Wednesday, February 2, 2011
Oh insulin sensitivity you confound me. Seriously. Grace's have been puzzling me lately. Basal rates are good, they hold steady when she doesn't eat and they held her steady when she caught the stomach bug. Her I:C ratios work, they bring her within range after eating a specific carb count meal. It is her insulin sensitivity ratio that puzzles me, it just doesn't compute.
So, insulin sensitivity, otherwise known as the correction factor. In plain and simple terms, it's how much one unit of insulin brings blood sugar down. So it's a ratio. 1:100, 1:60, 1:300 - whatever works for your child and brings their high blood sugar down. It's also based on a calculation from one's TDD (Total Daily Dose) of insulin. So it has a basis, proven by the reduction of a blood sugar from a high. When she was first diagnosed, Grace's correction factor was 1:180, then 1:150 for a very long time. It's still in my head, 1:150, it was that number for so very long.
For the last year almost, they have been 1:80 during the day from 8am - 8 pm, then 1:90 from 8 pm to 8 am. One unit affected her less at night than during the day. She needed less insulin at night to bring her down than during the day. Within the last 3-4 months, things have changed and I have worked my tail off to figure them out correctly.
Grace would sometimes run a high at her bedtime check at 8pm, often from a carb guess from homemade dinner. There would be no insulin in board from eating, and none from a correction. I would bolus to correct the high, but 2 hours later, find that I had overcorrected, thus bringing about a low that needed to be corrected the other way. So she would be at a perfect night-time BGL, but there would be IOB that I know would cause her to crash. There is nothing I dislike more than ping-ponging between highs and lows. So I do my best to avoid it at all costs. And I must say, it's something Grace rarely does lately - EXCEPT for this darn correction factor! The correction factor of 1:90 was giving her too much insulin. I could feel it. So I raised it to 1:100 at night.
Only that was also giving her too much! So I then changed to 1:110 just three weeks ago.
Still too much. Still leaving IOB that causes crashes.
Then two week go, I changed it again to 1:130.
Another high at night after dinner, a correction and dang it all, another come within range within one hour, then a .30 IOB with a BGL of 130, which will result in a low at night, when she's sleeping.
So, I've done two things, lowered her I:C ratio at dinner so she gets more bolus for her dinner, thus not giving us this problem in the first place. And I've upp'ed her correction factor again!
She is currently at 1:160 at night......... Ok, four weeks ago she was 1:90.
Growth hormones? Increased activity levels?
We haven't had a high at night since last Thursday to correct, so I wait.
So you would think I have it figured out now huh?! I don't!
You wanna know why???
It's John Walsh's fault!
THIS sits in the back of mind. THIS haunts me day and night, taunting me, saying, something is wrong, other than her correction factor.
Her TDD averages 28 - 30 units per day. We use a 60/40 split on bolus/basal.
Her correction factor should be nearer 1:69 or 1:60!!!!!
So I did a little test... I programmed that correction factor ratio into her PDM of her OmniPod.
What would a correction factor of 1:60 give her in units of insulin as compared to 1:160?
Grace's range is 80-150 with a target of 120.
And here's what it said to me:
High of 250 BGL at correction factor of 1:160 = .80 units
High of 250 BGL at correction factor of 1:60 = 2.25 units
What a difference in dosing!
So, for now, we are 1:100 during the day and 1:160 at night.
Why is Grace defying some standard conventions of diabetes management?
Oh yeah, that's right, she has Type 1.
Posted by Penny at 9:21 AM