Using Your Square Bolus

I have been on the Medtronic Paradigm Pump for almost 17 years. i love it. i could never imagine myself going back to MDIs.not for a minute. i have used almost every feature it offers me. Almost every feature :blush:

i have never used the Square Bolus feature. i am writing this in the hope that pump users will share with me their experiences using this feature. when do you use it? why do you use it? how do you decide when to use it? how do you decide how much insulin to bolus and for how long you want that bolus to last? how do you figure all of these mathematical calculations out?

i look forward to hearing from all of you.
thanks ahead of time :wink:
Daisy Mae

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Square, Extended, Combo.

Different names from different pumps all for the same thing.

Generally we use it for foods which we expect to be slow carb foods. Or we use it based on experience. So a regular bolus which ā€œwould haveā€ been better served as a square/extended/combo bolus would show as a low following eating. We would then have to correct for the low and we would then experience a high. This would be caused by (unexpectedly) the insulin hitting prior to the food. (Usually the food hits well before the insulin and requires a pre-bolus for things such as rice, cold cereal, oatmeal, etcā€¦) So the square/extended/combo slows up the insulin and gives the ā€œslowā€ food time to hit.

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We use extended bolus for every meal for Liam. We set our extended bolus for 1 hour, zero percent up front and the remaining over the next hour. We feed him at the 30 minute mark. I also use extended bolus in combination with temp basal of 95% more basal over X number of hours after a slow digesting meal (such as pizza, pastas, etc.,)

Itā€™s a way of administering insulin slowly, over a prolonged period of time. Weā€™ve found extended bolus works best for Liam than just a straight bolus and waiting 15 minutes.

If I am at a restaurant, and want to start with an appetizer, or a few drinks before dinner. I will hit the extended for 30 minutes, take some up front and the rest over the next 30 minutes. Itā€™s just a way for me to not have to worry about doing it twice, or forgetting to bolus again when the main course comes a bit later.

Or if I am at one of those parties with small little plates, and buffet style eating, and I know I will have to go back and get 7 or 8 plates to get enough food. I just extend so I donā€™t have to worry about dropping, which would happen if I took it all up front.

We use it for PIZZA!

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this sounds to me as what my pump calls a ā€œdual bolus.ā€ yesterday i went for a very large, high carb, high fat meal (burgers, fries, guacamole and chips.) i knew that it would digest slowly b/c of all the beef and fat which would slow everything down. so i did a split bolus of 20% up front, and 80% over a 3.5 hour period. i stayed completely flat the entire day. since i ate at 2:30pm, the bolus insulin stayed with me to even my digestion out, and the insulin didnt finish until 10pm in the evening (4 hours for the up-front, and then the remaining 3.5 hours drizzling out over 7.5 hours total) my BG didnt rise above 85 the entire day. ( a major success )

what i am trying to refer to is not a dual bolus. it is a square bolus. the bolus that doesnā€™t give you anything up front; it simply dispenses the insulin flat over a specific (pre-programed ) period of time. say, for example, 6 units over 3 hours. nothing up front.

has anyone used this and how does it work?( i completely understand the dual bolus feature.) what i am trying to learn is completely about the Square bolus. and if i have misunderstood any of your responses, i apologize for being such a dummy :wink:

Right, I gotcha. They all have different names for things. The omnipod lets you do a square or dual, but they are both under the category of ā€œextendedā€, and they just donā€™t use those words.

So, a normal bolus is all at once.

An extended bolus can be either square or dual. But they donā€™t use those terms on the omnipod.

Anyway, I donā€™t do much with what you call square. Sometimes I bump my basal up for several hours. Thatā€™s kind of like a square. But really, for things involving food, I have not found a reason to do it that way.

i use the dual (split ) bolus for pizza, too. i use it basically for anything involving cheese, meat or grease. otherwise i will drop immediately and then spike later on.

how long do you generally pre-bolus for for the slow carbs meals? my idiot endo has recommended to wait 1/2 hour before eating things like oatmeal. as i cannot rely upon him for most of his suggestions, i would be very curious on your use of this feature.

