I'm not great at doing basal testing, and I'm sure many people would like to minimize the number of basal tests they have to do until they "get it right". Does anyone know of a coherent strategy for adjusting? Change the dose on the same hour that has the problem, or one hour behind, and what size of adjustments to make according to how big the problem is? I asked my diabetes doctor if you could deduce anything from the bolus correction factor, but she said definitely not and that it was just trial and error. I've searched previous forum entries and it looks like the book by John Walsh, "Pumping Insulin" might contain something concrete?
I use the fasting numbers to adjust basals. If it runs up, I try for that "chunk" of time. I have them running from 12-1A, 1-3:30, 3:30-7, 7-10A, 10-5:30 and 5:30-midnight. A lot of them are the same, with a few minor adjustments, .75U from 1-3:30 period and then .9U until 10A for DP. It seems to work ok. I had some turbulence w/ late dinners causing crashing and, according to the CGM, some rebounding but the .75U seems to have adjusted that? It's a totally lazy way to do it and I've had about 2 weeks of "woah" numbers but maybe it'll work for a while now?
I think it depends on the situation. Are you new to pumping and trying to get your initial basals set ? Or been using pump for a while and think you need an 'overhaul'. If so, then Pumping Insulin has good suggestions for doing that. My endo also had provided forms that show when to fast, test, etc, and I've seen others online.
Or has there been a pattern of highs or lows at certain times of the day ? If so, can you provide more details ?
Generally, the pump adjustment would be 1-2 hours prior to the time needed. If it's during the day, sometimes I do a trial with a 6-8 hour temp basal rate based on percent, for example 85-90% if my pattern was lows, or 110-120 if highs. Of course, this is when the highs/lows are not attributed to exercise, or incorrect bolus, etc. So it's important to act based on a pattern. If my temp basals help (after a couple days of trial), then I make the adjustments to my basal settings.
You are on the right track, as basal rates should be worked out first - before determining the correct Insulin-to-Carb ratio and Correction Factors. I definitely recommend Pumping Insulin by John Walsh as he has a very methodical process for ironing out basal rates, etc. I refer to it regularly. Gary Scheiner also has a great article in the diaTribe archives on the basics of Basal Rate Testing.
Good luck and happy basal testing!
I've never done basal testing, but just tweak my basal based on the numbers I see, and I now have 9 separate basal rates which work well. I go according to two hours ahead, so if I'm seeing highs around noon I'll change the rates around 10AM. I can't remember without looking, but I think John Walsh says 3 hours - whatever works! I really like Pumping Insulin but he does rely a bit on formulas, and I, like your doctor, think trial and error works best. It's one of the things I love best about my pump, seeing that I have highs or lows in a certain time period and adjusting a small amount to stabilize.
Thanks for all the helpful replies. I had had some recurring problems at various points of the day, and was reluctant to change anything without basal testing in case the problem was the bolus factors. But I printed out the current settings from the pump and thought about it and I think it is possible to get an idea of whats wrong without the basal testing, even if its a lot less perfect. After a couple of adjustments to basal and the bolus factors, things are a good bit better now but could still improve.
@GracieSF, great article - that’s pretty much exactly what I was looking for! Although, the list of steps/conditions for carrying out the test just about explain why I can’t get round to doing one…
I use dexcom clarity and look up about the last week in hourly and see which hour has the most highs. I adjust about 2 hours before the high occurs. With my dexcom I don’t worry so much that it might be too high of an adjustment as it will let me know.