First things first: this approach works for Caleb. It may or may not work for you. I am by no means suggesting that anyone should apply the following theories to their diabetes care. I am only explaining what I do for Caleb.
For weeks, Caleb’s most predictable BG of the day was pre-lunch. Without exception it had been in range. It was sensor change day and we were operating in the blind start-up period. No worries though because this time of day hadn’t posed an issue in quite a while.
It’s approaching lunch time so let’s do a finger stick. 289.
Okay. Oh well. It happens. There was more fiber in his breakfast than usual and he was a little low at the postprandial check. Ah yes, hindsight is 20/20. Moving on. Now back to this 298 and we are getting hungry for lunch.
John Walsh explains it as follows: “A Super Bolus is created when some of the basal insulin delivery is stopped or partially reduced, and delivered instead as additional bolus insulin on top of a normal carb or correction bolus.”
The intent is to get glucose levels back in range quickly without inducing hypoglycemia. Here is how Caleb’s super bolus went that day:
Correction: 1.50 units, plus
Meal bolus for 50 carbs: 2.00 units, plus
Basal for the next two hours: 0.70 units, equals
Total units delivered: 4.20 units.
Lastly (this is critical) turn basal to “off” for two hours.
The change in the timing of the basal insulin makes all the difference. Front-loading it and delivering it with the meal and correction bolus makes it act faster and all at once, thus bringing glucose levels back in range sooner. If left as basal, the end result will be the same, but it will take more time and hyperglycemia will last longer. The same amount of insulin is delivered when using a super bolus, it is only the timing that is different.
Back to life, start preparing lunch.
1/2 hour after superbolus: 169
Perfect. Coming down fast and lunch is ready, let’s eat. 50 carbs consumed.
1 hour after superbolus (1/2 hour after eating 50 carbs): 109
Excellent. The first time I tried this, I panicked a little at this point. A 109 an hour after a bolus that large is cause for worry. But his basal had been zero for an hour and he still has food in his system. Plus his basal will be zero for another hour.
DexCom had been calibrated with that lovely 289, which we confirmed after washing hands with a 288. DexCom showed him cruising between 85 and 100 over the next hour.
2 hours after super bolus: 89. Wonderful.
I know a bolus of that size is still hanging around in Caleb’s system beyond the 2 hour insulin duration that we use. However Caleb’s basal insulin has just now resumed. He hasn’t received any basal or other delivery of insulin for the last two hours. Any tail of insulin duration from that super bolus is required for his basal needs.
And it worked. He continued to hover with a nice flat arrow through the afternoon until dinnertime when a finger stick confirmed a BG of 98.
I invite you to read more of what John Walsh has to say about using a super bolus. He suggests its use for high glycemic foods or large intakes of food in order to avoid blood glucose spikes. I haven’t tried in those situations yet, but I plan to. He also speaks of pumps giving us the option to deliver a super bolus automatically. The thought of it gives me chills.
In what ways have you used the super bolus?