Reflections on starting a pump and related issues

I'm praying right now that the paperwork will be finished quickly by your doctor's office and that it will change your life as much as it has mine!!! I really don't think you will be disappointed!!! It blew me away and with the new Dexcom 505 software installed on my receiver it is even more accurate! Got my Dexcom in April 2014 and just installed the software update a week ago. Very impressive.

Thanks! :)

I’m not educated enough on pumping to know niccolo, but maybe a long time pumper would know? Yes, it’s that active tail that I’m worried about. My doctor said stopping the spike may stop my own 2nd phase from kicking in, but we won’t know until I try the rapid acting insulin. That’s why I will try afrezza when it comes out too, supposed to have a mechanism of action much closer to our own 1st phase with less tail, less hypos, and less need to match carbs to dose.

!!! How can you post pics of a road bike that we can't see what it is, wheels, brakes, transmission, etc. in the pics!!

Niccolo is correct about the superbolus concept, which can be useful for things like cereal, that are particularly spiky. You increase the bolus and then cut out some basal on the back end. So if your're at a 10-1 ratio and eat 40G of cereal carbs and ordinarily have a 1.0U/ hour basal rate (note the level of math of which I am capable...) you might bolus like 5U of insulin, an extra unit, but then cut your basal by 50% for the next 2 hour. The same dose but more concentrated, as the food seems to be. A pump will do all the math and you just have to conceptualize that "well, if a straight bolus doesn't work, where do I need more insulin?" and figure out a way to describe it to your pump. The range of possibilities is almost endless but all sort of boils down to more or less insulin to cover whatever you are "inputting".

I’m confused about pumping. I thought I read that pumps only use bolus insulin?

Actually pumps cover "meal" (or correction, or whatever...) insulin with bolus insulin, like a shot for now. They also pump out a small (mostly...) steady stream of basal insulin, designed to cover you like long-term insulin, Lantus/ Levemir/ NPH or whatever. This is generally expressed as a rate, like .8U/ hour. One of the big advantages of a pump is that if you have a regular occurrence, say elevated BG in the AM, you can set a different basal for each 1/2 hour so you can be .8U/ hour most of the day but go up to .925/hour (or whatever...) before breakfast, to fix dawn phenomenon.

There’s also a setting where you can make a %age adjustment to your basal rate. If I’m going to run say 6 miles, I might set my basal rate to 50% of the normal rate as I will be burning off some BG during the run. Or if I’m sick, like yesterday, I can “redline” my basal at 200% of normal.

This pic of my line from yesterday illustrates, with the “hashmarks” across the bottom of the pump that I was on a temp basal of 200% for much of the day fighting off bronchitis.

Thanks for that explanation acidrock!

Leah, get some Unisolve for removing your pods. Soak the adhesive pad with it, wipe away the excess on your skin around the pad, then wait a few minutes (use the time to fill and prep your next pod).

The pod will then just come right off without irritating the skin -- if you wait lng enough, it will sometimes just fall off! Clean up the area with an alcohol prep pad, dry with a soft cloth, cotton ball, kleenex... Your skin will be smooth and happy, no irritation at all, except for the puncture site, which is always a little irrritated from, well, being punctured.

I have both Unisolve liquid in a bottle that I use at home, and individual packet "towelettes" with Unisolve that I have in my D kit, and use when out and about and need to change a pod.

Trust me, an adhesive remover will make an enormous difference. It's the difference between a rash that takes days to heal, and absolutely no injury/irritation AT ALL.

I find the argument that stacking insulin doses is problematic, and that insulin on board or bolus on board should be subtracted from a subsequent bolus, to be odd [...] What am I missing?
Can't speak forf the t:slim, but for every other pump that I'm aware of you're understanding of IOB calculations is wrong.

IOB is only relevant in determining correction boluses. It's never accounted for in a meal bolus. You eat X carbs, it must be covered by Y units of insulin based on your IC, regardless of what your BG level is at the time of eating.

The problem is, exogenous insulin doesn't have the same pharmacodynamics in the body as endogenous insulin. The issue mainly is that digested glucose enters the blood much more quickly than injected insulin is available to act on it. So BG rises before the insulin can finish acting on it, bringing it down.

If you start at 80mg/dl, eat and bolus, then 2 hours later see BG at 140, it would be wrong to correct purely on this number as there are 2-3 hours of insulin action from the meal bolus still to come. If your IC is accurate, in another 2-3 hours you'll come back down in the vicinity of 80.

So, whatever insulin is "left" 2 hours after the bolus is subtracted from any correction bolus you might want to administer when you see that 140.

Similarly, if, while in fasting state (haven't eaten for 3-4 hours) you have a 150, and correct, the same gradual action of the correction bolus must be accounted for in any subsequent correction that is calculated before the duration of action has passed.

So, to summarize: Meal boluses are always directly calculated, with not IOB impact. Correction boluses will have IOB from either previous meal or correction boluses subtracted to prevent stacking.

Agreed, Uni-solve is wonderful stuff, so glad I discovered it! And I imagine all the more so for folks like you using the OmniPod, with its significantly more robust adhesive.

