Getting my pump on.

This week has brought a big development in my insulin therapy.  Instead of having to do multiple daily injections of insulin, I have progressed to using an insulin pump which will attach to me and deliver insulin on a pre-programmed level for 3 days.  So instead of two daily basal injections and  3-5 injections every time I eat, I now simply stick a 'pod' onto my belly or arm and get stuck only once.

Waterproof.  No tubes, no wires.  It comes with a separate controller that I'll need with me pretty much all of the time, but since it doubles as a blood glucose meter, it's a break even as far as number of items to carry.  (See last blog rant).

There are many nice features that I am gaining comfort with.  I can program in the number of carbs that I plan to consume.  Next, the pump calculates my bolus insulin dose for those carbs based on my current blood glucose level and my correction factor and carb factors. These levels are unique to me and are a measure of how many points 1 gram of carbs will raise my blood sugar, and how many carbs 1 unit will cover in my body, respectively.

Right now my basal rate is set to 0.35U/hr (8.4U/day).  My goal is allow my 'basal' insulin to account for about 50% of my total insulin each day.  The other insulin will come as 'bolus' doses timed with each meal.  All I do is enter the carbs, press a button and the insulin goes from the 'pod' to me.

My current correction factor due primarily to my mass (215#) is 2.  For every gram of carbs I consume, my blood glucose will raise 2 points.  For example if I'm at 70 and need to go to 100, I'll need 30/2 = 15g of carbs.

My carb factor is currently set at 1:30.  That means that for every 30 grams of carbs that I consume (assuming that my blood sugar is at 100 mg/dL) I can cover those carbs with 1U of insulin.

It gets a little more complicated when my BG is lower or higher than 100.  I need to combine both of the above formulas. I also need to consider the amount of insulin currently in my system. This final detail is rather difficult to calculate, but if your interested I'll explain those details on how I conceptualize 'basal on board'.

If I just ate a dinner with 60 gram of CHO and I was at 100, I would take 2U.  But say I want to have an additional snack 90 minutes later, what to do?  First I'd retest my BG just to double check, then I'd think about the fact that the type of insulin I'm using has a 4 hour time course (peaking after 2 hrs).  Since I'm only 90 min post meal, my insulin has not yet peaked, or has it?  Has the sugar load of my meal peaked - I don't actually know.  Uhh, what to do?  I could make an educated guess... erring on the side of less insulin rather than more (stacking too much insulin is where the danger lies).

Compound this with my rather high carb ratio and the fact that even my 'juvenile' insulin pen with it's 0.5U increments requires that my snack is at least 15grams.  Granted this was twice as refined as my adult pens which only dial in single unit volumes.  Plus knowing what I know about accuracy of syringes at low volume ranges, and it's not long before I realized there had to be a solution with more fine tuning options.

The solution lies in my insulin pump.  This thing pumps increments of 0.05U.  So if 1U covers 30, I can fine tune my dosing at steps for every 1.5grams of CHO! Not even I'm so anal to as actually bolus for that.  That would be two small grapes.  But you get the point.

Added bonus is that the control unit for my pod (PDM - personal diabetes manager) records not only my blood glucose history, but also my insulin dose history.  This not only makes record keeping easier, it dummy proofs the process.  I live a busy life.  There have been plenty of times where I'm been standing there with the insulin pen in my hand with the cap off only to realize that that phone call, or commotion with the dogs left me not remembering whether or not I actually injected.  You'd think that would be obvious, but it's an easy mistake to make.  Especially when you're not fully awake, or you're not thinking clearly due to poorly controlled blood sugar.

There is definitely some fine tuning to be done.  I may already lower my basal rate down to 0.30U/hr (7.2U/day).  I've only been on the pump 3 days but each evening I've had to snack on carbs before bed to ensure my levels would stay stable overnight.  And I can eventually figure out any daily rhythms.  I suspect that I could keep my day/afternoon insulin at 0.35U/hr and perhaps lower it after dinner to 0.3U/hr until noon the next day.

I'm already much more relaxed about the pump.  My original concern was with ditching my Lantus (18 hour time course) as basal insulin. I fear operating without it, it has been pretty good.  But this is better.  My only major complaint is that the minimum reservoir volume for my pump is 90U.  That means that I will be wasting a lot of insulin, which wastes a lot of money.  But they design these pods for the masses.  The full capacity is 200U.  I bet there are many more people out there using more then 200U/3days than there are people like me using less than half of 90U/3day.   And I can't suck the insulin out of the pod - I ask.  While I can suck it out, in the process I could verify that the insulin was now starting to become cloudy, indicating that being at body temperature for 3 days does degrade the insulin - I wouldn't trust it for another 3 days.  Only in an emergency when there are no other resorts.

Speaking of emergencies - I get to fly with this whole setup in two weeks.  The pod is safe to go through the scanner.  The rest of my supplies will all be scanned. Can't wait to try to get a bunch of needles and vials with electronics through security... in foreign languages.  Luckily I can leave the USA with fruit and food.  I'd hate to get on the USA Border Security 'Fruit Violator' list.  (an issue that seriously affects my ability to bring home fresh Okanagan peaches the next time I visit Penticton, B.C.

That's plenty for today!  Thanks for reading.