I've been using the Medtronic Revel 723 pump for just over 3 years and have been happy with it. I met a new Endocrinologist yesterday for the first time and she was quite surprised that I use the square/dual wave bolus for most of my meals. I have not been diagnosed with gastroparesis. The Endo said that the square/dual wave bolus is for people with that condition.
Can anyone explain to me or post a link where I might learn the recommended uses for the normal, square and dual wave? I was on MDI for 2 years prior to the pump and had really bad after meal spikes. I still have problems with after meal spikes, so I thought using the dual wave was a good idea. Thank you to anyone who has time to respond.
I use the square wave for high carb/high fat/high protein meals--or whenever I go to a restaurant. My BIGGEST weakness is Oriental food--Chinese, Thai, Viet Namese--PHO! Love it. I use a square wave, usually over 2 hours. Works like a charm.
For usual meals, never use it. And I agree with the article FHS linked that, without gastroparesis, the extended bolus is for a specific use--grazing, high fat/high protein meals.
I use the dual wave bolus for every meal. That is, I deliver an immediate bolus calibrated to metabolize the carb portion of my meal. Then I deliver an extended bolus over a 1-5 hour period calibrated to metabolize the protein and fat in the meal. It's my understanding that in the absence of adequate carbs, the body will convert protein to glucose in the liver. This extended bolus is intended to metabolize that nutrition.
I've been using this dosing system for the last 20 months. It delivers good and very consistent results. I often see post meal BGs on my CGM that only fluctuate 10-20 mg/dl for hours on end.
I eat a low carb, high fat diet, currently limited to < 50 grams carbs/day.
I also use the extended bolus feature for every meal(omnipod's version of the square wave). If you follow a low carb diet and eat alot of fat and protein, foods typically will barely begin digesting before today's fast-acting insulins begin to work, if you bolus before you start eating that is. If you give all the insulin at once, it may drop you low. I also use the extended bolus if i know i will be grazing for several hours, like in the evening after supper. I dont think its 'meant' for anything in particular, its just there as a tool to help you better manage your diabetes, and if you can use for that reason than do it! some endos have a hard time thinking outside the box imo
I use an extended bolus for just about every meal. I don't have gastroparesis as far as I know but I do find if I take 50% initially and extend the other 50% over the next hour or two I don't get the big spikes, nor do I get the big drops from having too much insulin and not enough food. So far it seems to be working exactly as advertised. The CDE who trained me on the pump didn't recommend this, I just worked it out on my own. Last time I saw her she was perfectly ok with what I was doing.
I have a Medtronic Revel. There are two "extended" functions: Square Wave releases the programmed insulin evenly over the time period requested. So the 2 units over 2 hours would be delivered as 1/4 of a unit per hour.
Dual Wave delivers the dose in two distinct doses: 1/2 when the bolus is programmed and another 1/2 at the time set (like 1 hour.)
I don't understand an extended bolus. I think about the square and dual waves as totally different entities for totally different uses.
the extended bolus is what omnipod calls the square wave, releasing a set amount evenly over a designated time period. omnipod doesnt have the dual wave. they are totally different yes, sometimes i wish omnipod had a dual wave feature but i get by fine w/ the extended bolus only
Omnipod only has an extension feature -- a portion of the bolus (between 0-100%) can be delivered immediately, then the rest extended over a period of time. The terms, "square-wave, dual-wave" are not used in Omnipod nomenclature, so I'd be very grateful if someone would describe in detail what these are.
I think the square-wave is the same on the omnipod as choosing to extend 100% of the bolus over a time-period -- thereby delivering a "square-wave" of constant infusion during that time that totals up to the bolused amount.
"Normal" is the same as delivering 100% of the bolus -- without extending it -- immediately (at the maximum infusion rate of the pod).
Not sure what "dual-wave" is. Sounds to me like two insulin spikes with an intervening flat level in between, but I don't think that's what it is. Rather, I'm guessing it's what omnipod calls an extended bolus, with just part extended. I.e., bolus a total of 10U, with 65% delivered immediately, and the other 35% delivered over, say, 2 hours.
