Use Instructions
262
23Understanding Insulin Delivery and Calculations
Insulin on board (IOB) calculations
Duration of insulin action – time since previous bolus
x previous bolus
Duration of insulin action
IOB from a previous correction bolus is called a “correction IOB.”
IOB from a previous meal bolus is called a “m e a l IO B.”
Correction IOB example
Duration of insulin action: 3 hours
Time since previous correction bolus: 1 hour
Previous correction bolus: 3 U
3 hours – 1 hour
x 3 U = 2 U correction IOB
3 hours
Final IOB shown to you:
2U correction IOB + 1U Automatic adjustment = 3U overall IOB
In other words, one hour aer your previous correction bolus, your body has
used up 1 unit from the correction bolus. e remaining 2 units of insulin
are still in your body. Additionally, the system can automatically adjust the
correction IOB based on its estimate of your insulin needs. In this example,
the automatic adjustment added 1 unit for a total of 3 units working to reduce
your glucose.
Meal IOB example
Duration of insulin action: 3 hours
Time since previous meal bolus: 2 hours
Previous meal bolus: 4.5 U
3 hours – 2 hours
x 4.5 U = 1.5 U meal IOB
3 hours
In other words, two hours aer your previous meal bolus, your body has used
up 3 units from the meal bolus. e remaining 1.5 units of insulin are still in
your body working to cover your meal.
Additional
Information
Effective Date: 22DEC2020, PCO-000267