Faster than a speeding bolus

I am not a medical professional and this is not medical advice. People who think the internet can substitute for real medical attention can find themselves in a boatload of trouble. Like this woman. So be smart, and talk to your own doctor before making any rash decisions, mmmkay?

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Super Bolus, personified

At the beginning of Diabetes Blog Week, I made a passing comment about the Super Bolus. That seemed to generate quite a bit of interest in the comments, and I promised to write more about it. So, here’s my attempt at explaining what it is and how I use it.

I’ll get my obligatory jab at the FDA out of the way now, proclaiming that this feature might already be programmed into pumps if it didn’t first require decades of research and clinical studies, volumes of reports and charts and data, and a healthy dose of ambition and luck. Needless to say, it has none of those things, hence my italicized warning at the top.

So, on to the Super Bolus. A Super Bolus is like getting an advance on basal insulin. It’s getting the next hour or two’s worth of basal in one large bolus of rapid-acting insulin up-front. This can only practically be done with a pump, so if you are on MDI, you might as well just skip the rest of this article and move on to the next blog in your reader. Unless you’re just reading out of curiosity — which, really, is the only reason you should be reading anyway (remember the italicized warning?).

There is no way I can describe the super bolus as well as this article by John Walsh at Diabetes Net, so you’ll need to go there for awhile to read his description and admire his beautifully-illustrated graphs, to fully understand it. (John Walsh is also the author of Pumping Insulin, but my edition of PI doesn’t go into nearly as much detail as the linked article does.)

But if you’re not into clicking links, here’s an example. Try to follow along (and if you’re outside of the United States, be warned that all units are in mg/dl).

Let’s say, hypothetically, my blood sugar is 180. My normal correction factor (aka sensitivity) is 60, meaning one unit of insulin will  bring me down to 120. However,  it will take three hours to do so. My basal rate also happens to be, hypothetically, one unit per hour.

If I want to bring my sugar down to a healthy range, but don’t want to wait three hours, I can bolus two units of correction — that should get me where I need to be in less than half the time. But I don’t want to have a hypoglycemic low of 60 in three hours (if one unit brings me down by 60, then two would drop my BG by 120).

So what do I do? I can still take those two units of correction, but then offset that excess bolus by stopping my basal delivery for one hour (via a “zero” temporary basal, because suspending would require me to remember to un-suspend). Now I’m still getting the same amount of insulin as before – so my ending BG is the same – but I’m getting it even sooner than a regular correction bolus and an hour-long basal.

Think of it this way: this whole process is kind of like the reverse of temporary suspending a basal to prevent an impeding low. In that case, you’re taking a previous over-bolus and “converting” some of it into basal. With a Super Bolus, you’re “converting” basal into bolus. Not much different.

Faster than a speeding bolus… it’s a Super Bolus!

(OK, that was a stretch. I’m trying to weave my clever meanderings into an otherwise mundane topic. It’s not easy.)

Anyway, this seems to work well for quicker corrections of highs. I use it a lot after breakfast, when my blood sugar seems to spike because I’ve just piled a stack of Eggo Waffles on top of my dawn phenomenon. Sometimes, I combine the Super Bolus with my regular meal/carb bolus (Recommended for fast-acting, high glycemic-index meals, or if my pre-meal BG is higher than I’d like.)

Super Bolusing also works well, they say, after forgetting a meal bolus (something that I have absolutely NEVER done – since Monday). Since I’m playing “catch-up” as it is, might as well give that after-meal bolus some extra “oomph.”

However, there are a couple of quirks that come along with the Super Bolus:

1. The “Active Insulin” gauge on my Medtronic pump gets all screwy. Since I’m delivering my basal as a bolus, the pump counts it as bolus, so calculations of any subsequent corrections can be wrong. One trick to get around this is to use the prime/fill-cannula feature for a Super Bolus, but then my daily IOB’s are wrong and my CareLink reports don’t show it at all. (I’ve heard some other pumps treat all insulin-on-board, both basal and bolus, equally. I’m not quite sure how that works).
2. Quickly descending blood sugars can go from a down-arrow CGM situation to a plateau rather quickly. Seeing a 125 with down (or double-down!) arrows may beckon correction, but if I can fight the urge, usually it works out (I actually see a slight bump UP before the plateau).
3. If my basal rate is scheduled to change sometime in the next two hours, then there’s a whole mathematical game involved in figuring out how much to Super Bolus. As I write this, I realize that when I’ve Super-Bolused after 7:30 am, I’ve done it wrong (my basal rate decreases at 8:30).

To tell the truth, I don’t know how much advance-basal can be safely lumped into a Super Bolus. Typically, I’ll only do one hour, though I have followed it up with another Super Bolus when that hour expires (my basals are so low to begin with, one hour’s worth often seems meaningless). Two hours worth should work too (though that little BG “bump” that I mentioned earlier would be more pronounced). Three hours is safe, I guess, considering that even rapid-acting insulin stays in the system for at least that long. Beyond that, I wouldn’t take the chance. I’m afraid of not having any insulin in my system, and when I was first pump-trained, they put the fear of God into me when it came to no insulin and DKA.

That’s in in a nutshell.

Ask your doctor if Super Bolus is right for you.