Dual-wave (combo) bolus help

OK - I’m slowly getting into the whole dual-wave bolus on my Minime. I just had lunch w/ the work crew at what was formerly my favorite lunchtime spot. Ordered a plate of rigatoni broccoli pink, bolused for about 90 carbs (just as much broccoli as rigatoni) and had 50% up front with 50% delivered over the next 3 hours. My readings were as follows:

Before lunch: 72
1 hour post-prandial: 119
2 hours post-prandial: 133
3 hours post-prandial: 140
4 hours post-prandial: 157

Does anybody have any suggestions? I don’t know whether I needed to deliver more insulin during the extended/square wave part or if I needed to extend the wave longer or what. I’m 99% that I had a correct carb count on the food, too. Just FYI - I usually make it back to at least the low 100’s 2 hours after I eat.

I think it depends on the kind of food. When I eat mexican or taco bell (totally NOT the same things!) I do 30% up front & the rest over 2 hrs. With other high fat foods (like Chinese), I do 50% up front & 50% over the next 2 hrs. It’s really trial & error until you figure out what you need to do for what foods. Maybe for the meal you had you should deliver a little less up from & give more over the extended period. It might make for a little higher number at the 1 & 2 hr marks, but keep the overall down some. Good luck!

I didn’t unstand this either… So I went to a class on the Dual-wave Bolus in Wichita, Ks to understand how to do it… The only time that I dual-wave bolus when I eat pasta. Pasta makes my BG do funny things… Like 2 hours it’s 120, 3hours its 200, 4 hours it’s 177… Also It’s depends on what you eat too…

Hi Kim,

IMO you were a tad light on the carb count and another tad light on the time for the extended bolus. If I bolus for pizza with an exact carb count I will go hypo about 1 hour post meal. The fat (I assume “Pink” was the sause, perhaps a cheese/milkfat or olive oil with tomato) can extend the absorption of carbs for up to 6 hours for me. I gotta say that a 90 carb lunch with that kind of response is, well, really great! You almost had it perfect. nice job! -Joe

hey Kim, I just read your profile… you said you were dxd in 2007? You are probably still making a little insulin and this will really mess with your responses to meals. If you are making a little insulin on your own you may want to take what you learn with these experiments as “advisements” because the rules may change over the next year or so. anyway… all the best to you!! Joe


It’s really a question of trial and error, there’s no magic formula for the square wave. Three possible explanations are 1) you underestimated the carbs 2) you underestimated the absorption rate of the carbs (hard to get right) 3) you used the wrong ratio.

For a heavy pasta meal with lots of fat, I tend to load up on the back end (40/60) for two or three hours. Still I don’t always get it perfectly on.

Keep a record of this attempt and adjust your next attempt accordingly. Keep a record of that one, and adjust again.

Trial and error. Trial and error.

hey kim – my response is a bit different from the others. knowing how long it takes the insulin to get going, i start a good 30-45 minutes before i eat pasta. because of the time delay, with your 2 hours out number, i would think that your initial bolus isn’t high enough since you want to keep a 40 mg/dl difference at two hours. i do a 70/30 with pasta or high fat meals which keeps me within 40-50 mg/dl of my pre-meal tests. the other tip that i’ve found helpful for high-fat meals is to add 2 units to the pump’s suggested bolus with a 70/30 split. that works like a dream for me…but, again, it’s all trial and error!