I did my best to answer the question ... but I knew I had failed. I wanted to explain everything clearly, but my red wine muddled brain quickly became frustrated. In the end, I said something silly like, "It's really complicated."
The following day I continued to replay this conversation in my head desperately trying to come up with a better response.
I think part of the problem is some parents, who luckily don’t live with T1, imagine insulin dosing instructions should look similar to the chart found on the side of a Children’s Tylenol bottle.
Instead of giving a child who weighs 70 lbs 2 ½ teaspoons of Tylenol, the chart on an insulin bottle would say something like for 50 carbs eaten give 2 ½ units of insulin. But insulin bottles don’t come with a simple chart. The dosage calculation is more complicated.
I decided what I needed for the next party was a pocket card I could pull out with a bolus calculation. (That would be a pretty cool party trick.) It would include all the variables that we consider when calculating Ben’s insulin dose. In my head I envisioned the finished product looking something like one of the chalk board formulas from “Good Will Hunting.”
I thought that sounded like a fun little exercise. (I am a total nerd.) So I drew up this bolus calculation …
But I was unsatisified.
What I wanted to show was all the variables that can affect this calculation. I also wanted to show how each of the variables are not quite that certain. I couldn’t figure out how to incorporate all that variability into one calculation.
When you look at the chart on the Tylenol bottle the only thing you need to know is how much your child weighs, which isn’t a difficult thing to figure out. All you have to do is stand on a scale. But to calculate an insulin dose you need to know how many carbs are in a meal, the insulin to carb ratio, current blood sugar, target blood sugar, sensitivity factor, and insulin on board. And the trickiest part is, other than target blood sugar, there is no way to know for certain what any of these numbers are.
You can read the nutrition label to find the number of carbs, for example on a box of crackers, but that number is not absolute. The carbs listed on a nutrition label can be off by +/- 20%.
You can get your current blood sugar by using a glucose meter. But again this is not an absolute number! This number again can be off by +/- 20%.
Then there is the insulin to carb ratio and sensitivity factor which your doctor helps figure out. But again these numbers are not absolute! These numbers vary during the day, change constantly (especially for a growing child) and in the end are only educated guesses.
Trying to come up with this calculation proved to be less fun and more frustrating than I expected. I am certain even Good Will Hunting couldn’t have done much better. So in the end I gave up. There would be no fun party card tricks. I saved my formula … and then forgot about it.
Until this week ... After reading fellow bloggers posts about the Strip Safely Campaign. The basic complaint is that blood glucose test strips are not all that accurate and there is no post-market inspection of these strips. This campaign reminded me how difficult it is to calculate a proper insulin dose and how frustrating it was for me to even attempt to explain why.
I hope (and pray) the FDA listens and figures out a way to ensure the accuracy of blood glucose test strips. Because wouldn’t it be nice to have at least one of these variables be more certain. And wouldn’t it be really nice if we had to deal with less “diabetes moments.” But wouldn’t it be really, really nice if it wasn’t quite so hard to manage Ben’s blood sugar!