A question for those on MDI

T1D Tech & Daily Management Support
1

I feel silly asking this question but it’s been so long since I’ve been on injections I don’t know the answer​:blush:. If you take shots, when dosing for meals so you use a sliding scale, or get as close as you can with a carb ratio?

2

Dorie @wadawabbit , I don’t currently utilize management method currently known as MDI - originally referred to, as you may recall, as IGC or Intense Glucose Control. I used as close to exact as possible calculations rather than hit=or-miss pre-printed sliding scale that slides over two critical factors for proper insulin dosing.

The formular we(*) developed in its most basic written arithmetic format is A+B-C, which I calculated in my head, and which form the underlying theory of many dose calculators [such as in pumps] in use today. I’ll try to explain this formular:

A = (BG-Target) / ISF [this value can be either negative or positive}

B = Total Carbs x I:Cr

C = Estimated bolus still active

NOTE “we(*)”: In 1975, I was recruited, or shall we say assigned, by the Medical Director of Joslin Clinic to work with a Joslin diabetes scientist in an attempt to develop better methods for diabetes management. Up to that period, insulin dosing by using a single daily injection (sometimes split into two half doses per day) of Long-Acting insulin [not to be confused with long0duration background formulations which became available in 2002 with Lantus] such as NPH or the just arrived Humulin-N. The success of our work was proven by the worldwide DCCT Study of the 1980s.

3

Think Like a Pancreas

Gary Scheiner, MS, CDCES
4th ed., p. 182-183

Chapter 7 In Search of the Perfect Bolus

There are many unusual factors that can influence bolus requirements; several will be covered in the next chapter. For our purposes here we will focus on the five primary factors that should be considered when determining bolus doses:

  1. the amount of carbohydrates in the meal or snack
  2. the glucose level at the time of the meal or snack
  3. the direction the glucose is headed
  4. the amount of insulin still remaining from previous boluses
  5. the amount of planned (or recently completed) physical activity

If you are into math (you know who you are - your favorite shows are The Big Bang Theory and whatever the latest iteration of Star Trek happens to be), boluses are calculated as follows:

Bolus dose = (food dose + correction dose + rate-of-change adjustment - insulin on board) x activity adjustment

When I was on MDI earlier this year this is what I did, except I’d memorized the food doses so I didn’t use a carb ratio to math the food dose.

Are you working on your what to do when your pump fails plan or got something else going on?