Using Temporary Rates on the Pump

The other day, I went on a mild hike with my family. It was a bit of a spur-of-the-moment thing; we had gone out for lunch and then decided to explore a nearby trail since the weather was beautiful.

After 20 minutes of hiking, I started feeling hypoglycemic. Without my glucometer, though, I couldn't be sure. Going somewhere without a glucometer is always a risk, but I'm used to running for up to an hour at a time without anything on me but glucose tablets. The trick is to just check your blood sugar before and after, and stay "in tune" with your body in case you need to use the glucose tabs.

However, this time I didn't have any glucose source with me. I had figured that we would be walking for about 40 minutes, and we had just eaten lunch, so hypoglycemia wasn't especially likely. Of course, we had eaten lunch at a restaurant with unfamiliar food, which meant that I had to guesstimate how much insulin to take for the meal since I couldn't be sure of the carbohydrate count. That factor alone should have made me be more careful to monitor my sugars after lunch. I did think about it - but I thought that, if anything, I would have problems with high blood sugars rather than low ones.

Anyway, after I realized that I had no way of treating a hypoglycemic episode, I considered how I could prevent it. I did not yet feel "really low," just as if my blood sugar was dropping.

I decided to temporarily turn off the basal rate on my pump. This way, my blood sugar had a chance to rise, or at least not decrease quite as rapidly. On my pump, the Deltec Cozmo, temporary rates can be programmed for time periods of 30 minutes to 72 hours; they can be used to deliver only 50% of the regular basal rate, or 0%, or 125%, or anything above/in between. By "turn off," I mean that I programmed the temporary rate to 0%.   

This could have had no effect at all, especially if there was still a lot of insulin "on board" from my lunch bolus. However, I got lucky and managed to finish the hike without hypoglycemia. When we returned to the car, my blood sugar was 138. I don't really know what happened, though. My blood sugar may have been dropping during the hike, and then after 20 minutes of the temporary rate, it could have shot up. Or maybe my blood sugar was never getting very low at all, and had steadily declined from the high 300s to the 130s over the course of the hike (in which case the temporary rate would not have been a very good thing).

Wearing the Dexcom CGM could have helped a lot that day! However, I am glad that I could take advantage of an advanced feature on my pump and temporarily tweak my basal insulin delivery to suit my needs. It wasn't an ideal situation, and it wasn't planned out or anything; ideally, you should be comfortable using the same types of temporary rates at certain times, such as weekly soccer games (when you might need less of a basal) or on long car trips (when you might need to increase your basal rate) Temporary rates are also good for sick days.