For meals that digest over a long period of time, we use the extended bolus feature and set it to 0% up front and the remainder over the next 2 hours. We also use a temp basal increasing his normal basal by 95% and we do this over 5 hours. The main reason we use temp basal now is because it helps suppress the BGā€™s that are bound to rise after every meal, but more importantly, the ability to SUSPEND the temp basal if we see his BGā€™s are not rising much, if at all.

For every meal that Liam eats now, we do a 1 hour extended bolus. We do ZERO up front (so this would qualify as your square bolus), and we administer all 100% over 1 hour. At the 30 minute mark we feed him. Thatā€™s what weā€™ve found works best for Liam anyway!

i am curious when you say that you increase your TB to 95%. does that mean that you are adding an extra 5% basal rate? i ask b/c my TB would work the opposite way; my starting basal is 100%, then when i lower it, it becomes 95% (reduced from 100% ) and so on and so on, depending on how much i want to increase or decrease it. does that make sense to you? is that what you mean?

PS: how do you decide how much to increase or decrease his TB and how do you decide how long you want the extended bolus to last for?

The omnipod allows different ā€œtemp basalā€ configurations. We can set up an increase by X percentage and use that whenever we like. If you want to do one for 5%, OK. Another for 95% OK. I just turn it on and itā€™s running in the background and let it run.

sorry; still confused. if you set his TB for 95%, does that mean you are lowering it by 5%?

No, it means Iā€™m increasing his REGULAR basal rate by 95%. So, in Liams case, we have only two settings. .05/hr and .10/hr. If I set up a temp basal for 95% more, then he would get that .05 or .10% PLUS 95% MORE of whichever rate was active at the time.

So in the case of .05, he would be getting a total of .05 + .0475 = .0975/hr.
If heā€™s running .10, the temp basal of .95 extra would result in .10 + .095 = 19.5/hr.

His ā€œregularā€ basal is always running 24/7. The ā€œtemp basalā€ is above and beyond the normal basal program. Itā€™s extra that can be applied when needed.

i get it now. thats a very large increase. if you do that every time he eats, or most times, why dont you just change his I:C ratios ? wouldnt that be easier?

No, temp basal is easiest for us because different meals do different things to his body. Breakfast wreaks havoc on him (as Iā€™ve found out it does for many diabetics.) An I:C that is correct for Dinner will be WAY off for his breakfast meals. We could do presets for meals as well, but weā€™ve not gotten into that yet much. Temp basal allows us to give more insulin and the best part of it is that it can be suspended if we see itā€™s going to be too much. I:C gives more insulin periodā€¦once itā€™s IOB you canā€™t take it back out. We utilize those methods that allow us to suspend if we have too as much as possible, since heā€™s still so small.

If a slice of bread was a slice of bread was a slice of bread in a perfect world, yesā€¦adjust I:C and move on. But thatā€™s not the case with most diabetics (at least those as young as Liam). So we have the I:Cā€™s set such that he levels off like he should after the proper time has passed, then we deal with temp basals for everything else. If I:C is too high, heā€™ll go low for dinner, but will still spike high for breakfast. Hope that makes some sense!

In OmniPod lingo, it is a little different. You first enter if you are decreasing or increasing, and then you put in the percentage.

  • In Medtronic world, if you say 95%, that is 5% less.

  • But in OmniPod world, you would call it a 5% decrease.

In the example Harold is giving, he is increasing it 95%. With OmniPod, that is the highest percentage you can increase.

A ā€œ95% increaseā€ is basically 195% of normal.

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I canā€™t be sure, but it looks like they are doing this so they have more control. So for a meal they are using a higher temp basal as well as some bolus insulin. That way if he is not responding as expected they can adjust the basal to cover the meal.

For an Adult this probably would be a crazy strategy with more work than you use now, but for kids whose responses fluctuate, the extra work would give them more control.

We use different rates depending on the time of the day and what weā€™ve tested his sugars to do during those times of the day. So for lunch, we usually only do a 50% increase IF we do any at all because weā€™ve found his BGā€™s to not rise much during lunch. Breakfast definitely gets the 95%, though and generally one or two micro-boluses as well. Dinner we usually do 50 or 95% extra depending on what heā€™s eating.