I'm curious how you figure your combo (or square) bolus. I really don't have much rhyme or rhythm to mine at this point.
I was taught by the local Animas trainer to go 50/50 for high carb/high fat foods, and she commented that maybe some people need 60/40. Oh, and she said to make our I:C ratio stronger for a combo bolus, by about two. (So if my dinner I:C is normally 1:9, she's say change it to 1:7.)
That hasn't worked for me, and I go high. Through trial and error, I've figured out a couple foods that need a combo bolus of like 75/25, but with some foods, that'll make me go low first. I wish I could find some sort of guideline for what to do for different carb/fat ratios. I honestly don't even know how to look at a nutrition label and say, "OK, there's enough fat in this that I probably need a combo bolus." I can generally say whether a food is fatty based on just what it is, but that's hardly precise since things are made differently by different companies/people.
I haven't had a great deal of time to experiment with this yet and probably won't for the next few months (pregnancy doesn't seem like the time to experiment!!!), but I'd love to hear what others do so I have some ideas while I'm figuring it out.
I use the Medtronic 523. It has a similar delivery option. I was having problems at dinner time with the insulin going to work far faster than the carbos ( and fats) were. I would go low right after every meal and stay low for about four hours. Then I would bounce very high after eating a lot of glucose tablets . My Doctor suggested I deliver 33 percent at the meal and the remaining over the next three hours. It has worked remarkably. On the Medtroic pump there is a choice between square wave and dual wave bolus. I use the dual as it delivers one set right away then slowly delivers the remaining bolus over the time I set. I think you need to use it when necessary, but I only find it necessary for my dinner bolus.
For me, it's not so much how fatty a food is, but how much of it I am eating. If I'm only eating one small slice of pizza I can do a regular bolus. But if it's two pieces or more, I need to do 75/25. I spread out the second half over 1.5hrs, but some people do three hours.
Even for foods that aren't fatty, but I'm eating a lot of, I need to do a combo. Like for almost any restaurant meal, I will do a combo simply because the food is digesting slower because of how much of it there is.
Ri isnt on the pump but sometimes I do combo bolus her. Like last night it was Chinese and she was 360 something. I also knew she wasnt going to eat all her food. she needed a total of 12 units 5.3 of that was her correction. So I had her do 6 before and then waited to see what she actually ate. I had her do 3. She did need a correction later as well but her numbers have been wonky lately. She has been needing corrections 3 hours after a glass of milk. Most of the time its not 50/50 tho cause she isnt on the pump. More often than not the she gets more in the first place cause she is starting out on the higher end and needs a correction. If she is on the low end I give less in the first shot and more in the second but it also depends on the food she is eating. I dont know the splits tho cause its a judgement call for me nobody has taught me how to do it I just do it. When her numbers are not wonky its worked for me so far every time.
I wish there were a guide, too. For pizza, I use an I:C ratio of 1:16 instead of 1:18, and a combo bolus of 75:25 over 2.5 hours. For Ice cream, I use 1:18, 60:40, and 6 hours. For pasta, I use the same as pizza but 1:15.
But it only actually works out well about half the time. And also, as I've been around my family, not exercising, eating cookies over the holidays, I've been high a lot, usually 4-5 hours after I bolus, even with a combo bolus, so I'm thinking maybe I should be doing longer that 2.5 hours.
It's frustrating for me that I feel like I'm always experimenting. Even if I know something has worked before, I'm always wondering if it will work this time, too. Oh, diabetes.
I find that I sometimes need an upped temp basal rate for 4 - 6 hours with some foods (like pizza, pasta), in addition to the 2 to 3 hour combo bolus. Like, +50 to +80%. Give it a try, y'all.