Total Daily Dose

Derived from weight, total daily dose can be calculated by taking the weight in kilograms and multiplying it by the patient's units/kg ratio.

The units/kg ratio can be estimated from a variety of factors:

0.3 units/kg body weight:

• Underweight
• Older age
• Hemodialysis

0.4 units/kg body weight:

• Normal body habitus: BMI 18.5-24.9
• Normal weight

0.5 units/kg body weight:

• Overweight (BMI 25-29.9)

≥ 0.6 units/kg body weight:

• Obese
• Insulin resistant
• Glucocorticoids

Basal Dose

Most patients need basal coverage.

The basal dose is 50% the total daily dose for patients eating meals normally and via bolus tube feeds. For those on continuous tube feeds, 40% total daily dose is given.

The basal dose is composed of glargine (Lantus) or NPH (Novolin N) insulin. Glargine is preferred for its more predictable kinetics. Basal insulin does not need to be held if the patient is made NPO, but if using NPH, the NPH dose should be reduced 50%.

Nutritional Dose

Patients who are being fed, whether by meals or tube feeds, need scheduled short acting insulin even if they are at goal glucose.

The nutritional dose is the remaining dose after (TDD - basal). Patients eating meals normally and via bolus tube feeds have a nutritional dose of 50% the total daily dose. For those on continuous tube feeds, 60% the total daily dose is used.

Aspart (Novolog) or regular (Novolin R) is used. Aspart is preferred for the patient eating meals or receiving bolus tube feeds. Regular is preferred for the patient on continuous tube feeds. The scheduled nutritional insulin should be held if the patient will miss a meal or if tube feeds will be stopped or held. If the patient’s eating is unpredictable, aspart (NOT regular) may be administered during or after the meal.

Supplemental Dose

The supplemental dose is based on the patient’s known or estimated insulin sensitivity.

1. Low requirement: e.g. BMI <25 or TDD <40 units/day.
   Also for patients with higher risk of hypoglycemia due to renal, hepatic, or cardiac dysfunction or elderly age.
2. Medium requirement: e.g. BMI 25-29.9 or TDD 40-80 units/day.
   For those between low and high, or who don’t reach goal using the low requirement option.
3. High requirement: e.g. BMI ≥30 or TDD >80 units/day. Also for obesity, infections, post-CABG, open wounds, or receiving steroids.

If the default preprinted scales don’t seem to work (and they won’t every time!), build an individualized scale.

1. Calculate the correction factor. You may generally use the “rule of 1800.” The correction factor, (1800 / TDD), = the number of glucose units (mg/dL) that 1 unit of insulin will correct. For example, if a patient’s TDD = 40 units/day then 1800 / 40 = 45. So 1 unit of insulin is expected to drop the blood glucose by 45 points. The correction factor may be rounded to 40 or 50 to make building the scale easier.
2. Build the scale increments based on the correction factor. You must first decide though at what glucose level the supplemental scale should be initiated. So as not to drop the glucose too low, you might decide to set 100 as the minimum CBG you would want to see, which means supplemental insulin would not be administered until the CBG was >140. The scale would thus be: for CBG 141-180, give 1 unit of insulin; for CBG 181-220, give 2 units of insulin; and so on. On the other hand, if you wanted to be more aggressive, you might tolerate dropping the CBG to 80, so your scale would be initiated for CBG >120.

Remember to adjust the scale up or down based on the results it gets. One scale does not fit all!

Titrate insulin up or down once or twice daily.

There are various ways to adjust the insulin regimen, depending on which glucose values are out of range.

Adjusting basal or nutritional insulin:

• Basal:
  • Glargine (Lantus): Titrate every other day by 20%. Increase if fasting BG > 140, decrease if <100. Exception: if fasting BG is >200 after the first dose, then increase the next dose by 20-30%.
  • NPH: titrate daily. For evening dose: if fasting BG is <70, decrease by 50%. If fasting BG 140-200, increase by 20%. If fasting BG is >200, increase by 30%. For morning dose: adjust by 20% if pre-lunch BG is not at goal.
• Nutritional:
  • Increase the pre-meal dose if supplemental insulin is being given consistently. If pre-meal glucose is above goal, increase previous meal insulin by 1-2 units. If pre-meal glucose is below goal, lower previous meal insulin by 1-2 units.

Adjusting Total Daily Dose:

If fasting glucose is consistently >140 but <180 with no threat of hypoglycemia, increase the TDD by 10-20%.
If fasting glucose consistently >180, increase the TDD by 30%.
If 2 or more episodes of hypoglycemia (BG <70), start D5-1/2NS at 75 mL/hr and decrease the TDD by 20%.

1. Use the “Transfer from Adult LHS Critical Care Initial Subcutaneous Insulin Orders Post-Critical Care Intensive Insulin Drip Protocol” form.
2. Otherwise: Estimate the TDD requirement.
   1. Take the average hourly rate over the last 4 or 6 hours and multiply it by 20.
   2. If the patient was receiving nutrition (eating meals or on tube feeds) during that time, then this is the TDD.
   3. If the patient was not receiving a significant amount of nutrition, then double the number to get the TDD.
   4. Once you have the TDD, split it out into basal and nutritional components based on the nutritional regimen.

A1c

All inpatients with hyperglycemia should have an A1c done in the last 3 months:

• If <7%, home Rx is working well.
• If 7-8%, consider changing the home Rx.
• If >8%, it's time for a change.

Total Daily Dose

In terms of Total Daily Dose, will a patient need insulin at home?

• If a patient requires >40 units/day of insulin on the day prior to discharge, they may require insulin at home (sometimes temporarily).
  1. Communicate the need for teaching at least one day prior to discharge.
  2. contact the patient's PCP to communicate the need for insulin therapy and arrange for close outpatient follow up.
• New diagnosis Type 2 diabetes and patient on <40 units/day of insulin probably do not require insulin at home.
  1. Consider starting an insulin sensitizer (e.g., metformin, earily during the stay).
  2. For those requiring >2 units pre-meal insulin, consider a sulfonylurea.
  3. One day prior to anticipated discharge discontinue the pre-meal insulin and add a sulfonylurea to test the patient's response to the drug.
  4. If good responce, discharge patient on both sulfonylurea and an insulin sensitizer.
• For any patient new to insulin therapy, please notify the patient's PCP prior to discharge. Arrange for close outpatient follow-up.