Ha, but so much more lovely than the typical "here's my bike" photo, no? Took this yesterday evening, actually. It's a Specialized Roubaix specced decently but nothing super fancy, mostly 105. I rode an Italian steel frame from the mid-90s until recently, but finally took the plunge on a 21st century bike, and it's been a lot of fun. At some point I plan to do a professional fitting, and I'll almost certainly drop the stem a bit, but other than that I'm pretty happy with how I've been able to dial in the fit. I take it you're a fellow road biker?

You lost me on the "less need to match carbs to dose" part, why would that be? If anything, I would think Afrezza's rapid action would make it more important to accurately match carbs to dose. But that highlights what seems like the key shortcoming of Afrezza to me, which is extraordinarily crude dose adjustments, you can either take 4 units or 8 units or combinations of those, and nothing in between.

To clarify though Lili, you’re right the pump just contains one type of insulin-- usually one of the ultra rapids. They’re programmed to trickle in a “basal dose” continuously, and the user selects a “bolus dose” when they eat usually or for corrections, but it’s the same insulin doing both jobs

Niccolo there appears to me a different mechanism by which the inhaled insulin afrezza makes it less likely to cause hypoglycemia than injected— I don’t truly understand it myself I just know that they looked into it at tremendous lengths and the FDA determined that their dosing mechanism is also appropriate for t1. I am a stockholder in mannkind inc.

Interesting, I suspect what they're referring to is that there's less of a tail. Beyond that, I have a hard time understand how this could be the case. But I have to confess I'm skeptical of the concept in general, crude dosing and side effects on the lungs being my major reservations. But just because the appeal is lost on me doesn't mean it might not be a great fit for others.

I'm really impressed with my new t:slim pump, and with Tandem customer service, and with how they handled the recent recall, and the company in general, so I decided to invest a little in it. It's a pretty volatile stock, though. Some years back I was really impressed with the then-new Therasense Freestyle meter, and invested, and it turned out to be the best performing stock in the United States over that period until Abbott bought it out. If Tandem does half as well, I'll be happy.

Ok now I get it Sam, thanks! I didn’t think pumps had long acting and short acting in them but kept hearing people discuss their basel and bolus. Yes, the afrezza dosing confuses and worries people. I’m not a scientist so won’t attempt to explain the mechanism of action compared to rapid acting insulin. Here’s a good interview with Al Mann though…

I’m sure if they find very insulin sensitive people need smaller does they will market those, although it sounds like they are thinking if anything they will need larger doses. It may just be that since there is virtually no tail you don’t need to titrate doses and carbs so closely, I guess time will tell.

Interesting interview. On supposedly not having to match insulin to carbs, there's conflicting information in the interview. On the one hand, Mann says this basically substitutes on a one-for-one basis with injectable insulin, "The lowering of blood glucose should be comparable to what occurs with the "equivalent" dose of an injected RAA insulin, though the actual prandial effect is greater and the effect would probably be more consistent."

But he also says, "...unless the dose is taken on an empty stomach Afrezza should not cause a real hypoglycemic risk. During the prandial period it would be difficult to deliver enough Afrezza to cause a hypoglycemic incident and Afrezza is virtually gone before the digestion is completed. There should be almost no risk of a post prandial hypoglycemic event."

This is kind of bizarre. It's a bit like saying, you can take either the 4 unit or the 8 unit dose for a given meal, or maybe a whole bunch of the doses, and doesn't really matter as long as you eat *something*. Why would it be "difficult to deliver enough Afrezza to cause a hypoglycemic incident"? What if I took twice what my insulin/carb ratio called for, or four times, or eight times, or whatever? Just because the stuff was out of my body within two hours doesn't mean it couldn't set me up for a terrible hypo--yes, it gets to the bloodstream through the lungs, but it still acts as insulin in the bloodstream. I wish the interviewer had pushed him on this point, because it's pretty crucial.

Mann says something else that sheds light on what he means in downplaying hypo risks. He says, "Much of the hypoglycemia seen in insulin therapy today occurs in the postprandial period due to the hyperinsulinemia caused by the excessive persistence of current prandial insulin products." In other words, *correctly dosed* injectable insulin can still cause hypos because it persists so far beyond the digestion period. That's correct, and Afrezza is not afflicted by that problem, but I don't see how that eliminates the need to correctly dose it in the first place.

Mann seems like a smart (and generally laudable) guy, am I missing something? If so, what?

The FDA I believe determined that there was less risk of hypoglycemia as well with afrezza .And somehow the dosing supposedly doesn’t have to be near as precisely matched to carb intake. Reality is though the only way anyone will ever know if it works well for them is to try it… As it becomes available to the public there will be much more consumer reaction and feedback

I suspect what's going on here is that the test subjects are mostly not carb counting, but doing the more old-school thing where you just inject a given amount of insulin per meal and then eat to your insulin rather than the other way around. And for folks who can't/don't want to cope with the complexities of carb counting, that's a viable, if less desirable, alternative.

Less risk of hypoglycemia makes sense because of the more rapid action.

Dosing not mattering as much is the part that doesn't make sense to me. I wonder if someone will suggest a mechanism whereby that might be plausible. The shorter action definitely helps--if I take too much insulin, it's better to have the excess be gone in 2 hours than 5--but the claims being made seem to be bigger than that. But as you say, eventually we'll have actual experiences to assess.