If that's the case, then the capabilities of these pumps are the same, just different terminology (and possibly different ways to specify things). Can anyone clear this up?
I started doing this about 4 months ago (T2), and have had very good results and BG control. I impulse for the carbs, then deliver the protein portion as a flat extension over the next 2-3 hours (length depending on proportion and quantity of protein in the meal).
This approach is called TAG, and there is a group here on TuD that focuses on that method. I've been able to keep my post-meal spike under 180 100% of the time (damn good for a T2), and under 140 the vast majority of the time (like always, except when I "go off the reservation" and eat half a pan of brownies or something :-))
If I am really careful and plan well, pre-bolusing ahead of the meal, and structuring the extended bolus right, I can even do Panda Express with chow mein, kung pao, and a sweet sauce dish like Sweet Fire Chicken. I hadn't had any panda food in at least 3 months, went and splurged for lunch there Wednesday, and I was delighted I never spiked over 145!!
Of course, I timed it all perfectly, so that when my BG started to rise, I was @ 80, and already had a goodly amount of IOB working hard.
The amount of insulin though, even as a T2, was alarming. Probably terrifying to a T1, so I won't get specific
actually, the dual-wave is a totally different feature than the square wave and omnipod's extended bolus. dual wave is the initial bolus plus another single bolus at a specified time after the initial. square bolus and extended bolus is initial bolus plus a specified amount extended evenly over a set time after the initial. It would be nice if the pod had a dual wave feature, but like i said before, you make do with what you have...and its not a big enough deal for me to consider a different pump
I'm glad to read that you've been helped by the TAG method, too. My extended bolus technique was derived from the TAGgers United group here. I took their basic idea and tested and customized it for me.
For me, I can't get good results with a high carb meal like a Panda Express meal with noodles or rice. Once I get over about 20 or 30 carbs combined with high fat, I can't dose for that. I used to like their orange chicken.
Good for you that you've been able to adapt your insulin dosing to match your dietary interests. The size of insulin doses are all relative to each person's sensitivity. I used to take twice my current daily total and had poorer control. And some people need to take U500 insulin. Whatever works. That would be a disaster for me to use!
It's my understanding that most current insulin pumps can deliver a bolus immediately or over time. When they combine these two methods it's called a dual wave or combo bolus.
A square wave is a bolus delivered over time as is an extended bolus.
Some pumps allow the distribution of the bolus between immediate delivery and over time (square wave, extended bolus) to be allocated using a percentage. For example, you could dial up a total bolus of 10 units and then partition it to 60% delivered now and 40% over time, that is 6 units now and 4 units over some time period. I don't use this feature. In an attempt to make the arithmetic easier, it actually makes it more complicated for me. I just calculate the carb and protein/fat boluses separately and then administer a "normal" bolus to cover my carbs and an extended bolus for protein/fat.
Square wave bolus and dual wave bolus are Medtronic terms while an extended bolus and a combo bolus are Animas terms.
Yeah, combining the carb and protein and then figuring the percentages for programming a combo is a bit taxing on the fly. I just figured out the "do them separately" idea myself a few weeks ago, and started doing it that way. A major "DOH!" moment.
Another nice aspect of this approach is you can cancel the extended I'd you're heading for hypo. Gotta have a CGM to catch that, though...
Many times, when I correct a high, I'll take a correction bolus and then set a temporary basal rate of +100%. I'll watch my CGM and then cancel the temp basal when the trace starts heading down.
dual wave is the initial bolus plus another single bolus at a specified time after the initial.
If I get what you're saying, the dual wave releases an immediate bolus and a delayed bolus some time later. I do that manually sometimes when I'm eating various portions of food of uncertain timing, like at a holiday party.
John Walsh discusses the different bolus deliveries in his book Pumping Insulin (I'm sure your CDE has heard of him - so you can cash in on his street cred). Gotta remark about the unfortunate tendency on the part of medical team members to "one size fits all of us"
