1. Heparin Infusion Calculations
Chapter 19
Heparin Infusion Calculations

2. Heparin
Potent anticoagulant that inhibits new blood clot formation or extension of existing blood clots

3. Heparin Doses expressed in USP units May be administered:
Subcutaneously
By IV infusion
By IV bolus

4. Heparin
Vial and manufactured infusions usually have heparin printed in red on label
Due to critical action and potential adverse effect of bleeding
Requires frequent check of coagulation times

5. Heparin Available in several vial dosage strengths
Labels must be carefully read and rechecked

6. Subcutaneous Injections
Requires deep injection
Should not be aspirated after injecting needle
Should not be massaged after medication injected

7. Heparin IV Infusions
May be prescribed by mL/hr flow rate or by units/hr to infuse
Must use EID or microdrip
Preferably EID
Requires dedicated IV line

8. Heparin IV Infusions
Heparin dosages based on protocols, clotting time, and/or body weight in kg
Due to changes in clotting times during heparin infusion, rate may need to be changed or titrated before infusion complete

9. Calculation Example 1
Prescription for heparin to infuse at 1000 units/hr from solution of 20,000 units in 500 mL D5W
Calculate mL/hr flow rate

10. Using DA
= 25 mL/hr

11. Calculation Example 2
Prescribed for heparin to infuse 800 units/hour from solution of 40,000 units in 1000 mL D5W
Calculate mL/hr flow rate

12. Using DA
mL 1000 mL 800 units hr 40,000 units 1 hr ,000 1 = 20 mL/hr

13. Calculation Example 3
IV of 1000 mL containing 40,000 units is infusing at 30 mL/hr
Calculate number of units infusing per hour

14. Using DA
units 40,000 units 30 mL hr 1000 mL 1 hr 40, = 1200 units/hr

15. Heparin Flush Dosage Dosage strengths of heparin flush
10 to 100 units/mL
10 units/mL used for peripheral access flush
100 units/mL used for central venous access flush
Should never exceed 100 units