Insulin Administration
The basics of insulin and types of insulin were discussed in Unit 2. In this chapter, we will focus on the routine administration of subcutaneous insulin by multiple daily injections (MDI therapy) in the inpatient setting.
A Note on Insulin Pumps:
Currently, insulin pumps are not used for routine insulin administration in the inpatient setting.
- Patients with known diabetes on CSII in the outpatient setting will likely need to be converted to a subcutaneous MDI regimen while admitted.
- In rare circumstances where patients are allowed to continue their insulin pumps, the patient/family will be in charge of their own insulin administration.
- Hybrid-closed loop insulin pump systems may need to have automated insulin delivery discontinued temporarily (with backup basal rates updated as needed)
Basal insulin is usually administered once every 24 hours, most commonly around bedtime.
In children admitted with DKA, basal insulin is initiated and continued even while the patient is on an insulin drip.
For patients admitted with known diabetes, obtain the following information from the patient to ensure the correct type of long-acting insulin is given at the appropriate time:
Rapid-acting insulin in a basal/bolus regimen is used as mealtime insulin and correction insulin:
- Carbohydrate coverage (mealtime insulin)
- Mealtime insulin is given 15 minutes before breakfast, lunch, or dinner.
Figure 1 – Rapid-acting insulin is best dosed 15 minutes (or sometimes sooner) before a carbohydrate-containing meal. - Additional mealtime insulin should be given for large snacks (>15g of carbs) or other meals that do not fall during routine mealtimes.
- Children who are more insulin resistant may require carbohydrate coverage for snacks that are <15g of carbs (especially when their I:C ratios are less than 1:15)
- Mealtime insulin ≠ correction insulin, despite both being the same rapid-acting insulin. The principle of HOW rapid-acting insulin is being used makes the difference.
- Terminology when discussing rapid-acting insulin administration is very important (as discussed in Unit 3: “Consistency of Terminology”)
- For unpredictable eaters:
- Discuss dosing mealtime insulin after eating with the on-call endocrine faculty or fellow.
- In these cases, children should be:
- Encouraged to eat their carbohydrate-containing foods in the first 20-30 minutes
- After 20-30 minutes, the rapid-acting insulin dose should be calculated/determined by the total amount of carbohydrates eaten from food during that 20-30 minutes time period.
- After rapid-acting insulin administration, any remaining carb-containing food should be removed from the tray and the child can be allowed to eat the remaining “carb-free” foods on the tray.
- Mealtime insulin is given 15 minutes before breakfast, lunch, or dinner.
- Correction of hyperglycemia (hyperglycemia correction)
- Blood glucose is always checked before mealtimes and will determine the need for additional rapid-acting insulin used for the “correction of” hyperglycemia or ketones (if present). This correction insulin is added to the mealtime insulin dose.
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- Blood glucose is always checked before mealtimes and will determine the need for additional rapid-acting insulin used for the “correction of” hyperglycemia or ketones (if present). This correction insulin is added to the mealtime insulin dose.
- Correction of ketonuria/ketonemia (ketone correction)
Rules of Thumb for Correction Insulin:
Click on each of the following to read additional information!
Figure 2 is a Decision Tree that can be used when deciding what to do with a blood sugar reading.
Quiz Yourself:
Bibliography:
Figures:
- Figure 1: Image Attribution: Created by Alex Tuttle by compilation of the following images from left to right: “Insulin icons” by vectorsmarket15, “15 minutes icon” by Freepik, and “Eat icons” by Eucalyp from Flaticon.com
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