. And one carb exchange = 15 carbs. That ratio quickly proved to be a little off, but it was a hard number I could work with.
The second was correcting. I would take 1U for every 50 points above 100 I was. That number, too, was fairly quickly changed in the real world but there it was.
The third I still struggle with. It was an explanation of how long after correcting I should wait to eat. From memory, it was something like:
|100||0 + Meal||Now|
|120||0 + Meal||5 minutes|
|150||1 + Meal||10 Minutes|
|200||2 + Meal||15 Minutes|
|250||3 + Meal||20 Minutes|
|And so on|
The source of confusion, especially now, is my blood sugar doesn't change that fast. 20 Minutes after correcting with a blood sugar of 250 isn't going to put me anywhere near normal territory!
Logically, I can reckon that:
- The extra insulin from the meal will lead to a quicker fall than the correction dose by itself.
- A meal with fewer carbs will have less of a rebound than a meal with more, so you may be able to fudge and eat a little sooner that way.
- And last, you don't want to be #bgnow 100 with 12U active (and active without lag)
But Novalog, for me, tends to take 15-20 minutes before anything appreciable happens to my blood sugar. And with a hypothetical 250, an hour is unlikely to put me anywhere near 100.
So instead of dealing with a reasonable 10 minute pause, I tend to follow one of three (including lows) algorithms.
- For a blood sugar < 140ish
- I dose whatever fractional correction the pump spits out at me and eat.
- For higher blood sugars
- I rage bolus the high, check sugar every 20 minutes or so and once it's fallen by about half eat bolus the difference between active and what I'm meant to take for the food.
- And for low blood sugars
- I tend to take a 30 or 60 minute square wave depending how complex the carbs are and eat now - because remembering to bolus at some indeterminate point in the future is not one of my strengths.
Over the years, I've been able to adapt the first two rules from the initial diagnosis rather easily but just haven't ever figured out how to incorporate the delays/lags/etc defined in the third into my regiment. I may have a system but it too often leads to a low or high a couple hours in the future. I'd love to one day figure out a math function to give me an optimal time differential for correcting & eating.